CanvasSetClipRect
int CanvasSetClipRect (int panelHandle, int controlID, Rect clipRect);
Purpose
Sets the clipping rectangle for the canvas control. Canvas drawing operations do not extend beyond the clipping rectangle. Any drawing outside the clipping rectangle is not shown. The exception is CanvasClear, which is not limited to the clipping rectangle.
Changing the clipping rectangle does not affect the current contents of the canvas.
In the initial state for a canvas control, clipping is disabled.
Supported Controls
You can use CanvasSetClipRect with canvas controls.
Parameters
| Input | ||
| Name | Type | Description |
| panelHandle | int | Specifier for a particular panel that is currently in memory. You can obtain this handle from functions such as LoadPanel and NewPanel. |
| controlID | int | The defined constant, located in the .uir header file, that you assigned to the control in the User Interface Editor, or the ID returned by functions such as NewCtrl and DuplicateCtrl. |
| clipRect | Rect | Rect structure specifying into the location and size of the clipping rectangle. To disable clipping, set the height or width of clipRect to zero, or to a negative number. The macro VAL_EMPTY_RECT is convenient for this. The Rect structure is defined as follows: typedef struct { int top; int left; int height; int width; } Rect; You can create a Rect without having to declare a variable by using the following function: Rect MakeRect (int top, int left, int height, int width); Example CodeCanvasSetClipRect (panelHandle, controlID, MakeRect(20,30,50,50)); |
Return Value
| Name | Type | Description |
| status | int | Return value indicating whether the function was successful. A negative number indicates that an error occurred. |
Additional Information
Library: User Interface Library
Include file: userint.h
LabWindows/CVI compatibility: LabWindows/CVI 4.0 and later