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author | Timothy Pearson <[email protected]> | 2011-07-10 15:24:15 -0500 |
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committer | Timothy Pearson <[email protected]> | 2011-07-10 15:24:15 -0500 |
commit | bd0f3345a938b35ce6a12f6150373b0955b8dd12 (patch) | |
tree | 7a520322212d48ebcb9fbe1087e7fca28b76185c /doc/html/objecttrees.html | |
download | qt3-bd0f3345a938b35ce6a12f6150373b0955b8dd12.tar.gz qt3-bd0f3345a938b35ce6a12f6150373b0955b8dd12.zip |
Add Qt3 development HEAD version
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diff --git a/doc/html/objecttrees.html b/doc/html/objecttrees.html new file mode 100644 index 0000000..40b340a --- /dev/null +++ b/doc/html/objecttrees.html @@ -0,0 +1,68 @@ +<!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/object.doc:572 --> +<html> +<head> +<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"> +<title>Object Trees and Object Ownership</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>Object Trees and Object Ownership</h1> + + + +<p> <a href="qobject.html">QObjects</a> organize themselves in object trees. +When you create a <a href="qobject.html">QObject</a> with another object as parent, it's added to +the parent's <a href="qobject.html#children">children()</a> list, and +is deleted when the parent is. It turns out that this approach fits +the needs of GUI objects very well. For example, a <a href="qaccel.html">QAccel</a> (keyboard +accelerator) is a child of the relevant window, so when the user closes +that window, the accelerator is deleted too. +<p> The static function <a href="qobject.html#objectTrees">QObject::objectTrees</a>() provides access to all +the root objects that currently exist. +<p> <a href="qwidget.html">QWidget</a>, the base class of everything that appears on the screen, +extends the parent-child relationship. A child normally also becomes a +child widget, i.e. it is displayed in its parent's coordinate system +and is graphically clipped by its parent's boundaries. For example, +when the an application deletes a message box after it has been +closed, the message box's buttons and label are also deleted, just as +we'd want, because the buttons and label are children of the message +box. +<p> You can also delete child objects yourself, and they will remove +themselves from their parents. For example, when the user removes a +toolbar it may lead to the application deleting one of its <a href="qtoolbar.html">QToolBar</a> +objects, in which case the tool bar's <a href="qmainwindow.html">QMainWindow</a> parent would +detect the change and reconfigure its screen space accordingly. +<p> The debugging functions <a href="qobject.html#dumpObjectTree">QObject::dumpObjectTree</a>() and <a href="qobject.html#dumpObjectInfo">QObject::dumpObjectInfo</a>() are often useful when an application looks or +acts strangely. +<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> |