java - Binding a key to a JButton -

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• add key bindings jbuttons actions action commands? 1 answer

i have been looking answer attach keybinding jbutton many-many hours, , still didn't manage it. have following simple program consisting of 2 classes. tried using getinputmap() , getactionmap() several ways, without success. want following: when press key "1" on keyboard, press jbutton btn1, , when press key "2", press jbutton btn2 (and 1 or 2 appear on jlabel consequently).

//class1://

import javax.swing.*; import javax.swing.event.*; import java.awt.*; import java.awt.event.*;  public class event06 extends jframe {      event06b base = new event06b(this);      jbutton btn1 = new jbutton("1");     jbutton btn2 = new jbutton("2");     jlabel label = new jlabel("");      public event06() {         super();         setbounds(300,300, 200,150);         setresizable(true);         settitle("button keybinding");         setdefaultcloseoperation(jframe.exit_on_close);          btn1.addactionlistener(base);         btn2.addactionlistener(base);          flowlayout flo = new flowlayout(flowlayout.center);         setlayout(flo);         add(btn1);         add(btn2);         add(label);          setvisible(true);     }      public static void main(string[] args) {         event06 window = new event06();      } }   //class 2:// import javax.swing.*; import javax.swing.event.*; import java.awt.*; import java.awt.event.*;  public class event06b implements actionlistener {     event06 gui;      public event06b (event06 in) {         gui = in;     }         public void actionperformed(actionevent pressed) {             object source = pressed.getsource();             if (source == gui.btn1) {gui.label.settext("1");}             else if (source == gui.btn2) {gui.label.settext("2");}         } } 

update: (i still don't have reputation of 15 yet, cannot answer own question, , far know cannot post codes or long answers in comments, i'm modifying question instead).

what managed find out using keylisteners work, if no button has focus. see following example:

 //in class 1://  flowlayout flo = new flowlayout(flowlayout.center);     setlayout(flo);     add(btn1);     btn1.setenabled(false);     btn2.setenabled(false);     add(btn2);     add(label);      btn1.addactionlistener(base);     btn2.addactionlistener(base);     addkeylistener(base); 

here, 2 buttons, btn1 , btn2 disabled, don't have focus, instead window on focus. that's why keylistener can work:

public void keypressed (keyevent evt) {     int keycode = evt.getkeycode();     gui.label.settext(integer.tostring(keycode)); }  public void keyreleased(keyevent txt) {} public void keytyped(keyevent txt) {} 

in case, tha jlabel in class1 shows keycode of key has been pressed. (note, can keycode under keypressed method, , not under keytyped method - latter getting key character using getkeychar. better use getkeycode instead of getkeychar, since specific keys have keycode, not keychar).

for buttons use actionperformed method:

public void actionperformed(actionevent pressed) {     object source = pressed.getsource();     if (source == gui.btn1) {gui.label.settext("1");}     else if (source == gui.btn2) {gui.label.settext("2");} } 

since buttons disabled here, doesn't work. far, couldn't connect keycode actionperformed method. in example presented veluria, actionperformed method part of abstractaction, , inputmaps , actionmaps used there. seems correct answer here, though error, when i'm trying use suggestion: error: identifier expected

yeah, found solution!!!: (first show code, explain modified).

//class 1://

import javax.swing.*; import java.awt.event.*; import java.awt.*;  public class event06 extends jframe {      event06b base = new event06b(this);      jbutton btn1 = new jbutton("1");     jbutton btn2 = new jbutton("2");     jlabel label = new jlabel("");       public event06() {         super();         setbounds(300,300,250,75);         setresizable(false);         settitle("buttons key");         setdefaultcloseoperation(jframe.exit_on_close);          flowlayout flo = new flowlayout(flowlayout.center);         setlayout(flo);         add(btn1);         btn1.setenabled(true);         btn2.setenabled(true);         add(btn2);         add(label);          btn1.addactionlistener(base.act);                btn1.getinputmap(jcomponent.when_in_focused_window).put(keystroke.getkeystroke('1'), "pressed");         btn1.getactionmap().put("pressed", base.act);          btn2.addactionlistener(base.act);         btn2.getinputmap(jcomponent.when_in_focused_window).put(keystroke.getkeystroke('2'), "pressed");         btn2.getactionmap().put("pressed", base.act);           setvisible(true);     }      public static void main(string[] args) {         event06 window = new event06();     } } 

class2:

import javax.swing.*; import javax.swing.event.*; import java.awt.*; import java.awt.event.*;  public class event06b {     event06 gui;      public event06b (event06 in) {         gui = in;     }      action act = new abstractaction() {          @override         public void actionperformed(actionevent pressed) {             object source = pressed.getsource();             if (source == gui.btn1) {gui.label.settext("1");}             else if (source == gui.btn2) {gui.label.settext("2");}         }     }; } 

so, did following: - added actionlistener in class 1 btn1 , btn2:

btn1.addactionlistener(base.act); 

• i used inputmap:

  btn1.getinputmap(jcomponent.when_in_focused_window).put(keystroke.getkeystroke('1'), "pressed");

• two things note here: have put "jcomponent.when_in_focused_window" text in round brackets, input key when button not have focus. other thing is, when use getkeystroke('1'), have give character, use ' ' instead of " ". (i saw "" being used in many examples).

then used actionmap, so:

btn1.getactionmap().put("pressed", base.act); 

please note, here, , @ actionlistener, referring other class using base.act (base refers class2, , act refers action inside)

in class2, put actionperformed method inside abstractaction, , used @override. don't know, why @override has used, because works without it.

i'm sorry, if misinterpreted , didn't give right explanation. i'm hobby programmer, having no education in computer science. hope, question , provided answer might bring many others being in same boat.

here's 1 way it:

action action = new abstractaction("1") {     @override     public void actionperformed(actionevent e) {         label.settext("1");     } }; action.putvalue(action.accelerator_key, keystroke.getkeystroke("1")); btn1.setaction(action); btn1.getactionmap().put("setoneaction", action); btn1.getinputmap(jcomponent.when_in_focused_window).put(     (keystroke) action.getvalue(action.accelerator_key), "setoneaction");