This is not the exact answer to your question but can give of help. I remember to have used a canvas on top of a table drawing a rectangle synced with table rows; the rectangle was draw with:
CanvasDrawRoundedRect (panelHandle, PANEL_TABLE, MakeRect (row1 * 19 - 2, 2, row2 * 19 + 6, 6), 6, 3, VAL_DRAW_FRAME_AND_INTERIOR);
The task was simplified by these facts:
- I had manually aligned the canvas with the exact table rows-area
- The table had uniform rows with explicit height of 19 pixels
If you want Getting the coordinates relative to control can be obtained considering the column labels height and row labels width (GetCtrlAttribute with attribute ATTR_COLUMN_LABELS_HEIGHT and ATTR_ROW_LABELS_WIDTH respectively) plus the control frame width (ATTR_FRAME_THICKNESS).
