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PtClipAdd()

Add a clipping rectangle to the stack

Synopsis:

int PtClipAdd( PtWidget_t *widget, 
               PhRect_t *rect );

Description:

This function adds a clipping rectangle to the clipping stack. The rectangle added to the clipping stack is the intersection of the last rectangle on the stack and the rectangle defined in the PhRect_t pointed to by rect.

Prior to entering a widget's Draw method, the canvas rectangle derived from the PtBasic-class level is pushed onto the clipping stack. This prevents any children from drawing beyond the canvas of the parent container.

A widget can, however, draw beyond its own canvas or extent unless additional clipping is performed. PtAttemptResize() and PtResizeCanvas() set the Pt_UCLIP bit of a widget's resize flags if the widget requires additional clipping (to prevent it from drawing beyond its own canvas).

Returns:

The current level of stack clipping.

Classification:

Photon

See also:

PhRect_t, PtCalcCanvas(), PtClipRemove()

PtAttemptResize(), PtResizeCanvas() in Building Custom Widgets