File: Label.chs

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{-# LANGUAGE CPP #-}
-- -*-haskell-*-
--  GIMP Toolkit (GTK) Widget Label
--
--  Author : Manuel M. T. Chakravarty, Axel Simon, Andy Stewart
--
--  Created: 2 May 2001
--
--  Copyright (C) 1999-2005 Axel Simon
--  Copyright (C) 2009 Andy Stewart
--
--  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)
--
-- A widget that displays a small to medium amount of text
--
module Graphics.UI.Gtk.Display.Label (
-- * Detail
-- 
-- | The 'Label' widget displays a small amount of text. As the name implies,
-- most labels are used to label another widget such as a 'Button', a
-- 'MenuItem', or a 'OptionMenu'.

-- ** Mnemonics
-- 
-- | Labels may contain mnemonics. Mnemonics are underlined characters in the
-- label, used for keyboard navigation. Mnemonics are created by providing a
-- string with an underscore before the mnemonic character, such as
-- @\"_File\"@, to the functions 'labelNewWithMnemonic' or
-- 'labelSetTextWithMnemonic'.
--
-- Mnemonics automatically activate any activatable widget the label is
-- inside, such as a 'Button'; if the label is not inside the mnemonic's target
-- widget, you have to tell the label about the target using
-- 'labelSetMnemonicWidget'. Here's a simple example where the label is inside
-- a button: There's a convenience function to create buttons with a mnemonic
-- label already inside: To create a mnemonic for a widget alongside the label,
-- such as a 'Entry', you have to point the label at the entry with
-- 'labelSetMnemonicWidget':
-- 
-- >   -- Pressing Alt+H will activate this button
-- >   button <- buttonNew
-- >   label <- labelNewWithMnemonic "_Hello"
-- >   containerAdd button label
--
-- >   -- Pressing Alt+H will activate this button
-- >   button <- buttonNewWithMnemonic "_Hello"
--
-- >   -- Pressing Alt+H will focus the entry
-- >   entry <- entryNew
-- >   label <- labelNewWithMnemonic "_Hello"
-- >   labelSetMnemonicWidget label entry

-- ** Markup (styled text)
-- 
-- | To make it easy to format text in a label (changing colors, fonts, etc.),
-- label text can be provided in a simple markup format. Here's how to create a
-- label with a small font: (See complete documentation of available tags in
-- the Pango manual.)
--
-- >   label <- labelNew Nothing
-- >   labelSetMarkup label "<small>Small text</small>"
--
-- The markup passed to 'labelSetMarkup' must be valid; for example, literal
-- \<\/>\/& characters must be escaped as @\"&lt;\"@, @\"&gt;\"@, and
-- @\"&amp;@\". If you pass
-- text obtained from the user, file, or a network to 'labelSetMarkup', you\'ll
-- want to escape it with 'Graphics.Rendering.Pango.Layout.escapeMarkup'.

-- ** Selectable labels
-- 
-- | Labels can be made selectable with 'labelSetSelectable'. Selectable
-- labels allow the user to copy the label contents to the clipboard. Only
-- labels that contain useful-to-copy information - such as error messages -
-- should be made selectable.

-- ** Text layout
-- 
-- | A label can contain any number of paragraphs, but will have performance
-- problems if it contains more than a small number. Paragraphs are separated
-- by newlines or other paragraph separators understood by Pango.
--
-- Labels can automatically wrap text if you call 'labelSetLineWrap'.
--
-- 'labelSetJustify' sets how the lines in a label align with one another.
-- If you want to set how the label as a whole aligns in its available space,
-- see 'Graphics.UI.Gtk.Abstract.Misc.miscSetAlignment'.
-- 

-- * Class Hierarchy
-- |
-- @
-- |  'GObject'
-- |   +----'Object'
-- |         +----'Widget'
-- |               +----'Misc'
-- |                     +----Label
-- |                           +----'AccelLabel'
-- |                           +----'TipsQuery'
-- @

-- * Types
  Label,
  LabelClass,
  castToLabel, gTypeLabel,
  toLabel,

-- * Constructors
  labelNew,
  labelNewWithMnemonic,

-- * Methods
  labelSetText,
  labelSetLabel,
  labelSetTextWithMnemonic,
  labelSetMarkup,
  labelSetMarkupWithMnemonic,
  labelSetMnemonicWidget,
  labelGetMnemonicWidget,
  KeyVal,
  labelGetMnemonicKeyval,
  labelSetUseMarkup,
  labelGetUseMarkup,
  labelSetUseUnderline,
  labelGetUseUnderline,
  labelGetText,
  labelGetLabel,
  labelSetAttributes,
  labelGetAttributes,
  labelSetPattern,
  Justification(..),
  labelSetJustify,
  labelGetJustify,
  labelGetLayout,
  labelSetLineWrap,
  labelGetLineWrap,
  labelSetLineWrapMode,
  labelGetLineWrapMode,
  labelSetSelectable,
  labelGetSelectable,
  labelSelectRegion,
  labelGetSelectionBounds,
  labelGetLayoutOffsets,
#if GTK_CHECK_VERSION(2,6,0)
  labelSetEllipsize,
  labelGetEllipsize,
  labelSetWidthChars,
  labelGetWidthChars,
  labelSetMaxWidthChars,
  labelGetMaxWidthChars,
  labelSetSingleLineMode,
  labelGetSingleLineMode,
  labelSetAngle,
  labelGetAngle,
#endif

-- * Attributes
  labelLabel,
  labelUseMarkup,
  labelUseUnderline,
  labelJustify,
  labelWrap,
  labelWrapMode,
  labelSelectable,
  labelMnemonicWidget,
  labelMnemonicKeyval,
  labelPattern,
  labelCursorPosition,
  labelSelectionBound,
#if GTK_CHECK_VERSION(2,6,0)
  labelEllipsize,
  labelWidthChars,
  labelSingleLineMode,
  labelAngle,
  labelAttributes,
  labelMaxWidthChars,
#endif
  labelLineWrap,
  labelText,
  ) where

import Control.Monad    (liftM)

import System.Glib.FFI
import System.Glib.UTFString
import System.Glib.Attributes
import System.Glib.Properties
import System.Glib.GObject              (makeNewGObject)
{#import Graphics.Rendering.Pango.Layout#}
import Graphics.UI.Gtk.Abstract.Object  (makeNewObject)
{#import Graphics.UI.Gtk.Types#}
import Graphics.Rendering.Pango.Attributes ( withAttrList, fromAttrList)
import Graphics.UI.Gtk.Gdk.Keys         (KeyVal)
import Graphics.UI.Gtk.General.Enums    (Justification(..))
import Graphics.Rendering.Pango.Markup
{#import Graphics.Rendering.Pango.BasicTypes#}  (PangoLayout(PangoLayout),
                                         makeNewPangoString, PangoString(..) )
import Graphics.Rendering.Pango.Types (mkPangoLayoutRaw, PangoLayoutRaw)
import Graphics.Rendering.Pango.Enums   (PangoAttribute)
#if GTK_CHECK_VERSION(2,6,0)
import Graphics.Rendering.Pango.Enums   (EllipsizeMode(..))
#endif
import Data.IORef ( newIORef )

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

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

-- | Creates a new label with the given text inside it. You can pass @Nothing@
-- to get an empty label widget.
--
labelNew :: Maybe String -> IO Label
labelNew str =
  makeNewObject mkLabel $
  liftM (castPtr :: Ptr Widget -> Ptr Label) $
  maybeWith withUTFString str $ \strPtr ->
  {# call label_new #}
    strPtr

-- | Creates a new 'Label', containing the text in @str@.
--
-- If characters in @str@ are preceded by an underscore, they are
-- underlined. If you need a literal underscore character in a label, use
-- \'__\' (two underscores). The first underlined character represents a
-- keyboard accelerator called a mnemonic. The mnemonic key can be used to
-- activate another widget, chosen automatically, or explicitly using
-- 'labelSetMnemonicWidget'.
--
-- If 'labelSetMnemonicWidget' is not called, then the first activatable
-- ancestor of the 'Label' will be chosen as the mnemonic widget. For instance,
-- if the label is inside a button or menu item, the button or menu item will
-- automatically become the mnemonic widget and be activated by the mnemonic.
--
labelNewWithMnemonic :: 
    String   -- ^ @str@ - The text of the label, with an underscore in front
             -- of the mnemonic character
 -> IO Label
labelNewWithMnemonic str =
  makeNewObject mkLabel $
  liftM (castPtr :: Ptr Widget -> Ptr Label) $
  withUTFString str $ \strPtr ->
  {# call label_new_with_mnemonic #}
    strPtr

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

-- | Sets the text within the 'Label' widget. It overwrites any text that was
-- there before.
--
-- This will also clear any previously set mnemonic accelerators.
--
labelSetText :: LabelClass self => self -> String -> IO ()
labelSetText self str =
  withUTFString str $ \strPtr ->
  {# call label_set_text #}
    (toLabel self)
    strPtr

-- | Sets the text of the label. The label is interpreted as including
-- embedded underlines and\/or Pango markup depending on the markup and
-- underline properties.
--
labelSetLabel :: LabelClass self => self -> String -> IO ()
labelSetLabel self str =
  withUTFString str $ \strPtr ->
  {# call label_set_label #}
    (toLabel self)
    strPtr

-- | Sets a PangoAttrList; the attributes in the list are applied to the label
-- text.
--
-- Note: The attributes set with this function will be applied and merged with
-- any other attributes previously effected by way of the 'labelUseUnderline' or
-- 'labelUseMarkup' properties. While it is not recommended to mix markup strings
-- with manually set attributes, if you must; know that the attributes will be
-- applied to the label after the markup string is parsed.
--
labelSetAttributes :: LabelClass self => self 
 -> [PangoAttribute]   -- ^ @attr@ 'PangoAttribute'
 -> IO ()
labelSetAttributes self attrs = do
  txt <- labelGetText self
  ps <- makeNewPangoString txt
  withAttrList ps attrs $ \alPtr ->
    {#call unsafe label_set_attributes #} (toLabel self) alPtr

-- | Gets the attribute list that was set on the label using 'labelSetAttributes', if any. 
-- This function does not reflect attributes that come from the labels markup (see 'labelSetMarkup'). 
-- If you want to get the effective attributes for the label, use 'layoutGetAttributes' ('labelGetLayout' (label)).
--
labelGetAttributes :: LabelClass self => self
 -> IO [PangoAttribute]          -- ^ return the attribute list, or Emtpy if none was set. 
labelGetAttributes self = do
  txt <- labelGetText self
  (PangoString correct _ _ ) <- makeNewPangoString txt
  attrListPtr <- {# call unsafe label_get_attributes #} (toLabel self)
  attr <- fromAttrList correct attrListPtr
  return $ concat attr

-- | Parses @str@ which is marked up with the Pango text markup language,
-- as defined in "Graphics.Rendering.Pango.Markup",
-- setting the label's text and attribute list based on the parse results. If
-- the @str@ is external data, you may need to escape it.
--
labelSetMarkup :: LabelClass self => self
 -> Markup -- ^ @str@ - a markup string (see Pango markup format)
 -> IO ()
labelSetMarkup self str =
  withUTFString str $ \strPtr ->
  {# call label_set_markup #}
    (toLabel self)
    strPtr

-- | Parses @str@ which is marked up with the Pango text markup language,
-- as defined in "Graphics.Rendering.Pango.Markup",
-- setting the label's text and attribute list based on the parse results. If
-- characters in @str@ are preceded by an underscore, they are underlined
-- indicating that they represent a keyboard accelerator called a mnemonic.
--
-- The mnemonic key can be used to activate another widget, chosen
-- automatically, or explicitly using 'labelSetMnemonicWidget'.
--
labelSetMarkupWithMnemonic :: LabelClass self => self
 -> Markup -- ^ @str@ - a markup string (see Pango markup format)
 -> IO ()
labelSetMarkupWithMnemonic self str =
  withUTFString str $ \strPtr ->
  {# call label_set_markup_with_mnemonic #}
    (toLabel self)
    strPtr

-- | Underline parts of the text, odd indices of the list represent underlined
-- parts.
--
labelSetPattern :: LabelClass l => l -> [Int] -> IO ()
labelSetPattern self list =
  withUTFString str $
  {# call label_set_pattern #}
    (toLabel self)
  where
    str = concat $ zipWith replicate list (cycle ['_',' '])

-- | Sets the alignment of the lines in the text of the label relative to each
-- other. 'JustifyLeft' is the default value when the widget is first created
-- with 'labelNew'. If you instead want to set the alignment of the label as a
-- whole, use 'Graphics.UI.Gtk.Abstract.Misc.miscSetAlignment' instead.
-- 'labelSetJustify' has no effect on labels containing only a single line.
--
labelSetJustify :: LabelClass self => self -> Justification -> IO ()
labelSetJustify self jtype =
  {# call label_set_justify #}
    (toLabel self)
    ((fromIntegral . fromEnum) jtype)

-- | Returns the justification of the label. See 'labelSetJustify'.
--
labelGetJustify :: LabelClass self => self -> IO Justification
labelGetJustify self =
  liftM (toEnum . fromIntegral) $
  {# call unsafe label_get_justify #}
    (toLabel self)

-- | Gets the 'PangoLayout' used to display the label. The layout is useful to
-- e.g. convert text positions to pixel positions, in combination with
-- 'labelGetLayoutOffsets'.
--
labelGetLayout :: LabelClass self => self -> IO PangoLayout
labelGetLayout self = do
  plr <- makeNewGObject mkPangoLayoutRaw $ 
    {# call unsafe label_get_layout #} (toLabel self)
  txt <- labelGetText self
  ps <- makeNewPangoString txt
  psRef <- newIORef ps
  return (PangoLayout psRef plr)

-- | Toggles line wrapping within the 'Label' widget. @True@ makes it break
-- lines if text exceeds the widget's size. @False@ lets the text get cut off
-- by the edge of the widget if it exceeds the widget size.
--
labelSetLineWrap :: LabelClass self => self
 -> Bool  -- ^ @wrap@ - the setting
 -> IO ()
labelSetLineWrap self wrap =
  {# call label_set_line_wrap #}
    (toLabel self)
    (fromBool wrap)

-- | Returns whether lines in the label are automatically wrapped. See
-- 'labelSetLineWrap'.
--
labelGetLineWrap :: LabelClass self => self
 -> IO Bool -- ^ returns @True@ if the lines of the label are automatically
            -- wrapped.
labelGetLineWrap self =
  liftM toBool $
  {# call unsafe label_get_line_wrap #}
    (toLabel self)

-- | If line wrapping is on (see 'labelSetLineWrap') this controls how the line wrapping is done. 
-- The default is 'WrapWholeWords' which means wrap on word boundaries.
--
-- * Available since Gtk+ version 2.10
--
labelSetLineWrapMode :: LabelClass self => self
 -> LayoutWrapMode  -- ^ @wrapMode@ - the line wrapping mode 
 -> IO ()
labelSetLineWrapMode self wrapMode =
  {# call label_set_line_wrap_mode #}
    (toLabel self)
    (fromIntegral (fromEnum wrapMode))

-- | Returns line wrap mode used by the label. See 'labelSetLineWrapMode'.
--
-- * Available since Gtk+ version 2.10
--
labelGetLineWrapMode :: LabelClass self => self
 -> IO LayoutWrapMode  -- ^ return the line wrapping mode
labelGetLineWrapMode self = liftM (toEnum . fromIntegral) $  
  {# call label_get_line_wrap_mode #}
    (toLabel self)

-- | Obtains the coordinates where the label will draw the 'PangoLayout'
-- representing the text in the label; useful to convert mouse events into
-- coordinates inside the 'PangoLayout', e.g. to take some action if some part
-- of the label is clicked. Of course you will need to create a 'EventBox' to
-- receive the events, and pack the label inside it, since labels are a
-- \'NoWindow\' widget.
--
labelGetLayoutOffsets :: LabelClass self => self -> IO (Int, Int)
labelGetLayoutOffsets self =
  alloca $ \xPtr ->
  alloca $ \yPtr -> do
  {# call unsafe label_get_layout_offsets #}
    (toLabel self)
    xPtr
    yPtr
  x <- peek xPtr
  y <- peek yPtr
  return (fromIntegral x, fromIntegral y)

-- | If the label has been set so that it has an mnemonic key this function
-- returns the keyval used for the mnemonic accelerator.
--
labelGetMnemonicKeyval :: LabelClass self => self -> IO KeyVal
labelGetMnemonicKeyval self =
  liftM fromIntegral $
  {# call unsafe label_get_mnemonic_keyval #}
    (toLabel self)

-- | Gets whether the text selectable.
--
labelGetSelectable :: LabelClass self => self
 -> IO Bool -- ^ returns @True@ if the user can copy text from the label
labelGetSelectable self =
  liftM toBool $
  {# call unsafe label_get_selectable #}
    (toLabel self)

-- | Sets whether the text of the label contains markup in Pango's text markup
-- language. See 'labelSetMarkup'.
--
labelSetUseMarkup :: LabelClass self => self
 -> Bool  -- ^ @setting@ - @True@ if the label's text should be parsed for
          -- markup.
 -> IO ()
labelSetUseMarkup self setting =
  {# call label_set_use_markup #}
    (toLabel self)
    (fromBool setting)

-- | Returns whether the label's text is interpreted as marked up with the
-- Pango text markup language. See 'labelSetUseMarkup'.
--
labelGetUseMarkup :: LabelClass self => self
 -> IO Bool -- ^ returns @True@ if the label's text will be parsed for markup.
labelGetUseMarkup self =
  liftM toBool $
  {# call unsafe label_get_use_markup #}
    (toLabel self)

-- | If @True@, an underline in the text indicates the next character should be
-- used for the mnemonic accelerator key.
--
labelSetUseUnderline :: LabelClass self => self -> Bool -> IO ()
labelSetUseUnderline self useUnderline =
  {# call label_set_use_underline #}
    (toLabel self)
    (fromBool useUnderline)

-- | Returns whether an embedded underline in the label indicates a mnemonic.
-- See 'labelSetUseUnderline'.
--
labelGetUseUnderline :: LabelClass self => self -> IO Bool
labelGetUseUnderline self =
  liftM toBool $
  {# call unsafe label_get_use_underline #}
    (toLabel self)

-- | Gets the text from a label widget, as displayed on the screen. This
-- does not include any embedded underlines indicating mnemonics or Pango
-- markup. (See 'labelGetLabel')
--
labelGetText :: LabelClass self => self -> IO String
labelGetText self =
  {# call unsafe label_get_text #}
    (toLabel self)
  >>= peekUTFString

-- | Gets the text from a label widget including any embedded underlines
-- indicating mnemonics and Pango markup. (See 'labelGetText').
--
labelGetLabel :: LabelClass self => self -> IO String
labelGetLabel self =
  {# call unsafe label_get_label #}
    (toLabel self)
  >>= peekUTFString

-- | Selects a range of characters in the label, if the label is selectable.
-- See 'labelSetSelectable'. If the label is not selectable, this function has
-- no effect. If @startOffset@ or @endOffset@ are -1, then the end of the label
-- will be substituted.
--
labelSelectRegion :: LabelClass self => self
 -> Int   -- ^ @startOffset@ - start offset
 -> Int   -- ^ @endOffset@ - end offset
 -> IO ()
labelSelectRegion self startOffset endOffset =
  {# call label_select_region #}
    (toLabel self)
    (fromIntegral startOffset)
    (fromIntegral endOffset)

-- | Gets the selected range of characters in the label, if any. If there is
-- a range selected the result is the start and end of the selection as
-- character offsets.
--
labelGetSelectionBounds :: LabelClass self => self
 -> IO (Maybe (Int, Int))
labelGetSelectionBounds self =
  alloca $ \startPtr ->
  alloca $ \endPtr -> do
  isSelection <-
    liftM toBool $
    {# call unsafe label_get_selection_bounds #}
    (toLabel self)
    startPtr
    endPtr
  if isSelection
    then do start <- peek startPtr
            end <- peek endPtr
            return $ Just $ (fromIntegral start, fromIntegral end)
    else return Nothing

-- | If the label has been set so that it has an mnemonic key (using i.e.
-- 'labelSetMarkupWithMnemonic', 'labelSetTextWithMnemonic',
-- 'labelNewWithMnemonic' or the \"use_underline\" property) the label can be
-- associated with a widget that is the target of the mnemonic. When the label
-- is inside a widget (like a 'Button' or a 'Notebook' tab) it is automatically
-- associated with the correct widget, but sometimes (i.e. when the target is a
-- 'Entry' next to the label) you need to set it explicitly using this
-- function.
--
-- The target widget will be accelerated by emitting \"mnemonic_activate\"
-- on it. The default handler for this signal will activate the widget if there
-- are no mnemonic collisions and toggle focus between the colliding widgets
-- otherwise.
--
labelSetMnemonicWidget :: (LabelClass self, WidgetClass widget) => self
 -> widget -- ^ @widget@ - the target 'Widget'
 -> IO ()
labelSetMnemonicWidget self widget =
  {# call unsafe label_set_mnemonic_widget #}
    (toLabel self)
    (toWidget widget)

-- | Retrieves the target of the mnemonic (keyboard shortcut) of this label.
-- See 'labelSetMnemonicWidget'.
--
labelGetMnemonicWidget :: LabelClass self => self
 -> IO (Maybe Widget) -- ^ returns the target of the label's mnemonic, or
                      -- @Nothing@ if none has been set and the default
                      -- algorithm will be used.
labelGetMnemonicWidget self =
  maybeNull (makeNewObject mkWidget) $
  {# call unsafe label_get_mnemonic_widget #}
    (toLabel self)

-- | Selectable labels allow the user to select text from the label, for
-- copy-and-paste.
--
labelSetSelectable :: LabelClass self => self
 -> Bool  -- ^ @setting@ - @True@ to allow selecting text in the label
 -> IO ()
labelSetSelectable self setting =
  {# call unsafe label_set_selectable #}
    (toLabel self)
    (fromBool setting)

-- | Sets the label's text from the given string. If characters in the string are
-- preceded by an underscore, they are underlined indicating that they
-- represent a keyboard accelerator called a mnemonic. The mnemonic key can be
-- used to activate another widget, chosen automatically, or explicitly using
-- 'labelSetMnemonicWidget'.
--
labelSetTextWithMnemonic :: LabelClass self => self -> String -> IO ()
labelSetTextWithMnemonic self str =
  withUTFString str $ \strPtr ->
  {# call label_set_text_with_mnemonic #}
    (toLabel self)
    strPtr

#if GTK_CHECK_VERSION(2,6,0)
-- | Sets the mode used to ellipsize (add an ellipsis: \"...\") to the text if
-- there is not enough space to render the entire string.
--
-- * Available since Gtk+ version 2.6
--
labelSetEllipsize :: LabelClass self => self
 -> EllipsizeMode -- ^ @mode@ - a 'EllipsizeMode'
 -> IO ()
labelSetEllipsize self mode =
  {# call gtk_label_set_ellipsize #}
    (toLabel self)
    ((fromIntegral . fromEnum) mode)

-- | Sets the desired width in characters of @label@ to @nChars@.
--
-- * Available since Gtk+ version 2.6
--
labelSetWidthChars :: LabelClass self => self
 -> Int   -- ^ @nChars@ - the new desired width, in characters.
 -> IO ()
labelSetWidthChars self nChars =
  {# call gtk_label_set_width_chars #}
    (toLabel self)
    (fromIntegral nChars)

-- | Sets the desired maximum width in characters of @label@ to @nChars@.
--
-- * Available since Gtk+ version 2.6
--
labelSetMaxWidthChars :: LabelClass self => self
 -> Int   -- ^ @nChars@ - the new desired maximum width, in characters.
 -> IO ()
labelSetMaxWidthChars self nChars =
  {# call gtk_label_set_max_width_chars #}
    (toLabel self)
    (fromIntegral nChars)

-- | Returns the ellipsizing position of the label. See 'labelSetEllipsize'.
--
-- * Available since Gtk+ version 2.6
--
labelGetEllipsize :: LabelClass self => self
 -> IO EllipsizeMode -- ^ returns 'EllipsizeMode'
labelGetEllipsize self =
  liftM (toEnum . fromIntegral) $
  {# call gtk_label_get_ellipsize #}
    (toLabel self)

-- | Retrieves the desired width of @label@, in characters. See
-- 'labelSetWidthChars'.
--
-- * Available since Gtk+ version 2.6
--
labelGetWidthChars :: LabelClass self => self
 -> IO Int -- ^ returns the width of the label in characters.
labelGetWidthChars self =
  liftM fromIntegral $
  {# call gtk_label_get_width_chars #}
    (toLabel self)

-- | Retrieves the desired maximum width of @label@, in characters. See
-- 'labelSetWidthChars'.
--
-- * Available since Gtk+ version 2.6
--
labelGetMaxWidthChars :: LabelClass self => self
 -> IO Int -- ^ returns the maximum width of the label in characters.
labelGetMaxWidthChars self =
  liftM fromIntegral $
  {# call gtk_label_get_max_width_chars #}
    (toLabel self)

-- | Returns whether the label is in single line mode.
--
-- * Available since Gtk+ version 2.6
--
labelGetSingleLineMode :: LabelClass self => self
 -> IO Bool -- ^ returns @True@ when the label is in single line mode.
labelGetSingleLineMode self =
  liftM toBool $
  {# call gtk_label_get_single_line_mode #}
    (toLabel self)

-- | Gets the angle of rotation for the label. See gtk_label_set_angle.
--
-- * Available since Gtk+ version 2.6
--
labelGetAngle :: LabelClass self => self
 -> IO Double -- ^ returns the angle of rotation for the label
labelGetAngle self =
  liftM realToFrac $
  {# call gtk_label_get_angle #}
    (toLabel self)

-- | Sets whether the label is in single line mode.
--
-- * Available since Gtk+ version 2.6
--
labelSetSingleLineMode :: LabelClass self => self
 -> Bool  -- ^ @singleLineMode@ - @True@ if the label should be in single line
          -- mode
 -> IO ()
labelSetSingleLineMode self singleLineMode =
  {# call gtk_label_set_single_line_mode #}
    (toLabel self)
    (fromBool singleLineMode)

-- | Sets the angle of rotation for the label. An angle of 90 reads from from
-- bottom to top, an angle of 270, from top to bottom. The angle setting for
-- the label is ignored if the label is selectable, wrapped, or ellipsized.
--
-- * Available since Gtk+ version 2.6
--
labelSetAngle :: LabelClass self => self
 -> Double -- ^ @angle@ - the angle that the baseline of the label makes with
           -- the horizontal, in degrees, measured counterclockwise
 -> IO ()
labelSetAngle self angle =
  {# call gtk_label_set_angle #}
    (toLabel self)
    (realToFrac angle)
#endif

--------------------
-- Attributes

-- | The text of the label.
--
labelLabel :: LabelClass self => Attr self String
labelLabel = newAttr
  labelGetLabel
  labelSetLabel

-- | The text of the label includes XML markup. See pango_parse_markup().
--
-- Default value: @False@
--
labelUseMarkup :: LabelClass self => Attr self Bool
labelUseMarkup = newAttr
  labelGetUseMarkup
  labelSetUseMarkup

-- | If set, an underline in the text indicates the next character should be
-- used for the mnemonic accelerator key.
--
-- Default value: @False@
--
labelUseUnderline :: LabelClass self => Attr self Bool
labelUseUnderline = newAttr
  labelGetUseUnderline
  labelSetUseUnderline

-- | The alignment of the lines in the text of the label relative to each
-- other. This does NOT affect the alignment of the label within its
-- allocation. 
--
-- Default value: 'JustifyLeft'
--
labelJustify :: LabelClass self => Attr self Justification
labelJustify = newAttr
  labelGetJustify
  labelSetJustify

-- | If set, wrap lines if the text becomes too wide.
--
-- Default value: @False@
--
labelWrap :: LabelClass self => Attr self Bool
labelWrap = newAttrFromBoolProperty "wrap"

-- | If line wrapping is on (see the 'labelWrap' property) this controls how the line wrapping is done. 
-- The default is 'WrapWholeWords', which means wrap on word boundaries.
--
-- Default value: 'WrapWholeWords'
--
-- * Available since Gtk+ version 2.10
--
labelWrapMode :: LabelClass self => Attr self LayoutWrapMode
labelWrapMode = newAttrFromEnumProperty "wrap-mode"
                {# call pure unsafe gtk_label_get_type #}

-- | Whether the label text can be selected with the mouse.
--
-- Default value: @False@
--
labelSelectable :: LabelClass self => Attr self Bool
labelSelectable = newAttr
  labelGetSelectable
  labelSetSelectable

-- | The widget to be activated when the label's mnemonic key is pressed.
--
labelMnemonicWidget :: (LabelClass self, WidgetClass widget) => ReadWriteAttr self (Maybe Widget) widget
labelMnemonicWidget = newAttr
  labelGetMnemonicWidget
  labelSetMnemonicWidget

-- | The mnemonic accelerator key for this label.
--
-- Default value: 16777215
--
labelMnemonicKeyval :: LabelClass self => ReadAttr self Int
labelMnemonicKeyval = readAttrFromIntProperty "mnemonic-keyval"

-- | A string with _ characters in positions correspond to characters in the text to underline.
--
-- Default value: "\\"
--
labelPattern :: LabelClass self => WriteAttr self String
labelPattern = writeAttrFromStringProperty "pattern"

-- | The current position of the insertion cursor in chars.
--
-- Allowed values: >= 0
--
-- Default value: 0
--
labelCursorPosition :: LabelClass self => ReadAttr self Int
labelCursorPosition = readAttrFromIntProperty "cursor-position"

-- | The position of the opposite end of the selection from the cursor in
-- chars.
--
-- Allowed values: >= 0
--
-- Default value: 0
--
labelSelectionBound :: LabelClass self => ReadAttr self Int
labelSelectionBound = readAttrFromIntProperty "selection-bound"

#if GTK_CHECK_VERSION(2,6,0)
-- | The preferred place to ellipsize the string, if the label does not have
-- enough room to display the entire string, specified as a 'EllipsizeMode'.
--
-- Note that setting this property to a value other than 'EllipsizeNone' has
-- the side-effect that the label requests only enough space to display the
-- ellipsis \"...\". In particular, this means that ellipsizing labels don't
-- work well in notebook tabs, unless the tab's tab-expand property is set to
-- @True@. Other means to set a label's width are
-- 'Graphics.UI.Gtk.Abstract.Widget.widgetSetSizeRequest' and
-- 'labelSetWidthChars'.
--
-- Default value: 'EllipsizeNone'
--
labelEllipsize :: LabelClass self => Attr self EllipsizeMode
labelEllipsize = newAttr
  labelGetEllipsize
  labelSetEllipsize

-- | The desired width of the label, in characters. If this property is set to
-- -1, the width will be calculated automatically, otherwise the label will
-- request either 3 characters or the property value, whichever is greater. If
-- the width-chars property is set to a positive value, then the
-- max-width-chars property is ignored.
--
-- Allowed values: >= -1
--
-- Default value: -1
--
labelWidthChars :: LabelClass self => Attr self Int
labelWidthChars = newAttr
  labelGetWidthChars
  labelSetWidthChars

-- | Whether the label is in single line mode. In single line mode, the height
-- of the label does not depend on the actual text, it is always set to ascent
-- + descent of the font. This can be an advantage in situations where resizing
-- the label because of text changes would be distracting, e.g. in a statusbar.
--
-- Default value: @False@
--
labelSingleLineMode :: LabelClass self => Attr self Bool
labelSingleLineMode = newAttr
  labelGetSingleLineMode
  labelSetSingleLineMode

-- | The angle that the baseline of the label makes with the horizontal, in
-- degrees, measured counterclockwise. An angle of 90 reads from from bottom to
-- top, an angle of 270, from top to bottom. Ignored if the label is
-- selectable, wrapped, or ellipsized.
--
-- Allowed values: [0,360]
--
-- Default value: 0
--
labelAngle :: LabelClass self => Attr self Double
labelAngle = newAttr
  labelGetAngle
  labelSetAngle

-- | A list of style attributes to apply to the text of the label.
labelAttributes :: LabelClass self => Attr self [PangoAttribute]
labelAttributes = newAttr
  labelGetAttributes
  labelSetAttributes

-- | The desired maximum width of the label, in characters. If this property
-- is set to -1, the width will be calculated automatically, otherwise the
-- label will request space for no more than the requested number of
-- characters. If the width-chars property is set to a positive value, then the
-- max-width-chars property is ignored.
--
-- Allowed values: >= -1
--
-- Default value: -1
--
labelMaxWidthChars :: LabelClass self => Attr self Int
labelMaxWidthChars = newAttr
  labelGetMaxWidthChars
  labelSetMaxWidthChars
#endif

-- | \'lineWrap\' property. See 'labelGetLineWrap' and 'labelSetLineWrap'
--
labelLineWrap :: LabelClass self => Attr self Bool
labelLineWrap = newAttr
  labelGetLineWrap
  labelSetLineWrap

-- | \'text\' property. See 'labelGetText' and 'labelSetText'
--
labelText :: LabelClass self => Attr self String
labelText = newAttr
  labelGetText
  labelSetText