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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-charinput.html | |
| download | qt3-bd0f3345a938b35ce6a12f6150373b0955b8dd12.tar.gz qt3-bd0f3345a938b35ce6a12f6150373b0955b8dd12.zip | |
Add Qt3 development HEAD version
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| -rw-r--r-- | doc/html/emb-charinput.html | 111 |
1 files changed, 111 insertions, 0 deletions
diff --git a/doc/html/emb-charinput.html b/doc/html/emb-charinput.html new file mode 100644 index 0000000..4498ab2 --- /dev/null +++ b/doc/html/emb-charinput.html @@ -0,0 +1,111 @@ +<!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/charinput-qws.doc:36 --> +<html> +<head> +<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"> +<title>Character input in Qt/Embedded</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>Character input in Qt/Embedded</h1> + + + +<p> Internally in the client/server protocol, each key press and key +release is sent as a <tt>QWSKeyEvent</tt>. A QWSKeyEvent contains the +following fields: +<p> <center><table cellpadding="4" cellspacing="2" border="0"> +<tr bgcolor="#f0f0f0"> <td valign="top"><tt>unicode</tt> +<td valign="top">Unicode value +<tr bgcolor="#d0d0d0"> <td valign="top"><tt>keycode</tt> +<td valign="top">Qt keycode value as defined in <a href="qnamespace-h.html">qnamespace.h</a> +<tr bgcolor="#f0f0f0"> <td valign="top"><tt>modifier</tt> +<td valign="top">A bitfield consisting of some of <a href="qt.html#ButtonState-enum">Qt::ShiftButton</a>, +<a href="qt.html#ButtonState-enum">Qt::ControlButton</a>, and <a href="qt.html#ButtonState-enum">Qt::AltButton</a>. +<tr bgcolor="#d0d0d0"> <td valign="top"><tt>is_press</tt> +<td valign="top">TRUE if this is a key press, FALSE if it is a key release. +<tr bgcolor="#f0f0f0"> <td valign="top"><tt>is_auto_repeat</tt> +<td valign="top">TRUE if this event is caused by auto repeat. +</table></center> +<p> When the server receives a key event it is sent to each client process +which is responsible for processing the key event and sending it to +the right window, if any. Key events may come from several different +sources. +<p> <h2> Keyboard drivers +</h2> +<a name="1"></a><p> A keyboard driver reads data from a device and gives key events to the +server. +<p> Keyboard drivers can be compiled into the library or loaded as +plugins. Running ./configure -help lists the available keyboard drivers. +The "tty" driver is enabled in the default configuration. +<p> The keyboard drivers all follow the same pattern. They read keyboard +data from a device, find out which keys were pressed, and then call +the static function QWSServer::processKeyEvent() with the key information. +<p> At present, the console keyboard driver also handles console switching +(<b>Ctrl+Alt-F1</b>...<b>Ctrl+Alt+F10</b>) and termination +(<b>Ctrl+Alt+Backspace</b>). +<p> To add a keyboard driver for a new device, subclasses of +<a href="qwskeyboardhandler.html">QWSKeyboardHandler</a> and <a href="qkbddriverplugin.html">QKbdDriverPlugin</a> can be +written and installed as plugins. +<p> <h2> Key event filters (input methods) +</h2> +<a name="2"></a><p> When the server receives a key event from a keyboard driver, it first +passes it through a filter. +<p> This can be used to implement input methods, providing input of +characters that are not on the keyboard. +<p> To make an input method, subclass QWSServer::KeyboardFilter (in <tt>src/kernel/qwindowsystem_qws.h</tt>) and implement the virtual function <tt>filter()</tt>. If <tt>filter()</tt> returns <tt>FALSE</tt>, the event will be sent to +the clients (using <a href="qwsserver.html#sendKeyEvent">QWSServer::sendKeyEvent</a>()). If <tt>filter()</tt> returns +<tt>TRUE</tt>, the event will be stopped. To generate new key events, use +QWSServer::sendKeyEvent(). (Do not use processKeyEvent(), since this +will lead to infinite recursion.) +<p> To install a keyboard event filter, use +<a href="qwsserver.html#setKeyboardFilter">QWSServer::setKeyboardFilter</a>(). Currently, only one filter +can be installed at a time. +<p> Filtering must be done in the server process. +<p> The launcher example contains an example of a simple input method, +<tt>SimpleIM</tt> which reads a substitution table from a file. +<p> <h2> Pen input +</h2> +<a name="3"></a><p> Key events do not need to come from a keyboard device. The server +process may call QWSServer::sendKeyEvent() at any time. +<p> Typically, this is done by popping up a widget, and letting the user +specify characters with the pointer device. +<p> <b>Note</b>: the key input widget should not take focus, since the +server would then just send the key events back to the input widget. +One way to make sure that the input widget never takes focus is to set +the <tt>WStyle_Customize</tt> and <tt>WStyle_Tool</tt> widget flags in +the <a href="qwidget.html">QWidget</a> constructor. +<p> The <a href="http://www.trolltech.com/products/qtopia/">Qtopia</a> +environment contains various input widgets such as +Handwriting Recognition and Virtual Keyboard. +<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> |