Blooper 22: Poor initial window location

    From GUI Bloopers, by Jeff Johnson (Morgan Kaufman Publishers, 2000). Used without permission.

    Most GUI-based computer applications consist of a main window and a number of other windows. One issue that arises is: Where on the computer screen should an application's window first appear?

    A Common Blooper is to display windows in a location that more for the convenience of the programmer than for the convenience of users. There are several variations:

    • Variation A: Displaying all windows at the same coordinate. This forces users to move windows to uncover other ones or to prevent windows from being covered by the next displayed window.

      • GUI programs open all new windows in screen position (0,0), the upper-left corner of the screen


    • Variation B: Displaying subordinate windows in the middle of the parent. This creates the following problems:
      • All the subordinate windows of a parent window still appear over each other. If there are many windows, we are back to the "all on top of each other" problem.
      • Sometimes subordinate windows are larger than their parent windows. In such a case, the parent is completely obscured when the subordinate window appears.

    • Variation C: Displaying subordinate windows off-screen. This is the WORST variation of "poor initial window location" - placing windows off-screen, so users won't even know they are there.

    • Variation D: Displaying subordinate windows far away from the parent. If a user's computer has more than one display, bringing up subordinate windows far from their parent can cause the subordinate window to appear on a different display from the parent. Worse, the subordinate window might be split across displays.

     

    Design Rule: Avoiding Poor Initial Window Location Problem

    • Decide where each window should go
    • Optimal position may depend on the type of window
      • Error, warning and confirmation dialog boxes should appear in prominent locations, to capture users' attention. The best position for that is to center the window at the current mouse pointer position.
      • Object property dialog boxes should appear adjacent to the object whose properties they are displaying.
      • Application main windows and subordinate windows can appear just about anywhere, as long as they don't all appear in the same place.
      • When nothing else is possible, just try avoiding displaying all windows on top of each other. Even random placement is better than always using location (0,0).

       

      Some general heuristics

      • Windows should always appear entirely on-screen
      • Staggered placement - each new window appearing a little further rightward and downward from the last one - can be used in conjunction with other placement rules.
      • Don't cover important information, especially information in a previous window that the user will need to respond to the new window.