component.java

《移动Agent技术》一书的所有章节源代码。

     * Determines whether this component is enabled. An enabled component
     * can respond to user input and generate events. Components are
     * enabled initially by default. A component may be enabled or disabled by
     * calling its <code>setEnabled</code> method.
     * @return <code>true</code> if the component is enabled;
     * <code>false</code> otherwise.
     * @see #setEnabled
     * @since JDK1.0
     */
    public boolean isEnabled() {
	return enabled;
    }

    /**
     * Enables or disables this component, depending on the value of the
     * parameter <code>b</code>. An enabled component can respond to user
     * input and generate events. Components are enabled initially by default.
     * @param     <code>b</code>   If <code>true</code>, this component is
     *            enabled; otherwise this component is disabled.
     * @see #isEnabled
     * @since JDK1.1
     */
    public void setEnabled(boolean b) {
    	enable(b);
    }

    /**
     * @deprecated As of JDK version 1.1,
     * replaced by <code>setEnabled(boolean)</code>.
     */
    public void enable() {
    	if (enabled != true) {
	    //synchronized (getTreeLock()) { // Removed for Bug #4114201
		enabled = true;
		ComponentPeer peer = this.peer;
		if (peer != null) {
		    peer.enable();
		}
	    //}
	}
    }

    /**
     * @deprecated As of JDK version 1.1,
     * replaced by <code>setEnabled(boolean)</code>.
     */
    public void enable(boolean b) {
	if (b) {
	    enable();
	} else {
	    disable();
	}
    }

    /**
     * @deprecated As of JDK version 1.1,
     * replaced by <code>setEnabled(boolean)</code>.
     */
    public void disable() {
    	if (enabled != false) {
	    //synchronized (getTreeLock()) { //Removed for Bug #4114201
		enabled = false;
		ComponentPeer peer = this.peer;
		if (peer != null) {
		    peer.disable();
		}
	    //}
	}
    }

    /**
     * Shows or hides this component depending on the value of parameter
     * <code>b</code>.
     * @param <code>b</code>  If <code>true</code>, shows this component;
     * otherwise, hides this component.
     * @see #isVisible
     * @since JDK1.1
     */
    public void setVisible(boolean b) {
    	show(b);
    }

    /**
     * @deprecated As of JDK version 1.1,
     * replaced by <code>setVisible(boolean)</code>.
     */
    public void show() {
	if (visible != true) {
	    //synchronized (getTreeLock()) { //Removed for Bug #4114201
		visible = true;
    	    	ComponentPeer peer = this.peer;
		if (peer != null) {
		    peer.show();
		    if (peer instanceof java.awt.peer.LightweightPeer) {
			repaint();
		    }
		}
                if (componentListener != null ||
                    (eventMask & AWTEvent.COMPONENT_EVENT_MASK) != 0) {
                    ComponentEvent e = new ComponentEvent(this,
                                     ComponentEvent.COMPONENT_SHOWN);
                    Toolkit.getEventQueue().postEvent(e);
                }
	    //}
    	    Container parent = this.parent;
	    if (parent != null) {
		parent.invalidate();
	    }
	}
    }

    /**
     * @deprecated As of JDK version 1.1,
     * replaced by <code>setVisible(boolean)</code>.
     */
    public void show(boolean b) {
	if (b) {
	    show();
	} else {
	    hide();
	}
    }

    /**
     * @deprecated As of JDK version 1.1,
     * replaced by <code>setVisible(boolean)</code>.
     */
    public void hide() {
	if (visible != false) {
	    synchronized (getTreeLock()) {
		visible = false;
    	    	ComponentPeer peer = this.peer;
		if (peer != null) {
		    peer.hide();
		    if (peer instanceof java.awt.peer.LightweightPeer) {
			repaint();
		    }
		}
                if (componentListener != null ||
                    (eventMask & AWTEvent.COMPONENT_EVENT_MASK) != 0) {
                    ComponentEvent e = new ComponentEvent(this,
                                     ComponentEvent.COMPONENT_HIDDEN);
                    Toolkit.getEventQueue().postEvent(e);
                }
    	        Container parent = this.parent;
	        if (parent != null) {
		    parent.invalidate();
                }
	    }
	}
    }

    /**
     * Gets the foreground color of this component.
     * @return This component's foreground color. If this component does
     * not have a foreground color, the foreground color of its parent
     * is returned.
     * @see #java.awt.Component#setForeground(java.awt.Color)
     * @since JDK1.0
     */
    public Color getForeground() {
      	Color foreground = this.foreground;
	if (foreground != null) {
	    return foreground;
	}
    	Container parent = this.parent;
	return (parent != null) ? parent.getForeground() : null;
    }

    /**
     * Sets the foreground color of this component.
     * @param <code>c</code> The color to become this component's
     * foreground color.
     * @see #getForeground
     * @since JDK1.0
     */
    public void setForeground(Color c) {
	ComponentPeer peer = this.peer;
	foreground = c;
	if (peer != null) {
	    c = getForeground();
	    if (c != null) {
		peer.setForeground(c);
	    }
	}
    }

    /**
     * Gets the background color of this component.
     * @return This component's background color. If this component does
     * not have a background color, the background color of its parent
     * is returned.
     * @see java.awt.Component#setBackground(java.awt.Color)
     * @since JDK1.0
     */
    public Color getBackground() {
        Color background = this.background;
	if (background != null) {
	    return background;
	}
    	Container parent = this.parent;
	return (parent != null) ? parent.getBackground() : null;
    }

    /**
     * Sets the background color of this component.
     * @param <code>c</code> The color to become this component's
     * background color.
     * @see #getBackground
     * @since JDK1.0
     */
    public void setBackground(Color c) {
	ComponentPeer peer = this.peer;
	background = c;
	if (peer != null) {
	    c = getBackground();
	    if (c != null) {
		peer.setBackground(c);
	    }
	}
    }

    /**
     * Gets the font of this component.
     * @return This component's font. If a font has not been set
     * for this component, the font of its parent is returned.
     * @see #setFont
     * @since JDK1.0
     */
    public Font getFont() {
        Font font = this.font;
	if (font != null) {
	    return font;
	}
    	Container parent = this.parent;
	return (parent != null) ? parent.getFont() : null;
    }

    /**
     * Sets the font of this component.
     * @param <code>f</code> The font to become this component's font.
     * @see #getFont
     * @since JDK1.0
     */
    public void setFont(Font f) {
        synchronized (getTreeLock()) {
	    ComponentPeer peer = this.peer;
	    font = f;
	    if (peer != null) {
	        f = getFont();
		if (f != null) {
		    peer.setFont(f);
		}
	    }
	}
    }

    /**
     * Gets the locale of this component.
     * @return This component's locale. If this component does not
     * have a locale, the locale of its parent is returned.
     * @see #setLocale
     * @exception IllegalComponentStateException If the Component
     * does not have its own locale and has not yet been added to
     * a containment hierarchy such that the locale can be determined
     * from the containing parent.
     * @since  JDK1.1
     */
  public Locale getLocale() {
        Locale locale = this.locale;
	if (locale != null) {
	  return locale;
	}
    	Container parent = this.parent;

	if (parent == null) {
	    throw new IllegalComponentStateException("This component must have a parent in order to determine its locale");
	} else {
	    return parent.getLocale();
	}
    }

    /**
     * Sets the locale of this component.
     * @param <code>l</code> The locale to become this component's locale.
     * @see #getLocale
     * @since JDK1.1
     */
    public void setLocale(Locale l) {
	locale = l;
    }

    /**
     * Gets the instance of <code>ColorModel</code> used to display
     * the component on the output device.
     * @return The color model used by this component.
     * @see java.awt.image.ColorModel
     * @see java.awt.peer.ComponentPeer#getColorModel()
     * @see java.awt.Toolkit#getColorModel()
     * @since JDK1.0
     */
    public ColorModel getColorModel() {
    	ComponentPeer peer = this.peer;
	if ((peer != null) && ! (peer instanceof java.awt.peer.LightweightPeer)) {
	    return peer.getColorModel();
	}
	return getToolkit().getColorModel();
    }

    /**
     * Gets the location of this component in the form of a
     * point specifying the component's top-left corner.
     * The location will be relative to the parent's coordinate space.
     * @return An instance of <code>Point</code> representing
     * the top-left corner of the component's bounds in the coordinate
     * space of the component's parent.
     * @see #setLocation
     * @see #getLocationOnScreen
     * @since JDK1.1
     */
    public Point getLocation() {
	return location();
    }

    /**
     * Gets the location of this component in the form of a point
     * specifying the component's top-left corner in the screen's
     * coordinate space.
     * @return An instance of <code>Point</code> representing
     * the top-left corner of the component's bounds in the
     * coordinate space of the screen.
     * @see #setLocation
     * @see #getLocation
     */
    public Point getLocationOnScreen() {
	synchronized (getTreeLock()) {
	    if (peer != null && isShowing()) {
		if (peer instanceof java.awt.peer.LightweightPeer) {
		    // lightweight component location needs to be translated
		    // relative to a native component.
		    Container host = getNativeContainer();
		    Point pt = host.peer.getLocationOnScreen();
		    for(Component c = this; c != host; c = c.getParent()) {
			pt.x += c.x;
			pt.y += c.y;
		    }
		    return pt;
		} else {
		    Point pt = peer.getLocationOnScreen();
		    return pt;
		}
	    } else {
	        throw new IllegalComponentStateException("component must be showing on the screen to determine its location");
	    }
	}
    }


    /**
     * @deprecated As of JDK version 1.1,
     * replaced by <code>getLocation()</code>.
     */
    public Point location() {
	return new Point(x, y);
    }

    /**
     * Moves this component to a new location. The top-left corner of
     * the new location is specified by the <code>x</code> and <code>y</code>
     * parameters in the coordinate space of this component's parent.
     * @param <code>x</code> The <i>x</i>-coordinate of the new location's
     * top-left corner in the parent's coordinate space.
     * @param <code>y</code> The <i>y</i>-coordinate of the new location's
     * top-left corner in the parent's coordinate space.
     * @see #getLocation
     * @see #setBounds
     * @since JDK1.1
     */
    public void setLocation(int x, int y) {
	move(x, y);
    }

    /**
     * @deprecated As of JDK version 1.1,
     * replaced by <code>setLocation(int, int)</code>.
     */
    public void move(int x, int y) {
	setBounds(x, y, width, height);
    }

    /**
     * Moves this component to a new location. The top-left corner of
     * the new location is specified by point <code>p</code>. Point