highlighter.java

java实现浏览器等本地桌面的功能

     * depends on two factors: (i) whether the background color for this
     * <code>Highlighter</code> is null or not, and (ii) whether the cell
     * identified by the specified adapter
     * {@link ComponentAdapter#isSelected isSelected} or not.</p>
     *
     * <p>If the background color for this <code>Highlighter</code> is not
     * null, this method starts with an initial value that is equal to that
     * background color, and proceeds to check the selected state of the cell.
     * Otherwise, it starts with the background color of the component whose
     * cell is being rendererd (not the background color of the renderer component
     * that was passed in), and proceeds to check the selected state of the cell.</p>
     *
     * <p>If the cell identified by the specified adapter is selected, this
     * method returns the value computed by
     * {@link #computeSelectedBackground computeSelectedBackground} when passed
     * the initial background color computed earlier. Otherwise, it simply
     * returns the initial background color computed earlier.</p>
     *
     * @param renderer the cell renderer component that is to be decorated
     * @param adapter the {@link ComponentAdapter} for this decorate operation
     * @return a suitable background color for the specified component and adapter
     */
    protected Color computeBackground(Component renderer, ComponentAdapter adapter) {
        // If this.background is null, use adapter.target.getBackground();
        // Never use renderer.getBackground() as the seed in this decorator
        // class because renderer is too promiscuous!
        Color seed = background == null ? adapter.target.getBackground() : background;
        return adapter.isSelected() ? computeSelectedBackground(seed) : seed;
    }

    /**
     * <p>Computes a suitable foreground for the renderer component within the
     * specified adapter and returns the computed color. The computed color
     * depends on two factors: (i) whether the foreground color for this
     * <code>Highlighter</code> is null or not, and (ii) whether the cell
     * identified by the specified adapter
     * {@link ComponentAdapter#isSelected isSelected} or not.</p>
     *
     * <p>If the foreground color for this <code>Highlighter</code> is not
     * null, this method starts with an initial value that is equal to that
     * foreground color, and proceeds to check the selected state of the cell.
     * Otherwise, it starts with the foreground color of the component whose
     * cell is being rendererd (not the foreground color of the renderer component
     * that was passed in), and proceeds to check the selected state of the cell.</p>
     *
     * <p>If the cell identified by the specified adapter is selected, this
     * method returns the value computed by
     * {@link #computeSelectedForeground computeSelectedBackground} when passed
     * the initial foreground color computed earlier. Otherwise, it simply
     * returns the initial foreground color computed earlier.</p>
     *
     * @param renderer the cell renderer component that is to be decorated
     * @param adapter the {@link ComponentAdapter} for this decorate operation
     * @return a suitable foreground color for the specified component and adapter
     */
    protected Color computeForeground(Component renderer, ComponentAdapter adapter) {
        // If this.foreground is null, use adapter.target.getForeground();
        // Never use renderer.getForeground() as the seed in this decorator
        // class because renderer is too promiscuous!
        Color seed = foreground == null ? adapter.target.getForeground() : foreground;
        return adapter.isSelected() ? computeSelectedForeground(seed) : seed;
    }

    /**
     * Computes the selected background color. If the selected background color
     * of this <code>Highlighter</code> is not null, this method returns that
     * color. Otherwise, it returns a {@link java.awt.Color#darker} version of
     * the specified seed color.
     *
     * @param seed initial background color; must cope with null!
     * @return the background color for a selected cell
     */
    protected Color computeSelectedBackground(Color seed) {
        return selectedBackground == null ?
            seed == null ? Color.gray : seed.darker() : selectedBackground;
    }

    /**
     * Computes the selected foreground color. If the selected foreground color
     * of this <code>Highlighter</code> is not null, this method returns that
     * color. Otherwise, it returns {@link java.awt.Color#white}, ignoring the
     * specified seed color. 
     *
     * @param seed initial foreground color; must cope with null!
     * @return the foreground color for a selected cell
     */
    protected Color computeSelectedForeground(Color seed) {
        return selectedForeground == null ? Color.white : selectedForeground;
    }

    /**
     * Returns the background color of this <code>Highlighter</code>.
     *
     * @return the background color of this <code>Highlighter</code>,
     *          or null, if no background color has been set
     */
    public Color getBackground() {
        return background;
    }

    /**
     * Sets the background color of this <code>Highlighter</code>.
     *
     * @param color the background color of this <code>Highlighter</code>,
     *          or null, to clear any existing background color
     */
    public void setBackground(Color color) {
        background = color;
        fireStateChanged();
    }

    /**
     * Returns the foreground color of this <code>Highlighter</code>.
     *
     * @return the foreground color of this <code>Highlighter</code>,
     *          or null, if no foreground color has been set
     */
    public Color getForeground() {
        return foreground;
    }

    /**
     * Sets the foreground color of this <code>Highlighter</code>.
     *
     * @param color the foreground color of this <code>Highlighter</code>,
     *          or null, to clear any existing foreground color
     */
    public void setForeground(Color color) {
        foreground = color;
        fireStateChanged();
    }

    /**
     * Returns the selected background color of this <code>Highlighter</code>.
     *
     * @return the selected background color of this <code>Highlighter</code>,
     *          or null, if no selected background color has been set
     */
    public Color getSelectedBackground() {
        return selectedBackground;
    }

    /**
     * Sets the selected background color of this <code>Highlighter</code>.
     *
     * @param color the selected background color of this <code>Highlighter</code>,
     *          or null, to clear any existing selected background color
     */
    public void setSelectedBackground(Color color) {
        selectedBackground = color;
        fireStateChanged();
    }

    /**
     * Returns the selected foreground color of this <code>Highlighter</code>.
     *
     * @return the selected foreground color of this <code>Highlighter</code>,
     *          or null, if no selected foreground color has been set
     */
    public Color getSelectedForeground() {
        return selectedForeground;
    }

    /**
     * Sets the selected foreground color of this <code>Highlighter</code>.
     *
     * @param color the selected foreground color of this <code>Highlighter</code>,
     *          or null, to clear any existing selected foreground color
     */
    public void setSelectedForeground(Color color) {
        selectedForeground = color;
        fireStateChanged();
    }

    /**
     * Adds a <code>ChangeListener</code>.  The change listeners are run each
     * time any one of the Bounded Range model properties changes.
     *
     * @param l the ChangeListener to add
     * @see #removeChangeListener
     * @see BoundedRangeModel#addChangeListener
     */
    public void addChangeListener(ChangeListener l) {
        listenerList.add(ChangeListener.class, l);
    }
    

    /**
     * Removes a <code>ChangeListener</code>.
     *
     * @param l the <code>ChangeListener</code> to remove
     * @see #addChangeListener
     * @see BoundedRangeModel#removeChangeListener
     */
    public void removeChangeListener(ChangeListener l) {
        listenerList.remove(ChangeListener.class, l);
    }


    /**
     * Returns an array of all the change listeners
     * registered on this <code>DefaultBoundedRangeModel</code>.
     *
     * @return all of this model's <code>ChangeListener</code>s 
     *         or an empty
     *         array if no change listeners are currently registered
     *
     * @see #addChangeListener
     * @see #removeChangeListener
     *
     * @since 1.4
     */
    public ChangeListener[] getChangeListeners() {
        return (ChangeListener[])listenerList.getListeners(
                ChangeListener.class);
    }


    /** 
     * Runs each <code>ChangeListener</code>'s <code>stateChanged</code> method.
     * 
     * @see #setRangeProperties
     * @see EventListenerList
     */
    protected void fireStateChanged() 
    {
        Object[] listeners = listenerList.getListenerList();
        for (int i = listeners.length - 2; i >= 0; i -=2 ) {
            if (listeners[i] == ChangeListener.class) {
                if (changeEvent == null) {
                    changeEvent = new ChangeEvent(this);
                }
                ((ChangeListener)listeners[i+1]).stateChanged(changeEvent);
            }          
        }
    }   

    

}