#include <w32std.h>
| class RBackedUpWindow : public RDrawableWindow |
| Public Member Functions | |
|---|---|
| RBackedUpWindow() | |
| RBackedUpWindow(RWsSession &) | |
| IMPORT_C TInt | BitmapHandle() |
| IMPORT_C TInt | Construct(const RWindowTreeNode &, TDisplayMode, TUint32) |
| IMPORT_C void | MaintainBackup() |
| IMPORT_C void | UpdateBackupBitmap() |
| IMPORT_C void | UpdateScreen() |
| IMPORT_C void | UpdateScreen(const TRegion &) |
| Inherited Attributes | |
|---|---|
| MWsClientClass::iBuffer | |
| MWsClientClass::iWsHandle | |
| RWindowTreeNode::__DECLARE_TEST | |
| Inherited Enumerations | |
|---|---|
| RWindowBase:TCaptureFlags | |
| RWindowTreeNode:TFadeControl | |
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.
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.
| IMPORT_C | RBackedUpWindow | ( | ) |
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 | ) |
Constructor which creates an uninitialised backed-up window handle within a session.
| Parameter | Description |
|---|---|
| aWs | The window server session that owns the window. |
| IMPORT_C TInt | BitmapHandle | ( | ) | const |
Gets a handle to the backup bitmap.
This handle can then be passed to CFbsBitmap::Duplicate() 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 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.
Returns: The handle of the backup bitmap.
| IMPORT_C TInt | Construct | ( | const RWindowTreeNode & | parent, |
| TDisplayMode | aDisplayMode, | |||
| TUint32 | aHandle | |||
| ) | ||||
Completes the construction of a backed up window.
This method should be called after the 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 subsequently be altered.
The window will have the same display mode as the system display mode.
This function always causes a flush of the window server buffer.
See also: RWindowBase::SetSizeErr() RWindowBase::SetExtentErr() RWindow::Construct()
| Parameter | Description |
|---|---|
| parent | The window's parent. |
| aDisplayMode | Ignored. The window will always be created with the system display mode. |
| aHandle | The client's handle for the window. See RWindow::Construct() for a description of the client handle. |
Returns: KErrNone if successful, otherwise one of the system-wide error codes, the most likely of which is KErrNoMemory.
| IMPORT_C void | MaintainBackup | ( | ) |
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.
| IMPORT_C void | UpdateBackupBitmap | ( | ) |
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: MaintainBackup()
| IMPORT_C void | UpdateScreen | ( | ) |
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 | ) |
Copies a part of the backup bitmap to the on-screen bitmap.
This function behaves in the same way as 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.
| Parameter | Description |
|---|---|
| aRegion | Area of the backup bitmap to copy. |