CanvasDimRect
int CanvasDimRect (int panelHandle, int controlID, Rect rectangle);
Purpose
Overlays a partially opaque color field onto the specified rectangular area of a canvas control. This operation has the visual effect of dimming objects within this area.
CanvasDimRect uses as its color the current value of the ATTR_PEN_FILL_COLOR attribute.
Supported Controls
You can use CanvasDimRect 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. |
| rectangle | Rect | Rect structure specifying the location and size of the area to be dimmed. Use VAL_ENTIRE_OBJECT to specify the entire canvas. 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); ExampleCanvasDimRect (panelHandle, controlID, MakeRect(20,30,150,200)); |
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