The window xsize of and window ysize of functions can be applied to all regions. For a graphical region, the values returned are the X and Y dimensions of the size of the graphical region's window, and are in the graphical region's own coordinates. When applied to a textual region, ESL returns columns and lines. If ESL returns values of zero for these functions, you may have inquired about a key, dialog box, or a dialog control object.

In the following example, the user makes the window of Graph smaller in the Y dimension. After doing that, the program checks to see whether the new window height is large enough to be scaled down again. (The program will not allow the window height to go below zero.)  If it is too small to be scaled down again, the program removes the scale-down request key from the screen so that it cannot be selected again.

response to StretchHeight

    change Graph window size by 0 (-Squish)

    if (window ysize of Graph <= Squish) then

        make StretchHeight invisible

    end if