Java Swing programming Imitation js tree Folding Menu

A recent need to complete a demand: with swing a tree-like menu, with a Level two menu, click the First menu to expand the Level two menu, and the number of two-level menu more than the Preview view will appear scroll bar. Because of the lack of swing research, it took a lot of energy!

First look at the test:

To close a picture:

Expand Diagram:

Full Source:

1  PackageCom.xuwei.test2;2 3 Importjava.awt.BorderLayout;4 ImportJava.awt.Color;5 Importjava.awt.GridLayout;6 Importjava.awt.event.ActionEvent;7 ImportJava.awt.event.ActionListener;8 9 ImportJavax.swing.JButton;Ten ImportJavax.swing.JFrame; One ImportJavax.swing.JPanel; A ImportJavax.swing.JScrollPane; -  -  the  Public classTestFrm4extendsjframe{ -     PrivateJButton btn1,btn2,btn3,btn4,btn5; -     PrivateJPanel Pnorth,psouth,submenucontainer; -     PrivateJScrollPane Pcenter; +     Privatejbutton[] Btn =NULL; -     Private Static BooleanExpand=false; +      A      PublicTestFrm4 () { atbtn1=NewJButton ("Grade1 menu1"); - Btn1.setbackground (Color.cyan); -Btn2=NewJButton ("Grade1 menu2"); - Btn2.setbackground (Color.cyan); -btn3=NewJButton ("Grade1 menu3"); - Btn3.setbackground (Color.cyan); inBtn3.addactionlistener (NewActionhandler ()); -          tobtn4=NewJButton ("Grade1 menu4"); + Btn4.setbackground (Color.cyan); -btn5=NewJButton ("Grade1 menu5"); the Btn5.setbackground (Color.cyan); *Pnorth=NewJPanel (); $Pnorth.setlayout (NewGridLayout (3,1));Panax NotoginsengPsouth=NewJPanel (); -Psouth.setlayout (NewGridLayout (2,1)); theSubmenucontainer=NewJPanel (); +Submenucontainer.setlayout (NewGridLayout (25,1)); A       thebtn=NewJbutton[25];  +          for(inti=0;i<btn.length;i++){ -btn[i]=NewJButton ("[Menu" +i+ "]"); $ Btn[i].setbackground (color.white); $         } -          -          This. setlayout (NewBorderLayout ()); the          - Pnorth.add (BTN1); Pnorth.add (BTN2); Pnorth.add (BTN3) ;Wuyi          for(inti=0;i<btn.length;i++){ the Submenucontainer.add (Btn[i]); -         } WuPcenter=NewJScrollPane (submenucontainer); -          About Psouth.add (BTN4);p south.add (BTN5); $          This. Add (Pnorth, "North"); -          This. Add (Pcenter, "Center"); -          This. Add (Psouth, "South"); -         A          This. setvisible (true); +          This. SetSize (500,600); the          This. setresizable (false); -          This. Setlocationrelativeto (NULL); $          This. Setdefaultcloseoperation (jframe.exit_on_close); the          the     } the      the      -      in     Private classActionhandlerImplementsactionlistener{ the  the @Override About          Public voidactionperformed (ActionEvent e) { the             if(btn3==E.getsource ()) { the                 if(expand) {//Folding thePnorth.setlayout (NewGridLayout (3,1)); + Pnorth.remove (BTN4);p north.remove (BTN5); - Psouth.add (BTN4);p south.add (BTN5); the                     for(inti=0;i<btn.length;i++){Bayi Submenucontainer.add (Btn[i]); the                    }      the validate (); - Getcontentpane (). repaint (); -Expand=false; the}Else{//Expand the                      for(inti=0;i<btn.length;i++){ the Submenucontainer.remove (Btn[i]); the                     } - Psouth.removeall (); thePnorth.setlayout (NewGridLayout (5,1)); the Pnorth.add (BTN4); the Pnorth.add (BTN5);94 pnorth.repaint (); the pcenter.repaint (); the psouth.repaint (); the validate ();98 Getcontentpane (). repaint (); AboutExpand=true; -                 }101             }102         }103         104     } the     106      Public Static voidMain (string[] args) {107        108         NewTestFrm4 ();109     } the 111}

There are several ways that swing can be called repeatedly to remove components that need to refresh the interface in a timely manner:

Repaint (), validate (), invalidate (), Dolayout ().

Before I did not call validate () caused the interface refresh a lot of problems!

Swing has to do a lot of research and find things!

Java Swing programming Imitation js tree Folding Menu