gtk3/docs/reference/gdk/html/GdkDrawingContext.html
2019-04-11 09:41:47 +01:00

272 lines
15 KiB
HTML
Raw Blame History

This file contains invisible Unicode characters

This file contains invisible Unicode characters that are indistinguishable to humans but may be processed differently by a computer. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>GdkDrawingContext: GDK 3 Reference Manual</title>
<meta name="generator" content="DocBook XSL Stylesheets Vsnapshot">
<link rel="home" href="index.html" title="GDK 3 Reference Manual">
<link rel="up" href="reference.html" title="API Reference">
<link rel="prev" href="gdk3-GdkFrameTimings.html" title="Frame timings">
<link rel="next" href="GdkGLContext.html" title="GdkGLContext">
<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="#GdkDrawingContext.description" class="shortcut">Description</a></span><span id="nav_hierarchy">  <span class="dim">|</span> 
<a href="#GdkDrawingContext.object-hierarchy" class="shortcut">Object Hierarchy</a></span><span id="nav_properties">  <span class="dim">|</span> 
<a href="#GdkDrawingContext.properties" class="shortcut">Properties</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="reference.html"><img src="up.png" width="16" height="16" border="0" alt="Up"></a></td>
<td><a accesskey="p" href="gdk3-GdkFrameTimings.html"><img src="left.png" width="16" height="16" border="0" alt="Prev"></a></td>
<td><a accesskey="n" href="GdkGLContext.html"><img src="right.png" width="16" height="16" border="0" alt="Next"></a></td>
</tr></table>
<div class="refentry">
<a name="GdkDrawingContext"></a><div class="titlepage"></div>
<div class="refnamediv"><table width="100%"><tr>
<td valign="top">
<h2><span class="refentrytitle"><a name="GdkDrawingContext.top_of_page"></a>GdkDrawingContext</span></h2>
<p>GdkDrawingContext — Drawing context for GDK windows</p>
</td>
<td class="gallery_image" valign="top" align="right"></td>
</tr></table></div>
<div class="refsect1">
<a name="GdkDrawingContext.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="gdk3-Windows.html#GdkWindow"><span class="returnvalue">GdkWindow</span></a> *
</td>
<td class="function_name">
<a class="link" href="GdkDrawingContext.html#gdk-drawing-context-get-window" title="gdk_drawing_context_get_window ()">gdk_drawing_context_get_window</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<a href="/usr/share/gtk-doc/html/cairo/cairo-Regions.html#cairo-region-t"><span class="returnvalue">cairo_region_t</span></a> *
</td>
<td class="function_name">
<a class="link" href="GdkDrawingContext.html#gdk-drawing-context-get-clip" title="gdk_drawing_context_get_clip ()">gdk_drawing_context_get_clip</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<a href="/usr/share/gtk-doc/html/cairo/cairo-cairo-t.html#cairo-t"><span class="returnvalue">cairo_t</span></a> *
</td>
<td class="function_name">
<a class="link" href="GdkDrawingContext.html#gdk-drawing-context-get-cairo-context" title="gdk_drawing_context_get_cairo_context ()">gdk_drawing_context_get_cairo_context</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">gboolean</span>
</td>
<td class="function_name">
<a class="link" href="GdkDrawingContext.html#gdk-drawing-context-is-valid" title="gdk_drawing_context_is_valid ()">gdk_drawing_context_is_valid</a> <span class="c_punctuation">()</span>
</td>
</tr>
</tbody>
</table></div>
</div>
<div class="refsect1">
<a name="GdkDrawingContext.properties"></a><h2>Properties</h2>
<div class="informaltable"><table class="informaltable" border="0">
<colgroup>
<col width="150px" class="properties_type">
<col width="300px" class="properties_name">
<col width="200px" class="properties_flags">
</colgroup>
<tbody>
<tr>
<td class="property_type">
<span class="type">CairoRegion</span> *</td>
<td class="property_name"><a class="link" href="GdkDrawingContext.html#GdkDrawingContext--clip" title="The “clip” property">clip</a></td>
<td class="property_flags">Read / Write / Construct Only</td>
</tr>
<tr>
<td class="property_type">
<a class="link" href="gdk3-Windows.html#GdkWindow"><span class="type">GdkWindow</span></a> *</td>
<td class="property_name"><a class="link" href="GdkDrawingContext.html#GdkDrawingContext--window" title="The “window” property">window</a></td>
<td class="property_flags">Read / Write / Construct Only</td>
</tr>
</tbody>
</table></div>
</div>
<div class="refsect1">
<a name="GdkDrawingContext.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"> </td>
<td class="function_name"><a class="link" href="GdkDrawingContext.html#GdkDrawingContext-struct" title="GdkDrawingContext">GdkDrawingContext</a></td>
</tr></tbody>
</table></div>
</div>
<div class="refsect1">
<a name="GdkDrawingContext.object-hierarchy"></a><h2>Object Hierarchy</h2>
<pre class="screen"> GObject
<span class="lineart">╰──</span> GdkDrawingContext
</pre>
</div>
<div class="refsect1">
<a name="GdkDrawingContext.includes"></a><h2>Includes</h2>
<pre class="synopsis">#include &lt;gdk/gdkwayland.h&gt;
</pre>
</div>
<div class="refsect1">
<a name="GdkDrawingContext.description"></a><h2>Description</h2>
<p><a class="link" href="GdkDrawingContext.html" title="GdkDrawingContext"><span class="type">GdkDrawingContext</span></a> is an object that represents the current drawing
state of a <a class="link" href="gdk3-Windows.html#GdkWindow"><span class="type">GdkWindow</span></a>.</p>
<p>It's possible to use a <a class="link" href="GdkDrawingContext.html" title="GdkDrawingContext"><span class="type">GdkDrawingContext</span></a> to draw on a <a class="link" href="gdk3-Windows.html#GdkWindow"><span class="type">GdkWindow</span></a>
via rendering API like Cairo or OpenGL.</p>
<p>A <a class="link" href="GdkDrawingContext.html" title="GdkDrawingContext"><span class="type">GdkDrawingContext</span></a> can only be created by calling <a class="link" href="gdk3-Windows.html#gdk-window-begin-draw-frame" title="gdk_window_begin_draw_frame ()"><code class="function">gdk_window_begin_draw_frame()</code></a>
and will be valid until a call to <a class="link" href="gdk3-Windows.html#gdk-window-end-draw-frame" title="gdk_window_end_draw_frame ()"><code class="function">gdk_window_end_draw_frame()</code></a>.</p>
<p><a class="link" href="GdkDrawingContext.html" title="GdkDrawingContext"><span class="type">GdkDrawingContext</span></a> is available since GDK 3.22</p>
</div>
<div class="refsect1">
<a name="GdkDrawingContext.functions_details"></a><h2>Functions</h2>
<div class="refsect2">
<a name="gdk-drawing-context-get-window"></a><h3>gdk_drawing_context_get_window ()</h3>
<pre class="programlisting"><a class="link" href="gdk3-Windows.html#GdkWindow"><span class="returnvalue">GdkWindow</span></a> *
gdk_drawing_context_get_window (<em class="parameter"><code><a class="link" href="GdkDrawingContext.html" title="GdkDrawingContext"><span class="type">GdkDrawingContext</span></a> *context</code></em>);</pre>
<p>Retrieves the window that created the drawing <em class="parameter"><code>context</code></em>
.</p>
<div class="refsect3">
<a name="gdk-drawing-context-get-window.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>context</p></td>
<td class="parameter_description"><p>a <a class="link" href="GdkDrawingContext.html" title="GdkDrawingContext"><span class="type">GdkDrawingContext</span></a></p></td>
<td class="parameter_annotations"> </td>
</tr></tbody>
</table></div>
</div>
<div class="refsect3">
<a name="gdk-drawing-context-get-window.returns"></a><h4>Returns</h4>
<p>a <a class="link" href="gdk3-Windows.html#GdkWindow"><span class="type">GdkWindow</span></a>. </p>
<p><span class="annotation">[<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: <a class="link" href="api-index-3-22.html#api-index-3.22">3.22</a></p>
</div>
<hr>
<div class="refsect2">
<a name="gdk-drawing-context-get-clip"></a><h3>gdk_drawing_context_get_clip ()</h3>
<pre class="programlisting"><a href="/usr/share/gtk-doc/html/cairo/cairo-Regions.html#cairo-region-t"><span class="returnvalue">cairo_region_t</span></a> *
gdk_drawing_context_get_clip (<em class="parameter"><code><a class="link" href="GdkDrawingContext.html" title="GdkDrawingContext"><span class="type">GdkDrawingContext</span></a> *context</code></em>);</pre>
<p>Retrieves a copy of the clip region used when creating the <em class="parameter"><code>context</code></em>
.</p>
<div class="refsect3">
<a name="gdk-drawing-context-get-clip.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>context</p></td>
<td class="parameter_description"><p>a <a class="link" href="GdkDrawingContext.html" title="GdkDrawingContext"><span class="type">GdkDrawingContext</span></a></p></td>
<td class="parameter_annotations"> </td>
</tr></tbody>
</table></div>
</div>
<div class="refsect3">
<a name="gdk-drawing-context-get-clip.returns"></a><h4>Returns</h4>
<p>a Cairo region. </p>
<p><span class="annotation">[<acronym title="Free data after the code is done."><span class="acronym">transfer full</span></acronym>][<acronym title="NULL may be passed as the value in, out, in-out; or as a return value."><span class="acronym">nullable</span></acronym>]</span></p>
</div>
<p class="since">Since: <a class="link" href="api-index-3-22.html#api-index-3.22">3.22</a></p>
</div>
<hr>
<div class="refsect2">
<a name="gdk-drawing-context-get-cairo-context"></a><h3>gdk_drawing_context_get_cairo_context ()</h3>
<pre class="programlisting"><a href="/usr/share/gtk-doc/html/cairo/cairo-cairo-t.html#cairo-t"><span class="returnvalue">cairo_t</span></a> *
gdk_drawing_context_get_cairo_context (<em class="parameter"><code><a class="link" href="GdkDrawingContext.html" title="GdkDrawingContext"><span class="type">GdkDrawingContext</span></a> *context</code></em>);</pre>
<p>Retrieves a Cairo context to be used to draw on the <a class="link" href="gdk3-Windows.html#GdkWindow"><span class="type">GdkWindow</span></a>
that created the <a class="link" href="GdkDrawingContext.html" title="GdkDrawingContext"><span class="type">GdkDrawingContext</span></a>.</p>
<p>The returned context is guaranteed to be valid as long as the
<a class="link" href="GdkDrawingContext.html" title="GdkDrawingContext"><span class="type">GdkDrawingContext</span></a> is valid, that is between a call to
<a class="link" href="gdk3-Windows.html#gdk-window-begin-draw-frame" title="gdk_window_begin_draw_frame ()"><code class="function">gdk_window_begin_draw_frame()</code></a> and <a class="link" href="gdk3-Windows.html#gdk-window-end-draw-frame" title="gdk_window_end_draw_frame ()"><code class="function">gdk_window_end_draw_frame()</code></a>.</p>
<div class="refsect3">
<a name="gdk-drawing-context-get-cairo-context.returns"></a><h4>Returns</h4>
<p>a Cairo context to be used to draw
the contents of the <a class="link" href="gdk3-Windows.html#GdkWindow"><span class="type">GdkWindow</span></a>. The context is owned by the
<a class="link" href="GdkDrawingContext.html" title="GdkDrawingContext"><span class="type">GdkDrawingContext</span></a> and should not be destroyed. </p>
<p><span class="annotation">[<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: <a class="link" href="api-index-3-22.html#api-index-3.22">3.22</a></p>
</div>
<hr>
<div class="refsect2">
<a name="gdk-drawing-context-is-valid"></a><h3>gdk_drawing_context_is_valid ()</h3>
<pre class="programlisting"><span class="returnvalue">gboolean</span>
gdk_drawing_context_is_valid (<em class="parameter"><code><a class="link" href="GdkDrawingContext.html" title="GdkDrawingContext"><span class="type">GdkDrawingContext</span></a> *context</code></em>);</pre>
<p>Checks whether the given <a class="link" href="GdkDrawingContext.html" title="GdkDrawingContext"><span class="type">GdkDrawingContext</span></a> is valid.</p>
<div class="refsect3">
<a name="gdk-drawing-context-is-valid.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>context</p></td>
<td class="parameter_description"><p>a <a class="link" href="GdkDrawingContext.html" title="GdkDrawingContext"><span class="type">GdkDrawingContext</span></a></p></td>
<td class="parameter_annotations"> </td>
</tr></tbody>
</table></div>
</div>
<div class="refsect3">
<a name="gdk-drawing-context-is-valid.returns"></a><h4>Returns</h4>
<p> <code class="literal">TRUE</code> if the context is valid</p>
</div>
<p class="since">Since: <a class="link" href="api-index-3-22.html#api-index-3.22">3.22</a></p>
</div>
</div>
<div class="refsect1">
<a name="GdkDrawingContext.other_details"></a><h2>Types and Values</h2>
<div class="refsect2">
<a name="GdkDrawingContext-struct"></a><h3>GdkDrawingContext</h3>
<pre class="programlisting">typedef struct _GdkDrawingContext GdkDrawingContext;</pre>
</div>
</div>
<div class="refsect1">
<a name="GdkDrawingContext.property-details"></a><h2>Property Details</h2>
<div class="refsect2">
<a name="GdkDrawingContext--clip"></a><h3>The <code class="literal">“clip”</code> property</h3>
<pre class="programlisting"> “clip” <span class="type">CairoRegion</span> *</pre>
<p>The clip region applied to the drawing context.</p>
<p>Flags: Read / Write / Construct Only</p>
<p class="since">Since: <a class="link" href="api-index-3-22.html#api-index-3.22">3.22</a></p>
</div>
<hr>
<div class="refsect2">
<a name="GdkDrawingContext--window"></a><h3>The <code class="literal">“window”</code> property</h3>
<pre class="programlisting"> “window” <a class="link" href="gdk3-Windows.html#GdkWindow"><span class="type">GdkWindow</span></a> *</pre>
<p>The <a class="link" href="gdk3-Windows.html#GdkWindow"><span class="type">GdkWindow</span></a> that created the drawing context.</p>
<p>Flags: Read / Write / Construct Only</p>
<p class="since">Since: <a class="link" href="api-index-3-22.html#api-index-3.22">3.22</a></p>
</div>
</div>
</div>
<div class="footer">
<hr>Generated by GTK-Doc V1.29</div>
</body>
</html>