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<h1>GFC::Gdk::Visual Class Reference</h1>A GdkVisual C++ wrapper class.
<a href="#_details">More...</a>
<p>
<code>#include <<a class="el" href="visual_8hh-source.html">gfc/gdk/visual.hh</a>></code>
<p>
<p>Inheritance diagram for GFC::Gdk::Visual:
<p><center><img src="classGFC_1_1Gdk_1_1Visual.png" usemap="#GFC::Gdk::Visual_map" border="0" alt=""></center>
<map name="GFC::Gdk::Visual_map">
<area doxygen="gfccore.tag:" href="classGFC_1_1G_1_1Object.html" alt="GFC::G::Object" shape="rect" coords="0,112,134,136">
<area doxygen="gfccore.tag:" href="classGFC_1_1G_1_1TypeInstance.html" alt="GFC::G::TypeInstance" shape="rect" coords="0,56,134,80">
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</map>
<a href="classGFC_1_1Gdk_1_1Visual-members.html">List of all members.</a><h2>Public Member Functions</h2>
<tr><td colspan="2"><div class="groupHeader">Constructors</div></td></tr>
<ul>
<li><a class="anchor" name="z223_0" doxytag="GFC::Gdk::Visual::~Visual" ></a>
virtual <a class="el" href="classGFC_1_1Gdk_1_1Visual.html#z223_0">~Visual</a> ()
<dl class="el"><dd class="mdescRight">Destructor. <br></dl></ul>
<tr><td colspan="2"><div class="groupHeader">Accessors</div></td></tr>
<ul>
<li><a class="anchor" name="z224_0" doxytag="GFC::Gdk::Visual::gdk_visual" ></a>
GdkVisual * <a class="el" href="classGFC_1_1Gdk_1_1Visual.html#z224_0">gdk_visual</a> () const
<dl class="el"><dd class="mdescRight">Get a pointer to the GdkVisual structure. <br></dl><li><a class="anchor" name="z224_1" doxytag="GFC::Gdk::Visual::operator GdkVisual *" ></a>
<a class="el" href="classGFC_1_1Gdk_1_1Visual.html#z224_1">operator GdkVisual *</a> () const
<dl class="el"><dd class="mdescRight">Conversion operator; safely converts a <a class="el" href="classGFC_1_1Gdk_1_1Visual.html">Visual</a> to a GdkVisual pointer. <br></dl><li><a class="anchor" name="z224_2" doxytag="GFC::Gdk::Visual::type" ></a>
<a class="el" href="namespaceGFC_1_1Gdk.html#a290">VisualType</a> <a class="el" href="classGFC_1_1Gdk_1_1Visual.html#z224_2">type</a> () const
<dl class="el"><dd class="mdescRight">Returns the type of this visual. <br></dl><li><a class="anchor" name="z224_3" doxytag="GFC::Gdk::Visual::depth" ></a>
int <a class="el" href="classGFC_1_1Gdk_1_1Visual.html#z224_3">depth</a> () const
<dl class="el"><dd class="mdescRight">Returns the number of bits per pixel. <br></dl><li><a class="anchor" name="z224_4" doxytag="GFC::Gdk::Visual::byte_order" ></a>
<a class="el" href="namespaceGFC_1_1Gdk.html#a279">ByteOrder</a> <a class="el" href="classGFC_1_1Gdk_1_1Visual.html#z224_4">byte_order</a> () const
<dl class="el"><dd class="mdescRight">Returns the byte-order for this visual. <br></dl><li>int <a class="el" href="classGFC_1_1Gdk_1_1Visual.html#z224_5">colormap_size</a> () const
<dl class="el"><dd class="mdescRight">Returns the number of entries in the colormap, for visuals of type VISUAL_PSEUDO_COLOR or VISUAL_GRAY_SCALE, for other visual types, it is the number of possible levels per color component. <a href="#z224_5"></a><br></dl><li><a class="anchor" name="z224_6" doxytag="GFC::Gdk::Visual::bits_per_rgb" ></a>
int <a class="el" href="classGFC_1_1Gdk_1_1Visual.html#z224_6">bits_per_rgb</a> () const
<dl class="el"><dd class="mdescRight">Returns the number of significant bits per red, green, or blue when specifying colors for this visual (for instance, for <a class="el" href="classGFC_1_1Gdk_1_1Colormap.html#z108_0">Gdk::Colormap::alloc_color()</a>). <br></dl><li>unsigned int <a class="el" href="classGFC_1_1Gdk_1_1Visual.html#z224_7">red_mask</a> () const
<dl class="el"><dd class="mdescRight">Returns a mask giving the bits in a pixel value that correspond to the red field. <a href="#z224_7"></a><br></dl><li>int <a class="el" href="classGFC_1_1Gdk_1_1Visual.html#z224_8">red_shift</a> () const
<dl class="el"><dd class="mdescRight">Returns the red_shift. <a href="#z224_8"></a><br></dl><li><a class="anchor" name="z224_9" doxytag="GFC::Gdk::Visual::red_prec" ></a>
int <a class="el" href="classGFC_1_1Gdk_1_1Visual.html#z224_9">red_prec</a> () const
<dl class="el"><dd class="mdescRight">Returns the red_prec (see <a class="el" href="classGFC_1_1Gdk_1_1Visual.html#z224_8">red_shift()</a>). <br></dl><li><a class="anchor" name="z224_10" doxytag="GFC::Gdk::Visual::green_mask" ></a>
unsigned int <a class="el" href="classGFC_1_1Gdk_1_1Visual.html#z224_10">green_mask</a> () const
<dl class="el"><dd class="mdescRight">Returns a mask giving the bits in a pixel value that correspond to the green field. <br></dl><li>int <a class="el" href="classGFC_1_1Gdk_1_1Visual.html#z224_11">green_shift</a> () const
<dl class="el"><dd class="mdescRight">Returns the green_shift. <a href="#z224_11"></a><br></dl><li><a class="anchor" name="z224_12" doxytag="GFC::Gdk::Visual::green_prec" ></a>
int <a class="el" href="classGFC_1_1Gdk_1_1Visual.html#z224_12">green_prec</a> () const
<dl class="el"><dd class="mdescRight">Returns the green_prec (see <a class="el" href="classGFC_1_1Gdk_1_1Visual.html#z224_11">green_shift()</a>). <br></dl><li><a class="anchor" name="z224_13" doxytag="GFC::Gdk::Visual::blue_mask" ></a>
unsigned int <a class="el" href="classGFC_1_1Gdk_1_1Visual.html#z224_13">blue_mask</a> () const
<dl class="el"><dd class="mdescRight">Returns a mask giving the bits in a pixel value that correspond to the blue field. <br></dl><li>int <a class="el" href="classGFC_1_1Gdk_1_1Visual.html#z224_14">blue_shift</a> () const
<dl class="el"><dd class="mdescRight">Returns the blue_shift. <a href="#z224_14"></a><br></dl><li><a class="anchor" name="z224_15" doxytag="GFC::Gdk::Visual::blue_prec" ></a>
int <a class="el" href="classGFC_1_1Gdk_1_1Visual.html#z224_15">blue_prec</a> () const
<dl class="el"><dd class="mdescRight">Returns the blue_prec (see <a class="el" href="classGFC_1_1Gdk_1_1Visual.html#z224_14">blue_shift()</a>). <br></dl><li>int <a class="el" href="classGFC_1_1Gdk_1_1Visual.html#z224_16">get_best_depth</a> () const
<dl class="el"><dd class="mdescRight">Get the best available depth for the default <a class="el" href="classGFC_1_1Gdk_1_1Screen.html">Gdk::Screen</a>. <a href="#z224_16"></a><br></dl><li><a class="el" href="namespaceGFC_1_1Gdk.html#a290">VisualType</a> <a class="el" href="classGFC_1_1Gdk_1_1Visual.html#z224_17">get_best_type</a> () const
<dl class="el"><dd class="mdescRight">Return the best available visual type for the default <a class="el" href="classGFC_1_1Gdk_1_1Screen.html">Gdk::Screen</a>. <a href="#z224_17"></a><br></dl></ul>
<h2>Static Public Member Functions</h2>
<ul>
<li><a class="anchor" name="e0" doxytag="GFC::Gdk::Visual::get_best" ></a>
const <a class="el" href="classGFC_1_1Gdk_1_1Visual.html">Visual</a> * <a class="el" href="classGFC_1_1Gdk_1_1Visual.html#e0">get_best</a> ()
<dl class="el"><dd class="mdescRight">Returns the visual with the most available colors for the default <a class="el" href="classGFC_1_1Gdk_1_1Screen.html">Gdk::Screen</a>. <br></dl><li>const <a class="el" href="classGFC_1_1Gdk_1_1Visual.html">Visual</a> * <a class="el" href="classGFC_1_1Gdk_1_1Visual.html#e1">get_best</a> (int depth)
<dl class="el"><dd class="mdescRight">Get the best visual with depth <em>depth</em> for the default <a class="el" href="classGFC_1_1Gdk_1_1Screen.html">Gdk::Screen</a>. <a href="#e1"></a><br></dl><li>const <a class="el" href="classGFC_1_1Gdk_1_1Visual.html">Visual</a> * <a class="el" href="classGFC_1_1Gdk_1_1Visual.html#e2">get_best</a> (<a class="el" href="namespaceGFC_1_1Gdk.html#a290">VisualType</a> visual_type)
<dl class="el"><dd class="mdescRight">Get the best visual of the given visual_type for the default <a class="el" href="classGFC_1_1Gdk_1_1Screen.html">Gdk::Screen</a>. <a href="#e2"></a><br></dl><li>const <a class="el" href="classGFC_1_1Gdk_1_1Visual.html">Visual</a> * <a class="el" href="classGFC_1_1Gdk_1_1Visual.html#e3">get_best</a> (int depth, <a class="el" href="namespaceGFC_1_1Gdk.html#a290">VisualType</a> visual_type)
<dl class="el"><dd class="mdescRight">Get the best visual of the given <em>visual_type</em> with depth <em>depth</em> for the default <a class="el" href="classGFC_1_1Gdk_1_1Screen.html">Gdk::Screen</a>. <a href="#e3"></a><br></dl><li>const <a class="el" href="classGFC_1_1Gdk_1_1Visual.html">Visual</a> * <a class="el" href="classGFC_1_1Gdk_1_1Visual.html#e4">get_system</a> ()
<dl class="el"><dd class="mdescRight">Returns the system's default visual for the default <a class="el" href="classGFC_1_1Gdk_1_1Screen.html">Gdk::Screen</a>. <a href="#e4"></a><br></dl><li>std::vector< int > <a class="el" href="classGFC_1_1Gdk_1_1Visual.html#e5">query_depths</a> ()
<dl class="el"><dd class="mdescRight">This method returns the available bit depths for the default screen. <a href="#e5"></a><br></dl><li>bool <a class="el" href="classGFC_1_1Gdk_1_1Visual.html#e6">query_visual_types</a> (std::vector< <a class="el" href="namespaceGFC_1_1Gdk.html#a290">VisualType</a> > &visual_types)
<dl class="el"><dd class="mdescRight">This method returns the available visual types for the default screen. <a href="#e6"></a><br></dl><li>bool <a class="el" href="classGFC_1_1Gdk_1_1Visual.html#e7">list_visuals</a> (std::vector< const <a class="el" href="classGFC_1_1Gdk_1_1Visual.html">Visual</a> * > &visuals)
<dl class="el"><dd class="mdescRight">Lists the available visuals for the default screen (see <a class="el" href="classGFC_1_1Gdk_1_1Screen.html#z198_12">Gdk::Screen::list_visuals()</a>). <a href="#e7"></a><br></dl></ul>
<h2>Protected Member Functions</h2>
<tr><td colspan="2"><div class="groupHeader">Constructors</div></td></tr>
<ul>
<li><a class="el" href="classGFC_1_1Gdk_1_1Visual.html#z222_0">Visual</a> (GdkVisual *visual, bool <a class="elRef" doxygen="gfccore.tag:" href="classGFC_1_1Trackable.html#z143_1">owns_reference</a>=true)
<dl class="el"><dd class="mdescRight">Construct a new <a class="el" href="classGFC_1_1Gdk_1_1Visual.html">Visual</a> from an existing GdkVisual. <a href="#z222_0"></a><br></dl></ul>
<hr><a name="_details"></a><h2>Detailed Description</h2>
A GdkVisual C++ wrapper class.
<p>
A <a class="el" href="classGFC_1_1Gdk_1_1Visual.html">Visual</a> describes a particular video hardware display format. It includes information about the number of bits used for each color, the way the bits are translated into an RGB value for display, and the way the bits are stored in memory. For example, a piece of display hardware might support 24-bit color, 16-bit color, or 8-bit color; meaning 24/16/8-bit pixel sizes. For a given pixel size, pixels can be in different formats; for example the "red" element of an RGB pixel may be in the top 8 bits of the pixel, or may be in the lower 4 bits.<p>
Usually you can avoid thinking about visuals in GTK+. Visuals are useful to interpret the contents of a <a class="el" href="classGFC_1_1Gdk_1_1Image.html">Gdk::Image</a>, but you should avoid <a class="el" href="classGFC_1_1Gdk_1_1Image.html">Gdk::Image</a> precisely because its contents depend on the display hardware; use <a class="el" href="classGFC_1_1Gdk_1_1Pixbuf.html">Gdk::Pixbuf</a> instead, for all but the most low-level purposes. Also, anytime you provide a <a class="el" href="classGFC_1_1Gdk_1_1Colormap.html">Gdk::Colormap</a>, the visual is implied as part of the colormap (<a class="el" href="classGFC_1_1Gdk_1_1Colormap.html#z107_2">Gdk::Colormap::get_visual()</a>), so you won't have to provide a visual in addition.<p>
There are several standard visuals. The visual returned by <a class="el" href="classGFC_1_1Gdk_1_1Visual.html#e4">get_system()</a> is the system's default visual. A number of methods are provided for determining the "best" available visual. For the purposes of making this determination, higher bit depths are considered better, and for visuals of the same bit depth, VISUAL_PSEUDO_COLOR is preferred at 8bpp, otherwise, the visual types are ranked in the order of (highest to lowest) VISUAL_DIRECT_COLOR, VISUAL_TRUE_COLOR, VISUAL_PSEUDO_COLOR, VISUAL_STATIC_COLOR, VISUAL_GRAYSCALE, then VISUAL_STATIC_GRAY.
<p>
<hr><h2>Constructor & Destructor Documentation</h2>
<a class="anchor" name="z222_0" doxytag="GFC::Gdk::Visual::Visual" ></a><p>
<table class="mdTable" width="100%" cellpadding="2" cellspacing="0">
<tr>
<td class="mdRow">
<table cellpadding="0" cellspacing="0" border="0">
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<td class="md" nowrap valign="top"> GFC::Gdk::Visual::Visual </td>
<td class="md" valign="top">( </td>
<td class="md" nowrap valign="top">GdkVisual * </td>
<td class="mdname" nowrap> <em>visual</em>, </td>
</tr>
<tr>
<td class="md" nowrap align="right"></td>
<td></td>
<td class="md" nowrap>bool </td>
<td class="mdname" nowrap> <em>owns_reference</em> = <code>true</code></td>
</tr>
<tr>
<td></td>
<td class="md">) </td>
<td class="md" colspan="2"><code> [explicit, protected]</code></td>
</tr>
</table>
</td>
</tr>
</table>
<table cellspacing=5 cellpadding=0 border=0>
<tr>
<td>
</td>
<td>
<p>
Construct a new <a class="el" href="classGFC_1_1Gdk_1_1Visual.html">Visual</a> from an existing GdkVisual.
<p>
<dl compact><dt><b>Parameters:</b></dt><dd>
<table border="0" cellspacing="2" cellpadding="0">
<tr><td></td><td valign=top><em>visual</em> </td><td>A pointer to a GdkVisual. </td></tr>
<tr><td></td><td valign=top><em>owns_reference</em> </td><td>Set false if the initial reference count is floating, set true if it's not.</td></tr>
</table>
</dl>
<br>
The <em>visual</em> can be a newly created GdkVisual or an existing GdkVisual. (see <a class="elRef" doxygen="gfccore.tag:" href="classGFC_1_1G_1_1Object.html#z68_0">G::Object::Object</a>). </td>
</tr>
</table>
<hr><h2>Member Function Documentation</h2>
<a class="anchor" name="z224_14" doxytag="GFC::Gdk::Visual::blue_shift" ></a><p>
<table class="mdTable" width="100%" cellpadding="2" cellspacing="0">
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<td class="md" nowrap valign="top"> int GFC::Gdk::Visual::blue_shift </td>
<td class="md" valign="top">( </td>
<td class="mdname1" valign="top" nowrap> </td>
<td class="md" valign="top"> ) </td>
<td class="md" nowrap> const</td>
</tr>
</table>
</td>
</tr>
</table>
<table cellspacing=5 cellpadding=0 border=0>
<tr>
<td>
</td>
<td>
<p>
Returns the blue_shift.
<p>
The blue_shift and blue_prec give an alternate presentation of the information in blue_mask (see example in <a class="el" href="classGFC_1_1Gdk_1_1Visual.html#z224_8">red_shift()</a>). </td>
</tr>
</table>
<a class="anchor" name="z224_5" doxytag="GFC::Gdk::Visual::colormap_size" ></a><p>
<table class="mdTable" width="100%" cellpadding="2" cellspacing="0">
<tr>
<td class="mdRow">
<table cellpadding="0" cellspacing="0" border="0">
<tr>
<td class="md" nowrap valign="top"> int GFC::Gdk::Visual::colormap_size </td>
<td class="md" valign="top">( </td>
<td class="mdname1" valign="top" nowrap> </td>
<td class="md" valign="top"> ) </td>
<td class="md" nowrap> const</td>
</tr>
</table>
</td>
</tr>
</table>
<table cellspacing=5 cellpadding=0 border=0>
<tr>
<td>
</td>
<td>
<p>
Returns the number of entries in the colormap, for visuals of type VISUAL_PSEUDO_COLOR or VISUAL_GRAY_SCALE, for other visual types, it is the number of possible levels per color component.
<p>
If the visual has different numbers of levels for different components, the value of this field is undefined. </td>
</tr>
</table>
<a class="anchor" name="e3" doxytag="GFC::Gdk::Visual::get_best" ></a><p>
<table class="mdTable" width="100%" cellpadding="2" cellspacing="0">
<tr>
<td class="mdRow">
<table cellpadding="0" cellspacing="0" border="0">
<tr>
<td class="md" nowrap valign="top"> const <a class="el" href="classGFC_1_1Gdk_1_1Visual.html">Visual</a>* GFC::Gdk::Visual::get_best </td>
<td class="md" valign="top">( </td>
<td class="md" nowrap valign="top">int </td>
<td class="mdname" nowrap> <em>depth</em>, </td>
</tr>
<tr>
<td class="md" nowrap align="right"></td>
<td></td>
<td class="md" nowrap><a class="el" href="namespaceGFC_1_1Gdk.html#a290">VisualType</a> </td>
<td class="mdname" nowrap> <em>visual_type</em></td>
</tr>
<tr>
<td></td>
<td class="md">) </td>
<td class="md" colspan="2"><code> [static]</code></td>
</tr>
</table>
</td>
</tr>
</table>
<table cellspacing=5 cellpadding=0 border=0>
<tr>
<td>
</td>
<td>
<p>
Get the best visual of the given <em>visual_type</em> with depth <em>depth</em> for the default <a class="el" href="classGFC_1_1Gdk_1_1Screen.html">Gdk::Screen</a>.
<p>
<dl compact><dt><b>Parameters:</b></dt><dd>
<table border="0" cellspacing="2" cellpadding="0">
<tr><td></td><td valign=top><em>depth</em> </td><td>A bit depth. </td></tr>
<tr><td></td><td valign=top><em>visual_type</em> </td><td>A visual type. </td></tr>
</table>
</dl>
<dl compact><dt><b>Returns:</b></dt><dd>The best visual with both <em>depth</em> and <em>visual_type</em>, or null if none. </dd></dl>
</td>
</tr>
</table>
<a class="anchor" name="e2" doxytag="GFC::Gdk::Visual::get_best" ></a><p>
<table class="mdTable" width="100%" cellpadding="2" cellspacing="0">
<tr>
<td class="mdRow">
<table cellpadding="0" cellspacing="0" border="0">
<tr>
<td class="md" nowrap valign="top"> const <a class="el" href="classGFC_1_1Gdk_1_1Visual.html">Visual</a>* GFC::Gdk::Visual::get_best </td>
<td class="md" valign="top">( </td>
<td class="md" nowrap valign="top"><a class="el" href="namespaceGFC_1_1Gdk.html#a290">VisualType</a> </td>
<td class="mdname1" valign="top" nowrap> <em>visual_type</em> </td>
<td class="md" valign="top"> ) </td>
<td class="md" nowrap><code> [static]</code></td>
</tr>
</table>
</td>
</tr>
</table>
<table cellspacing=5 cellpadding=0 border=0>
<tr>
<td>
</td>
<td>
<p>
Get the best visual of the given visual_type for the default <a class="el" href="classGFC_1_1Gdk_1_1Screen.html">Gdk::Screen</a>.
<p>
<dl compact><dt><b>Parameters:</b></dt><dd>
<table border="0" cellspacing="2" cellpadding="0">
<tr><td></td><td valign=top><em>visual_type</em> </td><td>A visual type. </td></tr>
</table>
</dl>
<dl compact><dt><b>Returns:</b></dt><dd>The best visual of the given type; or null if no visual has type <em>visual_type</em>.</dd></dl>
<br>
Visuals with higher color depths are considered better. </td>
</tr>
</table>
<a class="anchor" name="e1" doxytag="GFC::Gdk::Visual::get_best" ></a><p>
<table class="mdTable" width="100%" cellpadding="2" cellspacing="0">
<tr>
<td class="mdRow">
<table cellpadding="0" cellspacing="0" border="0">
<tr>
<td class="md" nowrap valign="top"> const <a class="el" href="classGFC_1_1Gdk_1_1Visual.html">Visual</a>* GFC::Gdk::Visual::get_best </td>
<td class="md" valign="top">( </td>
<td class="md" nowrap valign="top">int </td>
<td class="mdname1" valign="top" nowrap> <em>depth</em> </td>
<td class="md" valign="top"> ) </td>
<td class="md" nowrap><code> [static]</code></td>
</tr>
</table>
</td>
</tr>
</table>
<table cellspacing=5 cellpadding=0 border=0>
<tr>
<td>
</td>
<td>
<p>
Get the best visual with depth <em>depth</em> for the default <a class="el" href="classGFC_1_1Gdk_1_1Screen.html">Gdk::Screen</a>.
<p>
<dl compact><dt><b>Parameters:</b></dt><dd>
<table border="0" cellspacing="2" cellpadding="0">
<tr><td></td><td valign=top><em>depth</em> </td><td>A bit depth. </td></tr>
</table>
</dl>
<dl compact><dt><b>Returns:</b></dt><dd>The best visual for the given depth, or null if no visual supports <em>depth</em>.</dd></dl>
<br>
<a class="el" href="classGFC_1_1Gdk_1_1Color.html">Color</a> visuals and visuals with mutable colormaps are preferred over grayscale or fixed-colormap visuals. Null may be returned if no visual supports depth. </td>
</tr>
</table>
<a class="anchor" name="z224_16" doxytag="GFC::Gdk::Visual::get_best_depth" ></a><p>
<table class="mdTable" width="100%" cellpadding="2" cellspacing="0">
<tr>
<td class="mdRow">
<table cellpadding="0" cellspacing="0" border="0">
<tr>
<td class="md" nowrap valign="top"> int GFC::Gdk::Visual::get_best_depth </td>
<td class="md" valign="top">( </td>
<td class="mdname1" valign="top" nowrap> </td>
<td class="md" valign="top"> ) </td>
<td class="md" nowrap> const</td>
</tr>
</table>
</td>
</tr>
</table>
<table cellspacing=5 cellpadding=0 border=0>
<tr>
<td>
</td>
<td>
<p>
Get the best available depth for the default <a class="el" href="classGFC_1_1Gdk_1_1Screen.html">Gdk::Screen</a>.
<p>
<dl compact><dt><b>Returns:</b></dt><dd>The best available depth.</dd></dl>
<br>
"Best" means "largest," i.e. 32 preferred over 24 preferred over 8 bits per pixel. </td>
</tr>
</table>
<a class="anchor" name="z224_17" doxytag="GFC::Gdk::Visual::get_best_type" ></a><p>
<table class="mdTable" width="100%" cellpadding="2" cellspacing="0">
<tr>
<td class="mdRow">
<table cellpadding="0" cellspacing="0" border="0">
<tr>
<td class="md" nowrap valign="top"> <a class="el" href="namespaceGFC_1_1Gdk.html#a290">VisualType</a> GFC::Gdk::Visual::get_best_type </td>
<td class="md" valign="top">( </td>
<td class="mdname1" valign="top" nowrap> </td>
<td class="md" valign="top"> ) </td>
<td class="md" nowrap> const</td>
</tr>
</table>
</td>
</tr>
</table>
<table cellspacing=5 cellpadding=0 border=0>
<tr>
<td>
</td>
<td>
<p>
Return the best available visual type for the default <a class="el" href="classGFC_1_1Gdk_1_1Screen.html">Gdk::Screen</a>.
<p>
<dl compact><dt><b>Returns:</b></dt><dd>The best visual type. </dd></dl>
</td>
</tr>
</table>
<a class="anchor" name="e4" doxytag="GFC::Gdk::Visual::get_system" ></a><p>
<table class="mdTable" width="100%" cellpadding="2" cellspacing="0">
<tr>
<td class="mdRow">
<table cellpadding="0" cellspacing="0" border="0">
<tr>
<td class="md" nowrap valign="top"> const <a class="el" href="classGFC_1_1Gdk_1_1Visual.html">Visual</a>* GFC::Gdk::Visual::get_system </td>
<td class="md" valign="top">( </td>
<td class="mdname1" valign="top" nowrap> </td>
<td class="md" valign="top"> ) </td>
<td class="md" nowrap><code> [static]</code></td>
</tr>
</table>
</td>
</tr>
</table>
<table cellspacing=5 cellpadding=0 border=0>
<tr>
<td>
</td>
<td>
<p>
Returns the system's default visual for the default <a class="el" href="classGFC_1_1Gdk_1_1Screen.html">Gdk::Screen</a>.
<p>
This is the visual for the root window of the display. </td>
</tr>
</table>
<a class="anchor" name="z224_11" doxytag="GFC::Gdk::Visual::green_shift" ></a><p>
<table class="mdTable" width="100%" cellpadding="2" cellspacing="0">
<tr>
<td class="mdRow">
<table cellpadding="0" cellspacing="0" border="0">
<tr>
<td class="md" nowrap valign="top"> int GFC::Gdk::Visual::green_shift </td>
<td class="md" valign="top">( </td>
<td class="mdname1" valign="top" nowrap> </td>
<td class="md" valign="top"> ) </td>
<td class="md" nowrap> const</td>
</tr>
</table>
</td>
</tr>
</table>
<table cellspacing=5 cellpadding=0 border=0>
<tr>
<td>
</td>
<td>
<p>
Returns the green_shift.
<p>
The green_shift and green_prec give an alternate presentation of the information in green_mask (see example in <a class="el" href="classGFC_1_1Gdk_1_1Visual.html#z224_8">red_shift()</a>). </td>
</tr>
</table>
<a class="anchor" name="e7" doxytag="GFC::Gdk::Visual::list_visuals" ></a><p>
<table class="mdTable" width="100%" cellpadding="2" cellspacing="0">
<tr>
<td class="mdRow">
<table cellpadding="0" cellspacing="0" border="0">
<tr>
<td class="md" nowrap valign="top"> bool GFC::Gdk::Visual::list_visuals </td>
<td class="md" valign="top">( </td>
<td class="md" nowrap valign="top">std::vector< const <a class="el" href="classGFC_1_1Gdk_1_1Visual.html">Visual</a> * > & </td>
<td class="mdname1" valign="top" nowrap> <em>visuals</em> </td>
<td class="md" valign="top"> ) </td>
<td class="md" nowrap><code> [static]</code></td>
</tr>
</table>
</td>
</tr>
</table>
<table cellspacing=5 cellpadding=0 border=0>
<tr>
<td>
</td>
<td>
<p>
Lists the available visuals for the default screen (see <a class="el" href="classGFC_1_1Gdk_1_1Screen.html#z198_12">Gdk::Screen::list_visuals()</a>).
<p>
<dl compact><dt><b>Parameters:</b></dt><dd>
<table border="0" cellspacing="2" cellpadding="0">
<tr><td></td><td valign=top><em>visuals</em> </td><td>A reference to a vector of const Visual* to hold the list of available visuals. </td></tr>
</table>
</dl>
<dl compact><dt><b>Returns:</b></dt><dd><em>true</em> if the vector is not empty.</dd></dl>
<br>
A visual describes a hardware image data format. For example, a visual might support 24-bit color, or 8-bit color, and might expect pixels to be in a certain format. </td>
</tr>
</table>
<a class="anchor" name="e5" doxytag="GFC::Gdk::Visual::query_depths" ></a><p>
<table class="mdTable" width="100%" cellpadding="2" cellspacing="0">
<tr>
<td class="mdRow">
<table cellpadding="0" cellspacing="0" border="0">
<tr>
<td class="md" nowrap valign="top"> std::vector<int> GFC::Gdk::Visual::query_depths </td>
<td class="md" valign="top">( </td>
<td class="mdname1" valign="top" nowrap> </td>
<td class="md" valign="top"> ) </td>
<td class="md" nowrap><code> [static]</code></td>
</tr>
</table>
</td>
</tr>
</table>
<table cellspacing=5 cellpadding=0 border=0>
<tr>
<td>
</td>
<td>
<p>
This method returns the available bit depths for the default screen.
<p>
<dl compact><dt><b>Returns:</b></dt><dd>A vector of int holding the available depths.</dd></dl>
<br>
It's equivalent to listing the visuals (<a class="el" href="classGFC_1_1Gdk_1_1Visual.html#e7">list_visuals()</a>) and then looking at the <a class="el" href="classGFC_1_1Gdk_1_1Visual.html#z224_3">depth()</a> field in each visual, removing duplicates. </td>
</tr>
</table>
<a class="anchor" name="e6" doxytag="GFC::Gdk::Visual::query_visual_types" ></a><p>
<table class="mdTable" width="100%" cellpadding="2" cellspacing="0">
<tr>
<td class="mdRow">
<table cellpadding="0" cellspacing="0" border="0">
<tr>
<td class="md" nowrap valign="top"> bool GFC::Gdk::Visual::query_visual_types </td>
<td class="md" valign="top">( </td>
<td class="md" nowrap valign="top">std::vector< <a class="el" href="namespaceGFC_1_1Gdk.html#a290">VisualType</a> > & </td>
<td class="mdname1" valign="top" nowrap> <em>visual_types</em> </td>
<td class="md" valign="top"> ) </td>
<td class="md" nowrap><code> [static]</code></td>
</tr>
</table>
</td>
</tr>
</table>
<table cellspacing=5 cellpadding=0 border=0>
<tr>
<td>
</td>
<td>
<p>
This method returns the available visual types for the default screen.
<p>
<dl compact><dt><b>Parameters:</b></dt><dd>
<table border="0" cellspacing="2" cellpadding="0">
<tr><td></td><td valign=top><em>visual_types</em> </td><td>A reference to a vector of VisualType to hold the available visual types. </td></tr>
</table>
</dl>
<dl compact><dt><b>Returns:</b></dt><dd><em>true</em> if the vector is not empty.</dd></dl>
<br>
It's equivalent to listing the visuals (<a class="el" href="classGFC_1_1Gdk_1_1Visual.html#e7">list_visuals()</a>) and then looking at the <a class="el" href="classGFC_1_1Gdk_1_1Visual.html#z224_2">type()</a> field in each visual, removing duplicates. </td>
</tr>
</table>
<a class="anchor" name="z224_7" doxytag="GFC::Gdk::Visual::red_mask" ></a><p>
<table class="mdTable" width="100%" cellpadding="2" cellspacing="0">
<tr>
<td class="mdRow">
<table cellpadding="0" cellspacing="0" border="0">
<tr>
<td class="md" nowrap valign="top"> unsigned int GFC::Gdk::Visual::red_mask </td>
<td class="md" valign="top">( </td>
<td class="mdname1" valign="top" nowrap> </td>
<td class="md" valign="top"> ) </td>
<td class="md" nowrap> const</td>
</tr>
</table>
</td>
</tr>
</table>
<table cellspacing=5 cellpadding=0 border=0>
<tr>
<td>
</td>
<td>
<p>
Returns a mask giving the bits in a pixel value that correspond to the red field.
<p>
Significant only for VISUAL_PSEUDOCOLOR and VISUAL_DIRECTCOLOR. </td>
</tr>
</table>
<a class="anchor" name="z224_8" doxytag="GFC::Gdk::Visual::red_shift" ></a><p>
<table class="mdTable" width="100%" cellpadding="2" cellspacing="0">
<tr>
<td class="mdRow">
<table cellpadding="0" cellspacing="0" border="0">
<tr>
<td class="md" nowrap valign="top"> int GFC::Gdk::Visual::red_shift </td>
<td class="md" valign="top">( </td>
<td class="mdname1" valign="top" nowrap> </td>
<td class="md" valign="top"> ) </td>
<td class="md" nowrap> const</td>
</tr>
</table>
</td>
</tr>
</table>
<table cellspacing=5 cellpadding=0 border=0>
<tr>
<td>
</td>
<td>
<p>
Returns the red_shift.
<p>
The <a class="el" href="classGFC_1_1Gdk_1_1Visual.html#z224_8">red_shift()</a> and <a class="el" href="classGFC_1_1Gdk_1_1Visual.html#z224_9">red_prec()</a> give an alternate presentation of the information in <a class="el" href="classGFC_1_1Gdk_1_1Visual.html#z224_7">red_mask()</a>. The <em>red_mask</em> is a contiguous sequence of <em>red_prec</em> bits starting at bit number <em>red_shift</em>.<p>
<b>Example:</b> Constructing a pixel value out of three 16 bit color values. <div class="fragment"><pre> <span class="keywordtype">unsigned</span> <span class="keywordtype">int</span>
pixel_from_rgb(<span class="keyword">const</span> Gdk::Visual& visual, <span class="keywordtype">unsigned</span> <span class="keywordtype">short</span> r, <span class="keywordtype">unsigned</span> <span class="keywordtype">short</span> b, <span class="keywordtype">unsigned</span> <span class="keywordtype">short</span> g)
{
<span class="keywordflow">return</span> ((r >> (16 - visual.red_prec())) << visual->red_shift()) |
((g >> (16 - visual.green_prec())) << visual->green_shift()) |
((r >> (16 - visual.blue_prec())) << visual->blue_shift());
}
</pre></div> </td>
</tr>
</table>
<hr>The documentation for this class was generated from the following file:<ul>
<li><a class="el" href="visual_8hh-source.html">visual.hh</a></ul>
<hr size="1"><address style="align: right;"><small>Generated on Tue Aug 24 00:34:36 2004 for GFC-UI by
<a href="http://www.doxygen.org/index.html">
<img src="doxygen.png" alt="doxygen" align="middle" border=0 ></a> 1.3.8 </small></address>
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