<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title>GtkOffscreenWindow: GTK+ 3 Reference Manual</title> <meta name="generator" content="DocBook XSL Stylesheets Vsnapshot"> <link rel="home" href="index.html" title="GTK+ 3 Reference Manual"> <link rel="up" href="WindowWidgets.html" title="Windows"> <link rel="prev" href="GtkInvisible.html" title="GtkInvisible"> <link rel="next" href="GtkWindowGroup.html" title="GtkWindowGroup"> <meta name="generator" content="GTK-Doc V1.29 (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="5"><tr valign="middle"> <td width="100%" align="left" class="shortcuts"> <a href="#" class="shortcut">Top</a><span id="nav_description"> <span class="dim">|</span> <a href="#GtkOffscreenWindow.description" class="shortcut">Description</a></span><span id="nav_hierarchy"> <span class="dim">|</span> <a href="#GtkOffscreenWindow.object-hierarchy" class="shortcut">Object Hierarchy</a></span><span id="nav_interfaces"> <span class="dim">|</span> <a href="#GtkOffscreenWindow.implemented-interfaces" class="shortcut">Implemented Interfaces</a></span> </td> <td><a accesskey="h" href="index.html"><img src="home.png" width="16" height="16" border="0" alt="Home"></a></td> <td><a accesskey="u" href="WindowWidgets.html"><img src="up.png" width="16" height="16" border="0" alt="Up"></a></td> <td><a accesskey="p" href="GtkInvisible.html"><img src="left.png" width="16" height="16" border="0" alt="Prev"></a></td> <td><a accesskey="n" href="GtkWindowGroup.html"><img src="right.png" width="16" height="16" border="0" alt="Next"></a></td> </tr></table> <div class="refentry"> <a name="GtkOffscreenWindow"></a><div class="titlepage"></div> <div class="refnamediv"><table width="100%"><tr> <td valign="top"> <h2><span class="refentrytitle"><a name="GtkOffscreenWindow.top_of_page"></a>GtkOffscreenWindow</span></h2> <p>GtkOffscreenWindow — A toplevel to manage offscreen rendering of child widgets</p> </td> <td class="gallery_image" valign="top" align="right"></td> </tr></table></div> <div class="refsect1"> <a name="GtkOffscreenWindow.functions"></a><h2>Functions</h2> <div class="informaltable"><table class="informaltable" width="100%" border="0"> <colgroup> <col width="150px" class="functions_return"> <col class="functions_name"> </colgroup> <tbody> <tr> <td class="function_type"> <a class="link" href="GtkWidget.html" title="GtkWidget"><span class="returnvalue">GtkWidget</span></a> * </td> <td class="function_name"> <a class="link" href="GtkOffscreenWindow.html#gtk-offscreen-window-new" title="gtk_offscreen_window_new ()">gtk_offscreen_window_new</a> <span class="c_punctuation">()</span> </td> </tr> <tr> <td class="function_type"> <a href="/usr/share/gtk-doc/html/cairo/cairo-cairo-surface-t.html#cairo-surface-t"><span class="returnvalue">cairo_surface_t</span></a> * </td> <td class="function_name"> <a class="link" href="GtkOffscreenWindow.html#gtk-offscreen-window-get-surface" title="gtk_offscreen_window_get_surface ()">gtk_offscreen_window_get_surface</a> <span class="c_punctuation">()</span> </td> </tr> <tr> <td class="function_type"> <a href="http://library.gnome.org/devel/gdk-pixbuf/unstable/gdk-pixbuf-The-GdkPixbuf-Structure.html#GdkPixbuf-struct"><span class="returnvalue">GdkPixbuf</span></a> * </td> <td class="function_name"> <a class="link" href="GtkOffscreenWindow.html#gtk-offscreen-window-get-pixbuf" title="gtk_offscreen_window_get_pixbuf ()">gtk_offscreen_window_get_pixbuf</a> <span class="c_punctuation">()</span> </td> </tr> </tbody> </table></div> </div> <div class="refsect1"> <a name="GtkOffscreenWindow.other"></a><h2>Types and Values</h2> <div class="informaltable"><table class="informaltable" width="100%" border="0"> <colgroup> <col width="150px" class="name"> <col class="description"> </colgroup> <tbody> <tr> <td class="datatype_keyword">struct</td> <td class="function_name"><a class="link" href="GtkOffscreenWindow.html#GtkOffscreenWindow-struct" title="struct GtkOffscreenWindow">GtkOffscreenWindow</a></td> </tr> <tr> <td class="datatype_keyword">struct</td> <td class="function_name"><a class="link" href="GtkOffscreenWindow.html#GtkOffscreenWindowClass" title="struct GtkOffscreenWindowClass">GtkOffscreenWindowClass</a></td> </tr> </tbody> </table></div> </div> <div class="refsect1"> <a name="GtkOffscreenWindow.object-hierarchy"></a><h2>Object Hierarchy</h2> <pre class="screen"> GObject <span class="lineart">╰──</span> GInitiallyUnowned <span class="lineart">╰──</span> <a class="link" href="GtkWidget.html" title="GtkWidget">GtkWidget</a> <span class="lineart">╰──</span> <a class="link" href="GtkContainer.html" title="GtkContainer">GtkContainer</a> <span class="lineart">╰──</span> <a class="link" href="GtkBin.html" title="GtkBin">GtkBin</a> <span class="lineart">╰──</span> <a class="link" href="GtkWindow.html" title="GtkWindow">GtkWindow</a> <span class="lineart">╰──</span> GtkOffscreenWindow </pre> </div> <div class="refsect1"> <a name="GtkOffscreenWindow.implemented-interfaces"></a><h2>Implemented Interfaces</h2> <p> GtkOffscreenWindow implements AtkImplementorIface and <a class="link" href="GtkBuildable.html" title="GtkBuildable">GtkBuildable</a>.</p> </div> <div class="refsect1"> <a name="GtkOffscreenWindow.includes"></a><h2>Includes</h2> <pre class="synopsis">#include <gtk/gtk.h> </pre> </div> <div class="refsect1"> <a name="GtkOffscreenWindow.description"></a><h2>Description</h2> <p>GtkOffscreenWindow is strictly intended to be used for obtaining snapshots of widgets that are not part of a normal widget hierarchy. Since <a class="link" href="GtkOffscreenWindow.html" title="GtkOffscreenWindow"><span class="type">GtkOffscreenWindow</span></a> is a toplevel widget you cannot obtain snapshots of a full window with it since you cannot pack a toplevel widget in another toplevel.</p> <p>The idea is to take a widget and manually set the state of it, add it to a GtkOffscreenWindow and then retrieve the snapshot as a <a href="/usr/share/gtk-doc/html/cairo/cairo-cairo-surface-t.html#cairo-surface-t"><span class="type">cairo_surface_t</span></a> or <a href="http://library.gnome.org/devel/gdk-pixbuf/unstable/gdk-pixbuf-The-GdkPixbuf-Structure.html#GdkPixbuf-struct"><span class="type">GdkPixbuf</span></a>.</p> <p>GtkOffscreenWindow derives from <a class="link" href="GtkWindow.html" title="GtkWindow"><span class="type">GtkWindow</span></a> only as an implementation detail. Applications should not use any API specific to <a class="link" href="GtkWindow.html" title="GtkWindow"><span class="type">GtkWindow</span></a> to operate on this object. It should be treated as a <a class="link" href="GtkBin.html" title="GtkBin"><span class="type">GtkBin</span></a> that has no parent widget.</p> <p>When contained offscreen widgets are redrawn, GtkOffscreenWindow will emit a <a class="link" href="GtkWidget.html#GtkWidget-damage-event" title="The “damage-event” signal"><span class="type">“damage-event”</span></a> signal.</p> </div> <div class="refsect1"> <a name="GtkOffscreenWindow.functions_details"></a><h2>Functions</h2> <div class="refsect2"> <a name="gtk-offscreen-window-new"></a><h3>gtk_offscreen_window_new ()</h3> <pre class="programlisting"><a class="link" href="GtkWidget.html" title="GtkWidget"><span class="returnvalue">GtkWidget</span></a> * gtk_offscreen_window_new (<em class="parameter"><code><span class="type">void</span></code></em>);</pre> <p>Creates a toplevel container widget that is used to retrieve snapshots of widgets without showing them on the screen.</p> <div class="refsect3"> <a name="gtk-offscreen-window-new.returns"></a><h4>Returns</h4> <p> A pointer to a <a class="link" href="GtkWidget.html" title="GtkWidget"><span class="type">GtkWidget</span></a></p> </div> <p class="since">Since: 2.20</p> </div> <hr> <div class="refsect2"> <a name="gtk-offscreen-window-get-surface"></a><h3>gtk_offscreen_window_get_surface ()</h3> <pre class="programlisting"><a href="/usr/share/gtk-doc/html/cairo/cairo-cairo-surface-t.html#cairo-surface-t"><span class="returnvalue">cairo_surface_t</span></a> * gtk_offscreen_window_get_surface (<em class="parameter"><code><a class="link" href="GtkOffscreenWindow.html" title="GtkOffscreenWindow"><span class="type">GtkOffscreenWindow</span></a> *offscreen</code></em>);</pre> <p>Retrieves a snapshot of the contained widget in the form of a <a href="/usr/share/gtk-doc/html/cairo/cairo-cairo-surface-t.html#cairo-surface-t"><span class="type">cairo_surface_t</span></a>. If you need to keep this around over window resizes then you should add a reference to it.</p> <div class="refsect3"> <a name="gtk-offscreen-window-get-surface.parameters"></a><h4>Parameters</h4> <div class="informaltable"><table class="informaltable" width="100%" border="0"> <colgroup> <col width="150px" class="parameters_name"> <col class="parameters_description"> <col width="200px" class="parameters_annotations"> </colgroup> <tbody><tr> <td class="parameter_name"><p>offscreen</p></td> <td class="parameter_description"><p>the <a class="link" href="GtkOffscreenWindow.html" title="GtkOffscreenWindow"><span class="type">GtkOffscreenWindow</span></a> contained widget.</p></td> <td class="parameter_annotations"> </td> </tr></tbody> </table></div> </div> <div class="refsect3"> <a name="gtk-offscreen-window-get-surface.returns"></a><h4>Returns</h4> <p>A <a href="/usr/share/gtk-doc/html/cairo/cairo-cairo-surface-t.html#cairo-surface-t"><span class="type">cairo_surface_t</span></a> pointer to the offscreen surface, or <code class="literal">NULL</code>. </p> <p><span class="annotation">[<acronym title="NULL may be passed as the value in, out, in-out; or as a return value."><span class="acronym">nullable</span></acronym>][<acronym title="Don't free data after the code is done."><span class="acronym">transfer none</span></acronym>]</span></p> </div> <p class="since">Since: 2.20</p> </div> <hr> <div class="refsect2"> <a name="gtk-offscreen-window-get-pixbuf"></a><h3>gtk_offscreen_window_get_pixbuf ()</h3> <pre class="programlisting"><a href="http://library.gnome.org/devel/gdk-pixbuf/unstable/gdk-pixbuf-The-GdkPixbuf-Structure.html#GdkPixbuf-struct"><span class="returnvalue">GdkPixbuf</span></a> * gtk_offscreen_window_get_pixbuf (<em class="parameter"><code><a class="link" href="GtkOffscreenWindow.html" title="GtkOffscreenWindow"><span class="type">GtkOffscreenWindow</span></a> *offscreen</code></em>);</pre> <p>Retrieves a snapshot of the contained widget in the form of a <a href="http://library.gnome.org/devel/gdk-pixbuf/unstable/gdk-pixbuf-The-GdkPixbuf-Structure.html#GdkPixbuf-struct"><span class="type">GdkPixbuf</span></a>. This is a new pixbuf with a reference count of 1, and the application should unreference it once it is no longer needed.</p> <div class="refsect3"> <a name="gtk-offscreen-window-get-pixbuf.parameters"></a><h4>Parameters</h4> <div class="informaltable"><table class="informaltable" width="100%" border="0"> <colgroup> <col width="150px" class="parameters_name"> <col class="parameters_description"> <col width="200px" class="parameters_annotations"> </colgroup> <tbody><tr> <td class="parameter_name"><p>offscreen</p></td> <td class="parameter_description"><p>the <a class="link" href="GtkOffscreenWindow.html" title="GtkOffscreenWindow"><span class="type">GtkOffscreenWindow</span></a> contained widget.</p></td> <td class="parameter_annotations"> </td> </tr></tbody> </table></div> </div> <div class="refsect3"> <a name="gtk-offscreen-window-get-pixbuf.returns"></a><h4>Returns</h4> <p>A <a href="http://library.gnome.org/devel/gdk-pixbuf/unstable/gdk-pixbuf-The-GdkPixbuf-Structure.html#GdkPixbuf-struct"><span class="type">GdkPixbuf</span></a> pointer, or <code class="literal">NULL</code>. </p> <p><span class="annotation">[<acronym title="NULL may be passed as the value in, out, in-out; or as a return value."><span class="acronym">nullable</span></acronym>][<acronym title="Free data after the code is done."><span class="acronym">transfer full</span></acronym>]</span></p> </div> <p class="since">Since: 2.20</p> </div> </div> <div class="refsect1"> <a name="GtkOffscreenWindow.other_details"></a><h2>Types and Values</h2> <div class="refsect2"> <a name="GtkOffscreenWindow-struct"></a><h3>struct GtkOffscreenWindow</h3> <pre class="programlisting">struct GtkOffscreenWindow;</pre> </div> <hr> <div class="refsect2"> <a name="GtkOffscreenWindowClass"></a><h3>struct GtkOffscreenWindowClass</h3> <pre class="programlisting">struct GtkOffscreenWindowClass { GtkWindowClass parent_class; }; </pre> <div class="refsect3"> <a name="GtkOffscreenWindowClass.members"></a><h4>Members</h4> <div class="informaltable"><table class="informaltable" width="100%" border="0"> <colgroup> <col width="300px" class="struct_members_name"> <col class="struct_members_description"> <col width="200px" class="struct_members_annotations"> </colgroup> <tbody></tbody> </table></div> </div> </div> </div> </div> <div class="footer"> <hr>Generated by GTK-Doc V1.29</div> </body> </html>