<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> <!-- /home/espenr/tmp/qt-3.2-espenr-29145/qt-x11-free-3.2.3/examples/layout/layout.doc:4 --> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"> <title>Layout Managers</title> <style type="text/css"><!-- h3.fn,span.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>Layout Managers</h1> <p> This example shows simple and intermediate use of Qt's layout classes, <a href="qgridlayout.html">QGridLayout</a>, <a href="qboxlayout.html">QBoxLayout</a> etc. <p> <hr> <p> Implementation: <p> <pre>/**************************************************************************** ** $Id: qt/layout.cpp 3.2.3 edited May 13 09:08 $ ** ** Copyright (C) 1992-2000 Trolltech AS. All rights reserved. ** ** This file is part of an example program for Qt. This example ** program may be used, distributed and modified without limitation. ** *****************************************************************************/ #include <<a href="qapplication-h.html">qapplication.h</a>> #include <<a href="qlabel-h.html">qlabel.h</a>> #include <<a href="qcolor-h.html">qcolor.h</a>> #include <<a href="qpushbutton-h.html">qpushbutton.h</a>> #include <<a href="qlayout-h.html">qlayout.h</a>> #include <<a href="qlineedit-h.html">qlineedit.h</a>> #include <<a href="qmultilineedit-h.html">qmultilineedit.h</a>> #include <<a href="qmenubar-h.html">qmenubar.h</a>> #include <<a href="qpopupmenu-h.html">qpopupmenu.h</a>> class ExampleWidget : public <a href="qwidget.html">QWidget</a> { public: ExampleWidget( <a href="qwidget.html">QWidget</a> *parent = 0, const char *name = 0 ); ~ExampleWidget(); }; <a name="f253"></a>ExampleWidget::ExampleWidget( <a href="qwidget.html">QWidget</a> *parent, const char *name ) : <a href="qwidget.html">QWidget</a>( parent, name ) { // Make the top-level layout; a vertical box to contain all widgets // and sub-layouts. <a href="qboxlayout.html">QBoxLayout</a> *topLayout = new <a href="qvboxlayout.html">QVBoxLayout</a>( this, 5 ); // Create a menubar... <a href="qmenubar.html">QMenuBar</a> *menubar = new <a href="qmenubar.html">QMenuBar</a>( this ); <a name="x493"></a> menubar-><a href="qmenubar.html#setSeparator">setSeparator</a>( QMenuBar::InWindowsStyle ); <a href="qpopupmenu.html">QPopupMenu</a>* popup; popup = new <a href="qpopupmenu.html">QPopupMenu</a>( this ); popup-><a href="qmenudata.html#insertItem">insertItem</a>( "&Quit", qApp, SLOT(<a href="qapplication.html#quit">quit</a>()) ); menubar-><a href="qmenudata.html#insertItem">insertItem</a>( "&File", popup ); // ...and tell the layout about it. <a name="x492"></a> topLayout-><a href="qlayout.html#setMenuBar">setMenuBar</a>( menubar ); // Make an hbox that will hold a row of buttons. <a href="qboxlayout.html">QBoxLayout</a> *buttons = new <a href="qhboxlayout.html">QHBoxLayout</a>( topLayout ); int i; for ( i = 1; i <= 4; i++ ) { <a href="qpushbutton.html">QPushButton</a>* but = new <a href="qpushbutton.html">QPushButton</a>( this ); <a href="qstring.html">QString</a> s; <a name="x495"></a> s.<a href="qstring.html#sprintf">sprintf</a>( "Button %d", i ); <a name="x483"></a> but-><a href="qbutton.html#setText">setText</a>( s ); // Set horizontal <a href="layout.html#stretch-factor">stretch factor</a> to 10 to let the buttons // stretch horizontally. The buttons will not stretch // vertically, since bigWidget below will take up vertical // stretch. <a name="x482"></a> buttons-><a href="qboxlayout.html#addWidget">addWidget</a>( but, 10 ); // (Actually, the result would have been the same with a // stretch factor of 0; if no items in a layout have non-zero // stretch, the space is divided equally between members.) } // Make another hbox that will hold a left-justified row of buttons. <a href="qboxlayout.html">QBoxLayout</a> *buttons2 = new <a href="qhboxlayout.html">QHBoxLayout</a>( topLayout ); <a href="qpushbutton.html">QPushButton</a>* but = new <a href="qpushbutton.html">QPushButton</a>( "Button five", this ); buttons2-><a href="qboxlayout.html#addWidget">addWidget</a>( but ); but = new <a href="qpushbutton.html">QPushButton</a>( "Button 6", this ); buttons2-><a href="qboxlayout.html#addWidget">addWidget</a>( but ); // Fill up the rest of the hbox with stretchable space, so that // the buttons get their minimum width and are pushed to the left. <a name="x481"></a> buttons2-><a href="qboxlayout.html#addStretch">addStretch</a>( 10 ); // Make a big widget that will grab all space in the middle. <a href="qmultilineedit.html">QMultiLineEdit</a> *bigWidget = new <a href="qmultilineedit.html">QMultiLineEdit</a>( this ); bigWidget-><a href="qtextedit.html#setText">setText</a>( "This widget will get all the remaining space" ); <a name="x484"></a> bigWidget-><a href="qframe.html#setFrameStyle">setFrameStyle</a>( QFrame::Panel | QFrame::Plain ); // Set vertical stretch factor to 10 to let the bigWidget stretch // vertically. It will stretch horizontally because there are no // widgets beside it to take up horizontal stretch. // topLayout-><a href="qboxlayout.html#addWidget">addWidget</a>( bigWidget, 10 ); topLayout-><a href="qboxlayout.html#addWidget">addWidget</a>( bigWidget ); // Make a grid that will hold a vertical table of QLabel/QLineEdit // pairs next to a large QMultiLineEdit. // Don't use hard-coded row/column numbers in QGridLayout, you'll // regret it when you have to change the layout. const int numRows = 3; const int labelCol = 0; const int linedCol = 1; const int multiCol = 2; // Let the grid-layout have a spacing of 10 pixels between // widgets, overriding the default from topLayout. <a href="qgridlayout.html">QGridLayout</a> *grid = new <a href="qgridlayout.html">QGridLayout</a>( topLayout, 0, 0, 10 ); int row; for ( row = 0; row < numRows; row++ ) { <a href="qlineedit.html">QLineEdit</a> *ed = new <a href="qlineedit.html">QLineEdit</a>( this ); // The line edit goes in the second column <a name="x486"></a> grid-><a href="qgridlayout.html#addWidget">addWidget</a>( ed, row, linedCol ); // Make a label that is a buddy of the line edit <a href="qstring.html">QString</a> s; s.<a href="qstring.html#sprintf">sprintf</a>( "Line &%d", row+1 ); <a href="qlabel.html">QLabel</a> *label = new <a href="qlabel.html">QLabel</a>( ed, s, this ); // The label goes in the first column. grid-><a href="qgridlayout.html#addWidget">addWidget</a>( label, row, labelCol ); } // The multiline edit will cover the entire vertical range of the // grid (rows 0 to numRows) and stay in column 2. <a href="qmultilineedit.html">QMultiLineEdit</a> *med = new <a href="qmultilineedit.html">QMultiLineEdit</a>( this ); <a name="x485"></a> grid-><a href="qgridlayout.html#addMultiCellWidget">addMultiCellWidget</a>( med, 0, -1, multiCol, multiCol ); // The labels will take the space they need. Let the remaining // horizontal space be shared so that the multiline edit gets // twice as much as the line edit. <a name="x487"></a> grid-><a href="qgridlayout.html#setColStretch">setColStretch</a>( linedCol, 10 ); grid-><a href="qgridlayout.html#setColStretch">setColStretch</a>( multiCol, 20 ); // Add a widget at the bottom. <a href="qlabel.html">QLabel</a>* sb = new <a href="qlabel.html">QLabel</a>( this ); sb-><a href="qlabel.html#setText">setText</a>( "Let's pretend this is a status bar" ); sb-><a href="qframe.html#setFrameStyle">setFrameStyle</a>( QFrame::Panel | QFrame::Sunken ); // This widget will use all horizontal space, and have a fixed height. // we should have made a subclass and implemented sizePolicy there... <a name="x498"></a><a name="x490"></a> sb-><a href="qwidget.html#setFixedHeight">setFixedHeight</a>( sb-><a href="qwidget.html#sizeHint">sizeHint</a>().height() ); <a name="x488"></a> sb-><a href="qlabel.html#setAlignment">setAlignment</a>( AlignVCenter | AlignLeft ); topLayout-><a href="qboxlayout.html#addWidget">addWidget</a>( sb ); <a name="x491"></a> topLayout-><a href="qlayout.html#activate">activate</a>(); } ExampleWidget::~ExampleWidget() { // All child widgets are deleted by Qt. // The top-level layout and all its sub-layouts are deleted by Qt. } int main( int argc, char **argv ) { <a href="qapplication.html">QApplication</a> a( argc, argv ); ExampleWidget f; a.<a href="qapplication.html#setMainWidget">setMainWidget</a>(&f); f.<a href="qwidget.html#setCaption">setCaption</a>("Qt Example - Caption"); f.<a href="qwidget.html#show">show</a>(); return a.<a href="qapplication.html#exec">exec</a>(); } </pre> <p>See also <a href="examples.html">Examples</a>. <!-- eof --> <p><address><hr><div align=center> <table width=100% cellspacing=0 border=0><tr> <td>Copyright © 2003 <a href="troll.html">Trolltech</a><td align=center><a href="trademarks.html">Trademarks</a> <td align=right><div align=right>Qt 3.2.3</div> </table></div></address></body> </html>