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SYMBIAN OS V9.3

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Location: W32STD.H
Link against: ws32.lib

Class RDrawableWindow

class RDrawableWindow : public RWindowBase;

Description

Handle to a drawable window.

This class cannot be constructed directly. The two concrete derived classes, RWindow and RBackedUpWindow, allow drawing but use different protocols because RWindow relies on the client to redraw invalid areas.

Derivation

Members

Defined in RDrawableWindow:
GetDrawRect(), Scroll(), Scroll(), Scroll(), Scroll()

Inherited from MWsClientClass:
WsHandle()

Inherited from RWindowBase:
AbsPosition(), Activate(), AddKeyRect(), AllocPointerMoveBuffer(), CancelPointerRepeatEventRequest(), ClaimPointerGrab(), DisablePointerMoveBuffer(), DiscardPointerMoveBuffer(), DisplayMode(), EnableBackup(), EnablePointerMoveBuffer(), FadeBehind(), FreePointerMoveBuffer(), GetPointerCapturePriority(), InquireOffset(), IsFaded(), IsNonFading(), MoveToGroup(), PasswordWindow(), PointerFilter(), Position(), RemoveAllKeyRects(), RequestPointerRepeatEvent(), RetrievePointerMoveBuffer(), SetCornerType(), SetExtentErr(), SetPointerCapture(), SetPointerCapturePriority(), SetPointerGrab(), SetPosition(), SetRequiredDisplayMode(), SetShadowDisabled(), SetShadowHeight(), SetShape(), SetSizeErr(), SetVisible(), Size(), TCaptureDisabled, TCaptureDragDrop, TCaptureEnabled, TCaptureFlagAllGroups, TCaptureFlagDragDrop, TCaptureFlagEnabled, TCaptureFlags

Inherited from RWindowTreeNode:
Child(), ClearPointerCursor(), Close(), Destroy(), DisableErrorMessages(), DisableFocusChangeEvents(), DisableGroupChangeEvents(), DisableGroupListChangeEvents(), DisableModifierChangedEvents(), DisableOnEvents(), DisableVisibilityChangeEvents(), EFadeIncludeChildren, EFadeWindowOnly, EnableErrorMessages(), EnableFocusChangeEvents(), EnableGroupChangeEvents(), EnableGroupListChangeEvents(), EnableModifierChangedEvents(), EnableOnEvents(), EnableVisibilityChangeEvents(), FullOrdinalPosition(), NextSibling(), OrdinalPosition(), OrdinalPriority(), Parent(), PrevSibling(), SetCustomPointerCursor(), SetFaded(), SetNonFading(), SetOrdinalPosition(), SetPointerCursor(), TFadeControl, WindowGroupId()


Member functions


Scroll()

IMPORT_C void Scroll(const TPoint &aOffset);

Description

Scrolls the window contents by an offset.

All parts of an RWindow are either drawn with content copied from another part of the window or are invalidated. Areas are invalidated when the source content of the scroll would be outside the window or obscured behind another window. The areas that are invalidated are not blanked off.

For example, if the window is scrolled towards the right, then there is no content (from outside the window) to move into area on the left hand side. This area is invalidated. Similarly, no content can be scrolled out from under an obscuring window, so the area from beneath the obscuring window is also invalidated.

Note that for an RBackedUpWindow, the contents of areas obscured by other windows are stored. In this case the window contents are scrolled out from "underneath" the obscuring window. In the example above the area on the left was invalidated but for this type of window the area simply contains its old pre-scroll contents.

Parameters

const TPoint &aOffset

Scroll offset, in pixels. Positive values cause the window contents to move downwards/right. Negative values cause contents to move upwards/left.


Scroll()

IMPORT_C void Scroll(const TRect &aClipRect, const TPoint &aOffset);

Description

Scrolls the contents of a clip rectangle, independently of the other contents of the window.

This function behaves in exactly the same way as the single parameter overload, except that the scroll region is a clipping rectangle rather than the whole window. All parts of the clipping rectangle are either drawn with content copied from another part of the rectangle or are invalidated.

The RBackedUpWindow behaviour is also similar to the behaviour in the function above.

Parameters

const TRect &aClipRect

Rectangle to which scrolling is to be clipped

const TPoint &aOffset

Scroll offset, in pixels. Positive values cause the window contents to move downwards and right. Negative values cause contents to move upwards and left.


Scroll()

IMPORT_C void Scroll(const TPoint &aOffset, const TRect &aRect);

Description

Scrolls a rectangle within a window.

This function effectively moves the specified rectangle by the given offset with respect to the window. The destination rectangle may overlap and cover the old rectangle.

Note that if the source of this rectangle is an invalid area, ie it is obscured or lies outside the window, then this area in the destination rectangle will be invalidated.

Parameters

const TPoint &aOffset

Scroll offset, in pixels. Positive values cause the window contents to move downwards and right. Negative values cause contents to move upwards and left.

const TRect &aRect

The source rectangle for the scroll.


Scroll()

IMPORT_C void Scroll(const TRect &aClipRect, const TPoint &aOffset, const TRect &aRect);

Description

Scrolls the contents of a source rectangle within a clipping rectangle.

The source rectangle is effectively copied from one position to another, with both the source and destination clipped to the clipping rectangle. Hence if the source and destination rectangles are inside the clipping region then this function behaves exactly like the Scroll(const TPoint &aOffset, const TRect &aRect) overload. However if the source or destination for the scrolled rectangle intersect the clipping rectangle then the function behaves similarly to the Scroll(const TRect &aClipRect,const TPoint &aOffset) overload, with regards to invalidated regions etc.

Parameters

const TRect &aClipRect

Rectangle to which scrolling is to be clipped.

const TPoint &aOffset

Scroll offset, in pixels. Positive values cause the window contents to move downwards and right. Negative values cause contents to move upwards and left.

const TRect &aRect

Source rectangle for the scroll.


GetDrawRect()

IMPORT_C TRect GetDrawRect();

Description

Obtains the current rectangle being drawn to this window, during a window redraw cycle.

This function can be called between a BeginRedraw() / EndRedraw() pair to obtain the current window redraw reference rectangle.

Return value

TRect

The current reference rectangle that is being redrawn