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diff --git a/gtk+-mingw/share/gtk-doc/html/gtk3/gtk-migrating-2-to-3.html b/gtk+-mingw/share/gtk-doc/html/gtk3/gtk-migrating-2-to-3.html deleted file mode 100644 index bb34f31..0000000 --- a/gtk+-mingw/share/gtk-doc/html/gtk3/gtk-migrating-2-to-3.html +++ /dev/null @@ -1,685 +0,0 @@ -<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> -<html> -<head> -<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> -<title>Migrating from GTK+ 2.x to GTK+ 3</title> -<meta name="generator" content="DocBook XSL Stylesheets V1.76.1"> -<link rel="home" href="index.html" title="GTK+ 3 Reference Manual"> -<link rel="up" href="migrating.html" title="Part V. Migrating from Previous Versions of GTK+"> -<link rel="prev" href="migrating.html" title="Part V. Migrating from Previous Versions of GTK+"> -<link rel="next" href="ch24s02.html" title="Changes that need to be done at the time of the switch"> -<meta name="generator" content="GTK-Doc V1.18.1 (XML mode)"> -<link rel="stylesheet" href="style.css" type="text/css"> -</head> -<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"> -<table class="navigation" id="top" width="100%" summary="Navigation header" cellpadding="2" cellspacing="2"><tr valign="middle"> -<td><a accesskey="p" href="migrating.html"><img src="left.png" width="24" height="24" border="0" alt="Prev"></a></td> -<td><a accesskey="u" href="migrating.html"><img src="up.png" width="24" height="24" border="0" alt="Up"></a></td> -<td><a accesskey="h" href="index.html"><img src="home.png" width="24" height="24" border="0" alt="Home"></a></td> -<th width="100%" align="center">GTK+ 3 Reference Manual</th> -<td><a accesskey="n" href="ch24s02.html"><img src="right.png" width="24" height="24" border="0" alt="Next"></a></td> -</tr></table> -<div class="chapter"> -<div class="titlepage"><div><div><h2 class="title"> -<a name="gtk-migrating-2-to-3"></a>Migrating from GTK+ 2.x to GTK+ 3</h2></div></div></div> -<div class="toc"><dl> -<dt><span class="section"><a href="gtk-migrating-2-to-3.html#id656483">Preparation in GTK+ 2.x</a></span></dt> -<dd><dl> -<dt><span class="section"><a href="gtk-migrating-2-to-3.html#id848790">Do not include individual headers</a></span></dt> -<dt><span class="section"><a href="gtk-migrating-2-to-3.html#id1372794">Do not use deprecated symbols</a></span></dt> -<dt><span class="section"><a href="gtk-migrating-2-to-3.html#id1427447">Use accessor functions instead of direct access</a></span></dt> -<dt><span class="section"><a href="gtk-migrating-2-to-3.html#id1390063">Replace GDK_<keyname> with GDK_KEY_<keyname></a></span></dt> -<dt><span class="section"><a href="gtk-migrating-2-to-3.html#id1404754">Use GIO for launching applications</a></span></dt> -<dt><span class="section"><a href="gtk-migrating-2-to-3.html#id1368017">Use cairo for drawing</a></span></dt> -</dl></dd> -<dt><span class="section"><a href="ch24s02.html">Changes that need to be done at the time of the switch</a></span></dt> -<dd><dl> -<dt><span class="section"><a href="ch24s02.html#id1365685">Replace size_request by get_preferred_width/height</a></span></dt> -<dt><span class="section"><a href="ch24s02.html#id1494062">Replace GdkRegion by cairo_region_t</a></span></dt> -<dt><span class="section"><a href="ch24s02.html#id1494562">Replace GdkPixmap by cairo surfaces</a></span></dt> -<dt><span class="section"><a href="ch24s02.html#id1494616">Replace GdkColormap by GdkVisual</a></span></dt> -<dt><span class="section"><a href="ch24s02.html#id1494706">GdkDrawable is gone</a></span></dt> -<dt><span class="section"><a href="ch24s02.html#id1494913">Event filtering</a></span></dt> -<dt><span class="section"><a href="ch24s02.html#id1495012">Backend-specific code</a></span></dt> -<dt><span class="section"><a href="ch24s02.html#id1495111">GtkPlug and GtkSocket</a></span></dt> -<dt><span class="section"><a href="ch24s02.html#id1495144">The GtkWidget::draw signal</a></span></dt> -<dt><span class="section"><a href="ch24s02.html#id1495341">GtkProgressBar orientation</a></span></dt> -<dt><span class="section"><a href="ch24s02.html#id1495498">Check your expand and fill flags</a></span></dt> -<dt><span class="section"><a href="ch24s02.html#id1495552">Scrolling changes</a></span></dt> -<dt><span class="section"><a href="ch24s02.html#id1495611">GtkObject is gone</a></span></dt> -<dt><span class="section"><a href="ch24s02.html#id1495658">GtkEntryCompletion signal parameters</a></span></dt> -<dt><span class="section"><a href="ch24s02.html#id1495686">Resize grips</a></span></dt> -<dt><span class="section"><a href="ch24s02.html#id1495752">Prevent mixed linkage</a></span></dt> -<dt><span class="section"><a href="ch24s02.html#id1495789">Install GTK+ modules in the right place</a></span></dt> -</dl></dd> -</dl></div> -<p> - GTK+ 3 is a major new version of GTK+ that breaks both API and ABI - compared to GTK+ 2.x, which has remained API- and ABI-stable for a - long time. Thankfully, most of the changes are not hard to adapt to - and there are a number of steps that you can take to prepare your - GTK+ 2.x application for the switch to GTK+ 3. After that, there's - a small number of adjustments that you may have to do when you actually - switch your application to build against GTK+ 3. - </p> -<div class="section"> -<div class="titlepage"><div><div><h2 class="title" style="clear: both"> -<a name="id656483"></a>Preparation in GTK+ 2.x</h2></div></div></div> -<p> - The steps outlined in the following sections assume that your - application is working with GTK+ 2.24, which is the final stable - release of GTK+ 2.x. It includes all the necessary APIs and tools - to help you port your application to GTK+ 3. If you are still using - an older version of GTK+ 2.x, you should first get your application - to build and work with 2.24. - </p> -<div class="section"> -<div class="titlepage"><div><div><h3 class="title"> -<a name="id848790"></a>Do not include individual headers</h3></div></div></div> -<p> - With GTK+ 2.x it was common to include just the header files for - a few widgets that your application was using, which could lead - to problems with missing definitions, etc. GTK+ 3 tightens the - rules about which header files you are allowed to include directly. - The allowed header files are are - </p> -<div class="variablelist"><table border="0"> -<col align="left" valign="top"> -<tbody> -<tr> -<td><p><span class="term"><code class="filename">gtk/gtk.h</code></span></p></td> -<td>for GTK</td> -</tr> -<tr> -<td><p><span class="term"><code class="filename">gtk/gtkx.h</code></span></p></td> -<td>for the X-specfic widgets <a class="link" href="GtkSocket.html" title="GtkSocket"><span class="type">GtkSocket</span></a> and <a class="link" href="GtkPlug.html" title="GtkPlug"><span class="type">GtkPlug</span></a> -</td> -</tr> -<tr> -<td><p><span class="term"><code class="filename">gtk/gtkunixprint.h</code></span></p></td> -<td>for low-level, UNIX-specific printing functions</td> -</tr> -<tr> -<td><p><span class="term"><code class="filename">gdk/gdk.h</code></span></p></td> -<td>for GDK</td> -</tr> -<tr> -<td><p><span class="term"><code class="filename">gdk/gdkx.h</code></span></p></td> -<td>for GDK functions that are X11-specific</td> -</tr> -<tr> -<td><p><span class="term"><code class="filename">gdk/gdkwin32.h</code></span></p></td> -<td>for GDK functions that are Windows-specific</td> -</tr> -</tbody> -</table></div> -<p> - (these relative paths are assuming that you are using the include - paths that are specified in the gtk+-2.0.pc file, as returned by - <code class="literal">pkg-config --cflags gtk+-2.0.pc</code>.) - </p> -<p> - To check that your application only includes the allowed headers, - you can use defines to disable inclusion of individual headers, - as follows: - </p> -<pre class="programlisting"> - make CFLAGS+="-DGTK_DISABLE_SINGLE_INCLUDES" - </pre> -<p> - </p> -</div> -<div class="section"> -<div class="titlepage"><div><div><h3 class="title"> -<a name="id1372794"></a>Do not use deprecated symbols</h3></div></div></div> -<p> - Over the years, a number of functions, and in some cases, entire - widgets have been deprecated. These deprecations are clearly spelled - out in the API reference, with hints about the recommended replacements. - The API reference for GTK+ 2 also includes an - <a class="ulink" href="http://developer.gnome.org/gtk/2.24/api-index-deprecated.html" target="_top">index</a> of all deprecated symbols. - </p> -<p> - To verify that your program does not use any deprecated symbols, - you can use defines to remove deprecated symbols from the header files, - as follows: - </p> -<pre class="programlisting"> - make CFLAGS+="-DGDK_DISABLE_DEPRECATED -DGTK_DISABLE_DEPRECATED" - </pre> -<p> - </p> -<p> - Note that some parts of our API, such as enumeration values, are - not well covered by the deprecation warnings. In most cases, using - them will require you to also use deprecated functions, which will - trigger warnings. But some things, like the <a href="http://library.gnome.org/devel/gtk3/GtkDialog.html#GTK-DIALOG-NO-SEPARATOR:CAPS"><code class="literal">GTK_DIALOG_NO_SEPARATOR</code></a> - flag that has disappeared in GTK+ 3, may not. - </p> -</div> -<div class="section"> -<div class="titlepage"><div><div><h3 class="title"> -<a name="id1427447"></a>Use accessor functions instead of direct access</h3></div></div></div> -<p> - GTK+ 3 removes many implementation details and struct members from - its public headers. - </p> -<p> - To ensure that your application does not have problems with this, you - define the preprocessor symbol <code class="literal">GSEAL_ENABLE</code> while - building your application against GTK+ 2.x. This will make the compiler - catch all uses of direct access to struct fields so that you can go - through them one by one and replace them with a call to an accessor - function instead. - </p> -<pre class="programlisting"> - make CFLAGS+="-DGSEAL_ENABLE" - </pre> -<p> - </p> -</div> -<div class="section"> -<div class="titlepage"><div><div><h3 class="title"> -<a name="id1390063"></a>Replace GDK_<keyname> with GDK_KEY_<keyname></h3></div></div></div> -<p> - Key constants have gained a <code class="literal">_KEY_</code> infix. - For example, <code class="literal">GDK_a</code> is now - <code class="literal">GDK_KEY_a</code>. In GTK+ 2, the old names continue - to be available. In GTK+ 3 however, the old names will require - an explicit include of the <code class="literal">gdkkeysyms-compat.h</code> header. - </p> -</div> -<div class="section"> -<div class="titlepage"><div><div><h3 class="title"> -<a name="id1404754"></a>Use GIO for launching applications</h3></div></div></div> -<p> - The <code class="literal">gdk_spawn</code> family of functions has been - deprecated in GDK 2.24 and removed from GDK 3. Various replacements - exist; the best replacement depends on the circumstances: - </p> -<div class="itemizedlist"><ul class="itemizedlist" type="disc"> -<li class="listitem">If you are opening a document or URI by launching a command - like <code class="literal">firefox http://my-favourite-website.com</code> or - <code class="literal">gnome-open ghelp:epiphany</code>, it is best to just use - <a class="link" href="gtk3-Filesystem-utilities.html#gtk-show-uri" title="gtk_show_uri ()"><code class="function">gtk_show_uri()</code></a>; as an added benefit, your application will henceforth - respect the users preference for what application to use.</li> -<li class="listitem">If you are launching a regular, installed application that - has a desktop file, it is best to use GIOs <a href="http://library.gnome.org/devel/gio/unstable/GAppInfo.html"><span class="type">GAppInfo</span></a> with a suitable - launch context. - <div class="informalexample"> - <table class="listing_frame" border="0" cellpadding="0" cellspacing="0"> - <tbody> - <tr> - <td class="listing_lines" align="right"><pre>1 -2 -3 -4 -5 -6 -7 -8 -9 -10 -11 -12 -13 -14 -15 -16</pre></td> - <td class="listing_code"><pre class="programlisting"><span class="usertype">GAppInfo</span><span class="normal"> </span><span class="symbol">*</span><span class="normal">info</span><span class="symbol">;</span> -<span class="usertype">GAppLaunchContext</span><span class="normal"> </span><span class="symbol">*</span><span class="normal">context</span><span class="symbol">;</span> -<span class="usertype">GError</span><span class="normal"> </span><span class="symbol">*</span><span class="normal">error </span><span class="symbol">=</span><span class="normal"> <a href="http://library.gnome.org/devel/glib/unstable/glib-Standard-Macros.html#NULL:CAPS">NULL</a></span><span class="symbol">;</span> - -<span class="normal">info </span><span class="symbol">=</span><span class="normal"> </span><span class="symbol">(</span><span class="normal"><a href="http://library.gnome.org/devel/gio/unstable/GAppInfo.html">GAppInfo</a></span><span class="symbol">*)</span><span class="normal"> </span><span class="function"><a href="http://library.gnome.org/devel/gio/unstable/gio-Desktop-file-based-GAppInfo.html#g-desktop-app-info-new">g_desktop_app_info_new</a></span><span class="normal"> </span><span class="symbol">(</span><span class="string">"epiphany.desktop"</span><span class="symbol">);</span> -<span class="normal">context </span><span class="symbol">=</span><span class="normal"> </span><span class="symbol">(</span><span class="normal"><a href="http://library.gnome.org/devel/gio/unstable/GAppInfo.html#GAppLaunchContext">GAppLaunchContext</a></span><span class="symbol">*)</span><span class="normal"> </span><span class="function"><a href="http://developer.gnome.org/gdk/GdkDisplay.html#gdk-display-get-app-launch-context">gdk_display_get_app_launch_context</a></span><span class="normal"> </span><span class="symbol">(</span><span class="normal">display</span><span class="symbol">);</span> -<span class="function"><a href="http://library.gnome.org/devel/gio/unstable/GAppInfo.html#g-app-info-launch">g_app_info_launch</a></span><span class="normal"> </span><span class="symbol">(</span><span class="normal">info</span><span class="symbol">,</span><span class="normal"> <a href="http://library.gnome.org/devel/glib/unstable/glib-Standard-Macros.html#NULL:CAPS">NULL</a></span><span class="symbol">,</span><span class="normal"> context</span><span class="symbol">,</span><span class="normal"> </span><span class="symbol">&</span><span class="normal">error</span><span class="symbol">);</span> - -<span class="keyword">if</span><span class="normal"> </span><span class="symbol">(</span><span class="normal">error</span><span class="symbol">)</span> -<span class="normal"> </span><span class="cbracket">{</span> -<span class="normal"> </span><span class="function"><a href="http://library.gnome.org/devel/glib/unstable/glib-Message-Logging.html#g-warning">g_warning</a></span><span class="normal"> </span><span class="symbol">(</span><span class="string">"Failed to launch epiphany: %s"</span><span class="symbol">,</span><span class="normal"> error</span><span class="symbol">-></span><span class="normal">message</span><span class="symbol">);</span> -<span class="normal"> </span><span class="function"><a href="http://library.gnome.org/devel/glib/unstable/glib-Error-Reporting.html#g-error-free">g_error_free</a></span><span class="normal"> </span><span class="symbol">(</span><span class="normal">error</span><span class="symbol">);</span> -<span class="normal"> </span><span class="cbracket">}</span> - -<span class="function"><a href="http://library.gnome.org/devel/gobject/unstable/gobject-The-Base-Object-Type.html#g-object-unref">g_object_unref</a></span><span class="normal"> </span><span class="symbol">(</span><span class="normal">info</span><span class="symbol">);</span> -<span class="function"><a href="http://library.gnome.org/devel/gobject/unstable/gobject-The-Base-Object-Type.html#g-object-unref">g_object_unref</a></span><span class="normal"> </span><span class="symbol">(</span><span class="normal">context</span><span class="symbol">);</span></pre></td> - </tr> - </tbody> - </table> -</div> - - Remember that you have to include - <code class="filename">gio/gdesktopappinfo.h</code> - and use the <code class="filename">gio-unix-2.0</code> pkg-config file - when using <a href="http://library.gnome.org/devel/gio/unstable/gio-Desktop-file-based-GAppInfo.html#g-desktop-app-info-new"><code class="function">g_desktop_app_info_new()</code></a>. - </li> -<li class="listitem">If you are launching a custom commandline, you can - still use <a href="http://library.gnome.org/devel/gio/unstable/GAppInfo.html#g-app-info-launch"><code class="function">g_app_info_launch()</code></a> with a GAppInfo that is constructed - with <a href="http://library.gnome.org/devel/gio/unstable/GAppInfo.html#g-app-info-create-from-commandline"><code class="function">g_app_info_create_from_commandline()</code></a>, or you can use the - more lowlevel <code class="literal">g_spawn</code> family of functions - (e.g. <a href="http://library.gnome.org/devel/glib/unstable/glib-Spawning-Processes.html#g-spawn-command-line-async"><code class="function">g_spawn_command_line_async()</code></a>), and pass <code class="envar">DISPLAY</code> - in the environment. <a href="http://developer.gnome.org/gdk/GdkScreen.html#gdk-screen-make-display-name"><code class="function">gdk_screen_make_display_name()</code></a> can be - used to find the right value for the <code class="envar">DISPLAY</code> - environment variable. - </li> -</ul></div> -<p> - </p> -</div> -<div class="section"> -<div class="titlepage"><div><div><h3 class="title"> -<a name="id1368017"></a>Use cairo for drawing</h3></div></div></div> -<p> - In GTK+ 3, the GDK drawing API (which closely mimics the X - drawing API, which is itself modeled after PostScript) has been - removed. All drawing in GTK+ 3 is done via cairo. - </p> -<p> - The <a href="http://library.gnome.org/devel/gdk3/gdk-Graphics-Contexts.html#GdkGC"><span class="type">GdkGC</span></a> and <a href="http://library.gnome.org/devel/gdk3/gdk-Images.html#GdkImage"><span class="type">GdkImage</span></a> objects, as well as all the functions using - them, are gone. This includes the <code class="literal">gdk_draw</code> family - of functions like <a href="http://library.gnome.org/devel/gdk3/gdk-Drawing-Primitives.html#gdk-draw-rectangle"><code class="function">gdk_draw_rectangle()</code></a> and <a href="http://library.gnome.org/devel/gdk3/gdk-Drawing-Primitives.html#gdk-draw-drawable"><code class="function">gdk_draw_drawable()</code></a>. As - <a href="http://library.gnome.org/devel/gdk3/gdk-Graphics-Contexts.html#GdkGC"><span class="type">GdkGC</span></a> is roughly equivalent to <a href="/usr/share/gtk-doc/html/cairo/cairo-cairo-t.html#cairo-t"><span class="type">cairo_t</span></a> and <a href="http://library.gnome.org/devel/gdk3/gdk-Images.html#GdkImage"><span class="type">GdkImage</span></a> was used for - drawing images to GdkWindows, which cairo supports automatically, - a transition is usually straightforward. - </p> -<p> - The following examples show a few common drawing idioms used by - applications that have been ported to use cairo and how the code - was replaced. - </p> -<div class="example"> -<a name="id1379258"></a><p class="title"><b>Example 112. Drawing a GdkPixbuf onto a GdkWindow</b></p> -<div class="example-contents"> -<p> - Drawing a pixbuf onto a drawable used to be done like this: - </p> -<div class="informalexample"> - <table class="listing_frame" border="0" cellpadding="0" cellspacing="0"> - <tbody> - <tr> - <td class="listing_lines" align="right"><pre>1 -2 -3 -4 -5 -6 -7 -8 -9</pre></td> - <td class="listing_code"><pre class="programlisting"><span class="function"><a href="http://library.gnome.org/devel/gdk3/gdk-Drawing-Primitives.html#gdk-draw-pixbuf">gdk_draw_pixbuf</a></span><span class="normal"> </span><span class="symbol">(</span><span class="normal">window</span><span class="symbol">,</span> -<span class="normal"> </span><span class="function"><a href="GtkWidget.html#gtk-widget-get-style">gtk_widget_get_style</a></span><span class="normal"> </span><span class="symbol">(</span><span class="normal">widget</span><span class="symbol">)-></span><span class="normal">black_gc</span><span class="symbol">,</span> -<span class="normal"> pixbuf</span><span class="symbol">,</span> -<span class="normal"> </span><span class="number">0</span><span class="symbol">,</span><span class="normal"> </span><span class="number">0</span> -<span class="normal"> x</span><span class="symbol">,</span><span class="normal"> y</span><span class="symbol">,</span> -<span class="normal"> </span><span class="function"><a href="http://library.gnome.org/devel/gdk-pixbuf/unstable/gdk-pixbuf-The-GdkPixbuf-Structure.html#gdk-pixbuf-get-width">gdk_pixbuf_get_width</a></span><span class="normal"> </span><span class="symbol">(</span><span class="normal">pixbuf</span><span class="symbol">),</span> -<span class="normal"> </span><span class="function"><a href="http://library.gnome.org/devel/gdk-pixbuf/unstable/gdk-pixbuf-The-GdkPixbuf-Structure.html#gdk-pixbuf-get-height">gdk_pixbuf_get_height</a></span><span class="normal"> </span><span class="symbol">(</span><span class="normal">pixbuf</span><span class="symbol">),</span> -<span class="normal"> <a href="http://library.gnome.org/devel/gdk3/gdk-GdkRGB.html#GDK-RGB-DITHER-NORMAL:CAPS">GDK_RGB_DITHER_NORMAL</a></span><span class="symbol">,</span> -<span class="normal"> </span><span class="number">0</span><span class="symbol">,</span><span class="normal"> </span><span class="number">0</span><span class="symbol">);</span></pre></td> - </tr> - </tbody> - </table> -</div> - -<p> - Doing the same thing with cairo: - </p> -<div class="informalexample"> - <table class="listing_frame" border="0" cellpadding="0" cellspacing="0"> - <tbody> - <tr> - <td class="listing_lines" align="right"><pre>1 -2 -3 -4</pre></td> - <td class="listing_code"><pre class="programlisting"><span class="usertype">cairo_t</span><span class="normal"> </span><span class="symbol">*</span><span class="normal">cr </span><span class="symbol">=</span><span class="normal"> </span><span class="function"><a href="http://developer.gnome.org/gdk/gdk3-Cairo-Interaction.html#gdk-cairo-create">gdk_cairo_create</a></span><span class="normal"> </span><span class="symbol">(</span><span class="normal">window</span><span class="symbol">);</span> -<span class="function"><a href="http://developer.gnome.org/gdk/gdk3-Cairo-Interaction.html#gdk-cairo-set-source-pixbuf">gdk_cairo_set_source_pixbuf</a></span><span class="normal"> </span><span class="symbol">(</span><span class="normal">cr</span><span class="symbol">,</span><span class="normal"> pixbuf</span><span class="symbol">,</span><span class="normal"> x</span><span class="symbol">,</span><span class="normal"> y</span><span class="symbol">);</span> -<span class="function"><a href="/usr/share/gtk-doc/html/cairo/cairo-cairo-t.html#cairo-paint">cairo_paint</a></span><span class="normal"> </span><span class="symbol">(</span><span class="normal">cr</span><span class="symbol">);</span> -<span class="function"><a href="/usr/share/gtk-doc/html/cairo/cairo-cairo-t.html#cairo-destroy">cairo_destroy</a></span><span class="normal"> </span><span class="symbol">(</span><span class="normal">cr</span><span class="symbol">);</span></pre></td> - </tr> - </tbody> - </table> -</div> - -<p> - Note that very similar code can be used when porting code - using GdkPixmap to <a href="/usr/share/gtk-doc/html/cairo/cairo-cairo-surface-t.html#cairo-surface-t"><span class="type">cairo_surface_t</span></a> by calling - <a href="/usr/share/gtk-doc/html/cairo/cairo-cairo-t.html#cairo-set-source-surface"><code class="function">cairo_set_source_surface()</code></a> instead of - <a href="http://developer.gnome.org/gdk/gdk3-Cairo-Interaction.html#gdk-cairo-set-source-pixbuf"><code class="function">gdk_cairo_set_source_pixbuf()</code></a>. - </p> -</div> -</div> -<br class="example-break"><div class="example"> -<a name="id1427648"></a><p class="title"><b>Example 113. Drawing a tiled GdkPixmap to a GdkWindow</b></p> -<div class="example-contents"> -<p> - Tiled pixmaps are often used for drawing backgrounds. - Old code looked something like this: - </p> -<div class="informalexample"> - <table class="listing_frame" border="0" cellpadding="0" cellspacing="0"> - <tbody> - <tr> - <td class="listing_lines" align="right"><pre>1 -2 -3 -4 -5 -6 -7 -8 -9 -10 -11 -12 -13 -14</pre></td> - <td class="listing_code"><pre class="programlisting"><span class="usertype">GdkGCValues</span><span class="normal"> gc_values</span><span class="symbol">;</span> -<span class="usertype">GdkGC</span><span class="normal"> </span><span class="symbol">*</span><span class="normal">gc</span><span class="symbol">;</span> - -<span class="comment">/* setup */</span> -<span class="normal">gc </span><span class="symbol">=</span><span class="normal"> </span><span class="function"><a href="GtkWidget.html#gtk-widget-get-style">gtk_widget_get_style</a></span><span class="normal"> </span><span class="symbol">(</span><span class="normal">widget</span><span class="symbol">)-></span><span class="normal">black_gc</span><span class="symbol">;</span> -<span class="function"><a href="http://library.gnome.org/devel/gdk3/gdk-Graphics-Contexts.html#gdk-gc-set-tile">gdk_gc_set_tile</a></span><span class="normal"> </span><span class="symbol">(</span><span class="normal">gc</span><span class="symbol">,</span><span class="normal"> pixmap</span><span class="symbol">);</span> -<span class="function"><a href="http://library.gnome.org/devel/gdk3/gdk-Graphics-Contexts.html#gdk-gc-set-fill">gdk_gc_set_fill</a></span><span class="normal"> </span><span class="symbol">(</span><span class="normal">gc</span><span class="symbol">,</span><span class="normal"> <a href="http://library.gnome.org/devel/gdk3/gdk-Graphics-Contexts.html#GDK-TILED:CAPS">GDK_TILED</a></span><span class="symbol">);</span> -<span class="function"><a href="http://library.gnome.org/devel/gdk3/gdk-Graphics-Contexts.html#gdk-gc-set-ts-origin">gdk_gc_set_ts_origin</a></span><span class="normal"> </span><span class="symbol">(</span><span class="normal">gc</span><span class="symbol">,</span><span class="normal"> x_origin</span><span class="symbol">,</span><span class="normal"> y_origin</span><span class="symbol">);</span> -<span class="comment">/* use */</span> -<span class="function"><a href="http://library.gnome.org/devel/gdk3/gdk-Drawing-Primitives.html#gdk-draw-rectangle">gdk_draw_rectangle</a></span><span class="normal"> </span><span class="symbol">(</span><span class="normal">window</span><span class="symbol">,</span><span class="normal"> gc</span><span class="symbol">,</span><span class="normal"> <a href="http://library.gnome.org/devel/glib/unstable/glib-Standard-Macros.html#TRUE:CAPS">TRUE</a></span><span class="symbol">,</span><span class="normal"> </span><span class="number">0</span><span class="symbol">,</span><span class="normal"> </span><span class="number">0</span><span class="symbol">,</span><span class="normal"> width</span><span class="symbol">,</span><span class="normal"> height</span><span class="symbol">);</span> -<span class="comment">/* restore */</span> -<span class="function"><a href="http://library.gnome.org/devel/gdk3/gdk-Graphics-Contexts.html#gdk-gc-set-tile">gdk_gc_set_tile</a></span><span class="normal"> </span><span class="symbol">(</span><span class="normal">gc</span><span class="symbol">,</span><span class="normal"> <a href="http://library.gnome.org/devel/glib/unstable/glib-Standard-Macros.html#NULL:CAPS">NULL</a></span><span class="symbol">);</span> -<span class="function"><a href="http://library.gnome.org/devel/gdk3/gdk-Graphics-Contexts.html#gdk-gc-set-fill">gdk_gc_set_fill</a></span><span class="normal"> </span><span class="symbol">(</span><span class="normal">gc</span><span class="symbol">,</span><span class="normal"> <a href="http://library.gnome.org/devel/gdk3/gdk-Graphics-Contexts.html#GDK-SOLID:CAPS">GDK_SOLID</a></span><span class="symbol">);</span> -<span class="function"><a href="http://library.gnome.org/devel/gdk3/gdk-Graphics-Contexts.html#gdk-gc-set-ts-origin">gdk_gc_set_ts_origin</a></span><span class="normal"> </span><span class="symbol">(</span><span class="normal">gc</span><span class="symbol">,</span><span class="normal"> </span><span class="number">0</span><span class="symbol">,</span><span class="normal"> </span><span class="number">0</span><span class="symbol">);</span></pre></td> - </tr> - </tbody> - </table> -</div> - -<p> - The equivalent cairo code to draw a tiled surface looks - like this: - </p> -<div class="informalexample"> - <table class="listing_frame" border="0" cellpadding="0" cellspacing="0"> - <tbody> - <tr> - <td class="listing_lines" align="right"><pre>1 -2 -3 -4 -5 -6 -7 -8 -9 -10</pre></td> - <td class="listing_code"><pre class="programlisting"><span class="usertype">cairo_t</span><span class="normal"> </span><span class="symbol">*</span><span class="normal">cr</span><span class="symbol">;</span> -<span class="usertype">cairo_surface_t</span><span class="normal"> </span><span class="symbol">*</span><span class="normal">surface</span><span class="symbol">;</span> - -<span class="normal">surface </span><span class="symbol">=</span><span class="normal"> </span><span class="symbol">...</span> -<span class="normal">cr </span><span class="symbol">=</span><span class="normal"> </span><span class="function"><a href="http://developer.gnome.org/gdk/gdk3-Cairo-Interaction.html#gdk-cairo-create">gdk_cairo_create</a></span><span class="normal"> </span><span class="symbol">(</span><span class="normal">window</span><span class="symbol">);</span> -<span class="function"><a href="/usr/share/gtk-doc/html/cairo/cairo-cairo-t.html#cairo-set-source-surface">cairo_set_source_surface</a></span><span class="normal"> </span><span class="symbol">(</span><span class="normal">cr</span><span class="symbol">,</span><span class="normal"> surface</span><span class="symbol">,</span><span class="normal"> x_origin</span><span class="symbol">,</span><span class="normal"> y_origin</span><span class="symbol">);</span> -<span class="function"><a href="/usr/share/gtk-doc/html/cairo/cairo-cairo-pattern-t.html#cairo-pattern-set-extend">cairo_pattern_set_extend</a></span><span class="normal"> </span><span class="symbol">(</span><span class="function"><a href="/usr/share/gtk-doc/html/cairo/cairo-cairo-t.html#cairo-get-source">cairo_get_source</a></span><span class="normal"> </span><span class="symbol">(</span><span class="normal">cr</span><span class="symbol">),</span><span class="normal"> <a href="/usr/share/gtk-doc/html/cairo/cairo-cairo-pattern-t.html#CAIRO-EXTEND-REPEAT:CAPS">CAIRO_EXTEND_REPEAT</a></span><span class="symbol">);</span> -<span class="function"><a href="/usr/share/gtk-doc/html/cairo/cairo-Paths.html#cairo-rectangle">cairo_rectangle</a></span><span class="normal"> </span><span class="symbol">(</span><span class="normal">cr</span><span class="symbol">,</span><span class="normal"> </span><span class="number">0</span><span class="symbol">,</span><span class="normal"> </span><span class="number">0</span><span class="symbol">,</span><span class="normal"> width</span><span class="symbol">,</span><span class="normal"> height</span><span class="symbol">);</span> -<span class="function"><a href="/usr/share/gtk-doc/html/cairo/cairo-cairo-t.html#cairo-fill">cairo_fill</a></span><span class="normal"> </span><span class="symbol">(</span><span class="normal">cr</span><span class="symbol">);</span> -<span class="function"><a href="/usr/share/gtk-doc/html/cairo/cairo-cairo-t.html#cairo-destroy">cairo_destroy</a></span><span class="normal"> </span><span class="symbol">(</span><span class="normal">cr</span><span class="symbol">);</span></pre></td> - </tr> - </tbody> - </table> -</div> - -<p> -The surface here can be either an image surface or a X surface, -and can either be created on the spot or kept around for caching purposes. -Another alternative is to use pixbufs instead of surfaces with -<a href="http://developer.gnome.org/gdk/gdk3-Cairo-Interaction.html#gdk-cairo-set-source-pixbuf"><code class="function">gdk_cairo_set_source_pixbuf()</code></a> instead of <a href="/usr/share/gtk-doc/html/cairo/cairo-cairo-t.html#cairo-set-source-surface"><code class="function">cairo_set_source_surface()</code></a>. - </p> -</div> -</div> -<br class="example-break"><div class="example"> -<a name="id1372930"></a><p class="title"><b>Example 114. Drawing a PangoLayout to a clipped area</b></p> -<div class="example-contents"> -<p> - Drawing layouts clipped is often used to avoid overdraw or to - allow drawing selections. Code would have looked like this: - </p> -<div class="informalexample"> - <table class="listing_frame" border="0" cellpadding="0" cellspacing="0"> - <tbody> - <tr> - <td class="listing_lines" align="right"><pre>1 -2 -3 -4 -5 -6 -7 -8 -9</pre></td> - <td class="listing_code"><pre class="programlisting"><span class="usertype">GdkGC</span><span class="normal"> </span><span class="symbol">*</span><span class="normal">gc</span><span class="symbol">;</span> - -<span class="comment">/* setup */</span> -<span class="normal">gc </span><span class="symbol">=</span><span class="normal"> </span><span class="function"><a href="GtkWidget.html#gtk-widget-get-style">gtk_widget_get_style</a></span><span class="normal"> </span><span class="symbol">(</span><span class="normal">widget</span><span class="symbol">)-></span><span class="normal">text_gc</span><span class="symbol">[</span><span class="normal">state</span><span class="symbol">];</span> -<span class="function"><a href="http://library.gnome.org/devel/gdk3/gdk-Graphics-Contexts.html#gdk-gc-set-clip-rectangle">gdk_gc_set_clip_rectangle</a></span><span class="normal"> </span><span class="symbol">(</span><span class="normal">gc</span><span class="symbol">,</span><span class="normal"> </span><span class="symbol">&</span><span class="normal">area</span><span class="symbol">);</span> -<span class="comment">/* use */</span> -<span class="function"><a href="http://library.gnome.org/devel/gdk3/gdk-Drawing-Primitives.html#gdk-draw-layout">gdk_draw_layout</a></span><span class="normal"> </span><span class="symbol">(</span><span class="normal">drawable</span><span class="symbol">,</span><span class="normal"> gc</span><span class="symbol">,</span><span class="normal"> x</span><span class="symbol">,</span><span class="normal"> y</span><span class="symbol">,</span><span class="normal"> layout</span><span class="symbol">);</span> -<span class="comment">/* restore */</span> -<span class="function"><a href="http://library.gnome.org/devel/gdk3/gdk-Graphics-Contexts.html#gdk-gc-set-clip-rectangle">gdk_gc_set_clip_rectangle</a></span><span class="normal"> </span><span class="symbol">(</span><span class="normal">gc</span><span class="symbol">,</span><span class="normal"> <a href="http://library.gnome.org/devel/glib/unstable/glib-Standard-Macros.html#NULL:CAPS">NULL</a></span><span class="symbol">);</span></pre></td> - </tr> - </tbody> - </table> -</div> - -<p> - With cairo, the same effect can be achieved using: - </p> -<div class="informalexample"> - <table class="listing_frame" border="0" cellpadding="0" cellspacing="0"> - <tbody> - <tr> - <td class="listing_lines" align="right"><pre>1 -2 -3 -4 -5 -6 -7 -8 -9 -10 -11 -12 -13 -14 -15 -16 -17 -18</pre></td> - <td class="listing_code"><pre class="programlisting"><span class="usertype">GtkStyleContext</span><span class="normal"> </span><span class="symbol">*</span><span class="normal">context</span><span class="symbol">;</span> -<span class="usertype">GtkStateFlags</span><span class="normal"> flags</span><span class="symbol">;</span> -<span class="usertype">GdkRGBA</span><span class="normal"> rgba</span><span class="symbol">;</span> -<span class="usertype">cairo_t</span><span class="normal"> </span><span class="symbol">*</span><span class="normal">cr</span><span class="symbol">;</span> - -<span class="normal">cr </span><span class="symbol">=</span><span class="normal"> </span><span class="function"><a href="http://developer.gnome.org/gdk/gdk3-Cairo-Interaction.html#gdk-cairo-create">gdk_cairo_create</a></span><span class="normal"> </span><span class="symbol">(</span><span class="normal">drawable</span><span class="symbol">);</span> -<span class="comment">/* clip */</span> -<span class="function"><a href="http://developer.gnome.org/gdk/gdk3-Cairo-Interaction.html#gdk-cairo-rectangle">gdk_cairo_rectangle</a></span><span class="normal"> </span><span class="symbol">(</span><span class="normal">cr</span><span class="symbol">,</span><span class="normal"> </span><span class="symbol">&</span><span class="normal">area</span><span class="symbol">);</span> -<span class="function"><a href="/usr/share/gtk-doc/html/cairo/cairo-cairo-t.html#cairo-clip">cairo_clip</a></span><span class="normal"> </span><span class="symbol">(</span><span class="normal">cr</span><span class="symbol">);</span> -<span class="comment">/* set the correct source color */</span> -<span class="normal">context </span><span class="symbol">=</span><span class="normal"> </span><span class="function"><a href="GtkWidget.html#gtk-widget-get-style-context">gtk_widget_get_style_context</a></span><span class="normal"> </span><span class="symbol">(</span><span class="normal">widget</span><span class="symbol">));</span> -<span class="normal">state </span><span class="symbol">=</span><span class="normal"> </span><span class="function"><a href="GtkWidget.html#gtk-widget-get-state-flags">gtk_widget_get_state_flags</a></span><span class="normal"> </span><span class="symbol">(</span><span class="normal">widget</span><span class="symbol">);</span> -<span class="function"><a href="GtkStyleContext.html#gtk-style-context-get-color">gtk_style_context_get_color</a></span><span class="normal"> </span><span class="symbol">(</span><span class="normal">context</span><span class="symbol">,</span><span class="normal"> state</span><span class="symbol">,</span><span class="normal"> </span><span class="symbol">&</span><span class="normal">rgba</span><span class="symbol">);</span> -<span class="function"><a href="http://developer.gnome.org/gdk/gdk3-Cairo-Interaction.html#gdk-cairo-set-source-rgba">gdk_cairo_set_source_rgba</a></span><span class="normal"> </span><span class="symbol">(</span><span class="normal">cr</span><span class="symbol">,</span><span class="normal"> </span><span class="symbol">&</span><span class="normal">rgba</span><span class="symbol">);</span> -<span class="comment">/* draw the text */</span> -<span class="function"><a href="/usr/share/gtk-doc/html/cairo/cairo-Paths.html#cairo-move-to">cairo_move_to</a></span><span class="normal"> </span><span class="symbol">(</span><span class="normal">cr</span><span class="symbol">,</span><span class="normal"> x</span><span class="symbol">,</span><span class="normal"> y</span><span class="symbol">);</span> -<span class="function"><a href="/home/mclasen/gnome/share/gtk-doc/html/pango/pango-Cairo-Rendering.html#pango-cairo-show-layout">pango_cairo_show_layout</a></span><span class="normal"> </span><span class="symbol">(</span><span class="normal">cr</span><span class="symbol">,</span><span class="normal"> layout</span><span class="symbol">);</span> -<span class="function"><a href="/usr/share/gtk-doc/html/cairo/cairo-cairo-t.html#cairo-destroy">cairo_destroy</a></span><span class="normal"> </span><span class="symbol">(</span><span class="normal">cr</span><span class="symbol">);</span></pre></td> - </tr> - </tbody> - </table> -</div> - -<p> - Clipping using <a href="/usr/share/gtk-doc/html/cairo/cairo-cairo-t.html#cairo-clip"><code class="function">cairo_clip()</code></a> is of course not restricted to text - rendering and can be used everywhere where GC clips were used. - And using <a href="http://developer.gnome.org/gdk/gdk3-Cairo-Interaction.html#gdk-cairo-set-source-color"><code class="function">gdk_cairo_set_source_color()</code></a> with style colors should - be used in all the places where a style’s GC was used to achieve - a particular color. - </p> -</div> -</div> -<br class="example-break"><div class="section"> -<div class="titlepage"><div><div><h4 class="title"> -<a name="id1365343"></a>What should you be aware of ?</h4></div></div></div> -<p><b>No more stippling. </b> - Stippling is the usage of a bi-level mask, called a <a href="http://library.gnome.org/devel/gdk3/gdk-Bitmaps-and-Pixmaps.html#GdkBitmap"><span class="type">GdkBitmap</span></a>. - It was often used to achieve a checkerboard effect. You can use - <a href="/usr/share/gtk-doc/html/cairo/cairo-cairo-t.html#cairo-mask"><code class="function">cairo_mask()</code></a> to achieve this effect. To get a checkerbox mask, - you can use code like this: - </p> -<div class="informalexample"> - <table class="listing_frame" border="0" cellpadding="0" cellspacing="0"> - <tbody> - <tr> - <td class="listing_lines" align="right"><pre>1 -2 -3 -4 -5 -6 -7 -8 -9 -10 -11 -12 -13 -14 -15 -16 -17 -18 -19 -20</pre></td> - <td class="listing_code"><pre class="programlisting"><span class="keyword">static</span><span class="normal"> <a href="/usr/share/gtk-doc/html/cairo/cairo-cairo-pattern-t.html#cairo-pattern-t">cairo_pattern_t</a> </span><span class="symbol">*</span> -<span class="function">gtk_color_button_get_checkered</span><span class="normal"> </span><span class="symbol">(</span><span class="type">void</span><span class="symbol">)</span> -<span class="cbracket">{</span> -<span class="normal"> </span><span class="comment">/* need to respect pixman's stride being a multiple of 4 */</span> -<span class="normal"> </span><span class="keyword">static</span><span class="normal"> </span><span class="type">unsigned</span><span class="normal"> </span><span class="type">char</span><span class="normal"> data</span><span class="symbol">[</span><span class="number">8</span><span class="symbol">]</span><span class="normal"> </span><span class="symbol">=</span><span class="normal"> </span><span class="cbracket">{</span><span class="normal"> </span><span class="number">0xFF</span><span class="symbol">,</span><span class="normal"> </span><span class="number">0x00</span><span class="symbol">,</span><span class="normal"> </span><span class="number">0x00</span><span class="symbol">,</span><span class="normal"> </span><span class="number">0x00</span><span class="symbol">,</span> -<span class="normal"> </span><span class="number">0x00</span><span class="symbol">,</span><span class="normal"> </span><span class="number">0xFF</span><span class="symbol">,</span><span class="normal"> </span><span class="number">0x00</span><span class="symbol">,</span><span class="normal"> </span><span class="number">0x00</span><span class="normal"> </span><span class="cbracket">}</span><span class="symbol">;</span> -<span class="normal"> </span><span class="usertype">cairo_surface_t</span><span class="normal"> </span><span class="symbol">*</span><span class="normal">surface</span><span class="symbol">;</span> -<span class="normal"> </span><span class="usertype">cairo_pattern_t</span><span class="normal"> </span><span class="symbol">*</span><span class="normal">pattern</span><span class="symbol">;</span> - -<span class="normal"> surface </span><span class="symbol">=</span><span class="normal"> </span><span class="function"><a href="/usr/share/gtk-doc/html/cairo/cairo-Image-Surfaces.html#cairo-image-surface-create-for-data">cairo_image_surface_create_for_data</a></span><span class="normal"> </span><span class="symbol">(</span><span class="normal">data</span><span class="symbol">,</span> -<span class="normal"> <a href="/usr/share/gtk-doc/html/cairo/cairo-Image-Surfaces.html#CAIRO-FORMAT-A8:CAPS">CAIRO_FORMAT_A8</a></span><span class="symbol">,</span> -<span class="normal"> </span><span class="number">2</span><span class="symbol">,</span><span class="normal"> </span><span class="number">2</span><span class="symbol">,</span> -<span class="normal"> </span><span class="number">4</span><span class="symbol">);</span> -<span class="normal"> pattern </span><span class="symbol">=</span><span class="normal"> </span><span class="function"><a href="/usr/share/gtk-doc/html/cairo/cairo-cairo-pattern-t.html#cairo-pattern-create-for-surface">cairo_pattern_create_for_surface</a></span><span class="normal"> </span><span class="symbol">(</span><span class="normal">surface</span><span class="symbol">);</span> -<span class="normal"> </span><span class="function"><a href="/usr/share/gtk-doc/html/cairo/cairo-cairo-surface-t.html#cairo-surface-destroy">cairo_surface_destroy</a></span><span class="normal"> </span><span class="symbol">(</span><span class="normal">surface</span><span class="symbol">);</span> -<span class="normal"> </span><span class="function"><a href="/usr/share/gtk-doc/html/cairo/cairo-cairo-pattern-t.html#cairo-pattern-set-extend">cairo_pattern_set_extend</a></span><span class="normal"> </span><span class="symbol">(</span><span class="normal">pattern</span><span class="symbol">,</span><span class="normal"> <a href="/usr/share/gtk-doc/html/cairo/cairo-cairo-pattern-t.html#CAIRO-EXTEND-REPEAT:CAPS">CAIRO_EXTEND_REPEAT</a></span><span class="symbol">);</span> -<span class="normal"> </span><span class="function"><a href="/usr/share/gtk-doc/html/cairo/cairo-cairo-pattern-t.html#cairo-pattern-set-filter">cairo_pattern_set_filter</a></span><span class="normal"> </span><span class="symbol">(</span><span class="normal">pattern</span><span class="symbol">,</span><span class="normal"> <a href="/usr/share/gtk-doc/html/cairo/cairo-cairo-pattern-t.html#CAIRO-FILTER-NEAREST:CAPS">CAIRO_FILTER_NEAREST</a></span><span class="symbol">);</span> - -<span class="normal"> </span><span class="keyword">return</span><span class="normal"> pattern</span><span class="symbol">;</span> -<span class="cbracket">}</span></pre></td> - </tr> - </tbody> - </table> -</div> - -<p> - Note that stippling looks very outdated in UIs, and is rarely - used in modern applications. All properties that made use of - stippling have been removed from GTK+ 3. Most prominently, - stippling is absent from text rendering, in particular <a class="link" href="GtkTextTag.html" title="GtkTextTag"><span class="type">GtkTextTag</span></a>. - </p> -<p><b>Using the target also as source or mask. </b> - The <a href="http://library.gnome.org/devel/gdk3/gdk-Drawing-Primitives.html#gdk-draw-drawable"><code class="function">gdk_draw_drawable()</code></a> function allowed using the same drawable - as source and target. This was often used to achieve a scrolling - effect. Cairo does not allow this yet. You can however use - <a href="/usr/share/gtk-doc/html/cairo/cairo-cairo-t.html#cairo-push-group"><code class="function">cairo_push_group()</code></a> to get a different intermediate target that - you can copy to. So you can replace this code: - </p> -<div class="informalexample"> - <table class="listing_frame" border="0" cellpadding="0" cellspacing="0"> - <tbody> - <tr> - <td class="listing_lines" align="right"><pre>1 -2 -3 -4 -5 -6</pre></td> - <td class="listing_code"><pre class="programlisting"><span class="function"><a href="http://library.gnome.org/devel/gdk3/gdk-Drawing-Primitives.html#gdk-draw-drawable">gdk_draw_drawable</a></span><span class="normal"> </span><span class="symbol">(</span><span class="normal">pixmap</span><span class="symbol">,</span> -<span class="normal"> gc</span><span class="symbol">,</span> -<span class="normal"> pixmap</span><span class="symbol">,</span> -<span class="normal"> area</span><span class="symbol">.</span><span class="normal">x </span><span class="symbol">+</span><span class="normal"> dx</span><span class="symbol">,</span><span class="normal"> area</span><span class="symbol">.</span><span class="normal">y </span><span class="symbol">+</span><span class="normal"> dy</span><span class="symbol">,</span> -<span class="normal"> area</span><span class="symbol">.</span><span class="normal">x</span><span class="symbol">,</span><span class="normal"> area</span><span class="symbol">.</span><span class="normal">y</span><span class="symbol">,</span> -<span class="normal"> area</span><span class="symbol">.</span><span class="normal">width</span><span class="symbol">,</span><span class="normal"> area</span><span class="symbol">.</span><span class="normal">height</span><span class="symbol">);</span></pre></td> - </tr> - </tbody> - </table> -</div> - -<p> - By using this code: - </p> -<div class="informalexample"> - <table class="listing_frame" border="0" cellpadding="0" cellspacing="0"> - <tbody> - <tr> - <td class="listing_lines" align="right"><pre>1 -2 -3 -4 -5 -6 -7 -8 -9 -10 -11 -12 -13</pre></td> - <td class="listing_code"><pre class="programlisting"><span class="usertype">cairo_t</span><span class="normal"> </span><span class="symbol">*</span><span class="normal">cr </span><span class="symbol">=</span><span class="normal"> </span><span class="function"><a href="/usr/share/gtk-doc/html/cairo/cairo-cairo-t.html#cairo-create">cairo_create</a></span><span class="normal"> </span><span class="symbol">(</span><span class="normal">surface</span><span class="symbol">);</span> -<span class="comment">/* clipping restricts the intermediate surface's size, so it's a good idea</span> -<span class="comment"> * to use it. */</span> -<span class="function"><a href="http://developer.gnome.org/gdk/gdk3-Cairo-Interaction.html#gdk-cairo-rectangle">gdk_cairo_rectangle</a></span><span class="normal"> </span><span class="symbol">(</span><span class="normal">cr</span><span class="symbol">,</span><span class="normal"> </span><span class="symbol">&</span><span class="normal">area</span><span class="symbol">);</span> -<span class="function"><a href="/usr/share/gtk-doc/html/cairo/cairo-cairo-t.html#cairo-clip">cairo_clip</a></span><span class="normal"> </span><span class="symbol">(</span><span class="normal">cr</span><span class="symbol">);</span> -<span class="comment">/* Now push a group to change the target */</span> -<span class="function"><a href="/usr/share/gtk-doc/html/cairo/cairo-cairo-t.html#cairo-push-group">cairo_push_group</a></span><span class="normal"> </span><span class="symbol">(</span><span class="normal">cr</span><span class="symbol">);</span> -<span class="function"><a href="/usr/share/gtk-doc/html/cairo/cairo-cairo-t.html#cairo-set-source-surface">cairo_set_source_surface</a></span><span class="normal"> </span><span class="symbol">(</span><span class="normal">cr</span><span class="symbol">,</span><span class="normal"> surface</span><span class="symbol">,</span><span class="normal"> dx</span><span class="symbol">,</span><span class="normal"> dy</span><span class="symbol">);</span> -<span class="function"><a href="/usr/share/gtk-doc/html/cairo/cairo-cairo-t.html#cairo-paint">cairo_paint</a></span><span class="normal"> </span><span class="symbol">(</span><span class="normal">cr</span><span class="symbol">);</span> -<span class="comment">/* Now copy the intermediate target back */</span> -<span class="function"><a href="/usr/share/gtk-doc/html/cairo/cairo-cairo-t.html#cairo-pop-group-to-source">cairo_pop_group_to_source</a></span><span class="normal"> </span><span class="symbol">(</span><span class="normal">cr</span><span class="symbol">);</span> -<span class="function"><a href="/usr/share/gtk-doc/html/cairo/cairo-cairo-t.html#cairo-paint">cairo_paint</a></span><span class="normal"> </span><span class="symbol">(</span><span class="normal">cr</span><span class="symbol">);</span> -<span class="function"><a href="/usr/share/gtk-doc/html/cairo/cairo-cairo-t.html#cairo-destroy">cairo_destroy</a></span><span class="normal"> </span><span class="symbol">(</span><span class="normal">cr</span><span class="symbol">);</span></pre></td> - </tr> - </tbody> - </table> -</div> - -<p> -The surface here can be either an image surface or a X surface, -and can either be created on the spot or kept around for caching purposes. -Another alternative is to use pixbufs instead of surfaces with -<a href="http://developer.gnome.org/gdk/gdk3-Cairo-Interaction.html#gdk-cairo-set-source-pixbuf"><code class="function">gdk_cairo_set_source_pixbuf()</code></a> instead of <a href="/usr/share/gtk-doc/html/cairo/cairo-cairo-t.html#cairo-set-source-surface"><code class="function">cairo_set_source_surface()</code></a>. - - The cairo developers plan to add self-copies in the future to allow - exactly this effect, so you might want to keep up on cairo - development to be able to change your code. - </p> -<p><b>Using pango_cairo_show_layout() instead of gdk_draw_layout_with_colors(). </b> - GDK provided a way to ignore the color attributes of text and use - a hardcoded text color with the <a href="http://library.gnome.org/devel/gdk3/gdk-Drawing-Primitives.html#gdk-draw-layout-with-colors"><code class="function">gdk_draw_layout_with_colors()</code></a> - function. This is often used to draw text shadows or selections. - Pango’s cairo support does not yet provide this functionality. If - you use Pango layouts that change colors, the easiest way to achieve - a similar effect is using <a href="/home/mclasen/gnome/share/gtk-doc/html/pango/pango-Cairo-Rendering.html#pango-cairo-layout-path"><code class="function">pango_cairo_layout_path()</code></a> and <a href="/usr/share/gtk-doc/html/cairo/cairo-cairo-t.html#cairo-fill"><code class="function">cairo_fill()</code></a> - instead of <a href="http://library.gnome.org/devel/gdk3/gdk-Drawing-Primitives.html#gdk-draw-layout-with-colors"><code class="function">gdk_draw_layout_with_colors()</code></a>. Note that this results in - a slightly uglier-looking text, as subpixel anti-aliasing is not - supported. - </p> -</div> -</div> -</div> -</div> -<div class="footer"> -<hr> - Generated by GTK-Doc V1.18.1</div> -</body> -</html>
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