diff -r 4816d766a08a -r f345bda72bc4 Symbian3/PDK/Source/GUID-97486385-88F7-4AF1-B880-D9A8AA4D7094.dita --- a/Symbian3/PDK/Source/GUID-97486385-88F7-4AF1-B880-D9A8AA4D7094.dita Tue Mar 30 11:42:04 2010 +0100 +++ b/Symbian3/PDK/Source/GUID-97486385-88F7-4AF1-B880-D9A8AA4D7094.dita Tue Mar 30 11:56:28 2010 +0100 @@ -1,102 +1,100 @@ - - - - - -Compound -controls in traditional architecture -

Compound controls are -controls that contain other controls. To create a compound control, you must -do the following:

- -

CCoeControl* CContainerContainer::ComponentControl(TInt aIndex) and CCoeControl::CountComponentControls work -in conjunction with each other. The Symbian platform can query the control -as to how many components it has and then request a pointer to each of the -component's controls. Controls can be added or removed at run time using these -two methods. The framework uses this information to draw the container.

-

The compound control usually owns the child controls and therefore it -is responsible of their construction and destruction. The compound control -should also set the positions and sizes of its child controls; it must ensure -that all child controls are inside the compound control rectangle and visible -child rectangles do not overlap each other.

+ + + + + +Compound +controls in traditional architecture +

Compound controls are +controls that contain other controls. To create a compound control, you must +do the following:

+
    +

  • construct the control in the parent control (main control +that owns the window in which the child control appears). The control should +be constructed in the constructor for the window. An example of an implementation +is as follows:

    + +void CMyViewContainer::ConstructL(const TRect& aRect) + { + CreateWindowL(); + + iLabel = new (ELeave) CEikLabel; + iLabel->SetContainerWindowL( *this ); + iLabel->SetTextL( _L("MyView 1\n\nSelect local view\nswitching from menu") ); + + SetRect(aRect); + ActivateL(); + } +

    , where

    +

    iLabel = new (ELeave) CEikLabel; creates a CEikLabel object, +which is a class that supports the display of text in the parent window.

    +

    CCoeControl::SetContainerWindowL() makes the non-window-owning control a +child of the window-owning control.

    +

    CEikLabel::SetTextL() sets a text for the label

    +

    The other methods are the standard methods for creating a window for +the window-owning control.

    +     +
    • +

  • add a method to the owning control that returns the number +of controls in the compound control. An example of an implementation is as +follows:

    + +TInt CMyViewAppContainer::CountComponentControls() const + { + return KNumberOfControls; // return nbr of controls inside this compound control + } +

    , where

    +

    CMyViewAppContainer::CountComponentControls() overrides CCoeControl::CountComponentControls() to +return the number of controls in the compound control

    +

    KNumberOfControls is a TInt constant +for the number of controls in the application. Other approaches could be used.

    +     +
    • +

  • Add a method to the owning control that returns each of the +controls by a zero-based index. An example of an implementation is as follows:

    + +CCoeControl* CContainerContainer::ComponentControl( + TInt aIndex) const + { + switch ( aIndex ) + { + case 0: + return iLabel; // return a pointer to the + //iLabel + default: + return NULL; + } + } + +

    , where

    +

    CCoeControl* CContainerContainer::ComponentControl(TInt aIndex) gets +an indexed component of a compound control. There are two ways to implement +a compound control. One way is to override this function. The other way is +to use the CCoeControlArray functionality (see the CCoeControl::InitComponentArrayL() method). +

    + +

    Within a compound control, each component control is identified by an +index.

    +     +

    All child controls should be accessible by CCoeControl::ComponentControl() at +any time, regardless of whether they are visible or not. You can adjust the +visibility of a control using the CCoeControl::MakeVisible() method.

    +     +
    • +
+

CCoeControl* CContainerContainer::ComponentControl(TInt aIndex) and CCoeControl::CountComponentControls() work in conjunction with each other. The Symbian platform can query the +control as to how many components it has and then request a pointer to each +of the component's controls. Controls can be added or removed at run time +using these two methods. The framework uses this information to draw the container.

+

The compound control usually owns the child controls and therefore it +is responsible of their construction and destruction. The compound control +should also set the positions and sizes of its child controls; it must ensure +that all child controls are inside the compound control rectangle and visible +child rectangles do not overlap each other.

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