Class RBackedUpWindow

class RBackedUpWindow : public RDrawableWindow;

Description

Client-side handle to a drawable window with a backup bitmap.

A backed-up window is associated with a backup bitmap which retains the contents of the window. When an area of the window is invalidated, the window server uses the bitmap directly to update the window without requiring an application redraw. The backup bitmap is owned by the font and bitmap server and resides on the font and bitmap server's shared heap, which is accessible to all client programs: functions are provided to allow the client application to access this bitmap directly and perform updates to the window under application control.

Derivation

• MWsClientClass - Base class for all classes whose objects are clients of the window server.

• RWindowTreeNode - A handle to a node in the server-side window tree.

• RWindowBase - Client-side handle to a server-side window.

• RDrawableWindow - Handle to a drawable window.

• RBackedUpWindow - Client-side handle to a drawable window with a backup bitmap.

Members

Defined in RBackedUpWindow:

• BitmapHandle()Gets a handle to the backup bitmap.
• Construct(const RWindowTreeNode &,TDisplayMode,TUint32)Completes the construction of a backed up window.
• MaintainBackup()Tells the window server to start maintaining a backup bitmap with the entire win...
• RBackedUpWindow()Default C++ constructor which creates a sessionless backed-up window handle.
• RBackedUpWindow(RWsSession &)Constructor which creates an uninitialised backed-up window handle within a sess...
• UpdateBackupBitmap()Copies to the backup bitmap any areas of the window which are not currently stor...
• UpdateScreen()Copies the backup bitmap's image to the on-screen bitmap.
• UpdateScreen(const TRegion &)Copies a part of the backup bitmap to the on-screen bitmap.

Inherited from MWsClientClass:

• WsHandle()constGets the server side handle for the object.

Inherited from RDrawableWindow:

• GetDrawRect()Obtains the current rectangle being drawn to this window, during a window redraw...
• Scroll(const TPoint &)Scrolls the window contents by an offset.
• Scroll(const TPoint &,const TRect &)Scrolls a rectangle within a window.
• Scroll(const TRect &,const TPoint &)Scrolls the contents of a clip rectangle, independently of the other contents of...
• Scroll(const TRect &,const TPoint &,const TRect &)Scrolls the contents of a source rectangle within a clipping rectangle.

Inherited from RWindowBase:

• AbsPosition()constGets a window's absolute position - ie the windows position relative to the curr...
• Activate()Displays the window and enables it to receive events.
• AddKeyRect(const TRect &,TInt,TBool)Adds an on-screen key rectangle.
• AllocPointerMoveBuffer(TInt,TUint)Allocates a buffer for storing pointer movements.
• CancelPointerRepeatEventRequest()Cancels a request for a pointer repeat event.
• ClaimPointerGrab(TBool)Claims the pointer grab from another window.
• DisablePointerMoveBuffer()Instructs the window server to stop adding pointer events to the pointer move bu...
• DiscardPointerMoveBuffer()Discards all events in the pointer move buffer.
• DisplayMode()Gets the window's current display mode.
• EnableBackup(TUint)Requests that this window backs up all or part of the screen's contents. There a...
• EnablePointerMoveBuffer()Enables the pointer move buffer for receiving pointer move events.
• FadeBehind(TBool)Sets whether or not all windows behind the current window, in the same window gr...
• FreePointerMoveBuffer()Frees the pointer move buffer.
• GetPointerCapturePriority()constGets the windows's pointer capture priority
• InquireOffset(const RWindowTreeNode &)constEnquires the offset between this and another window.
• IsFaded()Tests whether the current window is faded.
• IsNonFading()Tests whether the current window is non-fading.
• MoveToGroup(TInt)Moves this window to another window group.
• PasswordWindow(TPasswordMode)Makes this window the password window.
• PointerFilter(TUint32,TUint32)Sets the filter which controls which pointer events are sent to the client sessi...
• Position()constGets a window's position relative to its parent.
• RemoveAllKeyRects()Removes all the on-screen keys that have been added to this window.
• RequestPointerRepeatEvent(TTimeIntervalMicroSeconds32,const TRect &)Requests a pointer repeat event.
• RetrievePointerMoveBuffer(TDes8 &)Retrieves events from the pointer move buffer.
• SetCornerType(TCornerType,TInt)Sets the shape of a window's corners.
• SetExtentErr(const TPoint &,const TSize &)Sets a backed-up window's extent, relative to its parent, and returns an error c...
• SetPointerCapture(TInt)Sets the pointer capture state.
• SetPointerCapturePriority(TInt)Sets the window's pointer capture priority.
• SetPointerGrab(TBool)Allows or disallows pointer grabs in a window.
• SetPosition(const TPoint &)Sets the position of a window relative to its parent.
• SetRequiredDisplayMode(TDisplayMode)Sets the window's display mode.
• SetShadowDisabled(TBool)Enables or disables whether a window casts a shadow.
• SetShadowHeight(TInt)Sets a window's shadow height.
• SetShape(const TRegion &)Sets a window's shape arbitrarily, if rectangular windows are not required.
• SetSizeErr(const TSize &)Sets the size of a backed-up window.
• SetVisible(TBool)Sets the window's visibility.
• Size()constGets the window's current size.
• TCaptureDisabledEquivalent to disabling all the above flags.
• TCaptureDragDropEquivalent to the OR of the first three flags.
• TCaptureEnabledEquivalent to TCaptureFlagEnabled.
• TCaptureFlagAllGroupsCapture events from windows belonging to any group, not just the group of the wi...
• TCaptureFlagDragDropIf set, drag-drop events are sent to the window in which the pointer was lifted....
• TCaptureFlagEnabledIf set, capture is enabled, disabled otherwise.
• TCaptureFlagsCapture behaviour flags.

Inherited from RWindowTreeNode:

• Child()constGets the first child of the node.
• ClearPointerCursor()Clears pointer cursor settings.
• ClientHandle()constGets the window's client handle
• Close()Closes the node.
• Destroy()Closes and deletes the node.
• DisableErrorMessages()Cancels notification of error message events.
• DisableFocusChangeEvents()Disables delivery of focus changed events.
• DisableGroupChangeEvents()Cancels notification of group changed events.
• DisableGroupListChangeEvents()Disables reporting of window group list change events.
• DisableModifierChangedEvents()Cancels notification of modifier changed events.
• DisableOnEvents()Cancels notification of 'on' events.
• DisableVisibilityChangeEvents()Disables reporting of window visibility change events.
• EFadeIncludeChildrenInclude all child windows when fading/un-fading.
• EFadeWindowOnlyFade only the parent window.
• EnableErrorMessages(TEventControl)Requests notification of error message events.
• EnableFocusChangeEvents()Enables focus changed events.
• EnableGroupChangeEvents()Requests notification of group-change events.
• EnableGroupListChangeEvents()Enables reporting of window group list change events.
• EnableModifierChangedEvents(TUint,TEventControl)Requests notification of modifier changed events.
• EnableOnEvents(TEventControl)Requests notification of 'on' events. 'On' events are of type EEventSwitchOn.
• EnableVisibilityChangeEvents()Enables reporting of window visibility change events.
• FullOrdinalPosition()constGet the current full ordinal position of a window.
• NextSibling()constGets the next window after this one in its sibling list.
• OrdinalPosition()constGets the current ordinal position of the window tree node.
• OrdinalPriority()constGets the ordinal priority of the specified window.
• Parent()constGets the node's parent.
• PrevSibling()constGets the node before this one in the sibling list.
• SetCustomPointerCursor(const RWsPointerCursor &)Sets the pointer cursor to an application-defined cursor.
• SetFaded(TBool,TFadeControl)Sets the window as faded or unfaded.
• SetFaded(TBool,TFadeControl,TUint8,TUint8)Sets one or more windows as faded or unfaded, specifying a fading map.
• SetNonFading(TBool)Sets whether a window is non-fading.
• SetOrdinalPosition(TInt)Sets the ordinal position of a window.
• SetOrdinalPosition(TInt,TInt)Sets the ordinal position and ordinal priority of a window.
• SetPointerCursor(TInt)Sets the pointer cursor from the system pointer cursor list.
• TFadeControlFade control flags.
• WindowGroupId()Returns the window group Id of the parent window group

IMPORT_C RBackedUpWindow();

Description

Default C++ constructor which creates a sessionless backed-up window handle.

Handles to server-side objects must be created in a session in order to be operational; this constructor is merely a convenience to allow the handle to be stored as a data member. See RWindowTreeNode::RWindowTreeNode() for details of how the complete setup of a handle field may be deferred until the window server session is known.

IMPORT_C RBackedUpWindow(RWsSession &aWs);

Description

Constructor which creates an uninitialised backed-up window handle within a session.

Parameters

RWsSession &aWs The window server session that owns the window.

IMPORT_C TInt Construct(const RWindowTreeNode &parent, TDisplayMode aDisplayMode, TUint32 aHandle);

Description

Completes the construction of a backed up window.

This method should be called after the RBackedUpWindow::RBackedUpWindow(RWsSession &) constructor, and before any other functions are performed on the window. It creates a window in the window server corresponding to the RBackedUpWindow object, and allocates a bitmap with which to perform the window backup.

Unlike non backed up windows, the size of a backed up window is not inherited from its parent. The window will be created with an initial size of zero, but this can be altered. The display mode must be specified because it determines the amount of memory required to store the backup bitmap.

This function always causes a flush of the window server buffer.

Parameters

const RWindowTreeNode &parent The window's parent. TDisplayMode aDisplayMode The display mode for the window. TUint32 aHandle The client's handle for the window. See RWindow::Construct(const RWindowTreeNode &,TUint32) for a description of the client handle.

Return value

TInt KErrNone if successful, otherwise one of the system-wide error codes, the most likely of which is KErrNoMemory.

See also:

• RWindowBase::SetSizeErr(const TSize &)Sets the size of a backed-up window.
• RWindowBase::SetExtentErr(const TPoint &,const TSize &)Sets a backed-up window's extent, relative to its parent, and returns an error c...
• RWindow::Construct(const RWindowTreeNode &,TUint32)Completes the construction of the window handle.

IMPORT_C TInt BitmapHandle();

Description

Gets a handle to the backup bitmap.

This handle can then be passed to CFbsBitmap::Duplicate(TInt) to gain access to the bitmap. Once the bitmap has been obtained, it can be drawn to or read from by the application.

Notes: in most circumstances this function should be used only after RBackedUpWindow::MaintainBackup() has been called. Otherwise, the content of the backup bitmap will be unpredictable.

This function always causes a flush of the window server buffer.

Return value

TInt The handle of the backup bitmap.

IMPORT_C void UpdateScreen();

Description

Copies the backup bitmap's image to the on-screen bitmap.

This function should be used if the application draws directly to the backup bitmap. Any changes made to the backup bitmap will not be reflected on the screen until this function is called.

IMPORT_C void UpdateScreen(const TRegion &aRegion);

Description

Copies a part of the backup bitmap to the on-screen bitmap.

This function behaves in the same way as RBackedUpWindow::UpdateScreen(), but copies only the specified region of the backup bitmap to the window on screen.

This function always causes a flush of the window server buffer.

Parameters

const TRegion &aRegion Area of the backup bitmap to copy.

IMPORT_C void UpdateBackupBitmap();

Description

Copies to the backup bitmap any areas of the window which are not currently stored in the bitmap.

This method does not need to be called if the server has not been instructed to maintain the backup buffer constantly

See also:

• RBackedUpWindow::MaintainBackup()Tells the window server to start maintaining a backup bitmap with the entire win...

IMPORT_C void MaintainBackup();

Description

Tells the window server to start maintaining a backup bitmap with the entire window contents.

By default, the window only backs up the non-visible and shadowed part of the window. Calling this function makes drawing to the window much faster.

Once this function has been called, it cannot be reversed.