J2se interface Layout

Recently, I have been viewing j2se interface layout and event control, for example, processing list right-click events on the interface.

 

Mouselistener-mouse listener
Tool

Actionlistener -- parent class of all listeners

Itemlistener -- used to capture events generated by components with items

 

Sample Code:

 

Import Java. AWT. *; <br/> Import Java. AWT. event. *; <br/> Import Java. applet. applet; <br/> public class listdemo extends applet implements mouselistener, actionlistener, <br/> itemlistener {<br/> private textarea output; <br/> private list mainlist, filelist; <br/> private string newline; <br/> private popupmenu popmenu = new popupmenu (); <br/> Public void Init () {<br/> newline = system. getproperty ("line. SEP Arator "); <br/> // <br/> mainlist = new list (); // <br/> mainlist. add ("system information"); <br/> mainlist. add ("transaction member"); <br/> mainlist. add ("failed message processing"); <br/> mainlist. add ("download file list"); <br/> mainlist. addactionlistener (this); <br/> mainlist. additemlistener (this); <br/> mainlist. addmouselistener (this); <br/> string itemtext [] = {"start", "stop" };< br/> for (INT I = 0; I <itemtext. length; I ++) {<br/> menuitem item = new menuitem (I Temtext [I]); <br/> item. addactionlistener (this); <br/> popmenu. add (item); <br/>}< br/> // <br/> filelist = new list (); <br/> filelist. add ("http: // 127.0.0.1/test/test.txt"); <br/> filelist. addactionlistener (this); <br/> filelist. additemlistener (this); <br/> // <br/> gridbaglayout gridbag = new gridbaglayout (); <br/> setlayout (gridbag ); <br/> // <br/> gridbagconstraints lc = new gridbagconstraints (); <br/> LC. fi LL = gridbagconstraints. both; <br/> LC. weightx = 1.0; <br/> LC. weighty = 1.0; <br/> LC. gridheight = 2; <br/> gridbag. setconstraints (mainlist, LC); <br/> Add (mainlist); <br/> gridbag. setconstraints (filelist, LC); <br/> Add (filelist); <br/> output = new textarea (10,100); <br/> output. seteditable (false); <br/> gridbagconstraints Tc = new gridbagconstraints (); <br/> TC. fill = gridbagconstraints. both; <br/> TC. gr Idx = 0; <br/> TC. gridy = 2; <br/> TC. weightx = 1.0; <br/> TC. weighty = 1.0; <br/> TC. gridwidth = gridbagconstraints. remainder; // end row <br/> gridbag. setconstraints (output, Tc); <br/> Add (output); <br/> Add (popmenu ); <br/>}< br/> Public void actionreceivmed (actionevent e) {<br/> List list = (list) (E. getsource (); <br/> string Language = (list = mainlist )? "Main Menu": "file list"; <br/> output. append ("Action event occurred on/" "+ list. getselecteditem () <br/> + "/" in "+ language + ". "+ newline); <br/>}< br/> Public void itemstatechanged (itemevent e) {<br/> List list = (list) (E. getitemselectable (); <br/> string Language = (list = mainlist )? "Main Menu": "file list"; <br/> int Index = (integer) (E. getitem ())). intvalue (); <br/> If (E. getstatechange () = itemevent. selected) {<br/> output. append ("selected index =" + index + "(/" "<br/> + list. getitem (INDEX) + "/") in "+ language + ". "<br/> + newline); <br/>} else {// the item was deselected <br/> output. append ("deselected Index = #" + index + "(/" "<br/> + list. getitem (INDEX) + "/") in "+ language + ". "<br/> + newline); <br/>}< br/> Public void mouseclicked (mouseevent E) {<br/> // todo auto-generated method stub <br/>}< br/> Public void mouseentered (mouseevent E) {<br/> // todo auto-generated method stub <br/>}< br/> Public void mouseexited (mouseevent E) {<br/> // todo auto-generated method stub <br/>}< br/> Public void mousepressed (mouseevent E) {<br/> // todo auto-generated method stub <br/>}< br/> Public void mousereleased (mouseevent E) {<br/> // todo auto-generated method stub <br/> If (E. ispopuptrigger () {<br/> system. out. println ("e. getcomponent () "+ This +" E. getx () "<br/> + E. getx () + "E. gety () "+ E. gety (); <br/> popmenu. show (E. getcomponent (), E. getx (), E. gety (); <br/>}< br/>}