SIP Dialog Example

Dialog Class Implementation

In the constructor of Dialog, we start by obtaining the available geometry of the screen with availableGeometry(). The parameter used is 0 to indicate that we require the primary screen.

 Dialog::Dialog()
 {
     desktopGeometry = QApplication::desktop()->availableGeometry(0);

     setWindowTitle(tr("SIP Dialog Example"));
     QScrollArea *scrollArea = new QScrollArea(this);
     QGroupBox *groupBox = new QGroupBox(scrollArea);
     groupBox->setTitle(tr("SIP Dialog Example"));
     QGridLayout *gridLayout = new QGridLayout(groupBox);
     groupBox->setLayout(gridLayout);

We set the window's title to "SIP Dialog Example" and declare a QScrollArea object, scrollArea. Next we instantiate a QGroupBox, groupBox, with scrollArea as its parent. The title of groupBox is also set to "SIP Dialog Example". A QGridLayout object, gridLayout, is then used as groupBox's layout.

We create a QLineEdit, a QLabel and a QPushButton and we set the minimumWidth property to 220 pixels, respectively.

     QLineEdit* lineEdit = new QLineEdit(groupBox);
     lineEdit->setText(tr("Open and close the SIP"));
     lineEdit->setMinimumWidth(220);

     QLabel* label = new QLabel(groupBox);
     label->setText(tr("This dialog resizes if the SIP is opened"));
     label->setMinimumWidth(220);

     QPushButton* button = new QPushButton(groupBox);
     button->setText(tr("Close Dialog"));
     button->setMinimumWidth(220);

Also, all three widgets' text are set accordingly. The verticalSpacing property of gridLayout is set based on the height of desktopGeometry. This is to adapt to the different form factors of Windows Mobile. Then, we add our widgets to the layout.

     if (desktopGeometry.height() < 400)
         gridLayout->setVerticalSpacing(80);
     else
         gridLayout->setVerticalSpacing(150);

     gridLayout->addWidget(label);
     gridLayout->addWidget(lineEdit);
     gridLayout->addWidget(button);

The scrollArea's widget is set to groupBox. We use a QHBoxLayout object, layout, to contain scrollArea. The Dialog's layout is set to layout and the scroll area's horizontal scroll bar is turned off.

     scrollArea->setWidget(groupBox);
     QHBoxLayout* layout = new QHBoxLayout();
     layout->addWidget(scrollArea);
     setLayout(layout);
     scrollArea->setHorizontalScrollBarPolicy(Qt::ScrollBarAlwaysOff);

The following signals are connected to their respective slots:

• button's pressed() signal to QApplication's closeAllWindows() slot,
• QDesktopWidget's workAreaResized() signal to dialog's desktopResized() slot.

     connect(button, SIGNAL(clicked()),
         qApp, SLOT(closeAllWindows()));
     connect(QApplication::desktop(), SIGNAL(workAreaResized(int)),
         this, SLOT(desktopResized(int)));
 }

The desktopResized() function accepts an integer, screen, corresponding to the screen's index. We only invoke reactToSIP() if screen is the primary screen (e.g. index = 0).

 void Dialog::desktopResized(int screen)
 {
     if (screen != 0)
         return;
     reactToSIP();
 }

The reactToSIP() function resizes dialog accordingly if the desktop's available geometry changed vertically, as this change signifies that the SIP may have been opened or closed.

 void Dialog::reactToSIP()
 {
     QRect availableGeometry = QApplication::desktop()->availableGeometry(0);

     if (desktopGeometry != availableGeometry) {
         if (windowState() | Qt::WindowMaximized)
             setWindowState(windowState() & ~Qt::WindowMaximized);

         setGeometry(availableGeometry);
     }

     desktopGeometry = availableGeometry;
 }

If the height has decreased, we unset the maximized window state. Otherwise, we set the maximized window state. Lastly, we update desktopGeometry to the desktop's available geometry.

 int main(int argc, char *argv[])
 {
     QApplication app(argc, argv);
     Dialog dialog;
     return dialog.exec();
 }