JFrame

JComponent

JFrame JComponent

JFrame JComponent

source listener responder(s) event

four parts of processJava mechanisms stimulusevent (button press, timer tick, etc.) communication (event record of what happened) ActionEvent class (contains information about nature of stimulus) receiving mechanism (how are the stimulus and responding objects connected?) ActionListener interface (classes implementing can listen for a specific kind of event) response (listening object’s reaction to stimulus) actionPerformed (method called in response to stimulus)