HTML_PAINT_DRAW_INFO structure

Provides information that a rendering behavior might need to draw itself properly or more efficiently.

Syntax

typedef struct _HTML_PAINT_DRAW_INFO {
  RECT             rcViewport;
  HRGN             hrgnUpdate;
  HTML_PAINT_XFORM xform;
} HTML_PAINT_DRAW_INFO;

Members

• rcViewport
  RECT structure that contains the location of a scrolling area's visible area in relation to a scrolling area's document.

• hrgnUpdate
  HRGN value that contains the invalid region that needs to be repainted.

• xform
  HTML_PAINT_XFORM structure that contains the transformation matrices that the behavior should apply to its rendering output.

Remarks

The rcViewport member is useful, for example, in the case of a fixed background in a scrolling area. In order to keep the background fixed while the document in the scrolling area moves, you need to know the relationship of the visible area to the top-left corner of the document. For instance, if the scrolling area's window is 100 pixels high by 200 pixels wide, and the document within the window has scrolled down 40 pixels, rcViewport.top will be 40 (with no horizontal scrolling). You will know then to render the background image 40 pixels below the top of the document so that it will appear fixed in the scrolling window.

Requirements