Class CCoeControl

class CCoeControl : public CBase, public MObjectProvider;

Description

Control base class from which all other controls are derived.

Derivation

• MObjectProvider - An interface that allows an object to be part of a network of object providers.
• CBase - Base class for all classes to be instantiated on the heap.

• CCoeControl - Control base class from which all other controls are derived.

Members

Defined in CCoeControl:

• AccumulatedZoom()constReturn the zoom factor for this control. Takes account of zoom factors in parent...
• ActivateGc()constActivates the standard graphics context.
• ActivateL()Sets the control as ready to be drawn.
• BackedUpWindow()constGets the backed-up window owned by the control.
• Background()constReturns the background drawer object associated with this object, if any. Null i...
• CCoeControl()Default C++ constructor.
• CCoeControl(CCoeEnv *)C++ constructor.
• CCoeControl(const CCoeControl &)
• CapturesPointer()constTests whether pointer capture is set for the control.
• ClaimPointerGrab(TBool)Claims pointer grab from another control.
• CloseWindow()Closes the window owned by this control.
• ComponentArrayExists()const
• ComponentControl(TInt)constGets an indexed component of a compound control.
• Components()Returns a component array to store child controls.
• Components()constReturns a component array to store child controls.
• ConstructFromResourceL(TResourceReader &)Constructs the control from a resource file.
• ControlContext()constGets the control context being used by this control.
• ControlEnv()constGets the control environment object for this control.
• CopyControlContextFrom(const CCoeControl *)Sets the control's context from another control.
• CountComponentControls()constGets the number of controls contained in a compound control.
• CreateBackedUpWindowL(RWindowTreeNode &)Creates a control's window as a backed-up window.
• CreateBackedUpWindowL(RWindowTreeNode &,TDisplayMode)Creates a control's window as a backed-up window, specifying the display mode.
• CreateWindowL()Creates a control's window.
• CreateWindowL(RWindowGroup *)Creates a control's window, specifying its parent window group.
• CreateWindowL(RWindowTreeNode &)Creates a control's window, specifying its parent window and its extent.
• CreateWindowL(const CCoeControl *)Creates a control's window, specifying the parent control.
• CustomGc()constReturns the custom graphics context set for this control (if any). Note that unl...
• DeactivateGc()constDeactivates the standard graphics context owned by the UI control framework.
• Draw(const TRect &)constDraws the control.
• DrawBackground(const TRect &)constDraws the control's background using its graphics context. Unlike CCoeControl::D...
• DrawDeferred()constDraws the control, with low priority.
• DrawForeground(const TRect &)constDraws the control's foreground using the control's graphics context. Unlike CCoe...
• DrawNow()constDraws the entire control
• DrawNow(const TRect &)constDraws the control, its components and child windows, within the bounds defined b...
• DrawableWindow()constGets the control's associated drawable window.
• EAbsoluteZoom
• ERelativeZoom
• EnableDragEvents()Requests pointer drag events.
• EnableReportControlStateChange(TBool)Set the status of the report control state change.
• FindBackground()constReturn an MCoeControlBackground object, if there is one - looking up the parent ...
• FindFontProvider()constReturn the font provider used by this control
• FocusChanged(TDrawNow)Responds to a change in focus.
• GetColor(TInt,TRgb &)constGets the overridden physical colour.
• GetColorUseListL(CArrayFix< TCoeColorUse > &)constGets the list of logical colours used to draw the control.
• GetGc()constDeprecated. See CCoeControl::CustomGc()const.
• GetHelpContext(TCoeHelpContext &)constGets the control's help context.
• GetTextDrawer(CCoeTextDrawerBase *&,const CCoeControl *,TInt)constControls that want to change or replace the text drawer that it or its children ...
• GrabbingComponent()constGets the component of this control which is grabbing the pointer.
• HandleComponentControlsResourceChange(TInt)Handles a change to the resources in the components of a compound control.
• HandlePointerBufferReadyL()Handles pointer buffer ready events.
• HandlePointerEventL(const TPointerEvent &)Handles pointer events.
• HandleRedrawEvent(const TRect &)constHandles redraw events.
• HandleResourceChange(TInt)Handles a change to the control's resources.
• HasBorder()constTests if the control has a border.
• HitTest()constGets the object that defines the hit region inside the control's rectangle. The ...
• IgnoreEventsUntilNextPointerUp()Sets the control to ignore pointer events until the next pointer up.
• Index(const CCoeControl *)constGets the index of a control that is a component of this control.
• InitComponentArrayL()Creates a component array to store child controls.
• InputCapabilities()constGets the control's input capabilities.
• IsActivated()constTests if the control has been activated.
• IsBackedUp()constTests if the window owned by the control is a backed-up window.
• IsBeingDestroyed()constTests if the control is being destroyed.
• IsBlank()constTests if the control is blank.
• IsDimmed()constTests if the control is dimmed.
• IsFocused()constTests if the control has focus.
• IsNonFocusing()constTests if the control can receive focus.
• IsReadyToDraw()constTests if the control is ready for drawing.
• IsVisible()constTests if the control is visible.
• LayoutManager()constGets the layout manager
• MakeVisible(TBool)Sets this control as visible or invisible.
• MaximumWidth()constGets the control's maximum width
• MinimumSize()Sets the control's minimum required size.
• MopNext()Retrieves the control's parent.
• MopSupplyObject(TTypeUid)Retrieves an object of the same type as that encapsulated in aId.
• Observer()constGets the control's observer.
• OfferKeyEventL(const TKeyEvent &,TEventCode)Handles key events.
• OverrideColorL(TInt,TRgb)Overrides the control's colour setting, as specified in the application's colour...
• OwnsWindow()constTests if the control is window-owning.
• Parent()
• Parent()const
• Position()constGets the control's position.
• PositionChanged()Responds to changes in the position of a control.
• PositionRelativeToScreen()constGets the control's position relative to screen origin.
• PrepareForFocusGainL()Prepares the control for gaining focus.
• PrepareForFocusLossL()Prepares the control for loss of focus.
• Rect()constGets the control's extent.
• RecursivelyMergedInputCapabilities()constGets the input capabilities of the control and all its components.
• RequestRelayout(const CCoeControl *)Requests a relayout
• Reserved_2()
• ResetGc()constResets the standard graphics context.
• ScreenFont(const TCoeFont &)constReturn the correct font given the supplied font and taking into account the curr...
• SetAdjacent(TInt)Sets the control's appearance when it is next to other controls.
• SetAllowStrayPointers()Sets whether or not to allow stray pointer events.
• SetBackground(const MCoeControlBackground *)Sets a pointer to a MCoeControlBackground object that is responsible for drawing...
• SetBlank()Sets a flag to indicate that the control is blank.
• SetCanDrawOutsideRect()Allows the control to draw outside its own extent.
• SetComponentsToInheritVisibility(TBool)Sets the control's components to inherit the visibility setting of their contain...
• SetContainerWindowL(RBackedUpWindow &)Sets the control's containing window without transferring ownership of the windo...
• SetContainerWindowL(RWindow &)Sets the control's containing window, without transferring ownership of the wind...
• SetContainerWindowL(const CCoeControl &)Sets the control's containing window by copying it from aContainer.
• SetControlContext(MCoeControlContext *)Set the control context for this control.
• SetCornerAndSize(TGulAlignment,const TSize &)Sets the control's alignment and size.
• SetCustomGc(CWindowGc *)Sets the control's custom graphics context. This value overrides the system cont...
• SetDimmed(TBool)Sets the control to be dimmed.
• SetExtent(const TPoint &,const TSize &)Sets the control's extent, specifying a size and a position.
• SetExtentToWholeScreen()Sets the control's extent to the whole screen.
• SetFocus(TBool,TDrawNow)Sets this control to have the keyboard focus.
• SetFocusing(TBool)Sets the control as able to receive keyboard focus.
• SetFontProviderL(const CCoeFontProvider &)Set the font provider. This is an external object that takes the responsibililty...
• SetGc(CWindowGc *)constDeprecated. See CCoeControl::SetCustomGc(CWindowGc *).
• SetGloballyCapturing(TBool)Sets the global pointer capture flag.
• SetHitTest(const MCoeControlHitTest *)Installs a hit tester for this control. The tester defines the hit region, which...
• SetLayoutManagerL(MCoeLayoutManager *)Sets the layout manager
• SetMaximumWidth(TInt)Sets the controls maximum width.
• SetMopParent(MObjectProvider *)Sets the context - that is, the enclosing parent control - for this control. If ...
• SetNeighbor(CCoeControl *)Sets an associated control.
• SetNonFocusing()Deprecated. Use CCoeControl::SetFocusing(TBool).
• SetObserver(MCoeControlObserver *)Sets the control's observer.
• SetParent(CCoeControl *)Sets aParent as the parent of this control. If setting aParent as parent of this...
• SetPointerCapture(TBool)Sets pointer capture.
• SetPosition(const TPoint &)Sets the control's position.
• SetRect(const TRect &)Sets the control's extent, specifying a rectangle.
• SetSize(const TSize &)Sets the control's size.
• SetSizeWithoutNotification(const TSize &)Sets a control's size without calling CCoeControl::SizeChanged().
• SetTextBaselineSpacing(TInt)Sets the spacing between text baselines.
• SetUniqueHandle(TInt)Sets a Unique Handle (identifier). That the number is unique is the perogative o...
• SetZoomFactorL(TInt,TZoomType)Set the zoom factor for this control.
• Size()constGets the control's size.
• SizeChanged()Responds to changes to the size and position of the contents of this control.
• SystemGc()constGets the graphics context that is used when drawing the control.
• TZoomType
• TextBaselineOffset(const TSize &)constGets the offset to the first text baseline relative to the top of the control.
• TextDrawer(TInt)constGets the text drawer to be used for the control. This method returns a reference...
• UniqueHandle()constReturns a Unique Handle (identifier) previously allocated to the control.
• Window()constGets the control's associated window.
• WriteInternalStateL(RWriteStream &)const
• ZoomWithType()constReturn the zoom factor but without taking into account the zoom factor of the pa...
• iCoeEnv
• iContext
• iPosition
• iSize
• operator=(const CCoeControl &)
• ~CCoeControl()Destructor.

Inherited from CBase:

• Delete(CBase *)Deletes the specified object.
• Extension_(TUint,TAny *&,TAny *)Extension function
• operator new(TUint)Allocates the object from the heap and then initialises its contents to binary z...
• operator new(TUint,TAny *)Initialises the object to binary zeroes.
• operator new(TUint,TLeave)Allocates the object from the heap and then initialises its contents to binary z...
• operator new(TUint,TLeave,TUint)Allocates the object from the heap and then initialises its contents to binary z...
• operator new(TUint,TUint)Allocates the object from the heap and then initialises its contents to binary z...

Inherited from MObjectProvider:

• MopGetObject(T *&)Gets an object of the type defined by the template parameter.
• MopGetObjectNoChaining(T *&)Gets an object of the type defined by the template parameter.

Related Topics

 » Symbian OS v9.4 » Examples » Application Framework example code » AnimExample: An UI application with a toolbar

• Animation example

 » Symbian OS v9.4 » Examples » Application Framework example code » ControlFramework: An UI application with a toolbar

• ControlFramework: A UI application with a toolbar

 » Symbian OS v9.4 » Examples » Application Framework example code » EmbApp: An embedded application

• EmbApp: An embedded application » Class summary

 » Symbian OS v9.4 » Examples » Application Framework example code » Minimal: A minimal UI application

• Minimal: A minimal UI application » Class Summary

IMPORT_C CCoeControl();

Description

Default C++ constructor.

Initialises the CCoeControl base class.

Note: CCoeControl is normally used as a base class from which concrete control classes are derived. However, it can also be instantiated as a concrete class.

IMPORT_C CCoeControl(CCoeEnv *aCoeEnv);

Description

C++ constructor.

Initialises the CCoeControl base class.

Note: CCoeControl is normally used as a base class from which concrete control classes are derived. However, it can also be instantiated as a concrete class.

Parameters

IMPORT_C ~CCoeControl();

Description

Destructor.

It destroys the window owned by the control, if it is a window-owning control.

In debug builds, this checks if the control still exists on the control stack and raises a CONE 44 panic if it is. An application must remove every control that it has added to the stack.

protected: inline CCoeControl(const CCoeControl &aControl);

Description

Parameters

IMPORT_C TBool ComponentArrayExists() const;

Description

Return value

IMPORT_C virtual TKeyResponse OfferKeyEventL(const TKeyEvent &aKeyEvent, TEventCode aType);

Description

Handles key events.

If a control wishes to process key events, it should implement this function. The implementation must ensure that the function returns EKeyWasNotConsumed if it does not do anything in response to a key event, otherwise, other controls or dialogs may be prevented from receiving the key event. If it is able to process the event it should return EKeyWasConsumed.

When a key event occurs, the control framework calls this function for each control on the control stack, until one of them can process the key event (and returns EKeyWasConsumed).

Each keyboard key press results in three separate events: EEventKeyDown, EEventKey, and EEventKeyUp, in that order.

To receive key events, which can be processed by this function, the application should call CCoeAppUi::AddToStackL(const MCoeView &,CCoeControl *,TInt,TInt) to add the control to the stack. This only applies, however, to controls which are not components of a compound control. Compound controls should pass key events to their components as necessary: the components themselves do not go on the stack.

Classes that override CCoeControl::OfferKeyEventL(const TKeyEvent &,TEventCode) should also override the CCoeControl::InputCapabilities()const virtual function, returning a TCoeInputCapabilities object whose attributes correspond to the behaviour of the CCoeControl::OfferKeyEventL(const TKeyEvent &,TEventCode) function. Note that it is not necessary to call CCoeControl::InputCapabilities()const on any component controls from inside a class' CCoeControl::InputCapabilities()const function. This is done automatically by the UI Control Framework.

If overriding CCoeControl::OfferKeyEventL(const TKeyEvent &,TEventCode), the implementation must include a base call to CCoeControl's CCoeControl::OfferKeyEventL(const TKeyEvent &,TEventCode).

Parameters

Return value

IMPORT_C virtual void MakeVisible(TBool aVisible);

Description

Sets this control as visible or invisible.

This causes the control to disappear or reappear. When a control is created, it is made visible by default.

CCoeControl::MakeVisible(TBool) can be called before or after the control is activated.

Notes:

This function may be overridden.

The visibility of the control can be queried using CCoeControl::IsVisible()const.

If CCoeControl::MakeVisible(TBool) is used to make a component visible, and the control captures the pointer (see CCoeControl::CapturesPointer()const), CCoeControl::MakeVisible(TBool) throws away any pending pointer events for that control.

Typical uses are for scrollbars, or for dialogs where some user responses are not required in certain circumstances.

Parameters

IMPORT_C virtual void SetDimmed(TBool aDimmed);

Description

Sets the control to be dimmed.

This function sets a flag within the control which indicates whether or not the control is dimmed (greyed out). This is typically used to show that the control is temporarily unavailable.

CCoeControl::SetDimmed(TBool) does not initiate a redraw of the control. The application should call CCoeControl::DrawNow()const or CCoeControl::DrawDeferred()const if a redraw is required after calling CCoeControl::SetDimmed(TBool). The control's CCoeControl::Draw(const TRect &)const function should draw the control appropriately according to whether it is dimmed or not. (This can be enquired using CCoeControl::IsDimmed()const.)

If overriding CCoeControl::SetDimmed(TBool), the implementation must include a base call to CCoeControl's CCoeControl::SetDimmed(TBool).

Parameters

IMPORT_C virtual void SetContainerWindowL(const CCoeControl &aContainer);

Description

Sets the control's containing window by copying it from aContainer.

It also copies the control context from aContainer if one has not previously been set.

This function can only be called on non-window-owning (or 'lodger') controls.

If overriding CCoeControl::SetContainerWindowL(const CCoeControl &), the implementation must include a base call to CCoeControl's CCoeControl::SetContainerWindowL(const CCoeControl &).

Parameters

IMPORT_C virtual void ConstructFromResourceL(TResourceReader &aReader);

Description

Constructs the control from a resource file.

This function has an empty default implementation. It should be implemented if the control is to be displayed within a dialog. It should initialise the control, reading in resource values from the resource file.

Note: if a control is not displayed in a dialog, it is necessary to set the control's associated window using CCoeControl::SetContainerWindowL(const CCoeControl &). Since this may leave, the control should be constructed using ConstructL().

Parameters

IMPORT_C virtual void ActivateL();

Description

Sets the control as ready to be drawn.

The application should call this function on all controls that are not components in a compound control.

The purpose of this function is that controls are not always ready to be drawn as soon as they have been constructed. For example, it may not be possible to set the control's extent during construction, but its extent should always be set before it is drawn. Similarly, if a control is to be made invisible, this should be done before it is activated.

The default implementation sets a flag in the control to indicate it is ready to be drawn. If the control is a compound control, the default implementation also calls CCoeControl::ActivateL() for all the control's components. To get the control's components it uses CCoeControl::CountComponentControls()const and CCoeControl::ComponentControl(TInt)const, which should be implemented by the compound control.

CCoeControl::ActivateL() is typically called from the control's ConstructL() function .

Notes:

This function can be overridden. This is useful for doing late initialisation of the control, using information that was not available at the time the control was created. For example, a text editor might override CCoeControl::ActivateL() and use it to enquire whether it is focused: if it is, it makes the cursor and any highlighting visible. At the time when the editor is created, it doesn't know whether or not it has keyboard focus.

If overriding CCoeControl::ActivateL(), the implementation must include a base call to CCoeControl's CCoeControl::ActivateL().

IMPORT_C virtual void PrepareForFocusLossL();

Description

Prepares the control for loss of focus.

A control which is displayed within a dialog should implement this function if it wishes to validate data entered into the control.

This function is called by the dialog framework immediately before it removes keyboard focus from a control within a dialog. It is intended to be used for validating the state of the control: for example, if the control allows the user to enter a date, CCoeControl::PrepareForFocusLossL() would normally check to make sure the user did not enter an invalid date such as February 31st. If an invalid state is detected, CCoeControl::PrepareForFocusLossL() should leave and issue a message to the user if appropriate. If it does leave, the framework does not perform the action that would have resulted in the control losing focus, and focus remains with the control to allow valid data to be entered.

In standard GUI dialogs, various actions can result in a control losing focus, for instance if the user presses the OK button or the Enter key to close the dialog and enter the information, or if the user navigates away from the focussed control. These actions result in CCoeControl::PrepareForFocusLossL() being called on the control that currently has keyboard focus.

The default implementation of this function is empty, and it is not called from within the UI control framework. The function exists only to provide an interface to the control, for the GUI and any other UI library.

IMPORT_C virtual void PrepareForFocusGainL();

Description

Prepares the control for gaining focus.

Implementations may by taking any action required, such as updating control information. The default implementation is empty.

IMPORT_C virtual void SetAdjacent(TInt aAdjacent);

Description

Sets the control's appearance when it is next to other controls.

Its intended use is to remove the double border that may occur if two controls, both with borders, are adjacent within a container control.

This function has an empty default implementation, and is not used within the UI control framework. However, it may be implemented and used by derived control classes.

Parameters

IMPORT_C virtual void SetNeighbor(CCoeControl *aNeighbor);

Description

Sets an associated control.

This can be used to establish co-ordinated groups of controls for instance in dialogs without specific application co-operation.

This function has an empty default implementation, and is not used within the UI control framework. However, it may be implemented and used by derived control classes.

Parameters

IMPORT_C virtual TBool HasBorder() const;

Description

Tests if the control has a border.

When component controls are arranged in a container, the container control may need to know whether or not the components have borders, as this may affect the way the components are laid out within the container.

The default implementation of this function returns EFalse, but can be overridden to provide the required functionality.

Return value

IMPORT_C virtual TSize MinimumSize();

Description

Sets the control's minimum required size.

This function should be overridden by the concrete control class if the control is to be displayed inside a dialog. Standard GUI dialogs set the size and position of their components automatically, and use this function to enquire the minimum size that a control requires.

Other container controls that automatically calculate the layout of their components may also use this function.

Return value

IMPORT_C virtual void HandleResourceChange(TInt aType);

Description

Handles a change to the control's resources.

The types of resources handled are those which are shared across the environment, e.g. colours or fonts. For colour scheme changes, CCoeControl::DrawDeferred()const is called in order to redraw the control.

If overriding CCoeControl::HandleResourceChange(TInt), the implementation must include a base call to CCoeControl's CCoeControl::HandleResourceChange(TInt).

Parameters

See also:

• CCoeControl::HandleComponentControlsResourceChange(TInt)Handles a change to the resources in the components of a compound control.

IMPORT_C virtual void GetColorUseListL(CArrayFix< TCoeColorUse > &aColorUseList) const;

Description

Gets the list of logical colours used to draw the control.

The list includes an explanation of how each colour is used. The default implementation is empty.

If overriding CCoeControl::GetColorUseListL(CArrayFix< TCoeColorUse > &)const, the implementation must include a base call to CCoeControl's CCoeControl::GetColorUseListL(CArrayFix< TCoeColorUse > &)const.

Parameters

IMPORT_C virtual void GetHelpContext(TCoeHelpContext &aContext) const;

Description

Gets the control's help context.

The default implementation is empty. The function must be implemented in derived classes to associate the control with a particular Help file and topic in a context sensitive application. The implementation should set the public data members of TCoeHelpContext to the required Help file UID and context descriptor, as created using the Context-Sensitive Help Compiler.

Parameters

IMPORT_C virtual TCoeInputCapabilities InputCapabilities() const;

Description

Gets the control's input capabilities.

Classes that override CCoeControl::OfferKeyEventL(const TKeyEvent &,TEventCode) should also override this function, returning a TCoeInputCapabilities object whose attributes correspond to the behaviour of the CCoeControl::OfferKeyEventL(const TKeyEvent &,TEventCode) function. The default implementation returns TCoeInputCapabilities::ENone.

It is not necessary to call CCoeControl::InputCapabilities()const on any component controls from inside a class's CCoeControl::InputCapabilities()const function. This is done automatically by the UI Control Framework.

Return value

inline CCoeEnv* ControlEnv() const;

Description

Gets the control environment object for this control.

Return value

IMPORT_C RDrawableWindow* DrawableWindow() const;

Description

Gets the control's associated drawable window.

The control must be a window-owning control.

This function should be called if it is not known whether the window is of type RWindow or RBackedUpWindow. RDrawableWindow is an abstract base class from which RWindow and RBackedUpWindow are derived.

Return value

See also:

• CCoeControl::Window()constGets the control's associated window.

IMPORT_C TBool OwnsWindow() const;

Description

Tests if the control is window-owning.

Return value

IMPORT_C TBool IsBackedUp() const;

Description

Tests if the window owned by the control is a backed-up window.

Return value

IMPORT_C void SetContainerWindowL(RWindow &aWindow);

Description

Sets the control's containing window, without transferring ownership of the window to this control. The function also sets the window's extent to that of the control.

This function can only be called on non-window-owning ('lodger') controls.

Note: the container's window can be accessed using CCoeControl::Window()const, CCoeControl::DrawableWindow()const, or CCoeControl::BackedUpWindow()const.

Parameters

IMPORT_C void SetContainerWindowL(RBackedUpWindow &aWindow);

Description

Sets the control's containing window without transferring ownership of the window to this control. The function also sets the window's extent to that of the control.

The function can only be called on non-window-owning ('lodger') controls.

Note: the container's window can be accessed using CCoeControl::Window()const, CCoeControl::DrawableWindow()const, or CCoeControl::BackedUpWindow()const.

Parameters

IMPORT_C CCoeControl* Parent();

Description

Return value

IMPORT_C const CCoeControl* Parent() const;

Description

Return value

IMPORT_C virtual TInt SetParent(CCoeControl *aParent);

Description

Sets aParent as the parent of this control. If setting aParent as parent of this control will create a cyclic relationship, this method does nothing.

Parameters

Return value

IMPORT_C TRect Rect() const;

Description

Gets the control's extent.

The position of the top-left of the rectangle is (0,0) if the control owns its window. Otherwise, its position is relative to its window.

Return value

IMPORT_C void SetRect(const TRect &aRect);

Description

Sets the control's extent, specifying a rectangle.

Note: calling this function results in a call to CCoeControl::SizeChanged().

Parameters

IMPORT_C void SetExtent(const TPoint &aPosition, const TSize &aSize);

Description

Sets the control's extent, specifying a size and a position.

Note: calling this function results in a call to CCoeControl::SizeChanged().

Parameters

IMPORT_C void SetExtentToWholeScreen();

Description

Sets the control's extent to the whole screen.

Note: calling this function results in a call to CCoeControl::SizeChanged().

IMPORT_C TSize Size() const;

Description

Gets the control's size.

Return value

IMPORT_C void SetSize(const TSize &aSize);

Description

Sets the control's size.

If the size, but not the position, of a control is set, then its position will default to TPoint(0,0).

Note: calling this function results in a call to CCoeControl::SizeChanged().

Parameters

IMPORT_C TPoint Position() const;

Description

Gets the control's position.

Return value

IMPORT_C TPoint PositionRelativeToScreen() const;

Description

Gets the control's position relative to screen origin.

The screen origin is its top-left corner.

Return value

IMPORT_C void SetPosition(const TPoint &aPosition);

Description

Sets the control's position.

If the control owns its containing window, it achieves this by setting the position of the window. Otherwise, the position of the control is set relative to its containing window. The positions of the control's components are adjusted accordingly and CCoeControl::PositionChanged() is called.

Parameters

IMPORT_C TInt MaximumWidth() const;

Description

Gets the control's maximum width

Return value

IMPORT_C TInt SetMaximumWidth(TInt aMaxWidth);

Description

Sets the controls maximum width.

Parameters

Return value

IMPORT_C MCoeLayoutManager* LayoutManager() const;

Description

Gets the layout manager

Return value

IMPORT_C virtual void SetLayoutManagerL(MCoeLayoutManager *aLayout);

Description

Sets the layout manager

If the control already has a layout manager, its MCoeLayoutManager::Detatch() is called. MCoeLayoutManager::Attach() is called on aLayout

The control doesn't take ownership of the Layout manager.

Parameters

IMPORT_C virtual TBool RequestRelayout(const CCoeControl *aChildControl);

Description

Requests a relayout

The default implementation is to call the parents RequestRelayout() .

Should normally be overridden by top-level controls, such as scrollable containers. Classes that override this function must ensure that they don't cause infinite loops, since a relayout might cause calls to RequestRelayout() itself, This might be solved like this:

TBool CAnyControl::RequestRelayout(const CCoeControl* aChildControl)
    {
    if(iRelayoutInProgress) return EFalse;
    iRelayoutInProgress = ETrue;
    //perform the relayout
    iRelayoutInProgress = EFalse;
    return ETrue;
    }

When the request is addressed the requesting control knows that its SizeChanged() will be called.

Parameters

Return value

IMPORT_C TBool IsVisible() const;

Description

Tests if the control is visible.

Unless CCoeControl::MakeVisible(TBool) has been called with argument EFalse, the control is visible.

Return value

IMPORT_C void SetComponentsToInheritVisibility(TBool aInherit=ETrue);

Description

Sets the control's components to inherit the visibility setting of their container control.

If set, when CCoeControl::MakeVisible(TBool) is called on the compound control, the visibility setting is propagated to all its components.

Parameters

IMPORT_C TBool IsDimmed() const;

Description

Tests if the control is dimmed.

This function returns the value of a flag within the control which is set and unset using CCoeControl::SetDimmed(TBool).

Return value

IMPORT_C void SetObserver(MCoeControlObserver *aObserver);

Description

Sets the control's observer.

Parameters

IMPORT_C MCoeControlObserver* Observer() const;

Description

Gets the control's observer.

Return value

IMPORT_C TBool IsFocused() const;

Description

Tests if the control has focus.

Focus is set and unset using CCoeControl::SetFocus(TBool,TDrawNow).

Return value

IMPORT_C void SetFocus(TBool aFocus, TDrawNow aDrawNow=ENoDrawNow);

Description

Sets this control to have the keyboard focus.

It sets the value of a focus flag within the control to the value given by aFocus. This flag indicates whether or not the control has keyboard focus, and its value can be enquired using CCoeControl::IsFocused()const. It then calls CCoeControl::FocusChanged(TDrawNow), passing it the value given by aDrawNow, unless the control is invisible or not activated, in which case it passes ENoDrawNow.

Note that setting focus does not initiate a redraw. The control's implementation of CCoeControl::FocusChanged(TDrawNow) should do this if required. The control's CCoeControl::Draw(const TRect &)const function, or that of its container, should normally change the appearance of the control to indicate whether or not it currently has focus.

Parameters

IMPORT_C void SetNonFocusing();

Description

Deprecated. Use CCoeControl::SetFocusing(TBool).

Sets the control as unable to receive keyboard focus. The function would typically be called during construction of the control.

IMPORT_C void SetFocusing(TBool aFocusing);

Description

Sets the control as able to receive keyboard focus.

Parameters

IMPORT_C TBool IsNonFocusing() const;

Description

Tests if the control can receive focus.

Return value

See also:

• CCoeControl::SetNonFocusing()Deprecated. Use CCoeControl::SetFocusing(TBool).

IMPORT_C void DrawNow() const;

Description

Draws the entire control

This function is called by an application or other code. The application should call this function when the control is first created and is ready for drawing, or if a change in application data or the control's internal state means that entire control's appearance is no longer up-to-date.

Partial redrawing of a control is sometimes more appropriate than drawing the entire control, and in this case, use DrawNow(const TRect &aRect) instead.

CCoeControl::DrawNow()const is implemented by CCoeControl and MAY NOT be overridden. It calls CCoeControl::Draw(const TRect &)const on the control itself, and also on all its component controls, if it is a compound control. (To do this it uses CCoeControl::CountComponentControls()const and CCoeControl::ComponentControl(TInt)const, which should be implemented by the derived control class.) If the control is a window-owning control, it also calls CCoeControl::Draw(const TRect &)const for its child windows (if any).

IMPORT_C void DrawNow(const TRect &aRect) const;

Description

Draws the control, its components and child windows, within the bounds defined by the given rectangle.

Parameters

IMPORT_C void DrawDeferred() const;

Description

Draws the control, with low priority.

This function is called by an application or other code.

It causes the control area to be marked as invalid, which will eventually cause a redraw initiated by the window server. The control framework handles redraw events at a lower priority than user input events, which means that any pending user input events will be processed before the redraw event. CCoeControl::DrawDeferred()const therefore allows a control to do drawing at a lower priority than drawing performed by CCoeControl::DrawNow()const.

An advantage of using CCoeControl::DrawDeferred()const is that if you make multiple calls to CCoeControl::DrawDeferred()const on the same area of a control, the window server will not generate a redraw event to do drawing that has already been superceded. If you make multiple calls to CCoeControl::DrawNow()const, however, all of them get processed, even if they have already been superceded by the time they are processed.

IMPORT_C CWindowGc& SystemGc() const;

Description

Gets the graphics context that is used when drawing the control.

This function walks the CCoeControl hierarchy upwards from child to parent until a context is found. If no control in the hierarchy has defined its own graphics context, the default system graphics context (iCoeEnv->CCoeControl::SystemGc()const) is returned.

All drawing is carried out through a graphics context. A graphics context must be activated before it can be drawn to, and deactivated when it is no longer needed. When drawing is done using CCoeControl::Draw(const TRect &)const, CCoeControl::DrawNow()const or CCoeControl::DrawDeferred()const, the application does not have to do this, as it is done within the control framework. However, for application-initiated drawing which is not done using CCoeControl::DrawNow()const or CCoeControl::DrawDeferred()const, the application should activate and deactivate the graphics context using CCoeControl::ActivateGc()const and CCoeControl::DeactivateGc()const (or CWindowGc::Activate(RDrawableWindow &) and CWindowGc::Deactivate()).

Return value

IMPORT_C TInt SetCustomGc(CWindowGc *aGraphicsContext);

Description

Sets the control's custom graphics context. This value overrides the system context for this control and any children.

If aGraphicsContext is null, the control's graphics context is reset to the one it inherited from its parent, or to the default system graphics context (iCoeEnv->CCoeControl::SystemGc()const) if none of its parents have set their own graphics context.

This value is retrieved by CCoeControl::SystemGc()const.

Parameters

Return value

IMPORT_C CWindowGc* CustomGc() const;

Description

Returns the custom graphics context set for this control (if any). Note that unlike CCoeControl::SystemGc()const, this function ignores the parent window's state and returns the context set explicitly for this control instance, or NULL if none has been set.

Return value

IMPORT_C void SetControlContext(MCoeControlContext *aContext);

Description

Set the control context for this control.

Parameters

IMPORT_C void CopyControlContextFrom(const CCoeControl *aControl);

Description

Sets the control's context from another control.

Parameters

IMPORT_C MCoeControlContext* ControlContext() const;

Description

Gets the control context being used by this control.

The function does not transfer ownership to the caller.

Return value

IMPORT_C void SetPointerCapture(TBool aCapture=ETrue);

Description

Sets pointer capture.

Once set, pointer capture lasts until CCoeControl::SetPointerCapture(TBool) is called on the control with aCapture=EFalse.

This function is typically used by dialogs, to discard any pointer events that occur outside of the dialog.

Parameters

See also:

• RWindowBase::SetPointerCapture(TInt)Sets the pointer capture state.

IMPORT_C void ClaimPointerGrab(TBool aSendUpEvent=ETrue);

Description

Claims pointer grab from another control.

This ensures that all subsequent pointer events are delivered to it and not to the control that originally owned the grab.

The function allows a control to claim the pointer grab only if the pointer is already grabbed by another control.

Parameters

See also:

• RWindowBase::ClaimPointerGrab(TBool)Claims the pointer grab from another window.

IMPORT_C void IgnoreEventsUntilNextPointerUp();

Description

Sets the control to ignore pointer events until the next pointer up.

This means that all events until and including the next pointer up event are discarded and are not processed.

This can be used for example if the user presses the Esc key while selecting text by dragging the pointer device to endure that further dragging does not result in continued selection.

IMPORT_C void SetGloballyCapturing(TBool aGlobal);

Description

Sets the global pointer capture flag.

This flag indicates whether or not pointer capture should be global.

The flag is used by CCoeControl::SetPointerCapture(TBool) to determine what value to pass to RWindowBase::SetPointerCapture(TInt). The default for the global capture flag, when a control is created, is EFalse.

Parameters

IMPORT_C TInt SetHitTest(const MCoeControlHitTest *aHitTestControl);

Description

Installs a hit tester for this control. The tester defines the hit region, which is the area within the control that accepts pointer events. If no hit region is set, pointer events are accepted in the control's entire rectangle.

Parameters

Return value

IMPORT_C const MCoeControlHitTest* HitTest() const;

Description

Gets the object that defines the hit region inside the control's rectangle. The object is set by calling CCoeControl::SetHitTest(const MCoeControlHitTest *).

Return value

IMPORT_C void OverrideColorL(TInt aLogicalColor, TRgb aColor);

Description

Overrides the control's colour setting, as specified in the application's colour scheme.

This function does not change the application's colour scheme. It changes the colour mapping used in this control only.

Parameters

See also:

• CCoeControl::GetColor(TInt,TRgb &)constGets the overridden physical colour.

IMPORT_C TBool GetColor(TInt aLogicalColor, TRgb &aColor) const;

Description

Gets the overridden physical colour.

This is the colour which has been mapped to the logical colour specified by a call to CCoeControl::OverrideColorL(TInt,TRgb). If the logical colour specified has not been overridden, the aColor value is not changed.

Parameters

Return value

IMPORT_C void DrawBackground(const TRect &aRect) const;

Description

Draws the control's background using its graphics context. Unlike CCoeControl::DrawNow()const and CCoeControl::DrawDeferred()const, this function does not propagate the draw to component controls.

Parameters

IMPORT_C void DrawForeground(const TRect &aRect) const;

Description

Draws the control's foreground using the control's graphics context. Unlike CCoeControl::DrawNow()const and CCoeControl::DrawDeferred()const, this function does not propagate the draw to component controls.

Parameters

IMPORT_C const MCoeControlBackground* Background() const;

Description

Returns the background drawer object associated with this object, if any. Null is returned if there is no such object. Compare with CCoeControl::FindBackground()const, which looks up the parent chain to find a background drawer.

Return value

IMPORT_C const MCoeControlBackground* FindBackground() const;

Description

Return an MCoeControlBackground object, if there is one - looking up the parent chain as necessary. Compare to CCoeControl::Background()const, which does not go up the parent chain.

Return value

IMPORT_C void SetBackground(const MCoeControlBackground *aBackground);

Description

Sets a pointer to a MCoeControlBackground object that is responsible for drawing the control's background

Parameters

IMPORT_C void SetZoomFactorL(TInt aZoomFactor, TZoomType aZoomType=ERelativeZoom);

Description

Set the zoom factor for this control.

Parameters

IMPORT_C TZoomFactor AccumulatedZoom() const;

Description

Return the zoom factor for this control. Takes account of zoom factors in parent controls to calculate accumulated zoom factor.

Return value

IMPORT_C const TCoeZoomWithType* ZoomWithType() const;

Description

Return the zoom factor but without taking into account the zoom factor of the parent. Use of CCoeControl::AccumulatedZoom()const is recommended as it takes into account the zoom factor of the parent.

Return value

IMPORT_C const CCoeFontProvider& FindFontProvider() const;

Description

Return the font provider used by this control

Return value

IMPORT_C void SetFontProviderL(const CCoeFontProvider &aFontProvider);

Description

Set the font provider. This is an external object that takes the responsibililty for finding an appropriate font away from the control.

Parameters

IMPORT_C virtual TInt TextBaselineOffset(const TSize &aSize) const;

Description

Gets the offset to the first text baseline relative to the top of the control.

The default implementation calls CalcTextBaselineOffset of the layout manager if one is installed. It returns 0 if no layout manager is installed.

Derived classes that don't want to use the layout manager and still want to return a baseline offset should re-implement this function.

Parameters

Return value

IMPORT_C virtual void SetTextBaselineSpacing(TInt aSpacing);

Description

Sets the spacing between text baselines.

The default implementation calls SetTextBaselineSpacing of the layout manager if one is installed. It does nothing if there is no layout manager.

Derived classes that don't want to use the layout manager and still want to do something when the this function is called should re-implement it.

Parameters

IMPORT_C TCoeInputCapabilities RecursivelyMergedInputCapabilities() const;

Description

Gets the input capabilities of the control and all its components.

Return value

IMPORT_C void SetMopParent(MObjectProvider *aParent);

Description

Sets the context - that is, the enclosing parent control - for this control. If setting aParent as MopParent of this control creates a cyclic relationship, this method will do nothing.

Parameters

IMPORT_C TInt UniqueHandle() const;

Description

Returns a Unique Handle (identifier) previously allocated to the control.

Return value

See also:

• CCoeControl::SetUniqueHandle(TInt)Sets a Unique Handle (identifier). That the number is unique is the perogative o...

IMPORT_C TInt SetUniqueHandle(TInt aUniqueHandle);

Description

Sets a Unique Handle (identifier). That the number is unique is the perogative of the caller!

Parameters

Return value

See also:

• CCoeControl::UniqueHandle()constReturns a Unique Handle (identifier) previously allocated to the control.

IMPORT_C virtual void HandlePointerEventL(const TPointerEvent &aPointerEvent);

Description

Handles pointer events.

This function gets called whenever a pointer event occurs in the control, i.e. when the pointer is within the control's extent, or when the control has grabbed the pointer. The control should implement this function to handle pointer events.

Note: events of type EButton1Down are processed before CCoeControl::HandlePointerEventL(const TPointerEvent &) is called, in order to transfer keyboard focus to the control in which the EButton1Down event occurred.

If overriding CCoeControl::HandlePointerEventL(const TPointerEvent &), the implementation must include a base call to CCoeControl's CCoeControl::HandlePointerEventL(const TPointerEvent &).

Parameters

protected: IMPORT_C virtual void HandlePointerBufferReadyL();

Description

Handles pointer buffer ready events.

This function is called whenever the control receives an event of type EEventPointerBufferReady, unless one of its component controls has grabbed the pointer, in which case the function is called on that control. An event of type EEventPointerBufferReady will only be received if the pointer move buffer has been set up using window server functions.

The pointer move buffer is typically used when the application requires a continuous stream of pointer drag events, such as in a drawing application.

See also:

• RWindowBase::AllocPointerMoveBuffer(TInt,TUint)Allocates a buffer for storing pointer movements.

protected: IMPORT_C virtual void FocusChanged(TDrawNow aDrawNow);

Description

Responds to a change in focus.

This is called whenever the control gains or loses focus, as a result of a call to CCoeControl::SetFocus(TBool,TDrawNow). A typical use of CCoeControl::FocusChanged(TDrawNow) is to change the appearance of the control, for example by drawing a focus rectangle around it.

The default implementation is empty, and should be overridden by the CCoeControl-derived class.

Parameters

protected: IMPORT_C virtual void SizeChanged();

Description

Responds to changes to the size and position of the contents of this control.

For a simple control this might include text or graphics. For a compound control it sets the size and position of the components.

The function is called whenever CCoeControl::SetExtent(const TPoint &,const TSize &), CCoeControl::SetSize(const TSize &), CCoeControl::SetRect(const TRect &), CCoeControl::SetCornerAndSize(TGulAlignment,const TSize &), or CCoeControl::SetExtentToWholeScreen() are called on the control. Note that the window server does not generate size-changed events: CCoeControl::SizeChanged() gets called only as a result of calling the functions listed above. Therefore, if a resize of one control affects the size of other controls, it is up to the application to ensure that it handles the re-sizing of all affected controls.

protected: IMPORT_C virtual void PositionChanged();

Description

Responds to changes in the position of a control.

It has an empty default implementation which may be overridden by the CCoeControl-derived class.

This function is called whenever the application calls CCoeControl::SetPosition(const TPoint &) on the control.

IMPORT_C virtual TInt CountComponentControls() const;

Description

Gets the number of controls contained in a compound control.

There are 2 ways to implement a compound control. One way is to override this function. The other way is to use the CCoeControlArray functionality (see the InitComponentArrayL method).

Return value

IMPORT_C virtual CCoeControl* ComponentControl(TInt aIndex) const;

Description

Gets an indexed component of a compound control.

There are 2 ways to implement a compound control. One way is to override this function. The other way is to use the CCoeControlArray functionality (see the InitComponentArrayL method).

Note: within a compound control, each component control is identified by an index, where the index depends on the order the controls were added: the first is given an index of 0, the next an index of 1, and so on.

Parameters

Return value

IMPORT_C TInt Index(const CCoeControl *aControl) const;

Description

Gets the index of a control that is a component of this control.

Parameters

Return value

protected: IMPORT_C TBool IsActivated() const;

Description

Tests if the control has been activated.

A control is not ready to draw until it is activated.

Return value

protected: IMPORT_C TBool IsBeingDestroyed() const;

Description

Tests if the control is being destroyed.

Return value

protected: IMPORT_C void InitComponentArrayL();

Description

Creates a component array to store child controls.

This function is useful when the control is a compound control. It creates an array where the child controls can be stored. The CCoeControl::Components() return the created array. The CCoeControlArray class provides functions to easily add and remove controls.

protected: IMPORT_C CCoeControlArray& Components();

Description

Returns a component array to store child controls.

This function is useful when the control is a compound control. The CCoeControlArray class provides functions to easily add and remove controls. The array must have been created before this function can be called. The InitComponentArrayL does this.

Return value

See also:

• CCoeControl::InitComponentArrayL()Creates a component array to store child controls.

protected: IMPORT_C const CCoeControlArray& Components() const;

Description

Returns a component array to store child controls.

This function is useful when the control is a compound control. The CCoeControlArray class provides functions to easily add and remove controls. The array must have been created before this function can be called. The InitComponentArrayL does this.

Return value

See also:

• CCoeControl::InitComponentArrayL()Creates a component array to store child controls.

protected: IMPORT_C RWindow& Window() const;

Description

Gets the control's associated window.

The control must be window owning, and the window must be of type RWindow. If you don't know whether the window is of type RWindow or RBackedUpWindow, you should use CCoeControl::DrawableWindow()const.

Return value

protected: IMPORT_C RBackedUpWindow& BackedUpWindow() const;

Description

Gets the backed-up window owned by the control.

The window must be of type RBackedUpWindow. If you don't know whether the window is of type RWindow or RBackedUpWindow, you should use CCoeControl::DrawableWindow()const.

Return value

protected: IMPORT_C void CloseWindow();

Description

Closes the window owned by this control.

It is called from CCoeControl's destructor for window-owning controls.

protected: IMPORT_C void CreateWindowL();

Description

Creates a control's window.

The created window is the child of the application's window group.

This function makes the specified control a window-owning control, and would typically be called in the control's ConstructL() function.

Note:

The use of window owning controls is discouraged, as these tax run-time resources. Ideally only the top level control in an appUi would be window owning. There are some exceptions to this rule, e.g. floating controls like menus, dialogs and scroll bars.

protected: IMPORT_C void CreateWindowL(const CCoeControl *aParent);

Description

Creates a control's window, specifying the parent control.

The control's window is created as a child of the parent control's window.

This function makes the specified control a window-owning control, and would typically be called in the control's ConstructL() function.

Note:

The use of window owning controls is discouraged, as these tax run-time resources. Ideally only the top level control in an appUi would be window owning. There are some exceptions to this rule, e.g. floating controls like menus, dialogs and scroll bars.

In general, the overload with no parameters should be used.

Parameters

protected: IMPORT_C void CreateWindowL(RWindowTreeNode &aParent);

Description

Creates a control's window, specifying its parent window and its extent.

This function makes the specified control a window-owning control, and would typically be called in the control's ConstructL() function. It also sets the window's extent to that of the control.

Note:

The use of window owning controls is discouraged, as these tax run-time resources. Ideally only the top level control in an appUi would be window owning. There are some exceptions to this rule, e.g. floating controls like menus, dialogs and scroll bars.

In general, the overload with no parameters should be used.

Parameters

protected: IMPORT_C void CreateWindowL(RWindowGroup *aParent);

Description

Creates a control's window, specifying its parent window group.

This function makes the specified control a window-owning control, and would typically be called in the control's ConstructL() function.

Note:

The use of window owning controls is discouraged, as these tax run-time resources. Ideally only the top level control in an appUi would be window owning. There are some exceptions to this rule, e.g. floating controls like menus, dialogs and scroll bars.

In general, the overload with no parameters should be used.

Parameters

protected: IMPORT_C void CreateBackedUpWindowL(RWindowTreeNode &aParent);

Description

Creates a control's window as a backed-up window.

The new window is the child of aParent and the display mode of the control becomes the same as that of aParent.

Parameters

protected: IMPORT_C void CreateBackedUpWindowL(RWindowTreeNode &aParent, TDisplayMode aDisplayMode);

Description

Creates a control's window as a backed-up window, specifying the display mode.

The new window is the child of aParent and the display mode of the control is set to aDisplayMode. Furthermore, the window's extent is set to that of the control.

Parameters

protected: IMPORT_C void SetCornerAndSize(TGulAlignment aCorner, const TSize &aSize);

Description

Sets the control's alignment and size.

The control's position is calculated, relative to the screen, according to the requested alignment.

Note: calling this function results in a call to CCoeControl::SizeChanged().

Parameters

protected: IMPORT_C void SetSizeWithoutNotification(const TSize &aSize);

Description

Sets a control's size without calling CCoeControl::SizeChanged().

If the size, but not the position, of a control is set, then its position will default to TPoint(0,0).

Parameters

See also:

• CCoeControl::SetSize(const TSize &)Sets the control's size.

protected: IMPORT_C const CFont& ScreenFont(const TCoeFont &aFont) const;

Description

Return the correct font given the supplied font and taking into account the current zoom factor.

Parameters

Return value

protected: IMPORT_C CCoeTextDrawerBase& TextDrawer(TInt aKey=KErrNotFound) const;

Description

Gets the text drawer to be used for the control. This method returns a reference simply because the return value must never be NULL. The ownership transfer rules of the returned CCoeTextDrawerBase object obey specific rules. If the CCoeTextDrawerBase::IsReusable()const flag is set then the caller must call Reset when the object is not needed anymore else it should simply delete the object. The XCoeTextDrawer class is a wrapper around the CCoeTextDrawerBase that will implement this logic automatically. The method will start with the default text drawer. It then allows the childs background control to change the text drawer if the child itself is window owning. Otherwise only the parent control can change the text drawer.

Parameters

Return value

protected: IMPORT_C void EnableDragEvents();

Description

Requests pointer drag events.

This function should be called if a control is required to receive pointer drag and move events. The default behaviour for all controls is that pointer drag and move events are not delivered.

The control framework does not provide a function to disable drag events at a later time, but this can be done via the Window Server API, by calling CCoeControl::Window()const->PointerFilter().

Note:

By default, pointer move events are not delivered, even after calling CCoeControl::EnableDragEvents(), because they are not normally required in a pen-based system. The window server can be configured to deliver pointer move events if required, e.g. for a mouse-based system.

See also:

• RWindowBase::PointerFilter(TUint32,TUint32)Sets the filter which controls which pointer events are sent to the client sessi...

protected: IMPORT_C void HandleRedrawEvent(const TRect &aRect) const;

Description

Handles redraw events.

In normal circumstances this function should not be used or overridden by the derived control class.

Parameters

protected: IMPORT_C void SetAllowStrayPointers();

Description

Sets whether or not to allow stray pointer events.

This function sets a flag that affects the way the control framework handles pointer events. By default, the flag is not set, and the control will ignore any pointer drag events and up events where the matching pointer down event occurred in a different control. This would happen if a user pressed the pointer down in a control, but then dragged the pointer into a different control before releasing it.

CCoeControl::SetAllowStrayPointers() is typically used for menus, where stray pointer events are required because it is the pointer up event that is used to activate a menu option even when the pointer down event occured in a different menu pane. This is not the case in some other components such as command buttons, where a pointer down event and up event in succession are required to activate the button.

protected: IMPORT_C CCoeControl* GrabbingComponent() const;

Description

Gets the component of this control which is grabbing the pointer.

Return value

protected: IMPORT_C TBool CapturesPointer() const;

Description

Tests whether pointer capture is set for the control.

This returns true if CCoeControl::SetPointerCapture(TBool) has been called with aCapture=ETrue.

Return value

protected: IMPORT_C TBool IsReadyToDraw() const;

Description

Tests if the control is ready for drawing.

This returns true if the control has been activated and is visible.

Return value

protected: IMPORT_C TBool IsBlank() const;

Description

Tests if the control is blank.

This simply gets the value of the flag set by CCoeControl::SetBlank().

Return value

protected: IMPORT_C void SetBlank();

Description

Sets a flag to indicate that the control is blank.

Once set, this flag cannot be unset for the lifetime of the control.

See also:

• CCoeControl::IsBlank()constTests if the control is blank.

protected: IMPORT_C void SetCanDrawOutsideRect();

Description

Allows the control to draw outside its own extent.

When a compound control is drawn, all its component controls are also drawn. However, unless this flag is set, they are not drawn if the rectangle they inhabit on the screen doesn't intersect with the rectangle to be drawn.

Setting this flag has the effect of allowing a component control to draw outside its own extent. It should be used with caution! By default, this flag is not set.

protected: IMPORT_C void ActivateGc() const;

Description

Activates the standard graphics context.

This is the graphics context owned by the control environment (CCoeEnv).

Applications do not normally need to call this function, as it is called by the control framework whenever it is about to call CCoeControl::Draw(const TRect &)const.

protected: IMPORT_C void DeactivateGc() const;

Description

Deactivates the standard graphics context owned by the UI control framework.

Applications do not normally need to call this function, as it is called by the control framework whenever it has called CCoeControl::Draw(const TRect &)const and drawing is completed.

protected: IMPORT_C void ResetGc() const;

Description

Resets the standard graphics context.

The function resets the graphics context owned by the control environment to its default settings.

protected: IMPORT_C void ReportEventL(MCoeControlObserver::TCoeEvent aEvent);

Description

Sends an event to the control's observer (if the control has one).

Parameters

protected: IMPORT_C void HandleComponentControlsResourceChange(TInt aType);

Description

Handles a change to the resources in the components of a compound control.

Parameters

See also:

• CCoeControl::HandleResourceChange(TInt)Handles a change to the control's resources.

protected: inline CCoeControl& operator=(const CCoeControl &aControl);

Description

Parameters

Return value

protected: IMPORT_C virtual void HandleControlArrayEventL(CCoeControlArray::TEvent aEvent, const CCoeControlArray *aArray, CCoeControl *aControl, TInt aControlId);

Description

Handles events generated by the CCoeControlArray.

This function is useful when the control is a compound control and the CCoeControlArray functionality is used. The CCoeControlArray functions that add and remove controls will use this event handler to notify the control that child controls have been added or removed.

The default implementation of this function forwards the events to the layout manager (if there is one). If the event is EControlAdded it also sets the container window of the new child control unless the child control is a window owning control. If the event is EControlRemoved it also sets the parent of the removed child control to null.

Parameters

private: IMPORT_C virtual void GetTextDrawer(CCoeTextDrawerBase *&aTextDrawer, const CCoeControl *aDrawingControl, TInt aKey) const;

Description

Controls that want to change or replace the text drawer that it or its children controls use shall override this method. The aTextDrawer argument is guaranteed never to be NULL, and the control can choose to modify it or create a new text drawer in its place.

Parameters

protected: IMPORT_C virtual TTypeUid::Ptr MopSupplyObject(TTypeUid aId);

Description

Retrieves an object of the same type as that encapsulated in aId.

This function is used to allow controls to ask their owners for access to other objects that they own.

Other than in the case where NULL is returned, the object returned must be of the same object type - that is, the ETypeId member of the object pointed to by the pointer returned by this function must be equal to the iUid member of aId.

Parameters

Return value

private: IMPORT_C virtual MObjectProvider* MopNext();

Description

Retrieves the control's parent.

This function may be overridden to continue the chain of object providers which are to be asked to supply an object.

When overriding this function for any given class of control, it is important to ensure that the function does not return, either directly or indirectly, a pointer to the instance of that class on which the function was called. For example, suppose that bar is an object of class foo. The override for the class foo could legitimately return a pointer to the object provider in which bar is contained, but must never return a pointer either to bar or to an object provider which may return bar. Failure to observe this restriction may result in an infinite loop.

Return value

private: IMPORT_C virtual void Draw(const TRect &aRect) const;

Description

Draws the control.

All controls, except blank controls, should implement this function. The default implementation draws a blank control.

This function is called by window server. It is used for window server-initiated redrawing of controls, and for some application-initiated drawing. It should be implemented by each control, but is only called from within CCoeControl's member functions, and not from the derived class. For this reason it is a private member function of CCoeControl.

The rectangle aRect indicates the region of the control that needs to be redrawn. The implementation of CCoeControl::Draw(const TRect &)const must always draw to every pixel within this rectangle.

Notes:

For non-window-owning controls, care must be taken not to draw outside the control, as drawing will not be clipped to the control. Drawing is clipped to window-owning-controls, but not to non-window-owning controls.

Drawing outside aRect may cause flicker.

Drawing should be done using a graphics context (CWindowGc), which can be obtained using CCoeControl::SystemGc()const.

Parameters

protected: IMPORT_C virtual void WriteInternalStateL(RWriteStream &aWriteStream) const;

Description

Parameters

private: IMPORT_C virtual void Reserved_2();

Description

inline TInt SetGc(CWindowGc *aGraphicsContext) const;

Description

Deprecated. See CCoeControl::SetCustomGc(CWindowGc *).

Parameters

Return value

inline CWindowGc* GetGc() const;

Description

Deprecated. See CCoeControl::CustomGc()const.

Return value

IMPORT_C void EnableReportControlStateChange(TBool aState);

Description

Set the status of the report control state change.

Parameters

See also:

• CCoeControl::SetDimmed(TBool)Sets the control to be dimmed.
• CCoeControl::MakeVisible(TBool)Sets this control as visible or invisible.

TZoomType

Description

protected: CCoeEnv * iCoeEnv;

Description

protected: MCoeControlContext * iContext;

Description

protected: TPoint iPosition;

Description

protected: TSize iSize;

Description