diff -r 4816d766a08a -r f345bda72bc4 Symbian3/PDK/Source/GUID-1A26BD9E-5B8E-4E6D-904E-B8354B14E111.dita --- a/Symbian3/PDK/Source/GUID-1A26BD9E-5B8E-4E6D-904E-B8354B14E111.dita Tue Mar 30 11:42:04 2010 +0100 +++ b/Symbian3/PDK/Source/GUID-1A26BD9E-5B8E-4E6D-904E-B8354B14E111.dita Tue Mar 30 11:56:28 2010 +0100 @@ -1,104 +1,102 @@ - - - - - -Constructing -views in the view architecture -

The call on the first phase constructor method of the view occurs in UI controller. The -view serves as the top-level window under the UI controller.

-

The methods you need to implement for your CCoeControl-derived -view are as follows:

- -

If required for your application, you may need to implement other methods -for your control. For top-level windows, you would need to implement CCoeControl::SizeChanged to respond to -changes to the size and position of the contents of this control. This is -called by the Symbian platform when a change occurs. A typical implementation -for a compound control is:

-void CMyAppView::SizeChanged() - { - // Control resize code - iControl->SetExtent( const TPoint &aPosition, const TSize &aSize); - } + + + + + +Constructing +views in the view architecture +

The call on the first phase constructor method of the view occurs in UI controller. The +view serves as the top-level window under the UI controller.

+

The following are the methods that you need to derive for the view derived +from CCoeControl :

+
    +

  • Default constructor, which cannot contain code that leaves. +A common implementation is:

    + + +CMyAppView* CMyAppView::NewL( const TRect& aRect ) + { + CMyAppView* self = CMyAppView::NewLC( aRect ); + CleanupStack::Pop( self ); + return self; + } + +CMyAppView* CMyAppView::NewLC( const TRect& aRect ) + { + CMyAppView* self = new ( ELeave ) CMyAppView; + CleanupStack::PushL( self ); + self->ConstructL( aRect ); + return self; + } + +CMyAppView::CMyAppView() + { + // No implementation required + } +

    The declarations for CMyAppView::NewL() and CMyAppView::NewLC() in +the class header file needs to be public to support the construction method +required.

    +

    In this approach, CMyAppView::NewL() is called +from the UI controller. It creates a view object by calling CMyAppView::NewLC() to +create the object (and leave if it cannot), pushes a pointer to the clean-up stack in case the second phase construction method +leaves, and then calls the second phase construction method of the object. +When it returns to CMyAppView::NewL(), the pointer pushed +to the cleanup stack is removed.

    +     +
    • +

  • Symbian second phase constructor with code that might leave. +A common implementation is:

    + + +void CMyAppView::ConstructL( const TRect& aRect ) + { + // Create a window for this application view + CreateWindowL(); + + //add construction for other controls if required + + // Set the windows size + SetRect( aRect ); + + // Activate the window, which makes it ready to be drawn + ActivateL(); + } +

    CMyAppView is a private class providing the second +phase construction that accepts the rectangle the view is drawn to.

    +

    CCoeControl::CreateWindowL() creates a window for +the control. Note that this window is a child of the UI controller. This method +makes the control a window-owning +control. While, the use of window-owning controls is discouraged to +prevent the taxing of run-time resources, this is the top-level window for +the UI controller.

    +

    While this is a simple control that does not contain other controls, +other controls could be added to the control between CCoeControl::CreateWindowL() and CCoeControl::SetRect(aRect). For more information, see Compound +controls in the view architecture.

    +

    CCoeControl::SetRect(aRect) sets the window size +according to the requirements of the mobile device. The top-level control +rectangle is set to the area that the framework provides for the application. +Calling CCoeControl::SetRect(aRect) calls the CCoeControl::SizeChanged() method, +where the control should set the position and size for any child controls +and thus adjust the control layout to the UI.

    +

    CCoeControl::ActivateL() sets the control as ready +to be drawn.

    +     +
    • +
+

If required for your application, you may need to implement other methods +for your control. For top-level windows, you would need to implement CCoeControl::SizeChanged() to +respond to changes to the size and position of the contents of this control. +This is called by the Symbian platform when a change occurs. A typical implementation +for a compound control is:

+void CMyAppView::SizeChanged() + { + // Control resize code + iControl->SetExtent( const TPoint &aPosition, const TSize &aSize); + } \ No newline at end of file