buttontest.java

java编程的一些Applets例子。值得深入研究一下。

/** #EED5B7
 * Simple applet to test JanneButton class
 */
import java.awt.*;
import java.awt.image.*;
import java.applet.Applet;

public class ButtonTest extends Applet {
   Image joe;
   JanneButton button3;
   // used by ctrl panel...
   Checkbox isEnabled;
   Checkbox isVisible;
   Checkbox imageUsed;
   Checkbox labelUsed;
   Checkbox resizeImage;
   TextField labelText;
   
   public void init() {
      // test setting of background
      setBackground(new Color(0xEED5B7));

      // Create a grid where we add the buttons
      setLayout(new BorderLayout());
      Panel grid = new Panel();
      grid.setLayout(new GridLayout(0, 2));
      add("Center", grid);
      add("East", ctrlPanel());
      
      // get the image
      joe = getImage(getDocumentBase(), "images/joe.gif");

      // create buttons (one standard awt to compare...)
      // The 3'rd button is controlled by a ctrl panel
      grid.add(new Button("button1"));
      grid.add(new JanneButton(joe, "button2"));
      grid.add(button3 = new JanneButton(joe, "button3", false, false));
      grid.add(new JanneButton("button4"));

      show();
    }

   public Panel ctrlPanel() {
      Panel ctrlPanel = new Panel();
      ctrlPanel.setLayout(new BorderLayout());

      Panel p1 = new Panel();
      p1.setLayout(new BorderLayout());
      p1.add("North", new Label(""));
      p1.add("Center", new Label("Control Button 3:"));
      p1.add("South", new Label(""));
      ctrlPanel.add("North", p1);
      
      Panel p2 = new Panel();
      p2.setLayout(new GridLayout(0, 2, 4, 4));

      p2.add(new Label("Enabled:"));
      isEnabled = new Checkbox("", null, true);
      p2.add(isEnabled);
      
      p2.add(new Label("Visible:"));
      isVisible = new Checkbox("", null, true);
      p2.add(isVisible);
      
      p2.add(new Label("Display Image:"));
      imageUsed = new Checkbox("", null, true);
      p2.add(imageUsed);

      p2.add(new Label("Display Label:"));
      labelUsed = new Checkbox("", null, false);
      p2.add(labelUsed);

      p2.add(new Label("Resize Image:"));
      resizeImage = new Checkbox("", null, false);
      p2.add(resizeImage);

      p2.add(new Label("String Label:"));
      labelText = new TextField("button3", 8);
      p2.add(labelText);

      ctrlPanel.add("Center", p2);
      Panel p3 = new Panel();
      p3.setLayout(new FlowLayout());
      p3.add(new JanneButton("Update"));
      ctrlPanel.add("South", p3);
      
      return ctrlPanel;
   }
   
   
   /**
    * Called when we press the buttons
    */
   public boolean action(Event evt, Object arg) {
      if (evt.target instanceof Checkbox) {
      }
      else if(evt.target instanceof JanneButton &&
	      ("Update".equals(arg))) {
	 // update button 3
	 if (isEnabled.getState()) 
	    button3.enable();
	 else
	    button3.disable();
	 button3.show(isVisible.getState());
	 if (imageUsed.getState())
	    button3.setImage(joe);
	 else
	    button3.setImage(null);
	 button3.setResizeImage(resizeImage.getState());
	 button3.setShowLabel(labelUsed.getState());
	 button3.setLabel(labelText.getText());
      }
      else
	 System.out.println("Button selected: " + (String)arg);
      return true;
   }

}