<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <!--Rendered using the Haskell Html Library v0.2--> <HTML ><HEAD ><META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=UTF-8" ><TITLE >Graphics.UI.Gtk.Misc.DrawingArea</TITLE ><LINK HREF="haddock.css" REL="stylesheet" TYPE="text/css" ><SCRIPT SRC="haddock-util.js" TYPE="text/javascript" ></SCRIPT ><SCRIPT TYPE="text/javascript" >window.onload = function () {setSynopsis("mini_Graphics-UI-Gtk-Misc-DrawingArea.html")};</SCRIPT ></HEAD ><BODY ><TABLE CLASS="vanilla" CELLSPACING="0" CELLPADDING="0" ><TR ><TD CLASS="topbar" ><TABLE CLASS="vanilla" CELLSPACING="0" CELLPADDING="0" ><TR ><TD ><IMG SRC="haskell_icon.gif" WIDTH="16" HEIGHT="16" ALT=" " ></TD ><TD CLASS="title" >gtk-0.11.2: Binding to the Gtk+ graphical user interface library.</TD ><TD CLASS="topbut" ><A HREF="src/Graphics-UI-Gtk-Misc-DrawingArea.html" >Source code</A ></TD ><TD CLASS="topbut" ><A HREF="index.html" >Contents</A ></TD ><TD CLASS="topbut" ><A HREF="doc-index.html" >Index</A ></TD ></TR ></TABLE ></TD ></TR ><TR ><TD CLASS="modulebar" ><TABLE CLASS="vanilla" CELLSPACING="0" CELLPADDING="0" ><TR ><TD ><FONT SIZE="6" >Graphics.UI.Gtk.Misc.DrawingArea</FONT ></TD ><TD ALIGN="right" ><TABLE CLASS="narrow" CELLSPACING="0" CELLPADDING="0" ><TR ><TD CLASS="infohead" >Portability</TD ><TD CLASS="infoval" >portable (depends on GHC)</TD ></TR ><TR ><TD CLASS="infohead" >Stability</TD ><TD CLASS="infoval" >provisional</TD ></TR ><TR ><TD CLASS="infohead" >Maintainer</TD ><TD CLASS="infoval" >gtk2hs-users@lists.sourceforge.net</TD ></TR ></TABLE ></TD ></TR ></TABLE ></TD ></TR ><TR ><TD CLASS="s15" ></TD ></TR ><TR ><TD ><TABLE CLASS="vanilla" CELLSPACING="0" CELLPADDING="0" ><TR ><TD CLASS="section4" ><B >Contents</B ></TD ></TR ><TR ><TD ><DL ><DT ><A HREF="#1" >Detail </A ></DT ><DT ><A HREF="#2" >Class Hierarchy </A ></DT ><DT ><A HREF="#3" >Types </A ></DT ><DT ><A HREF="#4" >Constructors </A ></DT ><DT ><A HREF="#5" >Methods </A ></DT ></DL ></TD ></TR ></TABLE ></TD ></TR ><TR ><TD CLASS="s15" ></TD ></TR ><TR ><TD CLASS="section1" >Description</TD ></TR ><TR ><TD CLASS="doc" >A widget for custom user interface elements </TD ></TR ><TR ><TD CLASS="s15" ></TD ></TR ><TR ><TD CLASS="section1" >Synopsis</TD ></TR ><TR ><TD CLASS="s15" ></TD ></TR ><TR ><TD CLASS="body" ><TABLE CLASS="vanilla" CELLSPACING="0" CELLPADDING="0" ><TR ><TD CLASS="decl" ><SPAN CLASS="keyword" >data</SPAN > <A HREF="#t%3ADrawingArea" >DrawingArea</A > </TD ></TR ><TR ><TD CLASS="s8" ></TD ></TR ><TR ><TD CLASS="decl" ><SPAN CLASS="keyword" >class</SPAN > <A HREF="Graphics-UI-Gtk-Abstract-Widget.html#t%3AWidgetClass" >WidgetClass</A > o => <A HREF="#t%3ADrawingAreaClass" >DrawingAreaClass</A > o </TD ></TR ><TR ><TD CLASS="s8" ></TD ></TR ><TR ><TD CLASS="decl" ><A HREF="#v%3AcastToDrawingArea" >castToDrawingArea</A > :: <A HREF="/usr/share/doc/ghc/html/libraries/glib-0.11.2/System-Glib-GObject.html#t%3AGObjectClass" >GObjectClass</A > obj => obj -> <A HREF="Graphics-UI-Gtk-Misc-DrawingArea.html#t%3ADrawingArea" >DrawingArea</A ></TD ></TR ><TR ><TD CLASS="s8" ></TD ></TR ><TR ><TD CLASS="decl" ><A HREF="#v%3AgTypeDrawingArea" >gTypeDrawingArea</A > :: <A HREF="Graphics-UI-Gtk-Abstract-Widget.html#t%3AGType" >GType</A ></TD ></TR ><TR ><TD CLASS="s8" ></TD ></TR ><TR ><TD CLASS="decl" ><A HREF="#v%3AtoDrawingArea" >toDrawingArea</A > :: <A HREF="Graphics-UI-Gtk-Misc-DrawingArea.html#t%3ADrawingAreaClass" >DrawingAreaClass</A > o => o -> <A HREF="Graphics-UI-Gtk-Misc-DrawingArea.html#t%3ADrawingArea" >DrawingArea</A ></TD ></TR ><TR ><TD CLASS="s8" ></TD ></TR ><TR ><TD CLASS="decl" ><A HREF="#v%3AdrawingAreaNew" >drawingAreaNew</A > :: <A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/System-IO.html#t%3AIO" >IO</A > <A HREF="Graphics-UI-Gtk-Misc-DrawingArea.html#t%3ADrawingArea" >DrawingArea</A ></TD ></TR ><TR ><TD CLASS="s8" ></TD ></TR ><TR ><TD CLASS="decl" ><A HREF="#v%3AdrawingAreaGetDrawWindow" >drawingAreaGetDrawWindow</A > :: <A HREF="Graphics-UI-Gtk-Misc-DrawingArea.html#t%3ADrawingArea" >DrawingArea</A > -> <A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/System-IO.html#t%3AIO" >IO</A > <A HREF="Graphics-UI-Gtk-Gdk-DrawWindow.html#t%3ADrawWindow" >DrawWindow</A ></TD ></TR ><TR ><TD CLASS="s8" ></TD ></TR ><TR ><TD CLASS="decl" ><A HREF="#v%3AdrawingAreaGetSize" >drawingAreaGetSize</A > :: <A HREF="Graphics-UI-Gtk-Misc-DrawingArea.html#t%3ADrawingArea" >DrawingArea</A > -> <A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/System-IO.html#t%3AIO" >IO</A > (<A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/Data-Int.html#t%3AInt" >Int</A >, <A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/Data-Int.html#t%3AInt" >Int</A >)</TD ></TR ></TABLE ></TD ></TR ><TR ><TD CLASS="s15" ></TD ></TR ><TR ><TD CLASS="s15" ></TD ></TR ><TR ><TD CLASS="section1" ><A NAME="1" ><A NAME="1" >Detail </A ></A ></TD ></TR ><TR ><TD CLASS="s15" ></TD ></TR ><TR ><TD CLASS="doc" ><P >The <TT ><A HREF="Graphics-UI-Gtk-Misc-DrawingArea.html#t%3ADrawingArea" >DrawingArea</A ></TT > widget is used for creating custom user interface elements. It's essentially a blank widget; you can draw on the <TT ><A HREF="Graphics-UI-Gtk-Gdk-Drawable.html#t%3ADrawable" >Drawable</A ></TT > returned by <TT ><A HREF="Graphics-UI-Gtk-Misc-DrawingArea.html#v%3AdrawingAreaGetDrawWindow" >drawingAreaGetDrawWindow</A ></TT >. </P ><P >After creating a drawing area, the application may want to connect to: </P ><UL ><LI > Mouse and button press signals to respond to input from the user. </LI ><LI > The <TT ><A HREF="Graphics-UI-Gtk-Abstract-Widget.html#v%3Arealize" >realize</A ></TT > signal to take any necessary actions when the widget is instantiated on a particular display. (Create GDK resources in response to this signal.) </LI ><LI > The <TT ><A HREF="Graphics-UI-Gtk-Abstract-Widget.html#v%3AconfigureEvent" >configureEvent</A ></TT > signal to take any necessary actions when the widget changes size. </LI ><LI > The <TT ><A HREF="Graphics-UI-Gtk-Abstract-Widget.html#v%3AexposeEvent" >exposeEvent</A ></TT > signal to handle redrawing the contents of the widget. </LI ></UL ><P >Expose events are normally delivered when a drawing area first comes onscreen, or when it's covered by another window and then uncovered (exposed). You can also force an expose event by adding to the "damage region" of the drawing area's window; <TT ><A HREF="Graphics-UI-Gtk-Abstract-Widget.html#v%3AwidgetQueueDrawArea" >widgetQueueDrawArea</A ></TT > and windowInvalidateRect are equally good ways to do this. You'll then get an expose event for the invalid region. </P ><P >The available routines for drawing are documented on the GDK Drawing Primitives page. </P ><P >To receive mouse events on a drawing area, you will need to enable them with <TT ><A HREF="Graphics-UI-Gtk-Abstract-Widget.html#v%3AwidgetAddEvents" >widgetAddEvents</A ></TT >. To receive keyboard events, you will need to set the <TT ><A HREF="Graphics-UI-Gtk-Abstract-Widget.html#v%3AwidgetCanFocus" >widgetCanFocus</A ></TT > attribute on the drawing area, and should probably draw some user-visible indication that the drawing area is focused. </P ></TD ></TR ><TR ><TD CLASS="s15" ></TD ></TR ><TR ><TD CLASS="section1" ><A NAME="2" ><A NAME="2" >Class Hierarchy </A ></A ></TD ></TR ><TR ><TD CLASS="s15" ></TD ></TR ><TR ><TD CLASS="doc" ><PRE > | <TT ><A HREF="/usr/share/doc/ghc/html/libraries/glib-0.11.2/System-Glib-GObject.html#t%3AGObject" >GObject</A ></TT > | +----<TT ><A HREF="Graphics-UI-Gtk-Abstract-Object.html#t%3AObject" >Object</A ></TT > | +----<TT ><A HREF="Graphics-UI-Gtk-Abstract-Widget.html#t%3AWidget" >Widget</A ></TT > | +----DrawingArea </PRE ></TD ></TR ><TR ><TD CLASS="s15" ></TD ></TR ><TR ><TD CLASS="section1" ><A NAME="3" ><A NAME="3" >Types </A ></A ></TD ></TR ><TR ><TD CLASS="s15" ></TD ></TR ><TR ><TD CLASS="topdecl" ><TABLE CLASS="declbar" ><TR ><TD CLASS="declname" ><SPAN CLASS="keyword" >data</SPAN > <A NAME="t:DrawingArea" ><A NAME="t%3ADrawingArea" ></A ></A ><B >DrawingArea</B > </TD ><TD CLASS="declbut" ><A HREF="src/Graphics-UI-Gtk-Types.html#DrawingArea" >Source</A ></TD ></TR ></TABLE ></TD ></TR ><TR ><TD CLASS="body" ><TABLE CLASS="vanilla" CELLSPACING="0" CELLPADDING="0" ><TR ><TD CLASS="section4" ><IMG SRC="minus.gif" CLASS="coll" ONCLICK="toggle(this,'i:DrawingArea')" ALT="show/hide" > Instances</TD ></TR ><TR ><TD CLASS="body" ><DIV ID="i:DrawingArea" STYLE="display:block;" ><TABLE CLASS="vanilla" CELLSPACING="1" CELLPADDING="0" ><TR ><TD CLASS="decl" ><A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/Data-Eq.html#t%3AEq" >Eq</A > <A HREF="Graphics-UI-Gtk-Misc-DrawingArea.html#t%3ADrawingArea" >DrawingArea</A ></TD ></TR ><TR ><TD CLASS="decl" ><A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/Data-Ord.html#t%3AOrd" >Ord</A > <A HREF="Graphics-UI-Gtk-Misc-DrawingArea.html#t%3ADrawingArea" >DrawingArea</A ></TD ></TR ><TR ><TD CLASS="decl" ><A HREF="/usr/share/doc/ghc/html/libraries/glib-0.11.2/System-Glib-GObject.html#t%3AGObjectClass" >GObjectClass</A > <A HREF="Graphics-UI-Gtk-Misc-DrawingArea.html#t%3ADrawingArea" >DrawingArea</A ></TD ></TR ><TR ><TD CLASS="decl" ><A HREF="Graphics-UI-Gtk-Misc-DrawingArea.html#t%3ADrawingAreaClass" >DrawingAreaClass</A > <A HREF="Graphics-UI-Gtk-Misc-DrawingArea.html#t%3ADrawingArea" >DrawingArea</A ></TD ></TR ><TR ><TD CLASS="decl" ><A HREF="Graphics-UI-Gtk-Abstract-Widget.html#t%3AWidgetClass" >WidgetClass</A > <A HREF="Graphics-UI-Gtk-Misc-DrawingArea.html#t%3ADrawingArea" >DrawingArea</A ></TD ></TR ><TR ><TD CLASS="decl" ><A HREF="Graphics-UI-Gtk-Abstract-Object.html#t%3AObjectClass" >ObjectClass</A > <A HREF="Graphics-UI-Gtk-Misc-DrawingArea.html#t%3ADrawingArea" >DrawingArea</A ></TD ></TR ></TABLE ></DIV ></TD ></TR ></TABLE ></TD ></TR ><TR ><TD CLASS="s15" ></TD ></TR ><TR ><TD CLASS="topdecl" ><TABLE CLASS="declbar" ><TR ><TD CLASS="declname" ><SPAN CLASS="keyword" >class</SPAN > <A HREF="Graphics-UI-Gtk-Abstract-Widget.html#t%3AWidgetClass" >WidgetClass</A > o => <A NAME="t:DrawingAreaClass" ><A NAME="t%3ADrawingAreaClass" ></A ></A ><B >DrawingAreaClass</B > o </TD ><TD CLASS="declbut" ><A HREF="src/Graphics-UI-Gtk-Types.html#DrawingAreaClass" >Source</A ></TD ></TR ></TABLE ></TD ></TR ><TR ><TD CLASS="body" ><TABLE CLASS="vanilla" CELLSPACING="0" CELLPADDING="0" ><TR ><TD CLASS="s8" ></TD ></TR ><TR ><TD CLASS="section4" ><IMG SRC="minus.gif" CLASS="coll" ONCLICK="toggle(this,'i:DrawingAreaClass')" ALT="show/hide" > Instances</TD ></TR ><TR ><TD CLASS="body" ><DIV ID="i:DrawingAreaClass" STYLE="display:block;" ><TABLE CLASS="vanilla" CELLSPACING="1" CELLPADDING="0" ><TR ><TD CLASS="decl" ><A HREF="Graphics-UI-Gtk-Misc-DrawingArea.html#t%3ADrawingAreaClass" >DrawingAreaClass</A > <A HREF="Graphics-UI-Gtk-Misc-DrawingArea.html#t%3ADrawingArea" >DrawingArea</A ></TD ></TR ></TABLE ></DIV ></TD ></TR ></TABLE ></TD ></TR ><TR ><TD CLASS="s15" ></TD ></TR ><TR ><TD CLASS="topdecl" ><TABLE CLASS="declbar" ><TR ><TD CLASS="declname" ><A NAME="v:castToDrawingArea" ><A NAME="v%3AcastToDrawingArea" ></A ></A ><B >castToDrawingArea</B > :: <A HREF="/usr/share/doc/ghc/html/libraries/glib-0.11.2/System-Glib-GObject.html#t%3AGObjectClass" >GObjectClass</A > obj => obj -> <A HREF="Graphics-UI-Gtk-Misc-DrawingArea.html#t%3ADrawingArea" >DrawingArea</A ></TD ><TD CLASS="declbut" ><A HREF="src/Graphics-UI-Gtk-Types.html#castToDrawingArea" >Source</A ></TD ></TR ></TABLE ></TD ></TR ><TR ><TD CLASS="s15" ></TD ></TR ><TR ><TD CLASS="topdecl" ><TABLE CLASS="declbar" ><TR ><TD CLASS="declname" ><A NAME="v:gTypeDrawingArea" ><A NAME="v%3AgTypeDrawingArea" ></A ></A ><B >gTypeDrawingArea</B > :: <A HREF="Graphics-UI-Gtk-Abstract-Widget.html#t%3AGType" >GType</A ></TD ><TD CLASS="declbut" ><A HREF="src/Graphics-UI-Gtk-Types.html#gTypeDrawingArea" >Source</A ></TD ></TR ></TABLE ></TD ></TR ><TR ><TD CLASS="s15" ></TD ></TR ><TR ><TD CLASS="topdecl" ><TABLE CLASS="declbar" ><TR ><TD CLASS="declname" ><A NAME="v:toDrawingArea" ><A NAME="v%3AtoDrawingArea" ></A ></A ><B >toDrawingArea</B > :: <A HREF="Graphics-UI-Gtk-Misc-DrawingArea.html#t%3ADrawingAreaClass" >DrawingAreaClass</A > o => o -> <A HREF="Graphics-UI-Gtk-Misc-DrawingArea.html#t%3ADrawingArea" >DrawingArea</A ></TD ><TD CLASS="declbut" ><A HREF="src/Graphics-UI-Gtk-Types.html#toDrawingArea" >Source</A ></TD ></TR ></TABLE ></TD ></TR ><TR ><TD CLASS="s15" ></TD ></TR ><TR ><TD CLASS="section1" ><A NAME="4" ><A NAME="4" >Constructors </A ></A ></TD ></TR ><TR ><TD CLASS="s15" ></TD ></TR ><TR ><TD CLASS="topdecl" ><TABLE CLASS="declbar" ><TR ><TD CLASS="declname" ><A NAME="v:drawingAreaNew" ><A NAME="v%3AdrawingAreaNew" ></A ></A ><B >drawingAreaNew</B > :: <A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/System-IO.html#t%3AIO" >IO</A > <A HREF="Graphics-UI-Gtk-Misc-DrawingArea.html#t%3ADrawingArea" >DrawingArea</A ></TD ><TD CLASS="declbut" ><A HREF="src/Graphics-UI-Gtk-Misc-DrawingArea.html#drawingAreaNew" >Source</A ></TD ></TR ></TABLE ></TD ></TR ><TR ><TD CLASS="doc" >Creates a new drawing area. </TD ></TR ><TR ><TD CLASS="s15" ></TD ></TR ><TR ><TD CLASS="section1" ><A NAME="5" ><A NAME="5" >Methods </A ></A ></TD ></TR ><TR ><TD CLASS="s15" ></TD ></TR ><TR ><TD CLASS="topdecl" ><TABLE CLASS="declbar" ><TR ><TD CLASS="declname" ><A NAME="v:drawingAreaGetDrawWindow" ><A NAME="v%3AdrawingAreaGetDrawWindow" ></A ></A ><B >drawingAreaGetDrawWindow</B > :: <A HREF="Graphics-UI-Gtk-Misc-DrawingArea.html#t%3ADrawingArea" >DrawingArea</A > -> <A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/System-IO.html#t%3AIO" >IO</A > <A HREF="Graphics-UI-Gtk-Gdk-DrawWindow.html#t%3ADrawWindow" >DrawWindow</A ></TD ><TD CLASS="declbut" ><A HREF="src/Graphics-UI-Gtk-Misc-DrawingArea.html#drawingAreaGetDrawWindow" >Source</A ></TD ></TR ></TABLE ></TD ></TR ><TR ><TD CLASS="doc" >See <TT ><A HREF="Graphics-UI-Gtk-Abstract-Widget.html#v%3AwidgetGetDrawWindow" >widgetGetDrawWindow</A ></TT > </TD ></TR ><TR ><TD CLASS="s15" ></TD ></TR ><TR ><TD CLASS="topdecl" ><TABLE CLASS="declbar" ><TR ><TD CLASS="declname" ><A NAME="v:drawingAreaGetSize" ><A NAME="v%3AdrawingAreaGetSize" ></A ></A ><B >drawingAreaGetSize</B > :: <A HREF="Graphics-UI-Gtk-Misc-DrawingArea.html#t%3ADrawingArea" >DrawingArea</A > -> <A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/System-IO.html#t%3AIO" >IO</A > (<A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/Data-Int.html#t%3AInt" >Int</A >, <A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/Data-Int.html#t%3AInt" >Int</A >)</TD ><TD CLASS="declbut" ><A HREF="src/Graphics-UI-Gtk-Misc-DrawingArea.html#drawingAreaGetSize" >Source</A ></TD ></TR ></TABLE ></TD ></TR ><TR ><TD CLASS="doc" >See <TT ><A HREF="Graphics-UI-Gtk-Abstract-Widget.html#v%3AwidgetGetSize" >widgetGetSize</A ></TT > </TD ></TR ><TR ><TD CLASS="s15" ></TD ></TR ><TR ><TD CLASS="botbar" >Produced by <A HREF="http://www.haskell.org/haddock/" >Haddock</A > version 2.6.1</TD ></TR ></TABLE ></BODY ></HTML >