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| author | Timothy Pearson <kb9vqf@pearsoncomputing.net> | 2011-07-10 15:24:15 -0500 |
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| committer | Timothy Pearson <kb9vqf@pearsoncomputing.net> | 2011-07-10 15:24:15 -0500 |
| commit | bd0f3345a938b35ce6a12f6150373b0955b8dd12 (patch) | |
| tree | 7a520322212d48ebcb9fbe1087e7fca28b76185c /doc/html/emb-qvfb.html | |
| download | qt3-bd0f3345a938b35ce6a12f6150373b0955b8dd12.tar.gz qt3-bd0f3345a938b35ce6a12f6150373b0955b8dd12.zip | |
Add Qt3 development HEAD version
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| -rw-r--r-- | doc/html/emb-qvfb.html | 110 |
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diff --git a/doc/html/emb-qvfb.html b/doc/html/emb-qvfb.html new file mode 100644 index 0000000..df971cc --- /dev/null +++ b/doc/html/emb-qvfb.html @@ -0,0 +1,110 @@ +<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> +<!-- /home/espenr/tmp/qt-3.3.8-espenr-2499/qt-x11-free-3.3.8/doc/qvfb.doc:36 --> +<html> +<head> +<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"> +<title>Qt/Embedded Virtual Framebuffer</title> +<style type="text/css"><!-- +fn { margin-left: 1cm; text-indent: -1cm; } +a:link { color: #004faf; text-decoration: none } +a:visited { color: #672967; text-decoration: none } +body { background: #ffffff; color: black; } +--></style> +</head> +<body> + +<table border="0" cellpadding="0" cellspacing="0" width="100%"> +<tr bgcolor="#E5E5E5"> +<td valign=center> + <a href="index.html"> +<font color="#004faf">Home</font></a> + | <a href="classes.html"> +<font color="#004faf">All Classes</font></a> + | <a href="mainclasses.html"> +<font color="#004faf">Main Classes</font></a> + | <a href="annotated.html"> +<font color="#004faf">Annotated</font></a> + | <a href="groups.html"> +<font color="#004faf">Grouped Classes</font></a> + | <a href="functions.html"> +<font color="#004faf">Functions</font></a> +</td> +<td align="right" valign="center"><img src="logo32.png" align="right" width="64" height="32" border="0"></td></tr></table><h1 align=center>Qt/Embedded Virtual Framebuffer</h1> + + +<p> The virtual framebuffer allows Qt/Embedded programs to be developed on +a desktop machine, without switching between consoles and X11. +<p> The virtual framebuffer is located in <tt>$QTDIR/tools/qvfb</tt>. +<p> <h2> Using the Virtual Framebuffer +</h2> +<a name="1"></a><p> <ol type=1> +<li> Configure Qt/Embedded with the <tt>-qvfb</tt> argument and compile the library: +<pre> + ./configure -qvfb + make + </pre> + +<li> Compile <tt>qvfb</tt> as a normal Qt/X11 application and run it. Do <em>not</em> +compile it as a Qt/Embedded application. +<li> Start a Qt/Embedded master application (i.e., construct +<a href="qapplication.html">QApplication</a> with the QApplication::GuiServer flag or use the <tt>-qws</tt> command line parameter). You can specify to the server that +you wish to use the virtual framebuffer driver, e.g.: +<pre> + masterapp -qws -display QVFb:0 + </pre> + +<li> Qt/Embedded will autodetect qvfb, so you can omit the <tt>-display</tt> +command line parameter if you know that qvfb is running, and that +the Qt/Embedded library supports qvfb. (If this is not the case, +Qt/Embedded will write to the real framebuffer, and your X11 +display will be corrupted.) +<p> </ol> +<p> <tt>qvfb</tt> supports the following command line options: +<p> <center><table cellpadding="4" cellspacing="2" border="0"> +<tr bgcolor="#a2c511"> <th valign="top">Option <th valign="top">Meaning +<tr bgcolor="#f0f0f0"> +<td valign="top"><tt>-width</tt> <em>width</em> +<td valign="top">the width of the virtual framebuffer (default: 240). +<tr bgcolor="#d0d0d0"> +<td valign="top"><tt>-height</tt> <em>height</em> +<td valign="top">the height of the virtual framebuffer (default: 320). +<tr bgcolor="#f0f0f0"> +<td valign="top"><tt>-depth</tt> <em>depth</em> +<td valign="top">the depth of the virtual framebuffer (1, 8 or 32; default: 8). +<tr bgcolor="#d0d0d0"> +<td valign="top"><tt>-nocursor</tt> +<td valign="top">do not display the X11 cursor in the framebuffer window. +<tr bgcolor="#f0f0f0"> +<td valign="top"><tt>-qwsdisplay</tt> <em>:id</em> +<td valign="top">the Qt/Embedded display id to provide (default: :0). +</table></center> +<p> <h2> Virtual Framebuffer Design +</h2> +<a name="2"></a><p> The virtual framebuffer emulates a framebuffer using a shared memory region +(the virtual frame buffer) and a utility to display the framebuffer in a +window (<tt>qvfb</tt>). The regions of the display that have changed are updated +periodically, so you will see discrete snapshots of the framebuffer rather +than each individual drawing operation. For this reason drawing problems +such as flickering may not be apparent until the program is run using a real +framebuffer. +<p> The target refresh rate can be set via the <b>View|Refresh Rate</b> +menu item. This will cause <tt>qvfb</tt> to check for updated regions more +frequently. The rate is a target only. If little drawing is being +done, the framebuffer will not show any updates between drawing +events. If an application is displaying an animation the updates will +be frequent, then the application and <tt>qvfb</tt> will compete for +processor time. +<p> Mouse and keyboard events are passed to the Qt/Embedded master process via +named pipes. +<p> The virtual framebuffer is a development tool only. No security issues have +been considered in the virtual framebuffer design. It should be avoided +in a production environment; do not configure production libraries with <tt>-qvfb</tt>. +<p> +<!-- eof --> +<p><address><hr><div align=center> +<table width=100% cellspacing=0 border=0><tr> +<td>Copyright © 2007 +<a href="troll.html">Trolltech</a><td align=center><a href="trademarks.html">Trademarks</a> +<td align=right><div align=right>Qt 3.3.8</div> +</table></div></address></body> +</html> |