From Forum Nokia Wiki

ID	CS001438	Creation date	June 18, 2009
Platform	S60 3rd Edition, S60 5th Edition	Tested on devices	Nokia N95
Category	Symbian C++	Subcategory	Code Examples

Keywords (APIs, classes, methods, functions): CAknAppUi::HandleResourceChangeL(), CCoeControl::HandleResourceChange()

Overview

Layout and screen orientation change events are generated when the screen size or layout is changed. The S60 platform supports multiple screen resolutions. Handling this event can be implemented into application CAknAppUi class or application CCoeControl UI controls.

Source

Solution 1: UI control derived from CCoeControl can handle layout changes overriding the CCoeControl::HandleResourceChange() method

void CExampleControl::HandleResourceChange(TInt aType)
        {
        // Call base class implementation
        CCoeControl::HandleResourceChange(aType);
        if ( aType==KEikDynamicLayoutVariantSwitch )
              {
              TRect rect;
              // Ask where container's rectangle should be
              // EMainPane equals to area returned by
              // CEikAppUi::ClientRect()
              AknLayoutUtils::LayoutMetricsRect(
              AknLayoutUtils::EMainPane,rect);
              // Set new screen rect
              SetRect(rect);
              }
        }

Solution 2: Application UI class derived from CAknAppUi can override CEikAppUi::HandleResourceChangeL() to get the KEikDynamicLayoutVariantSwitch layout change event.

void CExampleAppUi::HandleResourceChangeL(TInt aType)
        {
        // Call base class implementation
        CAknAppUi::HandleResourceChangeL( aType );
        if ( aType == KEikDynamicLayoutVariantSwitch )
             {
              TRect rect;
              // Ask where container's rectangle should be
              // EMainPane equals to area returned by
              // CEikAppUi::ClientRect()
              AknLayoutUtils::LayoutMetricsRect(
              AknLayoutUtils::EMainPane,rect);
 
              // Set new screen rect
              // Must not call this if the iExampleControlContainer
              // component is on the control stack
              iExampleControlContainer->SetRect(rect);
             }
 
        // Must not call this if the iSomeDialog
        // component is on the control stack
        //iSomeDialog->HandleResourceChangeL( aType );
        }

See also

TSS001178 - Switching orientation in dialog-based applications

Postconditions

A layout change event is received and the new layout size is read.