TextTagTable.chs

-- -*-haskell-*-
--  GIMP Toolkit (GTK) Widget TextTagTable
--
--  Author : Duncan Coutts
--
--  Created: 4 August 2004
--
--  Copyright (C) 2004-2005 Duncan Coutts
--
--  This library is free software; you can redistribute it and/or
--  modify it under the terms of the GNU Lesser General Public
--  License as published by the Free Software Foundation; either
--  version 2.1 of the License, or (at your option) any later version.
--
--  This library 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
--  Lesser General Public License for more details.
--
-- |
-- Maintainer  : gtk2hs-users@lists.sourceforge.net
-- Stability   : provisional
-- Portability : portable (depends on GHC)
--
-- Collection of tags that can be used together
--
module Graphics.UI.Gtk.Multiline.TextTagTable (
-- * Detail
-- 
-- | You may wish to begin by reading the text widget conceptual overview
-- which gives an overview of all the objects and data types related to the
-- text widget and how they work together.

-- * Class Hierarchy
-- |
-- @
-- |  'GObject'
-- |   +----TextTagTable
-- @

-- * Types
  TextTagTable,
  TextTagTableClass,
  castToTextTagTable, gTypeTextTagTable,
  toTextTagTable,

-- * Constructors
  textTagTableNew,

-- * Methods
  textTagTableAdd,
  textTagTableRemove,
  textTagTableLookup,
  textTagTableForeach,
  textTagTableGetSize
  ) where

import Control.Monad	(liftM)

import System.Glib.FFI
import System.Glib.GObject	(constructNewGObject, makeNewGObject)
{#import Graphics.UI.Gtk.Types#}

{# context lib="gtk" prefix="gtk" #}

--------------------
-- Constructors

-- | Creates a new 'TextTagTable'. The table contains no tags by default.
--
textTagTableNew :: IO TextTagTable
textTagTableNew =
  constructNewGObject mkTextTagTable $
  {# call unsafe text_tag_table_new #}

--------------------
-- Methods

-- | Add a tag to the table. The tag is assigned the highest priority in the
-- table.
--
-- The tag must not be in a tag table already, and may not have the same name as
-- an already-added tag.
--
textTagTableAdd :: (TextTagTableClass self, TextTagClass tag) => self -> tag -> IO ()
textTagTableAdd self tag =
  {# call text_tag_table_add #}
    (toTextTagTable self)
    (toTextTag tag)

-- | Remove a tag from the table.
--
textTagTableRemove :: (TextTagTableClass self, TextTagClass tag) => self -> tag -> IO ()
textTagTableRemove self tag =
  {# call text_tag_table_remove #}
    (toTextTagTable self)
    (toTextTag tag)

-- | Look up a named tag.
--
textTagTableLookup :: TextTagTableClass self => self
 -> String             -- ^ @name@ - name of a tag
 -> IO (Maybe TextTag) -- ^ returns The tag, or @Nothing@ if none by that name
                       -- is in the table.
textTagTableLookup self name =
  maybeNull (makeNewGObject mkTextTag) $
  withCString name $ \namePtr ->
  {# call unsafe text_tag_table_lookup #}
    (toTextTagTable self)
    namePtr

-- | Maps over each tag in the table.
--
textTagTableForeach :: TextTagTableClass self => self
 -> (TextTag -> IO ())
 -> IO ()
textTagTableForeach self func = do
  funcPtr <- mkTextTagTableForeach (\tagPtr _ -> do
    tag <- makeNewGObject mkTextTag (return tagPtr)
    func tag)
  {# call text_tag_table_foreach #}
    (toTextTagTable self)
    funcPtr
    nullPtr

{#pointer TextTagTableForeach#}

foreign import ccall "wrapper" mkTextTagTableForeach ::
  (Ptr TextTag -> Ptr () -> IO ()) -> IO TextTagTableForeach

-- | Returns the size of the table (the number of tags).
--
textTagTableGetSize :: TextTagTableClass self => self -> IO Int
textTagTableGetSize self =
  liftM fromIntegral $
  {# call unsafe text_tag_table_get_size #}
    (toTextTagTable self)