Volume 6A: Motif Programming Manual

If you run the source code you may find that you get mixed messages about whether an action is a single or double

mouse click. A multiple mouse click means that the user has both pressed and released the mouse button more than

once. It is very common for a user to intend to double click on a button only to find that she really invoked a double

press; she quickly pressed the mouse button twice, but she failed to release it before the required time interval. This

problem makes it difficult to interpret double (multiple) button clicks. It is important that you inform the user of the

proper double−clicking method in any accompanying documentation you provide with your application, as attempting

to program around this problem will definitely cause you great distress.

If you are going to use multiple button clicks for PushButtons, it is important that the -multiple−click actions perform

a more global version of the single−click actions. The reason for this recommendation is that if the user intends to

perform a double click but doesn't click fast enough, the single−click action is invoked instead of the double−click

action. If the two actions are completely different, it can make an application difficult to use. You might also consider

displaying some visual cue to the user about the availability of double−click actions. For example, you could use a

multi−lined label in a PushButton, where the first line indicates the single−click action and the second line specifies

the double−click action. If ...