diff --git a/CHANGELOG.md b/CHANGELOG.md new file mode 100644 --- /dev/null +++ b/CHANGELOG.md @@ -0,0 +1,5 @@ +* 0.1.0 + - First version of `gi-gtk-declarative`! + - Basic widget without event handling + - Support for `Box` and `ScrolledWindow` containers + - Declarative CSS classes diff --git a/LICENSE b/LICENSE new file mode 100644 --- /dev/null +++ b/LICENSE @@ -0,0 +1,373 @@ +Mozilla Public License Version 2.0 +================================== + +1. Definitions +-------------- + +1.1. "Contributor" + means each individual or legal entity that creates, contributes to + the creation of, or owns Covered Software. + +1.2. "Contributor Version" + means the combination of the Contributions of others (if any) used + by a Contributor and that particular Contributor's Contribution. + +1.3. "Contribution" + means Covered Software of a particular Contributor. + +1.4. "Covered Software" + means Source Code Form to which the initial Contributor has attached + the notice in Exhibit A, the Executable Form of such Source Code + Form, and Modifications of such Source Code Form, in each case + including portions thereof. + +1.5. "Incompatible With Secondary Licenses" + means + + (a) that the initial Contributor has attached the notice described + in Exhibit B to the Covered Software; or + + (b) that the Covered Software was made available under the terms of + version 1.1 or earlier of the License, but not also under the + terms of a Secondary License. + +1.6. "Executable Form" + means any form of the work other than Source Code Form. + +1.7. "Larger Work" + means a work that combines Covered Software with other material, in + a separate file or files, that is not Covered Software. + +1.8. "License" + means this document. + +1.9. "Licensable" + means having the right to grant, to the maximum extent possible, + whether at the time of the initial grant or subsequently, any and + all of the rights conveyed by this License. + +1.10. "Modifications" + means any of the following: + + (a) any file in Source Code Form that results from an addition to, + deletion from, or modification of the contents of Covered + Software; or + + (b) any new file in Source Code Form that contains any Covered + Software. + +1.11. "Patent Claims" of a Contributor + means any patent claim(s), including without limitation, method, + process, and apparatus claims, in any patent Licensable by such + Contributor that would be infringed, but for the grant of the + License, by the making, using, selling, offering for sale, having + made, import, or transfer of either its Contributions or its + Contributor Version. + +1.12. "Secondary License" + means either the GNU General Public License, Version 2.0, the GNU + Lesser General Public License, Version 2.1, the GNU Affero General + Public License, Version 3.0, or any later versions of those + licenses. + +1.13. "Source Code Form" + means the form of the work preferred for making modifications. + +1.14. "You" (or "Your") + means an individual or a legal entity exercising rights under this + License. For legal entities, "You" includes any entity that + controls, is controlled by, or is under common control with You. For + purposes of this definition, "control" means (a) the power, direct + or indirect, to cause the direction or management of such entity, + whether by contract or otherwise, or (b) ownership of more than + fifty percent (50%) of the outstanding shares or beneficial + ownership of such entity. + +2. License Grants and Conditions +-------------------------------- + +2.1. Grants + +Each Contributor hereby grants You a world-wide, royalty-free, +non-exclusive license: + +(a) under intellectual property rights (other than patent or trademark) + Licensable by such Contributor to use, reproduce, make available, + modify, display, perform, distribute, and otherwise exploit its + Contributions, either on an unmodified basis, with Modifications, or + as part of a Larger Work; and + +(b) under Patent Claims of such Contributor to make, use, sell, offer + for sale, have made, import, and otherwise transfer either its + Contributions or its Contributor Version. + +2.2. Effective Date + +The licenses granted in Section 2.1 with respect to any Contribution +become effective for each Contribution on the date the Contributor first +distributes such Contribution. + +2.3. Limitations on Grant Scope + +The licenses granted in this Section 2 are the only rights granted under +this License. No additional rights or licenses will be implied from the +distribution or licensing of Covered Software under this License. +Notwithstanding Section 2.1(b) above, no patent license is granted by a +Contributor: + +(a) for any code that a Contributor has removed from Covered Software; + or + +(b) for infringements caused by: (i) Your and any other third party's + modifications of Covered Software, or (ii) the combination of its + Contributions with other software (except as part of its Contributor + Version); or + +(c) under Patent Claims infringed by Covered Software in the absence of + its Contributions. + +This License does not grant any rights in the trademarks, service marks, +or logos of any Contributor (except as may be necessary to comply with +the notice requirements in Section 3.4). + +2.4. Subsequent Licenses + +No Contributor makes additional grants as a result of Your choice to +distribute the Covered Software under a subsequent version of this +License (see Section 10.2) or under the terms of a Secondary License (if +permitted under the terms of Section 3.3). + +2.5. Representation + +Each Contributor represents that the Contributor believes its +Contributions are its original creation(s) or it has sufficient rights +to grant the rights to its Contributions conveyed by this License. + +2.6. Fair Use + +This License is not intended to limit any rights You have under +applicable copyright doctrines of fair use, fair dealing, or other +equivalents. + +2.7. Conditions + +Sections 3.1, 3.2, 3.3, and 3.4 are conditions of the licenses granted +in Section 2.1. + +3. Responsibilities +------------------- + +3.1. Distribution of Source Form + +All distribution of Covered Software in Source Code Form, including any +Modifications that You create or to which You contribute, must be under +the terms of this License. You must inform recipients that the Source +Code Form of the Covered Software is governed by the terms of this +License, and how they can obtain a copy of this License. You may not +attempt to alter or restrict the recipients' rights in the Source Code +Form. + +3.2. Distribution of Executable Form + +If You distribute Covered Software in Executable Form then: + +(a) such Covered Software must also be made available in Source Code + Form, as described in Section 3.1, and You must inform recipients of + the Executable Form how they can obtain a copy of such Source Code + Form by reasonable means in a timely manner, at a charge no more + than the cost of distribution to the recipient; and + +(b) You may distribute such Executable Form under the terms of this + License, or sublicense it under different terms, provided that the + license for the Executable Form does not attempt to limit or alter + the recipients' rights in the Source Code Form under this License. + +3.3. Distribution of a Larger Work + +You may create and distribute a Larger Work under terms of Your choice, +provided that You also comply with the requirements of this License for +the Covered Software. If the Larger Work is a combination of Covered +Software with a work governed by one or more Secondary Licenses, and the +Covered Software is not Incompatible With Secondary Licenses, this +License permits You to additionally distribute such Covered Software +under the terms of such Secondary License(s), so that the recipient of +the Larger Work may, at their option, further distribute the Covered +Software under the terms of either this License or such Secondary +License(s). + +3.4. Notices + +You may not remove or alter the substance of any license notices +(including copyright notices, patent notices, disclaimers of warranty, +or limitations of liability) contained within the Source Code Form of +the Covered Software, except that You may alter any license notices to +the extent required to remedy known factual inaccuracies. + +3.5. Application of Additional Terms + +You may choose to offer, and to charge a fee for, warranty, support, +indemnity or liability obligations to one or more recipients of Covered +Software. However, You may do so only on Your own behalf, and not on +behalf of any Contributor. You must make it absolutely clear that any +such warranty, support, indemnity, or liability obligation is offered by +You alone, and You hereby agree to indemnify every Contributor for any +liability incurred by such Contributor as a result of warranty, support, +indemnity or liability terms You offer. You may include additional +disclaimers of warranty and limitations of liability specific to any +jurisdiction. + +4. Inability to Comply Due to Statute or Regulation +--------------------------------------------------- + +If it is impossible for You to comply with any of the terms of this +License with respect to some or all of the Covered Software due to +statute, judicial order, or regulation then You must: (a) comply with +the terms of this License to the maximum extent possible; and (b) +describe the limitations and the code they affect. Such description must +be placed in a text file included with all distributions of the Covered +Software under this License. Except to the extent prohibited by statute +or regulation, such description must be sufficiently detailed for a +recipient of ordinary skill to be able to understand it. + +5. Termination +-------------- + +5.1. The rights granted under this License will terminate automatically +if You fail to comply with any of its terms. However, if You become +compliant, then the rights granted under this License from a particular +Contributor are reinstated (a) provisionally, unless and until such +Contributor explicitly and finally terminates Your grants, and (b) on an +ongoing basis, if such Contributor fails to notify You of the +non-compliance by some reasonable means prior to 60 days after You have +come back into compliance. Moreover, Your grants from a particular +Contributor are reinstated on an ongoing basis if such Contributor +notifies You of the non-compliance by some reasonable means, this is the +first time You have received notice of non-compliance with this License +from such Contributor, and You become compliant prior to 30 days after +Your receipt of the notice. + +5.2. If You initiate litigation against any entity by asserting a patent +infringement claim (excluding declaratory judgment actions, +counter-claims, and cross-claims) alleging that a Contributor Version +directly or indirectly infringes any patent, then the rights granted to +You by any and all Contributors for the Covered Software under Section +2.1 of this License shall terminate. + +5.3. In the event of termination under Sections 5.1 or 5.2 above, all +end user license agreements (excluding distributors and resellers) which +have been validly granted by You or Your distributors under this License +prior to termination shall survive termination. + +************************************************************************ +* * +* 6. Disclaimer of Warranty * +* ------------------------- * +* * +* Covered Software is provided under this License on an "as is" * +* basis, without warranty of any kind, either expressed, implied, or * +* statutory, including, without limitation, warranties that the * +* Covered Software is free of defects, merchantable, fit for a * +* particular purpose or non-infringing. The entire risk as to the * +* quality and performance of the Covered Software is with You. * +* Should any Covered Software prove defective in any respect, You * +* (not any Contributor) assume the cost of any necessary servicing, * +* repair, or correction. This disclaimer of warranty constitutes an * +* essential part of this License. No use of any Covered Software is * +* authorized under this License except under this disclaimer. * +* * +************************************************************************ + +************************************************************************ +* * +* 7. Limitation of Liability * +* -------------------------- * +* * +* Under no circumstances and under no legal theory, whether tort * +* (including negligence), contract, or otherwise, shall any * +* Contributor, or anyone who distributes Covered Software as * +* permitted above, be liable to You for any direct, indirect, * +* special, incidental, or consequential damages of any character * +* including, without limitation, damages for lost profits, loss of * +* goodwill, work stoppage, computer failure or malfunction, or any * +* and all other commercial damages or losses, even if such party * +* shall have been informed of the possibility of such damages. This * +* limitation of liability shall not apply to liability for death or * +* personal injury resulting from such party's negligence to the * +* extent applicable law prohibits such limitation. Some * +* jurisdictions do not allow the exclusion or limitation of * +* incidental or consequential damages, so this exclusion and * +* limitation may not apply to You. * +* * +************************************************************************ + +8. Litigation +------------- + +Any litigation relating to this License may be brought only in the +courts of a jurisdiction where the defendant maintains its principal +place of business and such litigation shall be governed by laws of that +jurisdiction, without reference to its conflict-of-law provisions. +Nothing in this Section shall prevent a party's ability to bring +cross-claims or counter-claims. + +9. Miscellaneous +---------------- + +This License represents the complete agreement concerning the subject +matter hereof. If any provision of this License is held to be +unenforceable, such provision shall be reformed only to the extent +necessary to make it enforceable. Any law or regulation which provides +that the language of a contract shall be construed against the drafter +shall not be used to construe this License against a Contributor. + +10. Versions of the License +--------------------------- + +10.1. New Versions + +Mozilla Foundation is the license steward. Except as provided in Section +10.3, no one other than the license steward has the right to modify or +publish new versions of this License. Each version will be given a +distinguishing version number. + +10.2. Effect of New Versions + +You may distribute the Covered Software under the terms of the version +of the License under which You originally received the Covered Software, +or under the terms of any subsequent version published by the license +steward. + +10.3. Modified Versions + +If you create software not governed by this License, and you want to +create a new license for such software, you may create and use a +modified version of this License if you rename the license and remove +any references to the name of the license steward (except to note that +such modified license differs from this License). + +10.4. Distributing Source Code Form that is Incompatible With Secondary +Licenses + +If You choose to distribute Source Code Form that is Incompatible With +Secondary Licenses under the terms of this version of the License, the +notice described in Exhibit B of this License must be attached. + +Exhibit A - Source Code Form License Notice +------------------------------------------- + + This Source Code Form is subject to the terms of the Mozilla Public + License, v. 2.0. If a copy of the MPL was not distributed with this + file, You can obtain one at http://mozilla.org/MPL/2.0/. + +If it is not possible or desirable to put the notice in a particular +file, then You may include the notice in a location (such as a LICENSE +file in a relevant directory) where a recipient would be likely to look +for such a notice. + +You may add additional accurate notices of copyright ownership. + +Exhibit B - "Incompatible With Secondary Licenses" Notice +--------------------------------------------------------- + + This Source Code Form is "Incompatible With Secondary Licenses", as + defined by the Mozilla Public License, v. 2.0. diff --git a/Setup.hs b/Setup.hs new file mode 100644 --- /dev/null +++ b/Setup.hs @@ -0,0 +1,2 @@ +import Distribution.Simple +main = defaultMain diff --git a/gi-gtk-declarative.cabal b/gi-gtk-declarative.cabal new file mode 100644 --- /dev/null +++ b/gi-gtk-declarative.cabal @@ -0,0 +1,47 @@ +name: gi-gtk-declarative +version: 0.1.0 +synopsis: Declarative GTK+ programming in Haskell +description: A declarative programming model for GTK+ user + interfaces, implementing support for various widgets + and generalized patching. This library aims to extend the + gi-gtk library as transparently as possible, and to be + a reusable library for multiple application architectures + and styles. + + See [the project README](https://github.com/owickstrom/gi-gtk-declarative#readme) + for more information. +license: MPL-2.0 +license-file: LICENSE +author: Oskar Wickström +maintainer: oskar.wickstrom@gmail.com +copyright: Oskar Wickström +category: Graphics +build-type: Simple +cabal-version: >=1.10 +extra-source-files: CHANGELOG.md + +library + exposed-modules: GI.Gtk.Declarative + , GI.Gtk.Declarative.Attributes + , GI.Gtk.Declarative.Attributes.Internal + , GI.Gtk.Declarative.Bin + , GI.Gtk.Declarative.Container + , GI.Gtk.Declarative.Container.Box + , GI.Gtk.Declarative.Container.Patch + , GI.Gtk.Declarative.CSS + , GI.Gtk.Declarative.EventSource + , GI.Gtk.Declarative.Markup + , GI.Gtk.Declarative.Patch + , GI.Gtk.Declarative.SingleWidget + build-depends: base >=4.10 && <4.12 + , gi-gobject >= 2 && <3 + , gi-gtk >= 3 && <4 + , haskell-gi >= 0.21 && <0.22 + , haskell-gi-base >= 0.21 && <0.22 + , haskell-gi-overloading == 1.0 + , mtl + , text + , unordered-containers >= 0.2 && < 0.3 + hs-source-dirs: src + default-language: Haskell2010 + ghc-options: -Wall diff --git a/src/GI/Gtk/Declarative.hs b/src/GI/Gtk/Declarative.hs new file mode 100644 --- /dev/null +++ b/src/GI/Gtk/Declarative.hs @@ -0,0 +1,19 @@ +-- | The declarative layer on top of GTK+ lets you describe your user +-- interface as a declarative hierarchy of objects, using data +-- structures and pure functions. You can leverage the declarative event +-- handling to build reusable widgets. The "Patch" typeclass, and the +-- instances provided by this library, performs minimal updates to GTK+ widgets +-- using the underlying imperative operations, so that your rendering can always +-- be a pure function your state to a "Widget". +module GI.Gtk.Declarative + ( module Export + ) where + +import GI.Gtk.Declarative.Attributes as Export +import GI.Gtk.Declarative.Bin as Export +import GI.Gtk.Declarative.Container as Export +import GI.Gtk.Declarative.Container.Box as Export +import GI.Gtk.Declarative.CSS as Export +import GI.Gtk.Declarative.Markup as Export +import GI.Gtk.Declarative.Patch as Export +import GI.Gtk.Declarative.SingleWidget as Export diff --git a/src/GI/Gtk/Declarative/Attributes.hs b/src/GI/Gtk/Declarative/Attributes.hs new file mode 100644 --- /dev/null +++ b/src/GI/Gtk/Declarative/Attributes.hs @@ -0,0 +1,227 @@ +{-# LANGUAGE DataKinds #-} +{-# LANGUAGE FlexibleContexts #-} +{-# LANGUAGE FlexibleInstances #-} +{-# LANGUAGE FunctionalDependencies #-} +{-# LANGUAGE GADTs #-} +{-# LANGUAGE KindSignatures #-} +{-# LANGUAGE LambdaCase #-} +{-# LANGUAGE MultiParamTypeClasses #-} +{-# LANGUAGE OverloadedLabels #-} +{-# LANGUAGE RankNTypes #-} +{-# LANGUAGE ScopedTypeVariables #-} +{-# LANGUAGE TypeApplications #-} +{-# LANGUAGE TypeFamilies #-} +{-# LANGUAGE TypeOperators #-} + +-- | Attribute lists on declarative objects, supporting the underlying +-- attributes from "Data.GI.Base.Attributes", along with CSS class lists, and +-- pure and impure event callbacks. + +module GI.Gtk.Declarative.Attributes + ( Attribute(..) + -- * + , classes + -- * Event Handling + , on + , onM + -- * Callbacks + , ToGtkCallback(..) + ) +where + +import Control.Monad (void) +import qualified Data.GI.Base.Attributes as GI +import qualified Data.GI.Base.Signals as GI +import qualified Data.HashSet as HashSet +import Data.Text (Text) +import Data.Typeable +import GHC.TypeLits (KnownSymbol, Symbol) +import qualified GI.Gtk as Gtk + +import GI.Gtk.Declarative.CSS + +-- * Attributes + +-- | The attribute GADT represent a supported attribute for a declarative +-- widget. This extends the regular notion of GTK+ attributes to also include +-- event handling and CSS classes. +data Attribute widget event where + -- | An attribute/value mapping for a declarative widget. The + -- 'GI.AttrLabelProxy' is parameterized by 'attr', which represents the + -- GTK-defined attribute name. The underlying GI object needs to support + -- the /construct/, /get/, and /set/ operations for the given attribute. + (:=) + :: (GI.AttrOpAllowed 'GI.AttrConstruct info widget + , GI.AttrOpAllowed 'GI.AttrSet info widget + , GI.AttrGetC info widget attr getValue + , GI.AttrSetTypeConstraint info setValue + , KnownSymbol attr + , Typeable attr + ) + => GI.AttrLabelProxy (attr :: Symbol) -> setValue -> Attribute widget event + -- | Defines a set of CSS classes for the underlying widget's style context. + -- Use the 'classes' function instead of this constructor directly. + Classes + :: Gtk.IsWidget widget + => ClassSet + -> Attribute widget event + -- | Emit events using a pure callback. Use the 'on function instead of this + -- constructor directly. + OnSignalPure + :: ( Gtk.GObject widget + , GI.SignalInfo info + , callback ~ GI.HaskellCallbackType info + , Functor (PureCallback callback) + , ToGtkCallback (PureCallback callback) + , callback ~ CustomGtkCallback (PureCallback callback) + ) + => Gtk.SignalProxy widget info + -> PureCallback callback event + -> Attribute widget event + -- | Emit events using an impure callback. Use the 'on function instead of + -- this constructor directly. + OnSignalImpure + :: ( Gtk.GObject widget + , GI.SignalInfo info + , callback ~ GI.HaskellCallbackType info + , Functor (ImpureCallback callback widget) + , ToGtkCallback (ImpureCallback callback widget) + , (widget -> callback) ~ CustomGtkCallback (ImpureCallback callback widget) + ) + => Gtk.SignalProxy widget info + -> ImpureCallback callback widget event + -> Attribute widget event + +-- | Attributes have a 'Functor' instance that maps events in all event +-- callbacks. +instance Functor (Attribute widget) where + fmap f = \case + attr := value -> attr := value + Classes cs -> Classes cs + OnSignalPure signal cb -> OnSignalPure signal (fmap f cb) + OnSignalImpure signal cb -> OnSignalImpure signal (fmap f cb) + +-- | Define the CSS classes for the underlying widget's style context. For these +-- classes to have any effect, this requires a 'Gtk.CssProvider' with CSS files +-- loaded, to be added to the GDK screen. You probably want to do this in your +-- entry point when setting up GTK. +classes :: Gtk.IsWidget widget => [Text] -> Attribute widget event +classes = Classes . HashSet.fromList + +-- | Emit events, using a pure callback, by subcribing to the specified +-- signal. +on + :: ( Gtk.GObject widget + , GI.SignalInfo info + , callback ~ GI.HaskellCallbackType info + , pure ~ ToPureCallback callback event + , Functor (PureCallback callback) + , ToGtkCallback (PureCallback callback) + , callback ~ CustomGtkCallback (PureCallback callback) + ) + => Gtk.SignalProxy widget info + -> pure + -> Attribute widget event +on signal = OnSignalPure signal . PureCallback + +-- | Emit events, using an impure callback receiving the 'widget' and returning +-- an 'IO' action of 'event', by subcribing to the specified signal. +onM + :: ( Gtk.GObject widget + , GI.SignalInfo info + , callback ~ GI.HaskellCallbackType info + , impure ~ ToImpureCallback callback event + , withWidget ~ (widget -> impure) + , Functor (ImpureCallback callback widget) + , ToGtkCallback (ImpureCallback callback widget) + , (widget -> callback) ~ CustomGtkCallback (ImpureCallback callback widget) + ) + => Gtk.SignalProxy widget info + -> withWidget + -> Attribute widget event +onM signal = OnSignalImpure signal . ImpureCallback + +-- * Pure Callbacks + +-- | Convert a GTK+ callback type to a pure callback type, i.e. a type +-- without 'IO'. The pure callback is either a single 'event', or a function of +-- the same arity and arguments as the GTK+ callback, but with the 'event' as +-- the range. +type family ToPureCallback gtkCallback event where + ToPureCallback (IO ()) event = event + ToPureCallback (a -> b) event = a -> ToPureCallback b event + +-- | A 'PureCallback' holds a pure callback, as defined by 'ToPureCallback'. +data PureCallback callback event where + PureCallback + :: (pure ~ ToPureCallback callback event) + => pure + -> PureCallback callback event + +-- The functor instances are pretty annoying, being repeated for each function +-- arity. Could this be done in another way? + +instance Functor (PureCallback (IO ())) where + fmap f (PureCallback e) = PureCallback (f e) + +instance Functor (PureCallback (x -> IO ())) where + fmap f (PureCallback g) = PureCallback (f . g) + +instance Functor (PureCallback (x -> y -> IO ())) where + fmap f (PureCallback g) = PureCallback (\x -> f . g x) + +-- * Impure Callbacks + +-- | Convert a GTK+ callback type to an impure callback type, i.e. a type +-- with 'IO event' as the range, instead of 'IO ()'. The impure callback is +-- either a single 'IO event', or a function of the same arity and arguments as +-- the GTK+ callback, but with 'IO event' as the range. +type family ToImpureCallback t e where + ToImpureCallback (IO ()) e = IO e + ToImpureCallback (a -> b) e = a -> ToImpureCallback b e + +-- | An 'ImpureCallback' holds an impure callback, as defined by +-- 'ToImpureCallback', but with an extra 'widget' argument. This is so that +-- impure callbacks can query their underlying GTK+ widgets for data. +data ImpureCallback callback widget event where + ImpureCallback + :: (impure ~ ToImpureCallback callback event) + => (widget -> impure) + -> ImpureCallback callback widget event + +-- The functor instances are pretty annoying, being repeated for each function +-- arity. Could this be done in another way? + +instance Functor (ImpureCallback (IO ()) widget) where + fmap f (ImpureCallback g) = ImpureCallback (\w -> f <$> g w) + +instance Functor (ImpureCallback (x -> IO ()) widget) where + fmap f (ImpureCallback g) = ImpureCallback (\w -> fmap f . g w) + +instance Functor (ImpureCallback (x -> y -> IO ()) widget) where + fmap f (ImpureCallback g) = ImpureCallback (\w x -> fmap f . g w x) + +-- * GTK+ Callback Conversions + +-- | Internal class for converting user callbacks to gi-gtk callbacks. +class ToGtkCallback userCallback where + type CustomGtkCallback userCallback :: * + -- | Converts a user callback, i.e. a pure or an impure callback, back to a + -- GTK+ callback. + toGtkCallback :: userCallback event -> (event -> IO ()) -> CustomGtkCallback userCallback + +instance ToGtkCallback (PureCallback (IO ())) where + type CustomGtkCallback (PureCallback (IO ())) = IO () + toGtkCallback (PureCallback cb) f = void (f cb) + +instance ToGtkCallback (PureCallback (x -> IO ())) where + type CustomGtkCallback (PureCallback (x -> IO ())) = x -> IO () + toGtkCallback (PureCallback cb) f x = void (f (cb x)) + +instance ToGtkCallback (PureCallback (x -> y -> IO ())) where + type CustomGtkCallback (PureCallback (x -> y -> IO ())) = x -> y -> IO () + toGtkCallback (PureCallback cb) f x y = void (f (cb x y)) + +instance ToGtkCallback (ImpureCallback (IO ()) widget) where + type CustomGtkCallback (ImpureCallback (IO ()) widget) = widget -> IO () + toGtkCallback (ImpureCallback cb) f w = void (cb w >>= f) diff --git a/src/GI/Gtk/Declarative/Attributes/Internal.hs b/src/GI/Gtk/Declarative/Attributes/Internal.hs new file mode 100644 --- /dev/null +++ b/src/GI/Gtk/Declarative/Attributes/Internal.hs @@ -0,0 +1,59 @@ +{-# LANGUAGE DataKinds #-} +{-# LANGUAGE LambdaCase #-} + +-- | Internal helpers for applying attributes and signal handlers to GTK+ +-- widgets. +module GI.Gtk.Declarative.Attributes.Internal + ( extractAttrConstructOps + , extractAttrSetOps + , addClass + , removeClass + , addSignalHandler + ) where + +import qualified Data.GI.Base.Attributes as GI +import qualified GI.GObject as GI +import qualified GI.Gtk as Gtk +import Control.Monad.IO.Class (MonadIO) + +import GI.Gtk.Declarative.Attributes +import GI.Gtk.Declarative.EventSource + +extractAttrConstructOps + :: Attribute widget event -> [GI.AttrOp widget 'GI.AttrConstruct] +extractAttrConstructOps = \case + (attr := value) -> pure (attr Gtk.:= value) + _ -> mempty + +extractAttrSetOps :: Attribute widget event -> [GI.AttrOp widget 'GI.AttrSet] +extractAttrSetOps = \case + (attr := value) -> pure (attr Gtk.:= value) + _ -> mempty + +addClass :: MonadIO m => Gtk.StyleContext -> Attribute widget event -> m () +addClass sc = \case + Classes cs -> mapM_ (Gtk.styleContextAddClass sc) cs + _ -> pure () + +removeClass :: MonadIO m => Gtk.StyleContext -> Attribute widget event -> m () +removeClass sc = \case + Classes cs -> mapM_ (Gtk.styleContextRemoveClass sc) cs + _ -> pure () + +addSignalHandler + :: (Gtk.IsWidget widget, MonadIO m) + => (event -> IO ()) + -> widget + -> Attribute widget event + -> m (Maybe Subscription) +addSignalHandler onEvent widget' = \case + OnSignalPure signal handler -> do + handlerId <- Gtk.on widget' signal (toGtkCallback handler onEvent) + w <- Gtk.toWidget widget' + pure (Just (fromCancellation (GI.signalHandlerDisconnect w handlerId))) + OnSignalImpure signal handler -> do + handlerId <- Gtk.on widget' signal (toGtkCallback handler onEvent widget') + w <- Gtk.toWidget widget' + pure (Just (fromCancellation (GI.signalHandlerDisconnect w handlerId))) + _ -> pure Nothing + diff --git a/src/GI/Gtk/Declarative/Bin.hs b/src/GI/Gtk/Declarative/Bin.hs new file mode 100644 --- /dev/null +++ b/src/GI/Gtk/Declarative/Bin.hs @@ -0,0 +1,167 @@ +{-# OPTIONS_GHC -fno-warn-unticked-promoted-constructors #-} +{-# LANGUAGE DataKinds #-} +{-# LANGUAGE FlexibleContexts #-} +{-# LANGUAGE FlexibleInstances #-} +{-# LANGUAGE FunctionalDependencies #-} +{-# LANGUAGE GADTs #-} +{-# LANGUAGE LambdaCase #-} +{-# LANGUAGE MultiParamTypeClasses #-} +{-# LANGUAGE OverloadedLabels #-} +{-# LANGUAGE ScopedTypeVariables #-} +{-# LANGUAGE TypeFamilies #-} +{-# LANGUAGE TypeOperators #-} + +-- | A declarative representation of 'Gtk.Bin' in GTK. +module GI.Gtk.Declarative.Bin + ( Bin + , bin + ) +where + +import Control.Monad ((>=>)) +import Data.Maybe +import Data.Typeable +import qualified GI.GObject as GI +import qualified GI.Gtk as Gtk + +import GI.Gtk.Declarative.Attributes +import GI.Gtk.Declarative.Attributes.Internal +import GI.Gtk.Declarative.EventSource +import GI.Gtk.Declarative.Markup +import GI.Gtk.Declarative.Patch + + +-- | Supported 'Gtk.Bin's. +class BinChild bin (child :: * -> *) | bin -> child where + getChild :: bin -> IO Gtk.Widget + +instance BinChild Gtk.ScrolledWindow Widget where + getChild scrolledWindow = do + viewPort <- getBinChild Gtk.Viewport scrolledWindow + getBinChild Gtk.Widget viewPort + +instance BinChild Gtk.ListBoxRow Widget where + getChild = getBinChild Gtk.Widget + +-- | Declarative version of a /bin/ widget, i.e. a widget with exactly one +-- child. +data Bin widget child event where + Bin + :: ( Typeable widget + , Gtk.IsContainer widget + , Gtk.IsBin widget + , Gtk.IsWidget widget + , Functor child + ) + => (Gtk.ManagedPtr widget -> widget) + -> [Attribute widget event] + -> child event + -> Bin widget child event + +instance Functor (Bin widget child) where + fmap f (Bin ctor attrs child) = + Bin ctor (fmap f <$> attrs) (fmap f child) + +-- | Construct a /bin/ widget, i.e. a widget with exactly one child. +bin :: + ( Patchable (Bin widget child) + , Typeable widget + , Typeable child + , Typeable event + , Functor child + , Gtk.IsContainer widget + , Gtk.IsBin widget + , Gtk.IsWidget widget + , FromWidget (Bin widget child) event target + , BinChild widget child + ) + => (Gtk.ManagedPtr widget -> widget) -- ^ A bin widget constructor from the underlying gi-gtk library. + -> [Attribute widget event] -- ^ List of 'Attribute's. + -> child event -- ^ The bin's child widget, whose type is decided by the 'BinChild' instance. + -> target -- ^ The target, whose type is decided by 'FromWidget'. +bin ctor attrs = fromWidget . Bin ctor attrs + +-- +-- Patchable +-- + +instance (BinChild parent child, Patchable child) => Patchable (Bin parent child) where + create (Bin ctor props child) = do + let attrOps = concatMap extractAttrConstructOps props + widget' <- Gtk.new ctor attrOps + + sc <- Gtk.widgetGetStyleContext widget' + mapM_ (addClass sc) props + + Gtk.containerAdd widget' =<< create child + Gtk.toWidget widget' + + patch (Bin _ oldAttributes oldChild) (Bin ctor newAttributes newChild) = + Modify $ \widget' -> do + + binWidget <- Gtk.unsafeCastTo ctor widget' + Gtk.set binWidget (concatMap extractAttrSetOps newAttributes) + + sc <- Gtk.widgetGetStyleContext binWidget + mapM_ (removeClass sc) oldAttributes + mapM_ (addClass sc) newAttributes + + childWidget <- getChild binWidget + + case patch oldChild newChild of + Modify modify -> modify childWidget + Replace createNew -> do + Gtk.containerRemove binWidget childWidget + Gtk.containerAdd binWidget =<< createNew + Keep -> return () + +-- +-- EventSource +-- + +instance (BinChild parent child, EventSource child) => + EventSource (Bin parent child) where + subscribe (Bin ctor props child) widget' cb = do + binWidget <- Gtk.unsafeCastTo ctor widget' + handlers' <- + mconcat . catMaybes <$> mapM (addSignalHandler cb binWidget) props + childWidget <- getChild binWidget + (<> handlers') <$> subscribe child childWidget cb + +-- +-- FromWidget +-- + +instance ( BinChild widget child + , Typeable widget + , Patchable child + , EventSource child + , Functor (Bin widget child) + ) => + FromWidget (Bin widget child) event (Widget event) where + fromWidget = Widget + +instance a ~ () => FromWidget (Bin widget child) event (MarkupOf (Bin widget child) event a) where + fromWidget = single + +instance ( BinChild widget child + , a ~ () + , Typeable widget + , Patchable child + , EventSource child + , Functor (Bin widget child) + ) => + FromWidget (Bin widget child) event (Markup event a) where + fromWidget = single . Widget + + +-- | Get a "Gtk.Bin" child, or fail, and cast it to the given widget type. +getBinChild + :: (Gtk.IsBin bin, GI.GObject child) + => (Gtk.ManagedPtr child -> child) + -> bin + -> IO child +getBinChild ctor = + Gtk.binGetChild + >=> maybe (fail "expected Bin to have a child") return + >=> Gtk.unsafeCastTo ctor diff --git a/src/GI/Gtk/Declarative/CSS.hs b/src/GI/Gtk/Declarative/CSS.hs new file mode 100644 --- /dev/null +++ b/src/GI/Gtk/Declarative/CSS.hs @@ -0,0 +1,35 @@ +-- | Helpers for modifying CSS classes in 'Gtk.StyleContext' +-- objects. + +module GI.Gtk.Declarative.CSS where + +import Data.HashSet (HashSet) +import qualified Data.HashSet as HashSet +import Data.Text (Text) +import qualified GI.Gtk as Gtk + +-- | A set of CSS classes. +type ClassSet = HashSet Text + +-- | Add the classes to the widget's style context. +addClasses + :: Gtk.IsWidget w + => w -- ^ The widget to add classes to. + -> ClassSet -- ^ New classes to add. + -> IO () +addClasses widget cs = do + sc <- Gtk.widgetGetStyleContext widget + mapM_ (Gtk.styleContextAddClass sc) cs + +-- | Replace all classes in 'old' with the ones in 'old' in the widget's style +-- context. +replaceClasses + :: Gtk.IsWidget w + => w -- ^ The widget to replace classes in. + -> ClassSet -- ^ Old classes to replace. + -> ClassSet -- ^ New classes to replace with. + -> IO () +replaceClasses widget old new = do + sc <- Gtk.widgetGetStyleContext widget + mapM_ (Gtk.styleContextRemoveClass sc) (HashSet.difference old new) + mapM_ (Gtk.styleContextAddClass sc) (HashSet.difference new old) diff --git a/src/GI/Gtk/Declarative/Container.hs b/src/GI/Gtk/Declarative/Container.hs new file mode 100644 --- /dev/null +++ b/src/GI/Gtk/Declarative/Container.hs @@ -0,0 +1,146 @@ +{-# OPTIONS_GHC -fno-warn-unticked-promoted-constructors #-} +{-# LANGUAGE DataKinds #-} +{-# LANGUAGE DeriveFunctor #-} +{-# LANGUAGE FlexibleContexts #-} +{-# LANGUAGE FlexibleInstances #-} +{-# LANGUAGE FunctionalDependencies #-} +{-# LANGUAGE GADTs #-} +{-# LANGUAGE LambdaCase #-} +{-# LANGUAGE MultiParamTypeClasses #-} +{-# LANGUAGE OverloadedLabels #-} +{-# LANGUAGE ScopedTypeVariables #-} +{-# LANGUAGE TypeFamilies #-} +{-# LANGUAGE TypeOperators #-} + +-- | Implementations for common "Gtk.Container". + +module GI.Gtk.Declarative.Container + ( Container + , container + ) +where + +import Control.Monad (forM_) +import Data.Maybe +import Data.Typeable +import qualified GI.Gtk as Gtk + +import GI.Gtk.Declarative.Attributes +import GI.Gtk.Declarative.Attributes.Internal +import GI.Gtk.Declarative.Container.Patch +import GI.Gtk.Declarative.EventSource +import GI.Gtk.Declarative.Markup +import GI.Gtk.Declarative.Patch + +-- | Declarative version of a /container/ widget, i.e. a widget with zero +-- or more child widgets. The type of 'children' is parameterized, and differs +-- across the supported container widgets, as some containers require specific +-- types of child widgets. These type relations are decided by 'IsContainer', +-- and instances can found in "GI.Gtk.Declarative.Container.Patch". +data Container widget children event where + Container + :: ( Typeable widget + , Gtk.IsWidget widget + , Gtk.IsContainer widget + , Functor children + ) + => (Gtk.ManagedPtr widget -> widget) + -> [Attribute widget event] + -> children event + -> Container widget children event + +instance Functor (Container widget children) where + fmap f (Container ctor attrs children) = + Container ctor (fmap f <$> attrs) (fmap f children) + +-- | Construct a /container/ widget, i.e. a widget with zero or more children. +container + :: ( Patchable (Container widget (Children child)) + , Typeable widget + , Typeable child + , Typeable event + , Functor child + , Gtk.IsWidget widget + , Gtk.IsContainer widget + , FromWidget (Container widget (Children child)) event target + ) + => (Gtk.ManagedPtr widget -> widget) -- ^ A container widget constructor from the underlying gi-gtk library. + -> [Attribute widget event] -- ^ List of 'Attribute's. + -> MarkupOf child event () -- ^ The container's 'child' widgets, in a 'MarkupOf' builder. + -> target -- ^ The target, whose type is decided by 'FromWidget'. +container ctor attrs = fromWidget . Container ctor attrs . toChildren + +newtype Children child event = Children { unChildren :: [child event] } + deriving (Functor) + +toChildren :: MarkupOf child event () -> Children child event +toChildren = Children . runMarkup + +-- +-- Patchable +-- + +instance (Patchable child, IsContainer container child) => + Patchable (Container container (Children child)) where + create (Container ctor props children) = do + let attrOps = concatMap extractAttrConstructOps props + widget' <- Gtk.new ctor attrOps + sc <- Gtk.widgetGetStyleContext widget' + mapM_ (addClass sc) props + forM_ (unChildren children) $ \child -> do + childWidget <- create child + appendChild widget' child childWidget + Gtk.toWidget widget' + patch (Container _ oldAttributes oldChildren) (Container ctor newAttributes newChildren) = + Modify $ \widget' -> do + containerWidget <- Gtk.unsafeCastTo ctor widget' + Gtk.set containerWidget (concatMap extractAttrSetOps newAttributes) + sc <- Gtk.widgetGetStyleContext widget' + mapM_ (removeClass sc) oldAttributes + mapM_ (addClass sc) newAttributes + patchInContainer + containerWidget + (unChildren oldChildren) + (unChildren newChildren) + +-- +-- EventSource +-- + +instance (Typeable child, EventSource child) => + EventSource (Container widget (Children child)) where + subscribe (Container ctor props children) widget' cb = do + parentWidget <- Gtk.unsafeCastTo ctor widget' + handlers' <- mconcat . catMaybes <$> mapM (addSignalHandler cb parentWidget) props + childWidgets <- Gtk.containerGetChildren parentWidget + subs <- + flip foldMap (zip (unChildren children) childWidgets) $ \(c, w) -> + subscribe c w cb + return (handlers' <> subs) + +-- +-- FromWidget +-- + +instance ( Typeable widget + , Typeable children + , Patchable (Container widget children) + , EventSource (Container widget children) + , Functor (Container widget children) + ) => + FromWidget (Container widget children) event (Widget event) where + fromWidget = Widget + +instance a ~ () => + FromWidget (Container widget children) event (MarkupOf (Container widget children) event a) where + fromWidget = single + +instance ( a ~ () + , Typeable widget + , Typeable children + , Patchable (Container widget children) + , EventSource (Container widget children) + , Functor (Container widget children) + ) => + FromWidget (Container widget children) event (Markup event a) where + fromWidget = single . Widget diff --git a/src/GI/Gtk/Declarative/Container/Box.hs b/src/GI/Gtk/Declarative/Container/Box.hs new file mode 100644 --- /dev/null +++ b/src/GI/Gtk/Declarative/Container/Box.hs @@ -0,0 +1,52 @@ +{-# OPTIONS_GHC -fno-warn-unticked-promoted-constructors #-} +{-# LANGUAGE DataKinds #-} +{-# LANGUAGE DeriveFunctor #-} +{-# LANGUAGE FlexibleContexts #-} +{-# LANGUAGE FlexibleInstances #-} +{-# LANGUAGE FunctionalDependencies #-} +{-# LANGUAGE GADTs #-} +{-# LANGUAGE LambdaCase #-} +{-# LANGUAGE MultiParamTypeClasses #-} +{-# LANGUAGE OverloadedLabels #-} +{-# LANGUAGE RecordWildCards #-} +{-# LANGUAGE ScopedTypeVariables #-} +{-# LANGUAGE TypeFamilies #-} +{-# LANGUAGE TypeOperators #-} + +-- | Implementation of 'Gtk.Box' as a declarative container. +module GI.Gtk.Declarative.Container.Box + ( BoxChild(..) + , boxChild + ) +where + +import Data.Word (Word32) + +import GI.Gtk.Declarative.EventSource +import GI.Gtk.Declarative.Patch +import GI.Gtk.Declarative.Markup + +-- | Described a child widget to be added with 'boxAppend' to a 'Box'. +data BoxChild event = BoxChild + { expand :: Bool + , fill :: Bool + , padding :: Word32 + , child :: Widget event + } + deriving (Functor) + +-- | Construct a box child with the given 'boxAppend' parameters. +boxChild + :: Bool + -> Bool + -> Word32 + -> Widget event + -> MarkupOf BoxChild event () +boxChild expand fill padding child = single BoxChild {..} + +instance Patchable BoxChild where + create = create . child + patch b1 b2 = patch (child b1) (child b2) + +instance EventSource BoxChild where + subscribe BoxChild{..} = subscribe child diff --git a/src/GI/Gtk/Declarative/Container/Patch.hs b/src/GI/Gtk/Declarative/Container/Patch.hs new file mode 100644 --- /dev/null +++ b/src/GI/Gtk/Declarative/Container/Patch.hs @@ -0,0 +1,120 @@ +{-# OPTIONS_GHC -fno-warn-unticked-promoted-constructors #-} + +{-# LANGUAGE DataKinds #-} +{-# LANGUAGE FlexibleContexts #-} +{-# LANGUAGE FlexibleInstances #-} +{-# LANGUAGE FunctionalDependencies #-} +{-# LANGUAGE GADTs #-} +{-# LANGUAGE LambdaCase #-} +{-# LANGUAGE MultiParamTypeClasses #-} +{-# LANGUAGE OverloadedLabels #-} +{-# LANGUAGE RecordWildCards #-} +{-# LANGUAGE ScopedTypeVariables #-} +{-# LANGUAGE TypeFamilies #-} +{-# LANGUAGE TypeOperators #-} + +-- | This module implements the patch algorithm for containers. +module GI.Gtk.Declarative.Container.Patch (IsContainer(..), patchInContainer) where + +import Control.Monad (forM_) +import Data.Int (Int32) +import Data.List (zip4) +import qualified GI.Gtk as Gtk + +import GI.Gtk.Declarative.Bin +import GI.Gtk.Declarative.Container.Box +import GI.Gtk.Declarative.Markup +import GI.Gtk.Declarative.Patch + + +-- | Describes supported GTK+ containers and their specialized APIs for +-- appending and replacing child widgets. +class IsContainer container child | container -> child where + -- | Append a child widget to the container. + appendChild + :: container -- ^ Container widget + -> child event -- ^ Declarative child widget + -> Gtk.Widget -- ^ GTK child widget to append + -> IO () + -- | Replace the child widget at the given index in the container. + replaceChild + :: container -- ^ Container widget + -> child event -- ^ Declarative child widget + -> Int32 -- ^ Index to replace at + -> Gtk.Widget -- ^ Old GTK widget to replace + -> Gtk.Widget -- ^ New GTK widget to replace with + -> IO () + +-- | Patch all children in a container. This does not feature any ID checking, +-- as seen in React, so reordering children in a container can produce many +-- updates. +patchInContainer + :: ( Gtk.IsWidget container + , Gtk.IsContainer container + , Patchable child + , IsContainer container child + ) + => container + -> [child e1] + -> [child e2] + -> IO () +patchInContainer container os' ns' = do + cs <- Gtk.containerGetChildren container + let maxLength = maximum [length cs, length os', length ns'] + indices = [0 .. pred (fromIntegral maxLength)] + forM_ (zip4 indices (padMaybes cs) (padMaybes os') (padMaybes ns')) $ \case + + -- In case we have a corresponding old and new declarative widget, we patch + -- the GTK widget. + (i, Just w, Just old, Just new) -> case patch old new of + Modify modify -> modify w + Replace createWidget -> replaceChild container new i w =<< createWidget + Keep -> return () + + -- When there is a new declarative widget, but there already exists a GTK + -- widget in the corresponding place, we need to replace the GTK widget with + -- one created from the declarative widget. + (i, Just w, Nothing, Just new) -> + replaceChild container new i w =<< create new + + -- When there is a new declarative widget, or one that lacks a corresponding + -- GTK widget, create and add it. + (_i, Nothing, _ , Just n ) -> create n >>= appendChild container n + + -- When an declarative widget has been removed, remove the GTK widget from + -- the container. + (_i, Just w , Just _ , Nothing) -> Gtk.containerRemove container w + + -- When there are more old declarative widgets than GTK widgets, we can + -- safely ignore the old declarative widgets. + (_i, Nothing, Just _ , Nothing) -> return () + + -- But, when there are stray GTK widgets without corresponding + -- declarative widgets, something has gone wrong, and we clean that up by + -- removing the GTK widgets. + (_i, Just w , Nothing, Nothing) -> Gtk.containerRemove container w + + -- No more GTK widgets or declarative widgets, we are done. + (_i, Nothing, Nothing, Nothing) -> return () + + Gtk.widgetQueueResize container + +instance IsContainer Gtk.ListBox (Bin Gtk.ListBoxRow Widget) where + appendChild box _ widget' = Gtk.listBoxInsert box widget' (-1) + replaceChild box _ i old new = do + Gtk.containerRemove box old + Gtk.listBoxInsert box new i + Gtk.widgetShowAll box + +instance IsContainer Gtk.Box BoxChild where + appendChild box BoxChild {..} widget' = + Gtk.boxPackStart box widget' expand fill padding + + replaceChild box boxChild' i old new = do + Gtk.containerRemove box old + appendChild box boxChild' new + Gtk.boxReorderChild box new i + Gtk.widgetShowAll box + +padMaybes :: [a] -> [Maybe a] +padMaybes xs = map Just xs ++ repeat Nothing diff --git a/src/GI/Gtk/Declarative/EventSource.hs b/src/GI/Gtk/Declarative/EventSource.hs new file mode 100644 --- /dev/null +++ b/src/GI/Gtk/Declarative/EventSource.hs @@ -0,0 +1,41 @@ +{-# LANGUAGE FunctionalDependencies #-} +{-# LANGUAGE GeneralizedNewtypeDeriving #-} +{-# LANGUAGE MultiParamTypeClasses #-} + +-- | Event handling for declarative widgets. +module GI.Gtk.Declarative.EventSource + ( EventSource (..) + , Subscription + , fromCancellation + , cancel + ) +where + +import qualified GI.Gtk as Gtk + +-- | Cancel a 'Subscription', meaning that the callback will not be invoked on +-- any subsequent signal emissions. +cancel :: Subscription -> IO () +cancel = sequence_ . cancellations + +-- | An 'EventSource' can be subscribed to, with a callback, returning a +-- 'Subscription'. +class EventSource widget where + subscribe + :: widget event -- ^ Declarative widget with event handlers. + -> Gtk.Widget -- ^ Actual 'Gtk.Widget' that has been created or patched. + -> (event -> IO ()) -- ^ Event callback, invoked on each emitted event until + -- the 'Subscription' is cancelled, or widget is otherwise + -- destroyed. + -> IO Subscription -- ^ A 'Subscription' is returned, which can be cancelled. + +-- | A 'Subscription' contains zero or more cancellation actions for connected +-- handlers (to a tree of widgets.) When subscribing to a container widget, all +-- child widgets are also subscribed to, and the 'Subscription's are combined +-- using the 'Semigroup' instance. +newtype Subscription = Subscription { cancellations :: [IO ()] } + deriving (Semigroup, Monoid) + +-- | Create a subscription from a cancellation IO action. +fromCancellation :: IO () -> Subscription +fromCancellation = Subscription . pure diff --git a/src/GI/Gtk/Declarative/Markup.hs b/src/GI/Gtk/Declarative/Markup.hs new file mode 100644 --- /dev/null +++ b/src/GI/Gtk/Declarative/Markup.hs @@ -0,0 +1,104 @@ +{-# LANGUAGE FlexibleInstances #-} +{-# LANGUAGE FunctionalDependencies #-} +{-# LANGUAGE GADTs #-} +{-# LANGUAGE GeneralizedNewtypeDeriving #-} +{-# LANGUAGE MultiParamTypeClasses #-} +{-# LANGUAGE ScopedTypeVariables #-} +{-# LANGUAGE TypeApplications #-} +{-# LANGUAGE TypeOperators #-} + +-- | 'MarkupOf' is the common builder type for the (declarative) GTK+ markup +-- language, supporting do syntax. 'MarkupOf' wraps many widgets, usually of +-- type 'Widget', but they can be of other types. +-- +-- A 'Widget' value can wrap any 'Patchable' widget, hiding the underlying +-- widget type, such that you can embed heterogeneous collections of widgets in +-- containers. +module GI.Gtk.Declarative.Markup + ( Widget(..) + -- * Markup + , MarkupOf + , Markup + , single + , multiple + , runMarkup + -- * Widget to Markup conversion + , FromWidget(..) + ) +where + +import Control.Monad.Writer +import Data.Typeable + +import GI.Gtk.Declarative.EventSource +import GI.Gtk.Declarative.Patch + +-- | A 'Widget' value wraps a 'Patchable' and 'EventSource' widget, providing +-- a constrained equivalent of a 'Dynamic' value. It is used to support +-- heterogeneous containers of widgets, and to support equality +-- checks on different types of widgets when calculating patches. +data Widget event where + Widget + :: ( Typeable widget + , Patchable widget + , Functor widget + , EventSource widget + ) + => widget event + -> Widget event + +instance Functor Widget where + fmap f (Widget w) = Widget (fmap f w) + +-- | 'Widget' is itself patchable, by delegating to the underlying +-- widget instances. +instance Patchable Widget where + create (Widget w) = create w + patch (Widget (w1 :: t1 e1)) (Widget (w2 :: t2 e2)) = + case eqT @t1 @t2 of + Just Refl -> patch w1 w2 + _ -> Replace (create w2) + +instance EventSource Widget where + subscribe (Widget w) = subscribe w + +-- * Markup + +-- | The declarative markup builder, primarily for using its 'Monad' instance +-- and do notation to construct adjacent widgets in containers. +-- +-- It is parameterized with 'widget' and 'event', such that containers can +-- restrict the type of their children to other types than 'Widget'. +-- +-- Note that the return type, 'a', is not used in this library. It's a more a +-- technical necessity to have the 'Monad' instance. You can still use it if +-- you need to return a value from a markup function, though. +newtype MarkupOf widget event a = + MarkupOf (Writer [widget event] a) + deriving (Functor, Applicative, Monad) + +-- | Run a 'MarkupOf' builder and get its widgets. +runMarkup :: MarkupOf widget event () -> [widget event] +runMarkup (MarkupOf w) = execWriter w + +-- | Handy type alias for the common case of markup containing 'Widget's. +type Markup event a = MarkupOf Widget event a + +-- | Construct markup from a single widget. +single :: widget event -> MarkupOf widget event () +single w = MarkupOf (tell [w]) + +-- | Construct markup from multiple widgets. +multiple :: [widget event] -> MarkupOf widget event () +multiple = MarkupOf . tell + +-- | Convert a widget to a target type. This is deliberately unconstrained in +-- it's types, and is used by smart constructors to implement return type +-- polymorphism, so that a smart contructor can return either a 'Widget', or +-- some specifically typed 'MarkupOf', depending on the context in which it's +-- used. +class FromWidget widget event target | target -> event where + fromWidget :: (Typeable widget, Typeable event) => widget event -> target + +instance FromWidget Widget event (Widget event) where + fromWidget = id diff --git a/src/GI/Gtk/Declarative/Patch.hs b/src/GI/Gtk/Declarative/Patch.hs new file mode 100644 --- /dev/null +++ b/src/GI/Gtk/Declarative/Patch.hs @@ -0,0 +1,34 @@ +{-# LANGUAGE MultiParamTypeClasses #-} +{-# LANGUAGE RankNTypes #-} + +module GI.Gtk.Declarative.Patch + ( Patch(..) + , Patchable(..) + ) where + +import qualified GI.Gtk as Gtk + +-- | A possible action to take on an existing 'Gtk.Widget', decided by the +-- 'patch' method when comparing declarative widgets. +data Patch + = Modify (Gtk.Widget -> IO ()) + -- ^ An 'IO' action to apply to a 'Gtk.Widget' to make it reflect an updated + -- declarative widget. The action to apply is calculated from the difference + -- between the old and the new declarative widget. + | Replace (IO Gtk.Widget) + -- ^ Replace the current 'Gtk.Widget' by the widget returned by the IO + -- action. + | Keep + -- ^ Do nothing, i.e. keep the 'Gtk.Widget' as it is. + +-- | A patchable widget is one that can create an underlying GTK widget, or +-- calculate a 'Patch' to be applied to an existing GTK widget that was +-- previously created. +class Patchable widget where + -- | Given a declarative widget that is 'Patchable', return an IO action that + -- can create a new corresponding 'Gtk.Widget'. The created widget should be + -- use in corresponding patch modifications, until it is replaced. + create :: widget e -> IO Gtk.Widget + -- | Given two declarative widgets of the same widget type (but not + -- necessarily of the same event types,) calculate a 'Patch'. + patch :: widget e1 -> widget e2 -> Patch diff --git a/src/GI/Gtk/Declarative/SingleWidget.hs b/src/GI/Gtk/Declarative/SingleWidget.hs new file mode 100644 --- /dev/null +++ b/src/GI/Gtk/Declarative/SingleWidget.hs @@ -0,0 +1,94 @@ +{-# LANGUAGE DataKinds #-} +{-# LANGUAGE FlexibleContexts #-} +{-# LANGUAGE FlexibleInstances #-} +{-# LANGUAGE GADTs #-} +{-# LANGUAGE LambdaCase #-} +{-# LANGUAGE MultiParamTypeClasses #-} +{-# LANGUAGE RankNTypes #-} +{-# LANGUAGE ScopedTypeVariables #-} +{-# LANGUAGE TypeApplications #-} +{-# LANGUAGE TypeOperators #-} + +-- | A declarative representation of 'Gtk.Widget' in GTK without children. +module GI.Gtk.Declarative.SingleWidget + ( SingleWidget + , widget + ) +where + +import Data.Maybe +import Data.Typeable +import qualified GI.Gtk as Gtk + +import GI.Gtk.Declarative.Attributes +import GI.Gtk.Declarative.Attributes.Internal +import GI.Gtk.Declarative.EventSource +import GI.Gtk.Declarative.Markup +import GI.Gtk.Declarative.Patch + +-- | Declarative version of a /leaf/ widget, i.e. a widget without any children. +data SingleWidget widget event where + SingleWidget + :: (Typeable widget, Gtk.IsWidget widget, Functor (Attribute widget)) + => (Gtk.ManagedPtr widget -> widget) + -> [Attribute widget event] + -> SingleWidget widget event + +instance Functor (SingleWidget widget) where + fmap f (SingleWidget ctor attrs) = SingleWidget ctor (fmap f <$> attrs) + +instance Patchable (SingleWidget widget) where + create = \case + (SingleWidget ctor props) -> do + let attrOps = concatMap extractAttrConstructOps props + widget' <- Gtk.new ctor attrOps + + sc <- Gtk.widgetGetStyleContext widget' + mapM_ (addClass sc) props + + Gtk.widgetShowAll widget' + Gtk.toWidget widget' + patch (SingleWidget (_ :: Gtk.ManagedPtr w1 -> w1) oldAttributes) + (SingleWidget (ctor :: Gtk.ManagedPtr w2 -> w2) newAttributes) = + case eqT @w1 @w2 of + Just Refl -> + Modify $ \widget' -> do + w <- Gtk.unsafeCastTo ctor widget' + Gtk.set w (concatMap extractAttrSetOps newAttributes) + + sc <- Gtk.widgetGetStyleContext widget' + mapM_ (removeClass sc) oldAttributes + mapM_ (addClass sc) newAttributes + + Gtk.widgetShowAll w + + Nothing -> Replace (create (SingleWidget ctor newAttributes)) + +instance EventSource (SingleWidget widget) where + subscribe (SingleWidget ctor props) widget' cb = do + w <- Gtk.unsafeCastTo ctor widget' + mconcat . catMaybes <$> mapM (addSignalHandler cb w) props + +instance (Typeable widget, Functor (SingleWidget widget)) + => FromWidget (SingleWidget widget) event (Widget event) where + fromWidget = Widget + +instance FromWidget (SingleWidget widget) event (MarkupOf (SingleWidget widget) event ()) where + fromWidget = single + +instance (Typeable widget, Functor (SingleWidget widget)) + => FromWidget (SingleWidget widget) event (Markup event ()) where + fromWidget = single . Widget + +-- | Construct a /leaf/ widget, i.e. one without any children. +widget :: + ( Typeable widget + , Typeable event + , Functor (Attribute widget) + , Gtk.IsWidget widget + , FromWidget (SingleWidget widget) event target + ) + => (Gtk.ManagedPtr widget -> widget) -- ^ A widget constructor from the underlying gi-gtk library. + -> [Attribute widget event] -- ^ List of 'Attribute's. + -> target -- ^ The target, whose type is decided by 'FromWidget'. +widget ctor = fromWidget . SingleWidget ctor