packages feed

happlets (empty) → 0.1.0.0

raw patch · 13 files changed

+2549/−0 lines, 13 filesdep +basedep +bytestringdep +colour

Dependencies added: base, bytestring, colour, containers, fail, lens, linear, mtl, semigroups, text, time, transformers, unordered-containers

Files

+ LICENSE view
@@ -0,0 +1,674 @@+              GNU GENERAL PUBLIC LICENSE+                Version 3, 29 June 2007++ Copyright (C) 2007 Free Software Foundation, Inc. <http://fsf.org/>+ Everyone is permitted to copy and distribute verbatim copies+ of this license document, but changing it is not allowed.++                     Preamble++  The GNU General Public License is a free, copyleft license for+software and other kinds of works.++  The licenses for most software and other practical works are designed+to take away your freedom to share and change the works.  By contrast,+the GNU General Public License is intended to guarantee your freedom to+share and change all versions of a program--to make sure it remains free+software for all its users.  We, the Free Software Foundation, use the+GNU General Public License for most of our software; it applies also to+any other work released this way by its authors.  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Of course, your program's commands+might be different; for a GUI interface, you would use an "about box".++  You should also get your employer (if you work as a programmer) or school,+if any, to sign a "copyright disclaimer" for the program, if necessary.+For more information on this, and how to apply and follow the GNU GPL, see+<http://www.gnu.org/licenses/>.++  The GNU General Public License does not permit incorporating your program+into proprietary programs.  If your program is a subroutine library, you+may consider it more useful to permit linking proprietary applications with+the library.  If this is what you want to do, use the GNU Lesser General+Public License instead of this License.  But first, please read+<http://www.gnu.org/philosophy/why-not-lgpl.html>.
+ happlets.cabal view
@@ -0,0 +1,116 @@+-- "happlets.cabal" build configuration for this project.+--+-- Copyright (C) 2017-2018  Ramin Honary.+--+-- "happlets" is free software: you can redistribute it and/or modify+-- it under the terms of the GNU Affero General Public License (AGPL)+-- as published by the Free Software Foundation.+--+-- "happlets" is distributed in the hope that it will be useful, but+-- WITHOUT ANY WARRANTY; without even the implied warranty of+-- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.+-- See the GNU Affero General Public License for more details.+--+-- You should have received a copy of the GNU General Public License+-- along with this program (see the file called "LICENSE"). If not, see+-- <http://www.gnu.org/licenses/agpl.html>.++NAME:           happlets+VERSION:        0.1.0.0+AUTHOR:         Ramin Honary+COPYRIGHT:      (C) 2017-2018 Ramin Honary, all rights reserved.+MAINTAINER:     RaminHAL9001@gmail.com+HOMEPAGE:       https://github.com/RaminHAL9001/happlets+LICENSE:        AGPL+LICENSE-FILE:   LICENSE+BUILD-TYPE:     Simple+CABAL-VERSION:  >= 1.18++CATEGORY:       GUI, Game+SYNOPSIS:       "Haskell Applets" provides an event handler and a canvas for building simple GUI apps.++DESCRIPTION:+    .+    This package is provides the Happlets API that is common to all Happlet+    back-end provider libraries. Along with this package, it is necessary to+    install a back-end library such as 'happlets-lib-gtk'.  Currently Gtk++    version 2 with a Cairo-based canvas is the only back-end available. Gtk++    version 3, Xlib, SDL2, GLUT, and (possibly) Wayland back-ends are all+    feasible and may be implemented in the future.+    .+    The goal of the Happlets project is to allow you to create very simple,+    thread-safe applications that contain nothing more than a single window+    with a drawing canvas that can respond to user input events, like mouse+    clicks, key-presses, or frame animation events. The intention is to+    create a minimal programming platform for small, single-purpose+    graphical applications which simply displays some interactive graphic,+    for example a plot of some data, or a simple game. Naturally, the+    Happlet program can be arbitrarily complex, but it may be better to+    consider other, FRP-based solutions if managing events becomes too+    difficult.+    .+    A happlet back-end provider may provide additional widget API functions,+    but using these APIs will result in your applet being dependent on the+    specific back-end and will thus not be as portable as programming for+    the "happlets" package alone. Happlets aims to achieve a balance between+    being as minimal as possible, but still provide enough graphics drawing+    primitives to be useful for the widest range of possible applications.+    .+    The Gtk+ v2 back-end provider can be downloaded from this link:+    .+    https://hackage.haskell.org/package/happlets-lib-gtk+    .++Library {++  HS-SOURCE-DIRS:    src+  DEFAULT-LANGUAGE:  Haskell2010++  GHC-OPTIONS:  -Wall+    -fno-warn-name-shadowing+    -fno-warn-unused-do-bind++  EXPOSED-MODULES:+    Happlets+    Happlets.Config+    Happlets.Draw+    Happlets.Draw.Color+    Happlets.Draw.SampCoord+    Happlets.Draw.Text+    Happlets.Draw.Types2D+    Happlets.Event+    Happlets.Initialize+    Happlets.Provider+    Happlets.GUI++  BUILD-DEPENDS:+    bytestring           >=0.10.0.0 && <1.0.0.0,+    colour               >=2.0.0    && <3.0.0,+    containers           >=0.5.5.0  && <=0.5.7.0,+    fail                 >=4.7      && <5.0,+    lens                 >=4.0.0.0  && <5.0.0.0,+    linear               >=1.20.0   && <2.0.0.0,+    mtl                  >=2.2.0    && <=2.2.1,+    semigroups           >=0.16.0   && <0.19.0,+    time                 >=1.4.0.0  && <=1.6.0.0,+    text                 >=1.1.1.4  && <=2.0.0.0,+    transformers         >=0.1.1    && <0.5.0,+    unordered-containers >=0.2.0.0  && <=0.3.0.0,+    base                 >=4.7      && <4.9++  DEFAULT-EXTENSIONS:+    DeriveDataTypeable+    DeriveFunctor+    ExistentialQuantification+    FlexibleContexts+    FlexibleInstances+    FunctionalDependencies+    GeneralizedNewtypeDeriving+    ImplicitParams+    LambdaCase+    MultiParamTypeClasses+    OverloadedStrings+    RankNTypes+    ScopedTypeVariables+    StandaloneDeriving+}
+ src/Happlets.hs view
@@ -0,0 +1,19 @@+-- | This module re-exports all symbols from all modules in the "happlets" package.+module Happlets+  ( module Happlets.Event+  , module Happlets.Config+  , module Happlets.Initialize+  , module Happlets.GUI+  , module Happlets.Draw.Color+  , module Control.Monad.State+  , module Control.Lens+  ) where++import           Happlets.Event+import           Happlets.Config+import           Happlets.Initialize+import           Happlets.GUI+import           Happlets.Draw.Color++import           Control.Monad.State+import           Control.Lens
+ src/Happlets/Config.hs view
@@ -0,0 +1,154 @@+-- | Methods and data types for working with the configuration. The Happlets configuration was+-- originally designed to be loaded from an INI file, but this functionality has since been moved+-- into a separate package. However many of the primitives for loading a configuration file from+-- disk are still provided here so that they are available universally to all Happlets back-end+-- providers.+module Happlets.Config+  ( Config(..),+    ConfigException(..), StrictFilePath,+    sanitizeName, configErrorsOnLoad, clearConfigErrors, configFilePath,+    registeredAppName, windowTitleBar, backgroundTransparency, backgroundGreyValue,+    recommendWindowPosition, recommendWindowSize, animationFrameRate,+    deleteWindowOnClose, quitOnWindowClose, decorateWindow,+  )+  where++import           Control.Arrow+import           Control.Exception+import           Control.Lens++import           Data.Char (isPrint)+import           Data.List (groupBy)+import qualified Data.Text as Strict++----------------------------------------------------------------------------------------------------++type StrictFilePath = Strict.Text++data ConfigException+  = ConfigErrorIO           StrictFilePath IOException+  | ConfigErrorIniParseFail StrictFilePath Strict.Text+  | ConfigErrorIniStructure StrictFilePath [Strict.Text]+  | ConfigError             Strict.Text+  | ConfigMultipleErrors    Strict.Text [ConfigException]+  deriving (Eq, Show)++instance Exception ConfigException where {}++----------------------------------------------------------------------------------------------------++-- | This is the data structure used to configure various parameters in the Happlet back-end+-- provider.+data Config+  = Config+    { theConfigErrorsOnLoad      :: [ConfigException]+    , theConfigFilePath          :: StrictFilePath+    , theRegisteredAppName       :: Strict.Text+    , theWindowTitleBar          :: Strict.Text+    , theBackgroundTransparency  :: (Maybe Double)+    , theBackgroundGreyValue     :: Double+    , theRecommendWindowPosition :: (Int, Int)+    , theRecommendWindowSize     :: (Int, Int)+    , theAnimationFrameRate      :: Double+    , willDecorateWindow         :: Bool+    , willQuitOnWindowClose      :: Bool+    , willDeleteWindowOnClose    :: Bool+    }+  deriving (Eq, Show)++-- | A string sanitizer for applied to strings assigned to 'registeredAppName' and 'windowTitleBar'.+sanitizeName :: Strict.Text -> Strict.Text+sanitizeName = let sp = ' ' in Strict.unpack >>>+  takeWhile (\ c -> c /= '\n' && c /= '\r')  >>> -- Take only the first line of text.+  fmap (\ c -> if c == '\t' then sp else c)  >>> -- Convert tabs to single-spaces.+  filter isPrint                             >>> -- Filter out non-printing characters.+  dropWhile (== sp)                          >>> -- Cut out leading spaces.+  groupBy (\ a b -> a == sp && b == sp)      >>> -- Group together spaces.+  ( let loop stk = \ case+          []           -> stk ""+          [' ':_]      -> stk ""                     -- Cut out trailing spaces.+          (' ':_):more -> loop (stk . (sp  : )) more -- Replace multi spaces with single spaces.+          txt    :more -> loop (stk . (txt ++)) more+    in loop id )                             >>> +  Strict.pack++-- | This is a list of errors that occurred while trying to load this configuration from the+-- filesystem.+configErrorsOnLoad :: Config -> [ConfigException]+configErrorsOnLoad = theConfigErrorsOnLoad++-- | The configuration errors are stored into the 'Config' data structure. This function erases the+-- errors.+clearConfigErrors :: Config -> Config+clearConfigErrors c = c{ theConfigErrorsOnLoad = [] }++-- | Reports the file path from which this config file was loaded, or a null string if this has not+-- been set.+configFilePath :: Config -> StrictFilePath+configFilePath = theConfigFilePath++-- | Gtk+ apps can register your GHCi/Happlet process with the window manager under a specific name,+-- which you can specify here. Using this lens to set a null name will not result in an error but+-- the update will not occur.+registeredAppName :: Lens' Config Strict.Text+registeredAppName = lens theRegisteredAppName $ \ b -> sanitizeName >>> \ a ->+  if Strict.null a then b else b{ theRegisteredAppName = sanitizeName a }++-- | Most window managers depict a title bar above every window that displays a descriptive name of+-- the content of that window. Specify that name here. Using this lens to set a title name will not+-- result in an error but the update will not occur.+windowTitleBar :: Lens' Config Strict.Text+windowTitleBar = lens theWindowTitleBar $ \ b -> sanitizeName >>> \ a ->+  if Strict.null a then b else b{ theWindowTitleBar = sanitizeName a }++-- | When the window is created, setting this parameter to a non-'Prelude.Nothing' value determines+-- whether an image buffer in memory is allocated with enough memory for an alpha channel, so that+-- the window background can be made partially or fully transparent, and also determines what the+-- default transparency value is, with 0.0 being fully transparent, and 1.0 being fully+-- opaque. However not all window managers will allow for windows with alpha channels, so this may+-- not work depending on how the GUI of your opreating system has been configured.+backgroundTransparency :: Lens' Config (Maybe Double)+backgroundTransparency = lens theBackgroundTransparency $ \ b a -> b{ theBackgroundTransparency=a }++-- | The default background "color", actually a gray value since no one in their right mind would+-- choose a non-grey solid color background for their applet. 0 is black, 1 is white, and everything+-- in between 0 and 1 are valid grey values.+backgroundGreyValue :: Lens' Config Double+backgroundGreyValue = lens theBackgroundGreyValue $ \ b a -> b{ theBackgroundGreyValue=a }++-- | Recommend to the window manager where to place the window. Pass @(0,0)@ to let the window+-- manager choose.+recommendWindowPosition :: Lens' Config (Int, Int)+recommendWindowPosition = lens theRecommendWindowPosition $ \ b a -> b{ theRecommendWindowPosition=a }++-- | Recommend to the window manager how large to make the window. Pass @(0,0)@ to let the+-- window manager choose.+recommendWindowSize :: Lens' Config (Int, Int)+recommendWindowSize = lens theRecommendWindowSize $ \ b a -> b{ theRecommendWindowSize=a }++-- | Recommend the frame rate to use when installing animation event handlers.+animationFrameRate :: Lens' Config Double+animationFrameRate = lens theAnimationFrameRate $ \ b a -> b{ theAnimationFrameRate=a }++-- | For window managers that allow windows to be created without a titlebar, close\/minimize\/hide+-- buttons, or other visible controls (on Linux systems, "reparenting" window managers will do+-- this), setting this value to 'Prelude.False' will tell the window manager to not draw these+-- decorations. Non-reparenting window managers like Xmonad are unable to draw a title bar, in which+-- case this parameter will have no effect, the Happlet window will behave as if this parameter is+-- always set to 'Prelude.True'. Other reparenting window managers may simply ignore this option, in+-- which case the Happlet window will behave as if this parameters is always set to 'Prelude.False'.+decorateWindow :: Lens' Config Bool+decorateWindow = lens willDecorateWindow $ \ b a -> b{ willDecorateWindow = a }++-- | If the Happlet window is closed, halt the Gtk+ event loop, returning control to the @main@+-- function. If the 'gtkLaunchEventLoop' is the final function called in @main@ the Haskell program+-- will end.+quitOnWindowClose :: Lens' Config Bool+quitOnWindowClose = lens willQuitOnWindowClose $ \ b a -> b{ willQuitOnWindowClose = a }++-- | If the Happlet window is closed, the image buffer allocated for it should be+-- deleted. Otherwise, the Happlet window is simply made invisible when it is closed, and the image+-- buffer is not deleted. Of course, if 'quitOnWindowClose' is set to 'Prelude.True', the entire+-- program may quit even if this parameter is set to 'Prelude.False'.+deleteWindowOnClose :: Lens' Config Bool+deleteWindowOnClose = lens willDeleteWindowOnClose $ \ b a -> b{ willDeleteWindowOnClose = a }
+ src/Happlets/Draw.hs view
@@ -0,0 +1,60 @@+-- | This module re-exports the "Happlets.Draw.Color" and "Happlets.Draw.Types2D" modules, and also+-- provides the 'HappletDrawing' class, which is a minimalist set of drawing primitives functions+-- for updateing the graphics in a Happlet window.+--+-- Future work on the Happlets project may result in the creation of a new package, perhaps called+-- @happlets-draw-ext@, which provides extended drawing primitives for a practical 2D graphics+-- library that can export to and import from SVG data, however no plans for such an extension have+-- been made at the time of this writing.+module Happlets.Draw+  ( module Happlets.Draw.Color+  , module Happlets.Draw.SampCoord+  , module Happlets.Draw.Text+  , module Happlets.Draw.Types2D+  , Happlet2DGraphics(..), modifyPoint,+  ) where++import           Happlets.Draw.Color+import           Happlets.Draw.SampCoord+import           Happlets.Draw.Text+import           Happlets.Draw.Types2D++import           Control.Monad.IO.Class++----------------------------------------------------------------------------------------------------++-- | This is a minimalist set of of drawing primitives functions for updating the graphics in a+-- Happlet window. This class must instantiate 'Control.Monad.Monad' and+-- 'Control.Monad.IO.Class.MonadIO' because it is expected to perform stateful updates to the+-- system, namely changing what graphics are displayed in a Happlet window.+--+-- The @render@ data type instantiated here is expected to be the the same as the @render@ type+-- instantiated into the 'Happlets.GUI.HappletWindow' type class, which should allow Happlet+-- programmers to evaluate all of these functions using the 'Happlets.GUI.onView' function and+-- perform the expected update on the Happlet window.+class (Functor render, Applicative render, Monad render, MonadIO render)+   => Happlet2DGraphics render where+  -- | Set all pixels in the screen graphics to the same color value, deleting all graphics that+  -- existed prior.+  clearScreen :: FillColor -> render ()++  -- | Draw a line on the canvas.+  drawLine :: LineColor -> LineWidth -> Line2D RealApprox -> render ()++  -- | Draw a sequence of lines from a list of points, from head-to-tail, on the canvas. Passing an+  -- empty list should result in a no-op. Passing a list with a single point should paint the point.+  drawPath :: LineColor -> LineWidth -> [Point2D RealApprox] -> render ()++  -- | Draw a rectangle on the canvas.+  drawRect :: LineColor -> LineWidth -> FillColor -> Rect2D RealApprox -> render ()++  -- | Update a pixel value somewhere on the canvas.+  setPoint :: Point2D RealApprox -> PackedRGBA32 -> render ()++  -- | Read a pixel value somewhere on the canvas. Out-of-bounds indicies throw an exception.+  getPoint :: Point2D RealApprox -> render PackedRGBA32++modifyPoint+  :: (Monad render, Happlet2DGraphics render)+  => Point2D RealApprox -> (PackedRGBA32 -> PackedRGBA32) -> render ()+modifyPoint p f = getPoint p >>= setPoint p . f
+ src/Happlets/Draw/Color.hs view
@@ -0,0 +1,214 @@+-- | This module provides a basic color data type that can be used to build apps without needing to+-- include additional packages into your project. This module is not imported automatically when you+-- import the "Happlets" module, so if you would prefer to use a better alternative color data type+-- it is easier to do so. This module can be imported with the "Happlets.Draw" module.+module Happlets.Draw.Color+  ( PackedRGBA32(..), FillColor, LineColor,+    unpackRGBA32Color, packRGBA32Color, packRGBA32, unpackRGBA32,+    quantizeColorChannel, unquantizeColorChannel,+    -- * British Spellings+    FillColour, LineColour,+    unpackRGBA32Colour, packRGBA32Colour, quantizeColourChannel, unquantizeColourChannel,+    -- * Fundamental Colors and Shades,+    red, green, blue, cyan, magenta, yellow, white, black, grey, gray, light, dark,+    -- * Color Channels+    redChannel, greenChannel, blueChannel, alphaChannel,+  ) where++import           Control.Arrow+import           Control.Lens++import           Data.Bits+import           Data.Char+import           Data.Word++import           Numeric++----------------------------------------------------------------------------------------------------++-- | For using a type name that describes how the 'PackedRGBA32' value is being used for.+type FillColor = PackedRGBA32++-- | For using a type name that describes how the 'PackedRGBA32' value is being used for.+type LineColor = PackedRGBA32++newtype PackedRGBA32 = PackedRGBA32{ unwrapPackedRGBA32 :: Word32 }+  deriving Eq++instance Show PackedRGBA32 where+  showsPrec _ (PackedRGBA32 w) = (++)+    ( case w of+        w | w <= 0xF -> "#0000000"+        w | w <= 0xFF -> "#000000"+        w | w <= 0xFFF -> "#00000"+        w | w <= 0xFFFF -> "#0000"+        w | w <= 0xFFFFF -> "#000"+        w | w <= 0xFFFFFF -> "#00"+        w | w <= 0xFFFFFFF -> "#0"+        _                   -> "#"+    ) . showHex w++instance Read PackedRGBA32 where+  readsPrec _ str = case str of+    '#' : str -> do+      (a, str) <- readHex str+      let done str = (PackedRGBA32 a, str)+      case str of+        ""                -> [done ""]+        s:str | isSpace s -> [done $ dropWhile isSpace str]+        _                 -> []+    _         -> []++-- | This function evaluates 'unpackRGBA32' and then performs a 'unquantizeColorChannel'+-- computation on each channel, including the alpha channel.+unpackRGBA32Color :: PackedRGBA32 -> (Double, Double, Double, Double)+unpackRGBA32Color p =+  let (r,g,b,a) = unpackRGBA32 p+      un = unquantizeColorChannel+  in (un r, un g, un b, un a)++-- | This function evaluates 'qunatizeColorChannel' on each given 'Prelude.Double'-precision color+-- channel value, then evaluates 'packRGBA32' on the four resulting quantized values.+packRGBA32Color :: Double -> Double -> Double -> Double -> PackedRGBA32+packRGBA32Color r g b a = packRGBA32 (q r) (q g) (q b) (q a) where+  q = quantizeColorChannel++-- | This function performs no transformation on the given 'Data.Word.Word8' values, they are simply+-- bit-packed into a 'Data.Word.Word32' data value by bit-shifting and the bitwise-OR operator.+packRGBA32 :: Word8 -> Word8 -> Word8 -> Word8 -> PackedRGBA32+packRGBA32 r g b a = PackedRGBA32 $! sh r 24 .|. sh g 16 .|. sh b 8 .|. sh a 0 where+  sh c s = shift (fromIntegral c) s++-- | This is the inverse operation of 'packRGBA32'.+unpackRGBA32 :: PackedRGBA32 -> (Word8, Word8, Word8, Word8)+unpackRGBA32 (PackedRGBA32 w) = (unsh 24, unsh 16, unsh 8, unsh 0) where+  unsh s = fromIntegral $! 0x000000FF .&. shift w (negate s)++-- | This function takes a linear color value expressed as a 'Prelude-Double'-precision+-- floating-point value, clamps it to a value between 0 and 1, then computes the square-root on this+-- value, then compresses the square-root to a 'Data.Word.Word8' value (because the human eye is+-- more sensitive to changes in brigher colors than in darker colors). Use this function to convert+-- a linear double-precision color channel intensity value to a value that can be stored efficiently+-- in memory or some other digital computing medium.+quantizeColorChannel :: Double -> Word8+quantizeColorChannel =+  round . (* (realToFrac (maxBound::Word8) :: Double)) . sqrt . min 1.0 . max 0.0++-- | This is the inverse operation of 'quantizeColorChannel', the 'Data.Word.Word8' value is+-- converted to a 'Prelude.Double'-precision floating point value between the numbers 0 and 1, then+-- returns the square of this value.+unquantizeColorChannel :: Word8 -> Double+unquantizeColorChannel = (** 2.0) . (/ (realToFrac (maxBound :: Word8) :: Double)) . realToFrac++----------------------------------------------------------------------------------------------------++-- | British spelling of 'FillColor'+type FillColour = FillColor++-- | British spelling of 'LineColor'+type LineColour = LineColor++-- | British spelling of 'unpackRGBA32Color'+unpackRGBA32Colour :: PackedRGBA32 -> (Double, Double, Double, Double)+unpackRGBA32Colour = unpackRGBA32Color++-- | British spelling of 'packRGBA32Color'+packRGBA32Colour :: Double -> Double -> Double -> Double -> PackedRGBA32+packRGBA32Colour = packRGBA32Color++-- | British spelling of 'quantizeColorChannel'+quantizeColourChannel :: Double -> Word8+quantizeColourChannel = quantizeColorChannel++-- | British spelling of 'unquantizeColorChannel'+unquantizeColourChannel :: Word8 -> Double+unquantizeColourChannel = unquantizeColorChannel++----------------------------------------------------------------------------------------------------++-- |+red :: PackedRGBA32+red = PackedRGBA32 0xFF0000FF++-- | +green :: PackedRGBA32+green = PackedRGBA32 0x00FF00FF++-- |+blue :: PackedRGBA32+blue = PackedRGBA32 0x0000FFFF++-- |+cyan :: PackedRGBA32+cyan = PackedRGBA32 0x00FFFFFF++-- |+magenta :: PackedRGBA32+magenta = PackedRGBA32 0xFF00FFFF++-- |+yellow :: PackedRGBA32+yellow = PackedRGBA32 0xFFFF00FF++-- |+white :: PackedRGBA32+white = PackedRGBA32 0xFFFFFFFF++-- |+black :: PackedRGBA32+black = PackedRGBA32 0x000000FF++-- |+grey :: PackedRGBA32+grey = PackedRGBA32 0x808080FF++-- |+gray :: PackedRGBA32+gray = grey++----------------------------------------------------------------------------------------------------++bitShiftColorChannelLens :: Int -> Lens' PackedRGBA32 Double+bitShiftColorChannelLens i = lens+  (\ (PackedRGBA32 c)   ->+     unquantizeColorChannel $ fromIntegral $ shift (shift 0xFF i .&. c) (negate i)+  )+  (\ (PackedRGBA32 c) a -> PackedRGBA32 $ (c .&. xor 0xFFFFFFFF (shift 0xFF i)) .|.+    shift (fromIntegral $ quantizeColorChannel a) i+  )++-- | A lens to change the linear (unquantized) alpha channel value without needing to unpack then+-- repack the 'PackedRGBA32' value.+alphaChannel :: Lens' PackedRGBA32 Double+alphaChannel = bitShiftColorChannelLens 0++-- | A lens to change the linear (unquantized) red channel value without needing to unpack then+-- repack the 'PackedRGBA32' value.+redChannel :: Lens' PackedRGBA32 Double+redChannel = bitShiftColorChannelLens 24++-- | A lens to change the linear (unquantized) green channel value without needing to unpack then+-- repack the 'PackedRGBA32' value.+greenChannel :: Lens' PackedRGBA32 Double+greenChannel = bitShiftColorChannelLens 16++-- | A lens to change the linear (unquantized) blue channel value without needing to unpack then+-- repack the 'PackedRGBA32' value.+blueChannel :: Lens' PackedRGBA32 Double+blueChannel = bitShiftColorChannelLens 8++-- | Shift the color toward white. For example @('light' 'red')@ may look like a "pink"+-- color. Please be aware that this is not necessarily the inverse function of 'dark' due to loss of+-- precision when packing the color channels.+light :: Double -> PackedRGBA32 -> PackedRGBA32+light = min 1.0 . max 0.0 >>> \ p ->+  unpackRGBA32Color >>> \ (r,g,b,a) ->+  packRGBA32Color (p * (1 - r) + r) (p * (1 - g) + g) (p * (1 - b) + b) a++-- | Shift the color toward black. For example @('dark' 'blue')@ may look like a "navy" color.+-- Please be aware that this is not necessarily the inverse function of 'light' due to loss of+-- precision when packing the color channels.+dark :: Double -> PackedRGBA32 -> PackedRGBA32+dark = min 1.0 . max 0.0 >>> \ p ->+  unpackRGBA32Color >>> \ (r,g,b,a) ->+  packRGBA32Color (p * r) (p * g) (p * b) a
+ src/Happlets/Draw/SampCoord.hs view
@@ -0,0 +1,34 @@+-- | This is a primitive data type for representing screen sizes and points on a screen in discrete+-- using 'Data.Int.Int32' values.+module Happlets.Draw.SampCoord where++import           Data.Int++import           Linear.V2++----------------------------------------------------------------------------------------------------++-- | A sample coordinate: this is a value that is used to count some integral number of units along+-- a 1-dimensional axis of some scan line, for example pixels along the edge of a view screen or+-- canvas. Alone, these elements can represent the amount of time (measured in the units of time+-- samples) of an audio signal. A 'Linear.V2.V2' pair's of 'PixCoords' can specify a 2D point on a+-- screen or canvas, 'Linear.V3.V3' triples of 'PixCoords' can specify a 3D point in a voxel space.+newtype SampCoord = SampCoord Int32+  deriving (Eq, Ord, Show, Read, Enum, Num, Integral, Real)++-- | A pair of 'SampCoord' indicating the location of a pixel in a raster image.+type PixCoord = V2 SampCoord++-- | A pair of 'SampCoord' values indicating the size of a rectangle of pixels.+type PixSize = V2 SampCoord++sampCoord :: Integral i => i -> SampCoord+sampCoord = SampCoord . fromIntegral++-- | This is a simple type tag used to indicate the difference between a source and target image,+-- for operations like blitting.+type Source image = image++-- | This is a simple type tag used to indicate the difference between a source and target image,+-- for operations like blitting.+type Target image = image
+ src/Happlets/Draw/Text.hs view
@@ -0,0 +1,74 @@+-- | This module provides an extended API for rendering text into a Happlet window.+module Happlets.Draw.Text+  ( SelectFont, FontExtents(..), TextExtents2D(..), HappletsDrawText(..),+  ) where++import           Happlets.Draw.Types2D+import           Happlets.Draw.Color++import           Control.Monad.IO.Class++import qualified Data.Text as Strict++----------------------------------------------------------------------------------------------------++-- | Fonts should be selected with descriptive strings like "Monospace" or "Arial Italic" or+-- "Helvetica Bold". Font sizes are passed as a 'Happlets.Draw.Types2D.RealApprox' parameter.+type SelectFont = Strict.Text++-- | Contains information about how to align a font in a window. If you construct a command line+-- interface with a monospace font, it should be possible to use the 'fontExtentsXadvance' and+-- 'fontExtentsYadvance' to compute which text character in the window is under the mouse if a mouse+-- coordinate is given.+data FontExtents font+  = FontExtents+    { fontExtentsIdentifier  :: font+    , fontExtentsAscent      :: RealApprox+    , fontExtentsDescent     :: RealApprox+    , fontExtentsHeight      :: RealApprox+    , fontExtentsMaxXadvance :: RealApprox+    , fontExtentsMaxYadvance :: RealApprox+    }+  deriving (Eq, Ord, Show, Read)++-- | A data structure containing informaion on rendered text.+data TextExtents2D+  = TextExtents2D+    { textFontSelector :: !SelectFont+      -- ^ A valid font name.+    , textStartPoint   :: !(Point2D RealApprox)+      -- ^ The point at which to draw the text in order for the 'textBoundingBox' below is to be+      -- realized.+    , textBoundingBox  :: !(Rect2D RealApprox)+      -- ^ The minimum bounding box that contains the visual representation of the text.+    , textToDraw       :: !Strict.Text+    }+  deriving Eq++-- | This class must instantiate 'Control.Monad.Monad' and 'Control.Monad.IO.Class.MonadIO' because+-- it is expected to perform stateful updates to the system, namely changing what graphics are+-- displayed in a Happlet window.+--+-- The @render@ data type instantiated here is expected to be the the same as the @render@ type+-- instantiated into the 'Happlets.GUI.HappletWindow' type class, which should allow Happlet+-- programmers to evaluate all of these functions using the 'Happlets.GUI.onView' function and+-- perform the expected update on the Happlet window.+class (Functor render, Applicative render, Monad render, MonadIO render, Show font)+   => HappletsDrawText render font | font -> render where+  -- | Obtain a list of fonts available to this @canvas@.+  listFonts :: render [font]++  -- | Select a font using a string descriptor of the font. If the selection is successful, return+  -- the new 'FontExtents' information. If the font could not be selected, returns+  -- 'Prelude.Nothing'.+  selectFont :: SelectFont -> render (Maybe (FontExtents font))++  -- | Obtain general information about the selected font.+  fontExtents :: render (FontExtents font)++  -- | Compute the 'TextExtents2D' data structure for this canvas for a given font and text.+  textExtents :: Point2D RealApprox -> Strict.Text -> render TextExtents2D++  -- | Draw text on the canvas. The 'LineColor' selects the text color, and the 'FillColor' selects+  -- the background color.+  drawText :: FillColor -> LineColor -> Point2D RealApprox -> Strict.Text -> render TextExtents2D
+ src/Happlets/Draw/Types2D.hs view
@@ -0,0 +1,174 @@+-- | This module provides a bare minimum of 2D drawing primitives for drawing text, lines, and+-- rectangles, along with setting foreground and background colors, and fill and stroke colors. Also+-- provided are functions for determining if points (for example, mouse cursor locations) lie within+-- a rectangular region. These primitives, along with the functionality in the+-- 'Happlets.GUI.CanBufferImages' type class to load from disk and blit to screen bitmap images,+-- should be enough to construct minimalist user interfaces.+module Happlets.Draw.Types2D+  ( RealApprox(..), realApprox,+    Point2D(..), point2D, pointX, pointY, pointXY,+    Line2D(..), line2D, line2DHead, line2DTail, line2DPoints,+    Rect2D(..), rect2D, rect2DHead, rect2DTail, pointInRect2D, rect2DPoints,+    rect2DMinBoundOf, rect2DIntersect, rect2DDiagonal,+    MaybeSingleton2D(..), HasBoundingBox(..),+    LineWidth,+  ) where++import           Control.Lens+import           Control.Monad++import           Data.Semigroup++import           Linear.V2++----------------------------------------------------------------------------------------------------++-- | This type represents an approximation of a 'Prelude.Real' number.+newtype RealApprox = RealApprox { unwrapRealApprox :: Double }+  deriving (Eq, Ord, Enum, Num, Real, Fractional, Floating, RealFrac)++instance Show RealApprox where { show = show . unwrapRealApprox; }++instance Read RealApprox where+  readsPrec p str = readsPrec p str >>= \ (n, rem) -> [(RealApprox n, rem)]++-- | This type represents a single point.+newtype Point2D n = Point2D (V2 n)+  deriving (Eq, Functor)++instance Num n => Semigroup (Point2D n) where+  (Point2D(V2 xa ya)) <> (Point2D(V2 xb yb)) = Point2D $ V2 (xa + xb) (ya + yb)++instance Num n => Monoid (Point2D n) where+  mempty = Point2D $ V2 0 0+  mappend = (<>)++-- | This type represents a line segment consisting of two points.+data Line2D n = Line2D !(Point2D n) !(Point2D n)+  deriving (Eq, Functor)++-- | This type represents a rectangle bounded by two where all sides of the rectangle points are+-- parallel to the orthogonal basis vectors of the drawing plane. This data type instantiates+-- 'Data.Semigroup.Semigroup' such that the smallest possible rectangle that can contain both+-- rectangles, no matter how far apart they are, is returned.+data Rect2D n = Rect2D !(Point2D n) !(Point2D n)+  deriving (Eq, Functor)++instance Ord n => Semigroup (Rect2D n) where { (<>) = rect2DMinBoundOf; }++-- | An initializing 'Point2D' where 'pointX' and 'pointY' are both zero.+point2D :: Num n => Point2D n+point2D = Point2D $ V2 0 0++realApprox :: Iso' RealApprox Double+realApprox = iso unwrapRealApprox RealApprox++-- | The X coordinate of a 'Point2D', a value expressing some distance along the horizontal axis.+pointX :: Lens' (Point2D n) n+pointX = lens (\ (Point2D(V2 x _)) -> x) $ \ (Point2D(V2 _ y)) x -> Point2D (V2 x y)++-- | The X coordinate of a 'Point2D', a value expressing some distance along the horizontal axis.+pointY :: Lens' (Point2D n) n+pointY = lens (\ (Point2D(V2 _ y)) -> y) $ \ (Point2D(V2 x _)) y -> Point2D (V2 x y)++-- | Expresses the point as a tuple of @(x, y)@ coordinates+pointXY :: Iso' (Point2D n) (n, n)+pointXY = iso (\ (Point2D (V2 x y)) -> (x, y)) (\ (x,y) -> Point2D $ V2 x y)++-- | An initializing 'Line2D' where 'lineHead' and 'lineTail' are both the zero 'point2D'.+line2D :: Num n => Line2D n+line2D = Line2D point2D point2D++-- | The point at which drawing of a line segment begins.+line2DHead :: Lens' (Line2D n) (Point2D n)+line2DHead = lens (\ (Line2D a _) -> a) $ \ (Line2D _ b) a -> Line2D a b++-- | The point at which drawing of a line segment ends.+line2DTail :: Lens' (Line2D n) (Point2D n)+line2DTail = lens (\ (Line2D _ b) -> b) $ \ (Line2D a _) b -> Line2D a b++-- | Expresses a 'Line2D' as a tuple of 'Point2D' values.+line2DPoints :: Iso' (Line2D n) (Point2D n, Point2D n)+line2DPoints = iso (\ (Line2D a b) -> (a, b)) (\ (a,b) -> Line2D a b)++-- | An initializing 'Line2D' where the 'rectLower' and 'rectUpper' values are the zero 'point2D'.+rect2D :: Num n => Rect2D n+rect2D = Rect2D point2D point2D++-- | The point at which drawing of a bounding rectangle begins.+rect2DHead :: Lens' (Rect2D n) (Point2D n)+rect2DHead = lens (\ (Rect2D a _) -> a) $ \ (Rect2D a _) b -> Rect2D a b++-- | The point at which drawing of a bounding rectangle ends.+rect2DTail :: Lens' (Rect2D n) (Point2D n)+rect2DTail = lens (\ (Rect2D _ b) -> b) $ \ (Rect2D _ b) a -> Rect2D a b++-- | Expresses a 'Rect2D' as a tuple of 'Point2D' values.+rect2DPoints :: Iso' (Rect2D n) (Point2D n, Point2D n)+rect2DPoints = iso (\ (Rect2D a b) -> (a, b)) (\ (a,b) -> Rect2D a b)++-- | Test if the given 'Point2D' lies within, or on the bounding box of, the given 'Rect2D'.+pointInRect2D :: Ord n => Point2D n -> Rect2D n -> Bool+pointInRect2D (Point2D(V2 x y)) (Rect2D(Point2D(V2 xa ya))(Point2D(V2 xb yb))) =+  let xlo = min xa xb+      ylo = min ya yb+      xhi = max xa xb+      yhi = max ya yb+      between a b c = a <= b && b <= c+  in  between xlo x xhi && between ylo y yhi++-- | Computes the smallest possible rectangle that can contain both rectangles, no matter how far+-- apart they are.+rect2DMinBoundOf :: Ord n => Rect2D n -> Rect2D n -> Rect2D n+rect2DMinBoundOf +  (Rect2D(Point2D(V2 xa ya))(Point2D(V2 xb yb)))+  (Rect2D(Point2D(V2 xc yc))(Point2D(V2 xd yd))) =+    let f4 comp a b c d = comp a $ comp b $ comp c d in Rect2D+      (Point2D (V2 (f4 min xa xb xc xd) (f4 min ya yb yc yd)))+      (Point2D (V2 (f4 max xa xb xc xd) (f4 max ya yb yc yd)))++-- | Returns an intersection of two 'Rect2D's if the two 'Rect2D's overlap.+rect2DIntersect :: Ord n => Rect2D n -> Rect2D n -> Maybe (Rect2D n)+rect2DIntersect+  (Rect2D(Point2D(V2 xa ya))(Point2D(V2 xb yb)))+  (Rect2D(Point2D(V2 xc yc))(Point2D(V2 xd yd))) = do+    (xa, xb) <- pure (min xa xb, max xa xb)+    (ya, yb) <- pure (min ya yb, max ya yb)+    (xc, xd) <- pure (min xc xd, max xc xd)+    (yc, yd) <- pure (min yc yd, max yc yd)+    let between a b c = a <= b && b <= c+    let isect a b c d = guard (between a c b || between c b d) >> return (min xa xc, max xb xd) +    (xlo, xhi) <- isect xa xb xc xd+    (ylo, yhi) <- isect ya yb yc yd+    return $ Rect2D (Point2D (V2 xlo ylo)) (Point2D (V2 xhi yhi))++-- | Convert a 'Rect2D' to a 'Line2D'+rect2DDiagonal :: Rect2D n -> Line2D n+rect2DDiagonal (Rect2D a b) = Line2D a b++----------------------------------------------------------------------------------------------------++-- | A class providing 'isSingleton2D' which whether a 'Rect2D' or a 'Line2D' are constructed from+-- two identical points. There are theoretically an infinite number of singletons in the 2D+-- plane. The 'line2D' and 'rect2D' constructors are singletons as they both start and end at the+-- zero 'point2D' value.+class MaybeSingleton2D a where { isSingleton2D :: Eq n => a n -> Maybe (Point2D n); }++instance MaybeSingleton2D Line2D where+  isSingleton2D (Line2D a b) = if a == b then Just a else Nothing++instance MaybeSingleton2D Rect2D where+  isSingleton2D (Rect2D a b) = if a == b then Just a else Nothing++----------------------------------------------------------------------------------------------------++class HasBoundingBox a where { theBoundingBox :: a n -> Rect2D n; }++instance HasBoundingBox Rect2D where { theBoundingBox = id; }++instance HasBoundingBox Line2D where { theBoundingBox (Line2D a b) = Rect2D a b; }++----------------------------------------------------------------------------------------------------++-- | Values of this type are used when drawing lines or borders around rectangls.+type LineWidth = RealApprox
+ src/Happlets/Event.hs view
@@ -0,0 +1,244 @@+-- | The Happlets library can be used with a few different back-end GUI libraries. This module+-- intends to provide an absraction over the most common similarities between all of these GUI+-- libraries. This allows developers using the Happlets library to rely mostly on the symbols+-- provided in this module to program Happlets in a platform-independent way.+module Happlets.Event where++import           Happlets.Draw.SampCoord++import           Control.Monad++import           Data.Bits+import qualified Data.ByteString as Strict+import           Data.Time.Clock+import           Data.Typeable+import           Data.Word++----------------------------------------------------------------------------------------------------++-- | Animations are ultimately a sequence of discrete events, so time is tracked by a 'Prelude.Int'+-- value. Internally to your document @model@, you can keep track of time using a 'Prelude.Double'+-- or 'Data.Time.Clock.UTCTime', but you must instantiate the @model@ into the+-- 'Controller.Wire.Session.HasTime' class such that it converts this time value to an+-- 'Prelude.Int'.+type AnimationMoment = NominalDiffTime++----------------------------------------------------------------------------------------------------++-- | A wrapper type to isolate values that indicate some distance from the left of some window or+-- view screen.+newtype FromLeft num = FromLeft { unwrapFfromLeft :: num }+  deriving (Eq, Ord, Show, Read, Typeable, Num, Enum, Bounded)++-- | A wrapper type to isolate values that indicate some distance from the top of some window or+-- view screen.+newtype FromTop num = FromTop { unwrapFromTop :: num }+  deriving (Eq, Ord, Show, Read, Typeable, Num, Enum, Bounded)++-- | A wrapper type to isolate values that indicate some left-to-right width value of objects+-- visible in a window or on a view screen.+newtype Width num = Width { unwrapWidth :: num }+  deriving (Eq, Ord, Show, Read, Typeable, Num, Enum, Bounded)++-- | A wrapper type to isolate values that indicate some top-to-bottom width value of objects+-- visible in a window or on a view screen.+newtype Height num = Height { unwrapHeight :: num }+  deriving (Eq, Ord, Show, Read, Typeable, Num, Enum, Bounded)++----------------------------------------------------------------------------------------------------++-- | Used to encode keyboard event types in a platform independent way.+data Keyboard+  = Keyboard !Pressed !ModifierBits !KeyPoint+    -- ^ Happlet back-ends should try to encode keyboard events using this constructor.+  | RawKey   !Pressed !ModifierBits !Word32+    -- ^ For back-ends that cannot encode keyboard events using the above, use this as a fall-back.+  deriving (Eq, Show, Typeable)++-- | True if the keyboard or mouse event was a key/button-down or "pressed" event, False if the event was+-- key/button-up or "released" event.+type Pressed = Bool++-- | Keyboard event modifier bits. This is just an abstract, opaque, intermediate type used to+-- encode information from various Happlet back-ends.+data ModifierBits = ModifierBits Word32+  deriving (Eq, Ord, Bounded, Typeable)++instance Show ModifierBits where+  show = show . unpackModifiers++-- | Keyboard event information. This is just an abstract intermediate type used to encode+-- information from various Happlet back-ends in a platform-independent way. It has a small list of+-- symbols found on typical commercial keyboards.+data KeyPoint+  = CharKey !Char+  | FuncKey !Int+    -- ^ Arbitrary function keys. Typical keybords typically have keys labeled "F1" through "F12".+  | UpArrowKey+  | DownArrowKey+  | LeftArrowKey+  | RighArrowKey+  | TabKey+  | EnterKey+  | EscapeKey+  | BackSpaceKey+  | DeleteKey+  | HomeKey+  | EndKey+  | PageUpKey+  | PageDownKey+  | InsertKey+  | PuaseKey+  | SymbolKey Strict.ByteString+    -- ^ For keys not included in this list. This will typically be the logical name mapped to a raw+    -- keyboard point by the operating system.+  deriving (Eq, Show, Typeable)++-- | Typical modifier keys provided by most GUI back-ends, platform-independent. These values are+-- extracted from the 'ModifierBits' bit field +data ModifierTag+  = Shift+  | CapsLock+  | LeftShift+  | RightShift+  | Ctrl+  | LeftCtrl+  | RightCtrl+  | Alt1+  | LeftAlt1+  | RightAlt1+  | Alt2+  | LeftAlt2+  | RightAlt2+  | Super1+  | LeftSuper1+  | RightSuper1+  | Super2+  | LeftSuper2+  | RightSuper2+  deriving (Eq, Ord, Enum, Bounded, Show, Read, Typeable)++noModifiers :: ModifierBits+noModifiers = ModifierBits 0++packModifiers :: [ModifierTag] -> ModifierBits+packModifiers = ModifierBits . (foldl (.|.) 0) . fmap (shift 1 . fromEnum)++unpackModifiers :: ModifierBits -> [ModifierTag]+unpackModifiers (ModifierBits bits) = [minBound .. maxBound] >>= \ tag ->+  guard (shift 1 (fromEnum tag) .&. bits /= 0) >> [tag]++isAlt1 :: ModifierTag -> Bool+isAlt1 = \ case+  Alt1      -> True+  LeftAlt1  -> True+  RightAlt1 -> True+  _         -> False++isAlt2 :: ModifierTag -> Bool+isAlt2 = \ case+  Alt2      -> True+  LeftAlt2  -> True+  RightAlt2 -> True+  _         -> False++isAlt :: ModifierTag -> Bool+isAlt tag = isAlt1 tag || isAlt2 tag++isCtrl :: ModifierTag -> Bool+isCtrl = \ case+  Ctrl      -> True+  LeftCtrl  -> True+  RightCtrl -> True+  _         -> False++isShift :: ModifierTag -> Bool+isShift = \ case+  Shift      -> True+  LeftShift  -> True+  RightShift -> True+  _          -> False++isSuper1 :: ModifierTag -> Bool+isSuper1 = \ case+  Super1      -> True+  LeftSuper1  -> True+  RightSuper1 -> True+  _           -> False++isSuper2 :: ModifierTag -> Bool+isSuper2 = \ case+  Super2      -> True+  LeftSuper2  -> True+  RightSuper2 -> True+  _           -> False++isSuper :: ModifierTag -> Bool+isSuper tag = isSuper1 tag || isSuper2 tag++----------------------------------------------------------------------------------------------------++type InputDeviceId = Strict.ByteString++-- | An abstraction for mouse events. Includes whether a button was pressed or released, which+-- keyboard keys were pressed when the button was pressed, which buttons were pressed. An+-- 'InputDeviceId' is also included in the event information in the case that there are multiple+-- mouse devices provided by the back-end, especially for two-player games.+data Mouse+  = Mouse !InputDeviceId !Pressed !ModifierBits !MouseButton !PixCoord+  deriving (Eq, Ord, Show, Typeable)++data MouseButton+  = MotionOnly  -- ^ indicates no button is pressed but there is still a mouse motion event+  | LeftClick   -- ^ this could also map to a track-pad tap event+  | RightClick  -- ^ this could also map to a track-pad hold event+  | MiddleClick -- ^ this could also map to a track-pad double-tap event+  | SideClick   -- ^ some mouses have four buttons+  | VWheelClick -- ^ the vertical scroller wheel was clicked+  | HWheelClick -- ^ the horizontal scroller wheel was clicked+  deriving (Eq, Ord, Show, Read, Enum, Bounded, Typeable)++----------------------------------------------------------------------------------------------------++-- | Force feedback intensity, for systems which provided this functionality.+type FFIntensity = Double++-- | Force feedback duration in seconds.+type FFDuration = NominalDiffTime++-- | Not all Happlet back-end providers will make use of this event type.+--+-- This could be a track-pad or a joy-stick/joy-pad continuous signal, it usually encodes pinches,+-- swipe velocities, and/or rotations.+--+-- Really, this type is a catch-all for various other input devices that might be provided by a+-- Happlets back-end. On 64-bit systems, this data point contains 6 full 64-bit (a total of 48 byte)+-- values all passed at once, along with a device ID so it is obviously not the most efficient way+-- of doing reactive programming.+--+-- It is expceted that lots and lots of events of this type will be generated if it should be+-- provided and installed by a Happlet front-end programmer, and it is expected that perhaps many of+-- the events generated will be thrown away immediately. The 'InputDeviceId' type is provided to+-- mitigate this problem, so when using the 'Happlets.GUI.trackPadEvents' function, you can select+-- which devices from which you want to receive events and reduce the total number of events your+-- Happlet receives.+--+-- That said, it is still best for back-end providers to provide a 'Mouse' event handler instead,+-- and for front-end Happlet developers to use all 'Mouse' event handlers available to you.+data Trackpad+  = Trackpad+    { padDeviceID :: !InputDeviceId+      -- ^ This is a logical identifier for a trackpad device provided by the back-end. Names may+      -- include "raw-trackpad", "player1", "player2", "raw-mouse", "stylus", or "touchscreen". It+      -- is entirely platform/back-end dependent what logical 'TrackpadDeviceID's are available, so+      -- refer to the back-end provider documentation for how to use this.+    , padPinch    :: !Double -- ^ Negative value for pinch-in, positive value for pinch-out.+    , padTwist    :: !Double -- ^ Twisting angle delta in radians.+    , padPressure :: !Double+      -- ^ How much force is an end-user applying to the device.+    , padJoystickForwardLean  :: !Double+      -- ^ forward-lean angle in radians (accellerometer or joystick value)+    , padJoystickSidewaysLean :: !Double+      -- ^ left-right lean angle in radians (accellerometer or joystick value)+    }+  deriving (Eq, Show, Read, Typeable)
+ src/Happlets/GUI.hs view
@@ -0,0 +1,490 @@+-- | This module defines the applet data type 'Happlet', and a function type 'GUI'. These two types+-- define what a Happlet is. When writting a Happlet program, you first define the @model@ data type+-- that your 'Happlet' will view and control, and then you define a variety of GUI functions which+-- manipulate the @model@ and then redraw the window in response to events. The 'GUI' function type+-- is the Happlets equivalent of the @IO@ function type.+--+-- The @model@ is stored into the 'Happlet' and can then be attached to a window using the+-- 'Happlets.Initialize.windowAttach' function in the "Happlets.Initialize" module. When attaching a+-- 'Happlet' to a window, it is also necessary to provide an initial 'GUI' function which will be+-- used to install other 'GUI' functions to be used as event handlers.+--+-- The "Happlets.Event" module provides a consistent API for all back-end+-- 'Happlets.Provider.Provider's, but the subset of which event data types that your 'Happlet'+-- program will be able to respond to depends on the back-end "Happlets.Provider" you are using and+-- which type classes the @window@ type instantiates. The type classes that provide the API+-- functions for installing 'GUI' event handlers include:+--+--  * 'Managed'+--  * 'CanResize'+--  * 'CanAnimate'+--  * 'CanMouse'+--  * 'CanKeyboard'+--  * 'CanTrackpad'+--  * 'CanForceFeedback'+--+--  These type classes provide the functions that allow you to install 'GUI' functions as event+--  handlers into your 'Happlet' when the 'Happlet' is attached to the @window@ using the+--  'Happlets.Initialize.windowAttach' function. You could also think of this as the functions which+--  allow your 'Happlet' to subscribe to certain event channels.+--+-- Once you have created a window and attached a happlet to it (see+-- 'Happlets.Initialize.windowAttach' in the "Happlets.Initialize" module), and end-users use the+-- 'Happlet', events come into your 'Happlet' program triggering the 'GUI' functions which can alter+-- the @model@ data stored in the 'Happlet' using the "Control.Monad.State.Class" functions+-- 'Control.Monad.State.Class.get', 'Control.Monad.State.Class.put',+-- 'Control.Monad.State.Class.modify', and the 'Control.Monad.State.Class.state' functions. However+-- the 'getModel', 'putModel', and 'modifyModel' functions are also provided in this module which+-- are 'GUI'-specific versions of the "Contorol.Monad.State.Class" functions.+--+-- GUI functions update the window using the 'onView' function which evaluates a screen updating+-- function specific to the back-end 'Happlets.Provider.Provider' as defined by the 'HappletWindow'+-- type class.+module Happlets.GUI+  ( -- * The Happlet Data Type+    Happlet, HappletWindow(..), Display(..),++    -- * The GUI Function Type+    GUI, disable, failGUI, getModel, getSubModel, putModel, modifyModel,++    -- * Installing Event Handlers+    -- $InstallingEventHandlers+    Managed(..),+    CanResize(..),+    CanAnimate(..),+    CanMouse(..), MouseEventPattern(..),+    CanKeyboard(..),+    CanTrackpad(..),++    -- * Other Capabilities+    -- $OtherCapabilities+    CanBufferImages(..),+    CanForceFeedback(..),+    DeviceHandler(..), unrecognizedInputDevices, failUnrecognizedInputDevices,++    -- * Low-level details+    -- $LowLevel_Details+    GUIState(..), GUIContinue(..),+    guiModel, guiWindow, guiIsLive, evalGUI,+    makeHapplet, onHapplet, peekModel, sameHapplet,+    getGUIState, putGUIState, askHapplet,++  ) where++import           Prelude hiding ((.), id)++import           Happlets.Event+import           Happlets.Draw.SampCoord++import           Control.Arrow+import           Control.Category+import           Control.Concurrent.MVar+import           Control.Lens+import           Control.Monad.Cont+import qualified Control.Monad.Fail    as Monad+import           Control.Monad.Reader+import           Control.Monad.State++import           Data.Semigroup+import           Data.Typeable++import           System.IO.Unsafe (unsafePerformIO) -- used for generating unique Happlet IDs.++----------------------------------------------------------------------------------------------------++-- | This is a handle containing the current @model@ state of the 'Happlet'. It is constructed with+-- 'makeHapplet', but it is better to use 'Happlets.Initialize.makeHapplet' in the+-- "Happlets.Initialize" module in order to construct a 'Happlet' and associate it with a @window@+-- in a single step.+data Happlet model = Happlet { happletId :: Int, happletMVar :: MVar model }+  deriving (Eq, Typeable)++happletIdGen :: MVar Int+happletIdGen = unsafePerformIO $ newMVar minBound+{-# NOINLINE happletIdGen #-}++-- | It is possible to switch which 'Happlet' is attached to a window, and the window need not+-- attach to a window with a 'Happlet' of the same type as was attached before, the type may+-- switch. However just because the type could switch doesn't necessarily mean a careless 'Happlet'+-- programmer will ask the window to from the current happlet to itself. Since switching occurs+-- while the 'Happlet' is locked, doing this could result in a deadlock. So a method of being able+-- to tell whether two happlets are exactly the same at runtime has been devised, so that a simple+-- test can be performed to see if the window is being asked to re-attach from a 'Happlet' to the+-- same 'Happlet'.+sameHapplet :: Happlet a -> Happlet b -> Bool+sameHapplet a b = happletId a == happletId b++-- | Construct a new 'Happlet'. The given initial 'Happlets.GUI.GUI' function is stored with the+-- 'Happlet' value itself, it is not stored in a reference.+makeHapplet :: model -> IO (Happlet model)+makeHapplet mod = do+  mvar <- newMVar mod+  happId <- modifyMVar happletIdGen $ return . (id &&& id) . (+ 1)+  return Happlet{ happletId = happId, happletMVar = mvar }++-- | Lock the 'Happlet' and perform an IO function on the content of it.+onHapplet :: Happlet model -> (model -> IO (a, model)) -> IO (a, model)+onHapplet (Happlet{happletMVar=mvar}) f = modifyMVar mvar $+  liftM (\ (a, model) -> (model, (a, model))) . f++-- | Create a copy of the @model@ contained within the 'Happlet' from the current thread. Since this+-- @model@ is always being updated by various other threads, the value returned will only be a+-- snapshot of the @model@ at a particular point in time.+--+-- For the most part, a @model@ is only useful to the various 'Happlets.GUI.GUI' threads that run in+-- response to input events, but if it is necessary to view a snapshot of the @model@ from outside+-- of the event 'Happlet.GUI.GUI' proper, this is the function to use.+peekModel :: Happlet model -> IO model+peekModel (Happlet{happletMVar=mvar}) = readMVar mvar++----------------------------------------------------------------------------------------------------++-- | All Happlet back-end 'Happlets.Provider.Provider's must instantiate this type class at the very+-- least.+class HappletWindow window render | window -> render where++  -- | Similar to 'doWindowNewHapplet', except places an existing 'Happlet' into the @window@,+  -- removing the previous 'Happlet'. This is effectivel a context switch that occurs within a+  -- single @window@. This function disables all event handlers, then evaluates the given 'GUI'+  -- function which should install new event handlers. This function then evaluates to 'disable', so+  -- any line of code in the @do@ block written after this function is called will never execute.+  windowChangeHapplet+    :: forall newmodel oldmodel . Happlet newmodel+    -> (PixSize -> GUI window newmodel ())+    -> GUI window oldmodel ()++  -- | Construct a 'GUI' function which evaluates a @render@ function that updates the image of the+  -- @window@.+  onView :: forall model a . (PixSize -> render a) -> GUI window model a++-- | This is a type class similar to the 'Prelude.Show' class, except it displays to the 'GUI'.+class Display drawable render | drawable -> render where+  display :: HappletWindow window render => drawable -> GUI window model ()++----------------------------------------------------------------------------------------------------++newtype GUI window model a+  = GUI+    { unwrapGUI ::+        ( ReaderT (Happlet model)+          ( ContT (GUIState window model) (StateT (GUIState window model) IO))+          a+        )+    }+  deriving (Functor, Applicative, Monad, MonadIO)++-- | A data type indicating the condition of GUI evaluation. This value is part of the 'GUIState'+-- and is usually set when calling 'breakGUI'.+data GUIContinue+  = GUIHalt -- ^ Disable the event handler+  | GUIContinue -- ^ Allow the event handler to remain enabled for the next incoming event.+  | GUIFail !String -- ^ report a failure++-- | The 'GUIState' is the state that is constructed during the evaluation of a GUI function.+data GUIState window model+  = GUIState+    { theGUIModel    :: !model+    , theGUIWindow   :: !window+    , theGUIContinue :: !GUIContinue+    }++instance MonadState model (GUI window model) where+  state f = GUI $ lift $ lift $ state $ \ st ->+    let (a, model) = f (theGUIModel st) in (a, st{ theGUIModel = model })++instance MonadReader (Happlet model) (GUI window model) where+  ask = GUI ask+  local loc = GUI . local loc . unwrapGUI+  +instance Monad.MonadFail (GUI window model) where+  fail = breakGUI . (guiContinue .~) . GUIFail++instance Semigroup a => Semigroup (GUI window model a) where+  a <> b = (<>) <$> a <*> b++instance Monoid a => Monoid (GUI window model a) where+  mempty = return mempty+  mappend a b = mappend <$> a <*> b++-- | 'Control.Lens.Lens' for manipulating the 'GUIState'. It is better to use 'getModel',+-- 'updateModel', 'putModel', 'subModel', or 'liftGUI' instead of manipulating a 'GUIState'+-- directly.+guiModel :: Lens' (GUIState window model) model+guiModel = lens theGUIModel $ \ a b -> a{ theGUIModel = b }++-- | 'Control.Lens.Lens' for manipulating the 'GUIState'. It is better to not use this function at+-- all.+guiWindow :: Lens' (GUIState window model) window+guiWindow = lens theGUIWindow $ \ a b -> a{ theGUIWindow = b }++-- | 'Control.Lens.Lens' for manipulating the 'GUIState'. This will get or set a function that+-- constructs a continuation to be used after evaluation of the 'GUI' function halts. This function+-- is usually called internally by the back-end 'Happlets.Provider.Provider', so it is better to not+-- use this function at all.+guiContinue :: Lens' (GUIState window model) GUIContinue+guiContinue = lens theGUIContinue $ \ a b -> a{ theGUIContinue = b }++-- | Evaluate a 'GUI' function on a given 'Happlet'. The 'Happlet' is locked durnig evaluation. If+-- the 'GUI' function evaluates to 'Disable', the given halt function (of type @IO ()@) is evaluated+-- before unlocking the 'Happlet', and then 'Prelude.False' is returned. If the 'GUI' function+-- evalautes to anything other than the 'Disable' value, the halt function is not evaluated and+-- 'Prelude.True' is returned.+evalGUI+  :: GUI window model void -- ^ the 'GUI' function to evaluate+  -> Happlet model+  -> window -> model+  -> IO (GUIState window model)+evalGUI (GUI f) happ win model =+  evalStateT (runContT (runReaderT (f >> lift (lift get)) happ) return) GUIState+    { theGUIModel    = model+    , theGUIWindow   = win+    , theGUIContinue = GUIContinue+    }++-- | Once you install an event handler, the default behavior is to leave the event handler installed+-- after it has evaluated so that it can continue reacting to events without you needing to re-install the event handler after each reaction.+--+-- However if you wish for an event handler to remove itself, evaluate this function as the final+-- function call in your 'GUI' procedure. Calling this function tells your 'GUI' function to+-- immediately halt and remove itself from the event handling loop.+--+-- Under the hood, this function will evaluate 'breakGUI' with a 'GUIHalt' condition set in the+-- 'guiContinue' field.+disable :: GUI window model void+disable = breakGUI $ guiContinue .~ GUIHalt++-- | Break out of the current 'GUI' evaluation context, performing a final updating function that+-- will be applied to the 'GUIState' before returning to @IO@. This function will never return, and+-- the evaluating context will immediately receive a result as soon as this function is evaluated.+breakGUI+  :: (GUIState window model -> GUIState window model)+  -> GUI window model void+breakGUI = GUI . ReaderT . const . ContT . const . (>> get) . modify++-- | Calling this function tells your 'GUI' function to immediately halt, reporting an error+-- condition. Under the hood, this will evaluate 'breakGUI' with a 'GUIFail' message set in the+-- 'guiContinue' field.+failGUI :: String -> GUI window model void+failGUI = breakGUI . (guiContinue .~) . GUIFail++-- | The 'GUI' function type instantiates the 'Control.Monad.State.Class.MonadState' monad+-- transformer so you can use functions like 'Control.Monad.State.Class.get'. However this function+-- is provided as synonym for the 'Control.Monad.State.Class.get' function for convenience, and+-- perhaps for better readability in your code.+getModel :: GUI window model model+getModel = get++-- | The 'GUI' function type instantiates the 'Control.Monad.State.Class.MonadState' monad+-- transformer so you can use functions like 'Control.Monad.State.Class.gets'. However this function+-- is provided as synonym for the 'Control.Monad.State.Class.gets' function for convenience, and+-- perhaps for better readability in your code.+getSubModel :: (model -> a) -> GUI window model a+getSubModel = gets++-- | The 'GUI' function type instantiates the 'Control.Monad.State.Class.MonadState' monad+-- transformer so you can use functions like 'Control.Monad.State.Class.put'. However this function+-- is provided as synonym for the 'Control.Monad.State.Class.put' function for convenience, and+-- perhaps for better readability in your code.+putModel :: model -> GUI window model ()+putModel = put++-- | The 'GUI' function type instantiates the 'Control.Monad.State.Class.MonadState' monad+-- transformer so you can use functions like 'Control.Monad.State.Class.modify'. However this+-- function is provided as synonym for the 'Control.Monad.State.Class.modify' function for+-- convenience, and perhaps for better readability in your code.+modifyModel :: (model -> model) -> GUI window model ()+modifyModel = modify++----------------------------------------------------------------------------------------------------++-- $LowLevel_Details+--+-- These are functions that should only be used by the back-end+-- 'Happlets.Provider.Provider'. If you think you need to use these functions when programming an+-- ordinary Happlet, ask an expert how you might solve your problem without using them.++-- | Tests if a the 'GUIState' produced after evaluating 'GUI' function with 'evalGUI' is still+-- ready to receive further input signals.+guiIsLive :: GUIState window model -> Bool+guiIsLive = theGUIContinue >>> \ case { GUIContinue -> True; _ -> False; }++-- | Obtain a copy of the entire 'GUIState' data structure set for the current 'GUI' evaluation+-- context. This function should never be used unless you are programming a Happlet+-- 'Happlets.Provider.Provider'.+getGUIState :: GUI window model (GUIState window model)+getGUIState = GUI $ lift $ lift get++-- | Update the entire copy of the 'GUIState' data structure for the current context. This+-- function should never be used unless you are programming a Happlet 'Happlets.Provider.Provider'.+putGUIState :: GUIState window model -> GUI window model ()+putGUIState = GUI . lift . lift . put++-- | Obtain a reference to the 'Happlet' in which this 'GUI' function is being evaluated.+askHapplet :: GUI window model (Happlet model)+askHapplet = ask++----------------------------------------------------------------------------------------------------++-- $InstallingEventHandlers+--+-- These are functions your 'Happlet' can use to subscribe to receive certain types of events that+-- the back-end 'Happlets.Provider.Provider' may provide. Not all back-end+-- 'Happlets.Provider.Provider's provide all types of events. If the @window@ type you are using+-- does instantiate the below classes, you may program your 'Happlet' to receive that type of event.++-- | Windows that are manageable are part of multi-window GUI operating systems where a window+-- manager can display multiple windows, sending a signal when the window is made visible or+-- invisible, and sending a signal when the window received focus (is made to receive user input) or+-- loses focus.+class Managed window where+  -- | This event handler is evaluated when the window becomes visible or invisible+  visibleEvents :: (Bool -> GUI window model ()) -> GUI window model ()+  -- | This event handler is evaluated when the window gains or loses focus.+  focusEvents :: (Bool -> GUI window model ()) -> GUI window model ()+  -- | This function asks the operating system or desktop environment to show or hide the window+  -- associated with the given @window@.+  windowVisible :: Bool -> GUI window model ()++-- | Windows that can be resized can provide an instance of this class. Even on platforms where+-- there is only one window per screen, it may be possible to change screen sizes if the screen+-- resolutions or screen orientations can change.+class CanResize window where+  -- | This event handler is evaluated when the window is resized. It should NOT be called when the+  -- window is first initialized, or when it is made visible+  resizeEvents :: (PixSize -> GUI window model ()) -> GUI window model ()++-- | This class provides the ability to install animation event handlers which are repeatedly called+-- at fast, regular time intervals, usually 60 frames per second.+class CanAnimate window where+  -- | This function will be called repeatedly with a time delta indicating how much time has passed+  -- since the animation handler was installed. The given 'GUI' function should update the+  -- 'Happlet.View.Readraw' state each time.+  stepFrameEvents :: (AnimationMoment -> GUI window model ()) -> GUI window model ()+  -- | This function returns true of false if there is currently an animation event handler+  -- installed and running in the Happlet. To disable a running animation, evaluate+  -- @'stepFrameEvents' 'disable'@.+  animationIsRunning :: GUI window model Bool++-- | This class provides the ability to install keyboard event handlers.+class CanKeyboard window where+  -- | There may be more than one keyboard, although it is not likely. Just the same, it is possible+  -- to specify an 'Happlets.Event.InputDeviceId'. Remember that passing an empty list of+  -- 'Happlets.Event.InputDeviceId's will install the 'GUI' function to receive events from the+  -- default device.+  keyboardEvents :: (Keyboard -> GUI window model ()) -> GUI window model ()+  -- | This function should return a list of all possible keyboard devices. If an empty list is+  -- returned, only one device, the default device, is provided.+  providedKeyboardDevices :: GUI window model [InputDeviceId]+  providedKeyboardDevices = return []++-- | Mouse events can cause a lot of event throughput. To reduce this throughput and improve+-- efficiency, the 'mouseEvents' function take a parameter that lets you filter only certain mouse+-- events, so your 'GUI' function is only called when mouse events matching one of these patterns+-- occur.+data MouseEventPattern+  = MouseButton -- ^ Matches only mouse button click events.+  | MouseDrag   -- ^ Matches mouse motion events only when a button is clicked down.+  | MouseAll    -- ^ Matches all mouse motion and mouse button events.+  deriving (Eq, Ord, Show, Enum, Bounded)++-- | This class provides the ability to install mouse event handlers. Minimal complete definition is+-- 'mouseEvents'.+class CanMouse window where+  -- | Install a 'GUI' function that only responds to mouse button clicks. All mouse cursor motion+  -- is ignored.+  mouseEvents+    :: MouseEventPattern+    -> (Mouse -> GUI window model ())+    -> GUI window model ()+  -- | This function should return a list of all possible mouse devices. If an empty list is+  -- returned, only one device, the default device, is provided.+  providedMouseDevices :: GUI window model [InputDeviceId]+  providedMouseDevices = return []++-- | This class provides the ability to provide trackpad events handlers. Happlet programmers should+-- be not expect that many back-end providers will not provide events of this type at all.+--+-- 'Happlet.Event.Trackpad' events are a catch-all event type which cover all input devices that are+-- not keyboard or mouse devices. Back-end providers should strive to, as often as possible, eschew+-- a 'CanTrackpad' provider and define a 'CanMouse' provider a specific input device instead.+--+-- However, raw mouse events, stylus events, and touch screen events may all fall under the category+-- of 'CanTrackpad', so if the back-end providers would like to provide this type of event, it may.+class CanTrackpad window where+  -- | For 'Happlets.Event.Trackpad' events, it is important (but still not required) for you to+  -- specify an 'Happlets.Event.InputDeviceId'.+  trackpadEvents :: (Trackpad -> GUI window model ()) -> GUI window model ()+  -- | This function should return a list of all possible trackpad devices. If an empty list is+  -- returned, only one device, the default device, is provided. It is more important that back-end+  -- providers specify elements of this list, because of the wide variety of input devices that this+  -- event handler could be made to handle.+  providedTrackpadDevices :: GUI window model [InputDeviceId]+  providedTrackpadDevices = return []++----------------------------------------------------------------------------------------------------++-- $OtherCapabilities+--+-- These are functions which can be called when defining a GUI function which has nothing to do with+-- reacting to events.++class CanBufferImages window image render | window -> image, window -> render where+  -- | Create a new image buffer.+  newImageBuffer :: forall model a . PixSize -> render a -> GUI window model image+  -- | Resize the image buffer.+  resizeImageBuffer :: forall model a . image -> PixSize -> render a -> GUI window model a+  -- | Draw to the image buffer using a @draw@ function.+  drawImage :: forall model a . image -> render a -> GUI window model a+  -- | Blit an image buffer to the current @window@. You can offset the location of the blit+  -- operation by passing an offset value as the 'Happlets.Readraw.PixCoord'.+  blitImage :: image -> PixCoord -> GUI window model ()+  -- | Like 'blitImage' but blits to another @image@, rather than to the current @window@. The first+  -- @image@ parameter is the source from which to blit, the second @image@ is the target to which+  -- to blit, followed by the offset and mask.+  blitImageTo+    :: Source image+    -> Target image+    -> Target PixCoord+    -> GUI window model ()++-- | Some back-end providers may wish to provide force-feedback functionality along with+-- 'CanTrackapd' event handlers.+class CanForceFeedback window where+  -- | Happlet programmers should be able to program a force feedback pattern by specifying a list+  -- of intensities and durations. Multiple calls to this function __should__ delete later force+  -- feedback patterns, and only execute the first call to this function. In multi-threaded systems,+  -- it is up to the back-end provider to decide what should happen if multiple threads call+  -- 'forceFeedback' at the same time. It is recommended that the force feedback sent to the input+  -- device should work on a first-come-first-serve basis, and later patterns should cancle current+  -- patterns that are currently being sent to the input device.+  forceFeedback :: [(FFIntensity, FFDuration)] -> GUI window model ()++-- | For back-end 'Happlets.Provider.Provider's that allow 'Happlet.GUI.Happlet's to subscribe to+-- events from specific devices, this function asks the back-end 'Happlets.Provider.Provider' to+-- return a list of valid input device identifiers that can be used when installing event handlers.+class DeviceHandler window where+  -- | Provide an up-to-date list of available 'Happlets.Event.InputDeviceId's.+  providedInputDevices :: GUI window model [InputDeviceId]+  -- | Subscriber functions which install 'GUI' event handlers, for example 'keyboardEvents',+  -- 'mouseEvents', 'trackpadEvents', or 'forceFeedback', will by default subscribe to events from+  -- any and all devices sending input from the back-end 'Happlets.Provider.Provider'. However if+  -- you wish for your 'Happlet' to only subscribe to events coming from only certain specific+  -- devices, evaluate these subscriber functions within this 'onDevices' function to limit which+  -- devices will send input to your 'GUI' functions.+  onDevices :: [InputDeviceId] -> GUI window model () -> GUI window model ()++-- | Returns a list of input devices that are not recognized.+unrecognizedInputDevices+  :: DeviceHandler window+  => [InputDeviceId] -> GUI window model [InputDeviceId]+unrecognizedInputDevices test = do+  have <- providedInputDevices+  return [device | device <- test, not $ device `elem` have]++-- | Similar to 'unrecognizedInputDevices' but will throw a runtime exception if any of the given+-- 'InputDeviceId's are not provided by the 'providedInputDevices'.+failUnrecognizedInputDevices+  :: DeviceHandler window+  => [InputDeviceId] -> GUI window model ()+failUnrecognizedInputDevices = unrecognizedInputDevices >=> \ bad ->+  if null bad then return () else fail $ "Unrecognized input device IDs"++show bad
+ src/Happlets/Initialize.hs view
@@ -0,0 +1,239 @@+-- | To begin programming your 'Happlet', import the back-end 'Happlets.Provider.Provider' you want+-- to use, for example @import Happlets.Lib.Gtk@. The functions in this module provide a convenient+-- interface for evaluating the functions provided by the 'Happlets.Provider.Provider', making it+-- easy to setup your application from within the "main" function of your executable program.+--+-- If your Happlet is just a simple, single-window happlet, then use 'simpleHapplet' to initialize+-- your Happlet. The 'simpleHapplet' function takes a 'Happlets.Provider.Provider', a function for+-- setting the 'Happlets.Config.Config' parameters, an initial value for the document model data,+-- and an initializing 'Happlets.GUI.GUI' function for installing event handlers. See the+-- documentation for 'simpleHapplet' for an example.+--+-- It is also possible to define a Happlets where multiple Happlet windows are placed on screen when+-- the program is executed. To do this, the task of initializing the 'Happlets.GUI.Happlet'+-- container, creating a new window, and attaching a 'Happlets.GUI.Happlet' container to the window,+-- are all separate initialization steps which are evaluated in the 'Initialize' monad.+--+-- The 'happlet' function takes a back-end 'Happlets.Provider.Provider' and then evaluates an+-- 'Initialize' function, which behaves a lot like an imparative program in which you set parameter+-- variables and then call functions which make inspect the parameter variables.+--+-- In the 'Initialize' function, you can use the various+-- @'Control.Lens.Lens'' 'Happlets.Config.Config'@ lenses defined in the "Happlets.Config" module+-- with the @'(Control.Lens..=')@ operator to set various configuration settings in a stateful way,+-- much like setting environment variables.+--+-- After setting the 'Happlets.Config.Config' paramters, you must:+--+-- 1. call 'newWindow' to create a new window,+-- 2. call 'newHapplet' to create a new 'Happlets.GUI.Happlet' container which contains your+--    document object model.+-- 3. call 'attachWindow' to attach the 'Happlets.GUI.Happlet' to the window, passing an+--    initializing 'Happlets.GUI.GUI' function to setup the event handlers.+-- 4. perform the above 3 steps for as many windows as necessary.+-- 5. call 'launchGUIEventLoop' to start the application+-- 6. if necessary, call 'deleteWindow'.+--+-- @+-- main :: IO ()+-- main = 'happlet' gtkHapplet $ do+--     ---+--     --- setting the 'Happlets.Config.Config' paramters ---+--     ---+--     'Happlets.Config.registeredAppName' 'Control.Lens..=' "My First Happlet!"+--     'Happlets.Config.windowTitleBar' .= "Hello World Happlet"+--     'Happlets.Config.recommendWindowSize' 'Control.Lens..=' (640, 480)+--     ---+--     --- creating the new window ---+--     ---+--     win <- newWindow+--     ---+--     --- create a new 'Happlets.GUI.Happlet' to contain the document object model ---+--     ---+--     happ <- 'newHapplet' MyDocumentModel+--         { myFoo = emptyFoo+--         , myBar = emptyBar+--         }+--     ---+--     --- attaching the happlet container to the window and initializing the event handlers ---+--     ---+--     'attachWindow' win happ initMyHapplet+--     ---+--     'launchGUIEventLoop' -- Will not return until an exit condition halts the event loop.+--     ---+--     --- not always necessary, but delete the windows after the event loop halts ---+--     ---+--     'deleteWindow' win+-- @+--+-- The initializing function passed to 'attachWindow' takes a 'Happlets.Draw.SampCoord.PixSize', so+-- if your document model contains information sensitive to the geometry of the window, you can+-- initialize your document model using the given window size.+--+-- The document model stored in the 'Happlets.GUI.Happlet' container can be any data type at+-- all. Haskell's static type checker ensures that the 'GUI' function you use to initialize the+-- event handlers must match the content of the 'Happlets.GUI.Happlet' container. As your+-- 'Happlets.GUI.GUI' program begins receiving events from the operating system's window manager,+-- the document model is updated using the ordinary 'Control.Monad.State.Class.MonadState' API+-- functions like 'Control.Monad.State.Class.get', 'Control.Monad.State.Class.put',+-- 'Control.Monad.State.Class.modify', as well as the 'Control.Lens.Lens'' functions+-- 'Control.Lens.use', 'Control.Lens.assign' and it's infix form ('Control.Lens..='), and+-- 'Control.Lens.modifying' and it's infix form ('Control.Lens.%=').+--+-- Please also refer to the "Happlets.GUI" documentation on the 'Happlets.GUI.GUI' function type+-- which is the Happlets equivalent of the @IO@ function type. There you will find instructions on+-- how to install event handlers.+module Happlets.Initialize where++import           Happlets.Config+import           Happlets.Draw.SampCoord+import           Happlets.GUI+import           Happlets.Provider++import           Control.Monad.Reader+import           Control.Monad.State++----------------------------------------------------------------------------------------------------++-- | This function carries around with it a reference to a 'Happlets.Provider.Provider' and a+-- 'Happlets.Config.Config' data structure.+-- +-- The real use of this function type is provided by the various classes that can be instantiated by+-- the back-end provider.+newtype Initialize window a+  = Initialize { unwrapGUI :: ReaderT (Provider window) (StateT Config IO) a }+  deriving (Functor, Applicative, Monad, MonadIO)++instance MonadReader (Provider window) (Initialize window) where+  ask = Initialize ask+  local f = Initialize . local f . unwrapGUI++instance MonadState Config (Initialize window) where+  state = Initialize . state++-- | This function is an all-in-one setup function that lets you create a 'Happlets.GUI.Happlet'+-- with a single function call. Pass the back-end 'Happlets.Provider.Provider', a stateful function+-- for updating the default 'Happlets.Config.Config', an initial @model@, and an initial+-- 'Happlets.GUI.GUI' function for installing the 'Happlets.GUI.Happlet' event handlers. This+-- function will automatically call 'newHapplet', 'newWindow', 'attachWindow', 'happlet', and then+-- return when the GUI event loop halts. Here is an example of how you might use it:+--+-- @+-- import Happlets+--+-- -- Here you define your document model data type, which will be updated by the 'Happlets.GUI.GUI'+-- -- function whenever an event occurs.+-- data MyDocModel = MyDocModel+--      { someFoo      :: FooType+--        someBar      :: BarType+--        myDocWinSize :: 'Happlets.Draw.SampCoord.PixSize'+--      }+-- +-- -- Here you define your Haskell "main" function.+-- main :: IO ()+-- main = 'simpleHapplet' gtkHapplet <-- let's say we are using the Gtk+ 'Happlets.Provider.Provider'+--     (do registeredAppName   'Control.Lens..=' "My Happlet"+--         windowTitleBar      'Control.Lens..=' "New Document"+--         recommendWindowSize 'Control.Lens..=' (640, 480)+--         -- The type of this "do" block is ('Control.Monad.State.StateT' 'Happlets.Config.Config' IO ()).+--         -- You use the ('Control.Lens..=') function to set the various "Happlets.Config" parameters.+--         -- The configurable parameters are of type ('Control.Lens.Lens'' 'Happlets.Config.Config').+--     )+--     MyDocModel+--       { someFoo = initNewFoo+--       , someBar = emptyBar+--       , winSize = 'Linear.V2.V2' (-1) (-1)+--         -- Initialize your document model. Notice that your data type can contain a field+--         -- storing the size of the window. This is helpful for rendering graphics where the+--         -- geometry depends on the size of the window, for example, for graphics that you+--         -- like to center in the window.+--       }+--     (\\ winSiz -> do+--         -- This is the first function that runs before any event handlers are called.+--         -- Use this function to update your document model with the window size (if necessary),+--         -- and install the event handler functions.+--+--         'Happlets.GUI.modifyModel' $ \ mydoc ->+--             mydoc{ myDocWinSize = winSiz } --  <-- here you set the window size+--+--         'Happlets.GUI.mouseEvents' 'Happlets.GUI.MouseButton' $ \ mousEvt -> do+--             ---+--             --- some code for handling mouse events ...+--             ---+--+--         'Happlets.GUI.keyboardEvents' $ \ keyEvt -> do+--             ---+--             --- some code for handling key events ...+--             ---+--     )+-- @+simpleHapplet+  :: Provider window+  -> StateT Config IO ()+  -> model+  -> (PixSize -> GUI window model ())+  -> IO ()+simpleHapplet provider updcfg model init = happlet provider $ do+  get >>= liftIO . execStateT updcfg >>= put+  join $ attachWindow True <$> newWindow <*> newHapplet model <*> pure init++-- | Run the 'Initialize' function with the given back-end 'Happlets.Happlet.Provider'.+happlet :: Provider window -> Initialize window a -> IO a+happlet provider (Initialize f) = do+  doInitializeGUI provider+  (a, config) <- runStateT (runReaderT f provider) (defaultConfig provider)+  doGUIEventLoopLaunch provider config+  return a++-- | Create a new @window@. The @window@ itself only contains stateful information relevant to the+-- 'Happlets.GUI.GUI' back-end 'Happlets.Provider.Provider', it does not do anything on it's+-- own. This function does not place a window on the screen, only the 'attachWindow' function can do+-- that.+newWindow :: Initialize window window+newWindow = liftIO =<< asks doWindowNew <*> get++-- | Create a new 'Happlets.GUI.Happlet', which contains a document object model of any type. When+-- you call 'attachWindow' you must supply this 'Happlets.GUI.Happlet' container along with a+-- 'Happlets.GUI.GUI' function that installs all the necessary event handlers into the @window@. As+-- the @window@ begins reciving events from the operating system's window manager, these event+-- handlers are evaluated, and the content of this 'Happlets.GUI.Happlet' can be updated using the+-- 'Control.Monad.State.Class.MonadState' functions like 'Control.Monad.State.Class.get',+-- 'Control.Monad.State.Class.put', 'Control.Monad.State.Class.modify', as well as the+-- 'Control.Lens.Lens'' functions 'Control.Lens.use', 'Control.Lens.assign' and it's infix form+-- ('Control.Lens..='), and 'Control.Lens.modifying' and it's infix form ('Control.Lens.%=').+newHapplet :: model -> Initialize window (Happlet model)+newHapplet = liftIO . makeHapplet++-- | This function evaluates the given 'Happlets.GUI.GUI' function to install 'Happlets.GUI.GUI'+-- event handlers into the @window@ that can modify the content of the 'Happlets.GUI.Happlet'+-- container in response to events received from the operating system's window manager.+--+-- Note that it is possible to detach a 'Happlets.GUI.Happlet' container from a @window@ and+-- re-attach the @window@ to an entirely different type of 'Happlets.GUI.Happlet' container using+-- the 'Happlets.GUI.windowChangeHapplet' function as the program is running and receiving+-- events. This allows a single @window@ to switch between multiple 'Happlets.GUI.Happlet's during+-- program execution. Please refer to the 'Happlets.GUI.windowChangeHapplet' function documentation+-- for information about how to do this.+attachWindow+  :: Bool+  -> window+  -> Happlet model+  -> (PixSize -> GUI window model ())+  -> Initialize window ()+attachWindow vis win happ init = liftIO =<<+  asks doWindowAttach <*> pure vis <*> pure win <*> pure happ <*> pure init++-- | This function launches the GUI event loop. You must call this function once after all of your+-- Happlet setup has been performed. This function will not return until the GUI event loop has+-- halted, so it must be the last function called in the 'Initialize' "do" block, except perhaps for+-- the 'deleteWindow' function which can be evaluated after it.+launchGUIEventLoop :: Initialize window ()+launchGUIEventLoop = get >>= \ config -> asks doGUIEventLoopLaunch >>= liftIO . ($ config)++-- | Delete a window. It often is not necessary to delete a Happlet window because usually once the+-- 'Initialize' function has completed evaluating, there ought not be anything after the 'happlet'+-- function in the @main@ function, and so the executable program will quit, signaling to the+-- operating system window manager to delete all windows associated with this program. None the+-- less, this function exists for the purpose of explicitly deleting windows.+deleteWindow :: window -> Initialize window ()+deleteWindow win = liftIO =<< asks doWindowDelete <*> pure win
+ src/Happlets/Provider.hs view
@@ -0,0 +1,57 @@+-- | This module provides the 'Provider' data type used by various back-ends to initialize a working+-- GUI. In object-oriented jargon, this module provides an abstract interface for Happlets, and the+-- back-end providers are "factories" which must instantiate all of the methods in this interface.+module Happlets.Provider where++import           Happlets.Config+import           Happlets.Draw.SampCoord+import           Happlets.GUI++----------------------------------------------------------------------------------------------------++-- | The @provider@ is a data type containing all information necessary for a high-level 'Happlet' to+-- interface with the low-level back-end provider. The @provider@ is associated with a @window@ handle+-- type (usually a wrapper around a 'Control.Concurrent.MVar') and an @image@ type which store image+-- buffers. The @window@ and @image@ types are functionally dependent on the @provider@ type so it is+-- only necessary to specify the @provider@ type to the type checker in ambiguous situations where the+-- type variables cannot be resolved.+--+-- Furthermore, the @provider@ type may provided different types of @window@ which display different+-- types of @image@. One example of how this might be used is for a Gtk+ back-end might provide a+-- single @window@ type but create two different instances of @provider@, one with Cairo-based @image@+-- buffers, and one with OpenGL-based @image@ buffers.+data Provider window+  = Provider+    { -- | The default 'Happlet.Config.Config' parameters best suited for this partuclar back-end.+      defaultConfig :: Config++      -- | This is the pre-initialization function that should run before performing any GUI-related+      -- action at all.+    , doInitializeGUI :: IO ()++      -- | This function launches the event loop for the given @window@ and does not return until+      -- the GUI application's event handler thread has quit. In the case of Gtk+, since there can+      -- only be one event loop per application, calling this function on any window handle will+      -- launch the event loop for __all__ window handles.+    , doGUIEventLoopLaunch :: Config -> IO ()++      -- | This function creates a @window@ without installing any event handlers, and without+      -- making the window visible. The @window@ craeted can then have 'Happlet's attached to it+      -- using 'doWindowAttach'.+    , doWindowNew :: Config -> IO window++      -- | This function asks the operating system or desktop environment to delete the window+      -- associated with the given @window@. If the 'Happlets.Config.quitOnWindowClose' configuration+      -- parameter is 'Prelude.True', calling this function should also quit the whole application.+    , doWindowDelete :: window -> IO ()++      -- | This function __must__ delete all event handlers currently installed into the @window@+      -- and evaluate a new 'Happlets.GUI.GUI' function which can install new event handlers.+    , doWindowAttach+        :: forall model+        .  Bool -- ^ whether or not to make the window visible+        -> window -- ^ the window to which the 'Happlets.Happlet.Happlet' will be attached+        -> Happlet model -- ^ the 'Happlets.Happlet.Happlet' to attach.+        -> (PixSize -> GUI window model ())+        -> IO ()+    }