ATTR_DRAW_POLICY
| Type: | Control attribute |
| Description: | Each canvas has an offscreen bitmap which is used to restore the appearance of the canvas when the canvas region is exposed. This attribute determines if and when drawing operations are rendered on the offscreen bitmap and the screen. |
| Control Types: | Canvases. |
| Data Type: | integer |
| Default Value: | VAL_UPDATE_IMMEDIATELY |
| LabWindows/CVI Compatibility: |
LabWindows/CVI 4.0 and later |
Values
| VAL_DIRECT_TO_SCREEN | Drawing goes directly to the screen. The offscreen bitmap is not updated. Although this may result in a faster drawing time, whatever is drawn in this mode is lost when the canvas is redrawn. |
| VAL_UPDATE_IMMEDIATELY | Drawing takes place offscreen. The bitmap section corresponding to the area of the drawing operation is then copied into the canvas display. |
| VAL_MARK_FOR_UPDATE | Drawing takes place offscreen. The area on the canvas corresponding to the area of the drawing operation is marked for update instead of being copied into the display. The new drawing becomes visible when draw events are processed. |