The Java Developers Almanac 1.4


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Home > List of Packages > java.awt  [78 examples] > Components  [1 examples]

e570. Determining When a Component Has Been Made Visible, Moved, or Resized

A component fires a component event after it is made visible, hidden, moved, or resized.
    // Create a listener for component events
    ComponentListener listener = new ComponentAdapter() {
        // This method is called only if the component was hidden and setVisible(true) was called
        public void componentShown(ComponentEvent evt) {
            // Component is now visible
            Component c = (Component)evt.getSource();
        }
    
        // This method is called only if the component was visible and setVisible(false) was called
        public void componentHidden(ComponentEvent evt) {
            // Component is now hidden
            Component c = (Component)evt.getSource();
        }
    
        // This method is called after the component's location within its container changes
        public void componentMoved(ComponentEvent evt) {
            Component c = (Component)evt.getSource();
    
            // Get new location
            Point newLoc = c.getLocation();
        }
    
        // This method is called after the component's size changes
        public void componentResized(ComponentEvent evt) {
            Component c = (Component)evt.getSource();
    
            // Get new size
            Dimension newSize = c.getSize();
        }
    };
    
    // Register the listener with the component
    component.addComponentListener(listener);

 Related Examples

See also: Colors    Containers    Cursors    Drawing    Events    Focus    Frames    GridBagLayout    Images    Shapes    Simulating Events    Text    The Screen   


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