<!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/tutorial2.doc:1233 --> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"> <title>Setting Options</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>Setting Options</h1> <p> <p> <center><img src="chart-options.png" alt="The options dialog"></center> <p> We provide an options dialog so that the user can set options that apply to all data sets in one place. <p> (Extracts from <tt>optionsform.h</tt>.) <p> <pre> class OptionsForm : public <a href="ntqdialog.html">TQDialog</a> { <a href="metaobjects.html#TQ_OBJECT">TQ_OBJECT</a> public: OptionsForm( <a href="ntqwidget.html">TQWidget</a>* parent = 0, const char* name = "options form", bool modal = FALSE, WFlags f = 0 ); ~OptionsForm() {} <a href="ntqfont.html">TQFont</a> font() const { return m_font; } void setFont( <a href="ntqfont.html">TQFont</a> font ); <a href="ntqlabel.html">TQLabel</a> *chartTypeTextLabel; <a href="ntqcombobox.html">TQComboBox</a> *chartTypeComboBox; <a href="ntqpushbutton.html">TQPushButton</a> *fontPushButton; <a href="ntqlabel.html">TQLabel</a> *fontTextLabel; <a href="ntqframe.html">TQFrame</a> *addValuesFrame; <a href="ntqbuttongroup.html">TQButtonGroup</a> *addValuesButtonGroup; <a href="ntqradiobutton.html">TQRadioButton</a> *noRadioButton; <a href="ntqradiobutton.html">TQRadioButton</a> *yesRadioButton; <a href="ntqradiobutton.html">TQRadioButton</a> *asPercentageRadioButton; <a href="ntqlabel.html">TQLabel</a> *decimalPlacesTextLabel; <a href="ntqspinbox.html">TQSpinBox</a> *decimalPlacesSpinBox; <a href="ntqpushbutton.html">TQPushButton</a> *okPushButton; <a href="ntqpushbutton.html">TQPushButton</a> *cancelPushButton; protected slots: void chooseFont(); protected: <a href="qvboxlayout.html">TQVBoxLayout</a> *optionsFormLayout; <a href="qhboxlayout.html">TQHBoxLayout</a> *chartTypeLayout; <a href="qhboxlayout.html">TQHBoxLayout</a> *fontLayout; <a href="qvboxlayout.html">TQVBoxLayout</a> *addValuesFrameLayout; <a href="qvboxlayout.html">TQVBoxLayout</a> *addValuesButtonGroupLayout; <a href="qhboxlayout.html">TQHBoxLayout</a> *decimalPlacesLayout; <a href="qhboxlayout.html">TQHBoxLayout</a> *buttonsLayout; private: <a href="ntqfont.html">TQFont</a> m_font; }; </pre> <p> The layout of this dialog is slightly more complicated than for the set data form, but we only need a single slot. Unlike the "smart" set data form this is a "dumb" dialog that simply provides the widgets for the caller to set and read. The caller is responsible for updating things based on the changes the user makes. <p> (Extracts from <tt>optionsform.cpp</tt>.) <p> <pre> #include "images/options_horizontalbarchart.xpm" #include "images/options_piechart.xpm" #include "images/options_verticalbarchart.xpm" </pre> <p> We include some some pixmaps to use in the chart type combobox. <p> <h2> The Constructor </h2> <a name="1"></a><p> <pre> OptionsForm::OptionsForm( <a href="ntqwidget.html">TQWidget</a>* parent, const char* name, bool modal, WFlags f ) : <a href="ntqdialog.html">TQDialog</a>( parent, name, modal, f ) { <a href="ntqwidget.html#setCaption">setCaption</a>( "Chart -- Options" ); <a href="ntqwidget.html#resize">resize</a>( 320, 290 ); </pre> <p> We pass all the arguments on to the <a href="ntqdialog.html">TQDialog</a> constructor, set a caption and set an initial size. <p> The layout of the form will be to have the chart type label and combo box in a horizontal box layout, and similarly for the font button and font label, and for the decimal places label and spinbox. The buttons will also be placed in a horizontal layout, but with a spacer to move them to the right. The show values radio buttons will be vertically aligned within a frame. All of these will be laid out in a vertical box layout. <p> <pre> optionsFormLayout = new <a href="qvboxlayout.html">TQVBoxLayout</a>( this, 11, 6 ); </pre> <p> All the widgets will be laid out within the form's vertical box layout. <p> <pre> chartTypeLayout = new <a href="qhboxlayout.html">TQHBoxLayout</a>( 0, 0, 6 ); </pre> <p> The chart type label and combobox will be laid out side by side. <p> <pre> chartTypeTextLabel = new <a href="ntqlabel.html">TQLabel</a>( "&Chart Type", this ); <a name="x2631"></a> chartTypeLayout-><a href="qboxlayout.html#addWidget">addWidget</a>( chartTypeTextLabel ); chartTypeComboBox = new <a href="ntqcombobox.html">TQComboBox</a>( FALSE, this ); <a name="x2633"></a> chartTypeComboBox-><a href="ntqcombobox.html#insertItem">insertItem</a>( TQPixmap( options_piechart ), "Pie Chart" ); chartTypeComboBox-><a href="ntqcombobox.html#insertItem">insertItem</a>( TQPixmap( options_verticalbarchart ), "Vertical Bar Chart" ); chartTypeComboBox-><a href="ntqcombobox.html#insertItem">insertItem</a>( TQPixmap( options_horizontalbarchart ), "Horizontal Bar Chart" ); chartTypeLayout-><a href="qboxlayout.html#addWidget">addWidget</a>( chartTypeComboBox ); <a name="x2630"></a> optionsFormLayout-><a href="qboxlayout.html#addLayout">addLayout</a>( chartTypeLayout ); </pre> <p> We create the chart type label (with an accelerator which we'll relate to the chart type combobox later). We also create a chart type combobox, populating it with both pixmaps and text. We add them both to the horizontal layout and add the horizontal layout to the form's vertical layout. <p> <pre> fontLayout = new <a href="qhboxlayout.html">TQHBoxLayout</a>( 0, 0, 6 ); fontPushButton = new <a href="ntqpushbutton.html">TQPushButton</a>( "&Font...", this ); fontLayout-><a href="qboxlayout.html#addWidget">addWidget</a>( fontPushButton ); <a href="qspaceritem.html">TQSpacerItem</a>* spacer = new <a href="qspaceritem.html">TQSpacerItem</a>( 0, 0, TQSizePolicy::Expanding, TQSizePolicy::Minimum ); <a name="x2629"></a> fontLayout-><a href="qboxlayout.html#addItem">addItem</a>( spacer ); fontTextLabel = new <a href="ntqlabel.html">TQLabel</a>( this ); // Must be set by caller via setFont() fontLayout-><a href="qboxlayout.html#addWidget">addWidget</a>( fontTextLabel ); optionsFormLayout-><a href="qboxlayout.html#addLayout">addLayout</a>( fontLayout ); </pre> <p> We create a horizontal box layout to hold the font button and font label. The font button is straight-forward. We add a spacer to improve the appearance. The font text label is initially empty (since we don't know what font the user is using). <p> <pre> addValuesFrame = new <a href="ntqframe.html">TQFrame</a>( this ); <a name="x2640"></a> addValuesFrame-><a href="ntqframe.html#setFrameShape">setFrameShape</a>( TQFrame::StyledPanel ); <a name="x2639"></a> addValuesFrame-><a href="ntqframe.html#setFrameShadow">setFrameShadow</a>( TQFrame::Sunken ); addValuesFrameLayout = new <a href="qvboxlayout.html">TQVBoxLayout</a>( addValuesFrame, 11, 6 ); addValuesButtonGroup = new <a href="ntqbuttongroup.html">TQButtonGroup</a>( "Show Values", addValuesFrame ); <a name="x2641"></a> addValuesButtonGroup-><a href="ntqgroupbox.html#setColumnLayout">setColumnLayout</a>(0, TQt::Vertical ); <a name="x2647"></a> addValuesButtonGroup-><a href="ntqwidget.html#layout">layout</a>()->setSpacing( 6 ); addValuesButtonGroup-><a href="ntqwidget.html#layout">layout</a>()->setMargin( 11 ); addValuesButtonGroupLayout = new <a href="qvboxlayout.html">TQVBoxLayout</a>( addValuesButtonGroup-><a href="ntqwidget.html#layout">layout</a>() ); <a name="x2644"></a> addValuesButtonGroupLayout-><a href="qlayoutitem.html#setAlignment">setAlignment</a>( TQt::AlignTop ); noRadioButton = new <a href="ntqradiobutton.html">TQRadioButton</a>( "&No", addValuesButtonGroup ); <a name="x2645"></a> noRadioButton-><a href="ntqradiobutton.html#setChecked">setChecked</a>( TRUE ); addValuesButtonGroupLayout-><a href="qboxlayout.html#addWidget">addWidget</a>( noRadioButton ); yesRadioButton = new <a href="ntqradiobutton.html">TQRadioButton</a>( "&Yes", addValuesButtonGroup ); addValuesButtonGroupLayout-><a href="qboxlayout.html#addWidget">addWidget</a>( yesRadioButton ); asPercentageRadioButton = new <a href="ntqradiobutton.html">TQRadioButton</a>( "As &Percentage", addValuesButtonGroup ); addValuesButtonGroupLayout-><a href="qboxlayout.html#addWidget">addWidget</a>( asPercentageRadioButton ); addValuesFrameLayout-><a href="qboxlayout.html#addWidget">addWidget</a>( addValuesButtonGroup ); </pre> <p> The user may opt to display their own labels as they are or to add the values at the end of each label, either as-is or as percentages. <p> We create a frame to present the radio buttons in and create a layout for them. We create a button group (so that TQt will take care of handling the exclusive radio button behaviour automatically). Next we create the radio buttons, making "No" the default. <p> The decimal places label and spin box are laid out just like the other horizontal layouts, and the buttons are laid out in a very similar way to the buttons in the set data form. <p> <pre> <a href="ntqobject.html#connect">connect</a>( fontPushButton, TQ_SIGNAL( <a href="ntqbutton.html#clicked">clicked</a>() ), this, TQ_SLOT( chooseFont() ) ); <a href="ntqobject.html#connect">connect</a>( okPushButton, TQ_SIGNAL( <a href="ntqbutton.html#clicked">clicked</a>() ), this, TQ_SLOT( <a href="ntqdialog.html#accept">accept</a>() ) ); <a href="ntqobject.html#connect">connect</a>( cancelPushButton, TQ_SIGNAL( <a href="ntqbutton.html#clicked">clicked</a>() ), this, TQ_SLOT( <a href="ntqdialog.html#reject">reject</a>() ) ); </pre> <p> We only need three connections: <ol type=1> <li> When the user clicks the font button we execute our own chooseFont() slot. <li> If the user clicks OK we call <a href="ntqdialog.html#accept">TQDialog::accept</a>(); it is up to the caller to read the data from the dialog's widgets and perform any necessary actions. <li> If the user clicks Cancel we call <a href="ntqdialog.html#reject">TQDialog::reject</a>(). </ol> <p> <pre> <a name="x2642"></a> chartTypeTextLabel-><a href="ntqlabel.html#setBuddy">setBuddy</a>( chartTypeComboBox ); decimalPlacesTextLabel-><a href="ntqlabel.html#setBuddy">setBuddy</a>( decimalPlacesSpinBox ); </pre> <p> We use the setBuddy() function to associate widgets with label accelerators. <p> <h2> The Slots </h2> <a name="2"></a><p> <pre> void OptionsForm::chooseFont() { bool ok; <a name="x2638"></a> <a href="ntqfont.html">TQFont</a> font = TQFontDialog::<a href="ntqfontdialog.html#getFont">getFont</a>( &ok, m_font, this ); if ( ok ) <a href="ntqwidget.html#setFont">setFont</a>( font ); } </pre> <p> When the user clicks the Font button this slot is invoked. It simply calls the static <a href="ntqfontdialog.html#getFont">TQFontDialog::getFont</a>() function to obtain the user's choice of font. If they chose a font we call our setFont() slot which will present a textual description of the font in the font label. <p> <pre> void OptionsForm::<a href="ntqwidget.html#setFont">setFont</a>( <a href="ntqfont.html">TQFont</a> font ) { <a name="x2635"></a> <a href="ntqstring.html">TQString</a> label = font.<a href="ntqfont.html#family">family</a>() + " " + <a name="x2637"></a> TQString::<a href="ntqstring.html#number">number</a>( font.<a href="ntqfont.html#pointSize">pointSize</a>() ) + "pt"; <a name="x2634"></a> if ( font.<a href="ntqfont.html#bold">bold</a>() ) label += " Bold"; <a name="x2636"></a> if ( font.<a href="ntqfont.html#italic">italic</a>() ) label += " Italic"; fontTextLabel-><a href="ntqlabel.html#setText">setText</a>( label ); m_font = font; } </pre> <p> This function displays a textual description of the chosen font in the font label and holds a copy of the font in the <tt>m_font</tt> member. We need the font in a member so that we can provide a default font for chooseFont(). <p> <p align="right"> <a href="tutorial2-08.html">« Taking Data</a> | <a href="tutorial2.html">Contents</a> | <a href="tutorial2-10.html">The Project File »</a> </p> <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>TQt 3.3.8</div> </table></div></address></body> </html>