java me - How to highlight button when get focus on it in blackberry? -

i want make blackberry button images, 1 image should shown when focused , when unfocused.

or can blue color when focus off(by default) , red color when focus on, how can achieve such thing ?

see custom class

    import net.rim.device.api.system.bitmap;     import net.rim.device.api.ui.color;     import net.rim.device.api.ui.field;     import net.rim.device.api.ui.font;     import net.rim.device.api.ui.fontfamily;     import net.rim.device.api.ui.graphics;       public class mybuttonfield extends field {       // private int backgroundcolour = 0xffffff;      private bitmap button;      private bitmap on; //= bitmap.getbitmapresource("img/pink_scribble.bmp");      private bitmap off; // = bitmap.getbitmapresource("img/blue_scribble.bmp");      private int fieldwidth;      private int fieldheight;     // private int buffer = (display.getheight() - 105) / 2;      private string text;      private font fieldfont;      private boolean btn_text = true;      private static long style = field.field_hcenter | field.field_vcenter;       public mybuttonfield(string _text, string onpath, string offpath)  {       super(field.focusable | style);       text = _text;       on = bitmap.getbitmapresource(onpath);       off = bitmap.getbitmapresource(offpath);       fieldwidth = on.getwidth();       fieldheight = on.getheight();       button = off;       fieldfont = fieldfont();       }          public mybuttonfield(string _text, string onpath, string offpath, string focusedpath){              this(_text, onpath, offpath);      }       public mybuttonfield(string _text, string onpath, string offpath, boolean btn_text) {      this(_text, onpath , offpath);      this.btn_text = btn_text;      }       public mybuttonfield(string _text, string onpath, string offpath, boolean btn_text,     int style, int size)      {         this(_text, onpath , offpath, btn_text);         fieldfont = fieldfont(style, size);      }      public mybuttonfield(string _text, string onpath, string offpath, long style)      {      this(_text, onpath , offpath);    }     // public mybuttonfield(string _text, string onpath, string offpath, int background)    // {    //    this(_text, onpath , offpath);     ////     backgroundcolour = background;     // }      protected boolean navigationclick(int status, int time) {     fieldchangenotify(1);     return true;      }      protected void onfocus(int direction) {     button = on;     invalidate();    }       protected void onunfocus() {     button = off;     invalidate();     }      public int getpreferredwidth() {     return fieldwidth;     }      public int getpreferredheight() {     return fieldheight;     }      protected void layout(int arg0, int arg1) {     setextent(getpreferredwidth(), getpreferredheight());     }       public static font fieldfont()      {     try {     fontfamily thefam = fontfamily.forname("system");     return thefam.getfont(net.rim.device.api.ui.font.plain, 14);     } catch (classnotfoundexception ex) {     ex.printstacktrace();     }     return null;     }      public static font fieldfont(int style, int size)      {     try {     fontfamily thefam = fontfamily.forname("system");     return thefam.getfont(style, size);     } catch (classnotfoundexception ex) {     ex.printstacktrace();     }     return null;     }      protected void drawfocus(graphics graphics, boolean on) {         if (on) {             //graphics.setcolor(color.red);             int width = getwidth();            int height = getheight();            graphics.drawbitmap(0, 0, fieldwidth, fieldheight, button, 0, 0);             //draw border around field.           /*            graphics.fillroundrect(0, 0, 3, height,10,10); //left border            graphics.fillroundrect(0, 0, width, 3,10,10); //top border            graphics.fillroundrect(width-3, 0, 3, height,10,10); //right border            graphics.fillroundrect(0, height-3, width, 3,10,10); //bottom border          */            graphics.setcolor(color.gray);         }         invalidate();     }       public void setfocusimage()      {      button = on;      }      public void setunfocusimage()     {      button = off;      }       protected void fieldchangenotify(int context) {      this.getchangelistener().fieldchanged(this, context);      }      protected void paint(graphics graphics)        {      graphics.drawbitmap(0, 0, fieldwidth, fieldheight, button, 0, 0);      graphics.setfont(getfont().derive(font.plain, 8));      graphics.setcolor(color.lightgray);     // graphics.fillroundrect(0, 0, fieldwidth, fieldheight, 8, 8);     //  graphics.setcolor(color.gray);         //graphics.drawroundrect(0, 0, fieldwidth, fieldheight, 8, 8);       if(btn_text)          graphics.drawtext(text, 10, 5);     }         public string getlabel() {         return text;         }         } 

you should override onfocus(), onunfocus() , paint().

please refer custom button field article.