mwt
Class Button

java.lang.Object
  mwt.Component
      mwt.Button

public class Button
extends Component

A button is a component that can cause an action to happen when is pushed.

The action is determinated by the mwt.EventListener given during the button's creation:

 Button b = new Button(20, 4, 40, 30, "Press Me!", new EventListener() {
   public void processEvent(int eventType, Component c, Object[] args) {
     System.out.println("Pressed");
   }
 }, 0);
 

This works just fine, however, the java compiler creates a new class for each event listener implementation. When using a lot of buttons, the jar size will increase significally.

A solution is to group buttons' actions in the same event listener implementation:

 class MyCanvas extends Canvas implements EventListener {
   Window win = ...
   static final int NEW_GAME = 0;
   static final int OPTIONS = 1;
   static final int EXIT = 2;
          
   MyCanvas() {
     win.add(new Button(4, 4, 30, 20, "New Game", this, NEW_GAME));
     win.add(new Button(4,24, 30, 20, "Options",  this, OPTION));
     win.add(new Button(4,44, 30, 20, "Exit",     this, EXIT));
   }
   
   public void processEvent(int eventType, Component c, Object[] args) {
     switch(eventType) {
       case EVENT_ACTION:
         Button b = (Button) c;
         switch(c.getActionType()) {
           case NEW_GAME: System.out.println("New Game pressed: " + c); break;
           case OPTIONS:  System.out.println("Options pressed: " + c); break;
           case EXIT:     System.out.println("Exit pressed: " + c); break;
         }
         break;
       case EVENT_UNDEFINED: break; 
     }
   }
  
   ...
 }
 

The component parameter is the button that is triggering the event, the args parameter is null.
See also mwt.EventListener.

A button's action is triggered when it has focus and its owner window reports a Window.FOCUSACTION_FIRE.
You can trigger the action programmatically also. See processAction().

Styles

A button has four different "styles", and for each one, a skin and a font.
When a button is created, a copy of the default skin and fonts is assigned.
You can set the default style using setDefaultSkin(int, Skin) and setDefaultFont(int, Font).
After the button is created, you can still change its style using setSkin(int, Skin) and setFont(int, Font).
The style value must be any of the STYLE_* constants:

	STYLE_DEFAULT
	STYLE_FOCUSED
	STYLE_PRESSED
	STYLE_DISABLED

Field Summary

static int	STYLE_DEFAULT Constant value to get/set a skin/font.
static int	STYLE_DISABLED Constant value to get/set a skin/font.
static int	STYLE_FOCUSED Constant value to get/set a skin/font.
static int	STYLE_PRESSED Constant value to get/set a skin/font.

Fields inherited from class mwt.Component

ALIGN_BOTTOM_CENTER, ALIGN_BOTTOM_LEFT, ALIGN_BOTTOM_RIGHT, ALIGN_MIDDLE_CENTER, ALIGN_MIDDLE_LEFT, ALIGN_MIDDLE_RIGHT, ALIGN_TOP_CENTER, ALIGN_TOP_LEFT, ALIGN_TOP_RIGHT

Constructor Summary

Button(int x, int y, int width, int height, java.lang.String text, EventListener action, int actionType)
Creates a new button at the given position and size

Method Summary

void	click() Performs a "click" programmatically.
int	getActionType() Gets the action type value given when this button was created.
static Font	getDefaultFont(int style) Gets the default font for the given style.
static Skin	getDefaultSkin(int style) Gets the default skin for the given style.
Font	getFont(int style) Gets this button font for the given style.
Skin	getSkin(int style) Gets this button skin for the given style.
java.lang.String	getText() Gets this button's text.
int	getTextAlign() Gets the text align.
protected boolean	keyEvent(long key, Window window) Processes a key event.
protected void	onClick() Method permormed when the event listener is null.
protected void	paint(javax.microedition.lcdui.Graphics g, Window window) Paints this component.
void	processAction() Deprecated. use click() instead
static void	setDefaultFont(int style, Font font) Sets the default font for the given style.
static void	setDefaultSkin(int style, Skin skin) Sets the default skin for the given style.
void	setFont(int style, Font font) Sets this button font for the given style.
void	setSkin(int style, Skin skin) Sets this button skin for the given style.
void	setText(java.lang.String text) Sets this button's text.
void	setTextAlign(int textAlign) Sets the text align.

Methods inherited from class mwt.Component

acceptsFocus, add, add, focusGained, focusLost, getChild, getChild, getChild, getChildCount, getComponent, getComponentCount, getComponentIndex, getHeight, getId, getParent, getWidth, getX, getY, isContainer, isDoubleBuffered, isEnabled, isFocusable, isHierarchyEnabled, isHierarchyVisible, isVisible, paintChilds, remove, removeChild, setDoubleBuffered, setEnabled, setFocusable, setHeight, setId, setVisible, setWidth, setX, setY

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

STYLE_DEFAULT

public static final int STYLE_DEFAULT

Constant value to get/set a skin/font.

See Also:

Constant Field Values

STYLE_FOCUSED

public static final int STYLE_FOCUSED

Constant value to get/set a skin/font.

See Also:

Constant Field Values

STYLE_PRESSED

public static final int STYLE_PRESSED

Constant value to get/set a skin/font.

See Also:

Constant Field Values

STYLE_DISABLED

public static final int STYLE_DISABLED

Constant value to get/set a skin/font.

See Also:

Constant Field Values

Constructor Detail

Button

public Button(int x,
              int y,
              int width,
              int height,
              java.lang.String text,
              EventListener action,
              int actionType)

Creates a new button at the given position and size

Method Detail

getDefaultSkin

public static final Skin getDefaultSkin(int style)

Gets the default skin for the given style.

setDefaultSkin

public static final void setDefaultSkin(int style,
                                        Skin skin)

Sets the default skin for the given style.

getDefaultFont

public static final Font getDefaultFont(int style)

Gets the default font for the given style.

setDefaultFont

public static final void setDefaultFont(int style,
                                        Font font)

Sets the default font for the given style.

getSkin

public Skin getSkin(int style)

Gets this button skin for the given style.

setSkin

public void setSkin(int style,
                    Skin skin)

Sets this button skin for the given style.

getFont

public Font getFont(int style)

Gets this button font for the given style.

setFont

public void setFont(int style,
                    Font font)

Sets this button font for the given style.

getText

public java.lang.String getText()

Gets this button's text.

setText

public void setText(java.lang.String text)

Sets this button's text.

getTextAlign

public int getTextAlign()

Gets the text align. A Component ALIGN constant.

setTextAlign

public void setTextAlign(int textAlign)

Sets the text align. A Component ALIGN constant.

onClick

protected void onClick()

Method permormed when the event listener is null. Default implementation is empty.

Since:

1.2

click

public final void click()

Performs a "click" programmatically.

Since:

1.2

getActionType

public final int getActionType()

Gets the action type value given when this button was created.

processAction

public final void processAction()

Deprecated. use click() instead

Performs a "click" programmatically.

keyEvent

protected boolean keyEvent(long key,
                           Window window)

Description copied from class: Component

Processes a key event.

The higher 32 bits of the key parameter determines the type of this event.
1 for key pressed events.
0 for key released events.
Otherwise is a key repeated event, in such case, the value represents how long the key code was repeated. See also Keys.

The default implementation of this method returns false.
An implementation should return true if the key was consumed.

 protected void processKey(long key, Window window) {
        System.out.print("Keycode " + ((int) key));
  switch(key >> 32) {
        case 0: System.out.println(" released!"); break;
        case 1: System.out.println(" pressed!"); break;
        default: System.out.println(" repeated " + (key >> 32) + " times!"); break;
  }
  if(window.processInput(key) == Window.FOCUSACTION_FIRE) ...
  
  // let the window dispatch the key
  if(...) window.dispatchKey(key);
 }
 

Overrides:

keyEvent in class Component

Parameters:

key - the key

window - the window caller

Returns:

true if the key was be consumed

paint

protected void paint(javax.microedition.lcdui.Graphics g,
                     Window window)

Description copied from class: Component

Paints this component.

The default implementation calls Component.paintChilds(Graphics, Window).
An implementation should call Component.paintChilds(Graphics, Window) once (if the component is a container).

The graphics object was previously transformed to the current x and y, and the clip was setted according to this component width and height.

Overrides:

paint in class Component

Parameters:

g - the graphics to draw the component into

window - the window caller