Revision as of 10:21, 29 June 2011

16 Sep
2009

Note: This article is error prone, and needs code change in the example to work properly in Qt 4.7 in Symbian

PLEASE NOTE that the code in the arcticle doesn't work properly in Qt 4.7 on Symbian. The issue is in the example code's ResizeEvent::GetScreenCoordinates() method. The GetScreenCoordinates uses QDesktopWidget::availableGeometry and QDesktopWidget::screenGeometry methods. In all cases these methods do not reflect current screen geometry values during QWidget::resizeEvent call as the respective values are only changed after the resizeEvent has occured. This means that e.g. during the startup of the application these may return wrong values as the values are not yet set properly.

If the whole screen geometry information is needed from QDesktopWidget it's advised to connect to QApplication::desktop()'s workAreaResized(int) signal and call QApplication::desktop()->availableGeometry() in the connected slot function. This works in Qt 4.7.3 in Symbian but not (due to bug) in Qt 4.6.

See following bug report for more details. The QTBUG-14058's fix introduces documentation for QDesktopWidget on this issue.

Overview

This code example shows how to get notification when the screen mode changes using QWidget::resizeEvent(). This method gets called when the screen mode changes, so you have to implement that virtual method in your class.

This snippet can be self-signed.

Preconditions

• Download and install the Qt SDK

Source

//resizeEvent() method get called when user change screen mode.
void ResizeEvent::resizeEvent (QResizeEvent* event)
{
    QSize widgetSize = event->size();
	//Resize your custom control according to new size.
    QMainWindow::resizeEvent(event);
}

Postconditions

The code snippet is expected to notify change in screen mode.

Normal screen

Screen after changing mode to portrait

Related link

• CS001437 - Listening for screen orientation changes in Qt

Download Code Example

• File:QtResizeEvent.zip shows new screen size when user change screen mode. This example is tested on Nokia 5800 XpressMusic.