When you assign multiple content canvases and at least
one stacked canvas to the same window, be aware of how Oracle Forms manages
content canvases in the stacking order. Since Oracle Forms can display only one
content canvas at a time in a single window, it treats all content canvases
assigned to the same window as if each one had the same position in the
stacking order, relative to the stacked canvases assigned to that window.
Consider a window with four canvases: CNT_A and CNT_C are
content canvases; STK_B is a stacked canvas; TAB_D is a tab canvas.
At runtime, Oracle Forms displays one content canvas at a
time in the window. If, at form startup, the application navigates to an item
on CNT_A, it becomes the current content canvas displayed in the window. If the
end user then navigates to an item on CNT_C, it replaces CNT_A, but at the same
position in the stacking order, rather than at its design-time position as
specified in the Object Navigator.
This functionality allows the current content canvas to
be replaced without hiding stacked canvases currently displayed in the same
window. When CNT_C replaces CNT_A, the stacked and tab canvases, which are
positioned above CNT_A at design time, remain visible.
When you use this technique, make sure that the stacked
and tab canvases are sequenced in front of (above) the first content canvas
that will be displayed in the window.
