High Level Events
High level or semantic events encapsulate the meaning of
a user interface component. These include:
java.awt.event.ActionEvent
- do a command
java.awt.event.AdjustmentEvent
- value was adjusted
java.awt.event.ItemEvent
- item state has changed
java.awt.event.TextEvent
- the value of the text object changed
For example, when the user clicks the mouse on a button, then releases it, the
button gets two or three separate, low-level, mouse events. (One for mouse down, one for mouse up, and possibly one for mouse drag if the user moves the mouse while the button is pressed.) However, the button then fires one high level
ActionEvent.
If the user clicks the mouse on a button, moves the mouse off the button, then releases it, the Button gets two separate, low-level, mouse events. (One for mouse down, one for for mouse drag.) However, the button eats these events and does nothing.
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Last Modified October 28, 1999
Copyright 1997, 1999 Elliotte Rusty Harold
elharo@metalab.unc.edu