How to show ToolTip on FocusGained event

Question

Situation is like following:
A JTextField has some ToolTip associated with it, I want to show that ToolTip on FocusGained event of that JTextField.

Answer 1

Here it is (note that resource is simply a class file that contains color and font settings -- nohting mysterious):
import java.awt.*;
import java.applet.*;
import java.awt.event.*;
public class ToolTip extends Canvas {
   protected String tip;
   protected Component owner;
   private Container mainContainer;
   private LayoutManager mainLayout;
   private boolean shown;
   private int VERTICAL_OFFSET,HORIZONTAL_OFFSET,X,Y;
   private final int HORIZONTAL_ENLARGE=10;
   private FontMetrics fm;
   public ToolTip(String tip, Component owner, Container mc, int bp, resource res) {
      this.tip=tip;
      this.owner=owner;
      this.mainContainer=mc;
      setBackground(res.ToolTipBGColor);
      setForeground(res.ToolTipFGColor);
      setFont(res.ToolTipFont);
      fm=getFontMetrics(getFont());
      X=owner.getLocationOnScreen().x;
      Y=owner.getLocationOnScreen().y;
      int w=owner.getSize().width;
      int h=owner.getSize().height;
      if (bp==0) {                         // top
         HORIZONTAL_OFFSET=3;
         VERTICAL_OFFSET=h;
      } else if (bp==1) {                  // left
         HORIZONTAL_OFFSET=w;
         VERTICAL_OFFSET=0;
      } else if (bp==2) {                  // right
         HORIZONTAL_OFFSET=-fm.stringWidth(tip)-HORIZONTAL_ENLARGE;
         VERTICAL_OFFSET=0;
      } else {                             // bottom
         HORIZONTAL_OFFSET=3;
         VERTICAL_OFFSET=-fm.getHeight();
      owner.addMouseListener(new MAdapter());
   public void paint(Graphics g) {
      g.drawRect(0,0,getSize().width,getSize().height);
      g.drawString(tip,3,getSize().height-3);
   private void addToolTip() {
      mainContainer.setLayout(null);
      setSize(fm.stringWidth(tip)+HORIZONTAL_ENLARGE, fm.getHeight());
      setLocation(X-mainContainer.getLocationOnScreen().x+HORIZONTAL_OFFSET,
         Y-mainContainer.getLocationOnScreen().y+VERTICAL_OFFSET);
      if (mainContainer.getSize().width<(getLocation().x+getSize().width)) {
         setLocation(mainContainer.getSize().width-getSize().width, getLocation().y);
      mainContainer.add(this,0);
      mainContainer.validate();
      shown=true;
   private void removeToolTip() {
      if (shown) {
         mainContainer.remove(0);
         mainContainer.setLayout(mainLayout);
         mainContainer.validate();
      shown = false;
   class MAdapter extends MouseAdapter {
      public void mousePressed(MouseEvent me) {
         if (me.getModifiers()==4) {
            mainLayout=mainContainer.getLayout();
            addToolTip();
            me.consume();
      public void mouseReleased(MouseEvent me) {
         if (shown) removeToolTip();
}If you have problem modifying the code, noah.w is an expert in the GUI stuff, maybe he can help you.
Hope this helps!
;o)
V.V.