abstracttitle.java

Web图形化的Java库

    }

    /**
     * Sets the vertical alignment for the title, and notifies any registered
     * listeners of the change.
     * The constants TOP, MIDDLE and BOTTOM (defined in this class) can be used
     * to specify the alignment.
     *
     * @param alignment  the new vertical alignment (TOP, MIDDLE or BOTTOM).
     */
    public void setVerticalAlignment(int alignment) {
        if (this.verticalAlignment != alignment) {
            this.verticalAlignment = alignment;
            notifyListeners(new TitleChangeEvent(this));
        }
    }

    /**
     * Returns the spacer (determines the blank space around the edges) for
     * this title.
     *
     * @return the spacer for this title.
     */
    public Spacer getSpacer() {
        return this.spacer;
    }

    /**
     * Sets the spacer for the title, and notifies registered listeners of the
     * change.
     *
     * @param spacer  the new spacer.
     */
    public void setSpacer(Spacer spacer) {

        if (!this.spacer.equals(spacer)) {
            this.spacer = spacer;
            notifyListeners(new TitleChangeEvent(this));
        }

    }

    /**
     * Returns the flag that indicates whether or not the notification mechanism is enabled.
     *
     * @return the flag.
     */
    public boolean getNotify() {
        return this.notify;
    }

    /**
     * Sets the flag that indicates whether or not the notification mechanism
     * is enabled.  There are certain situations (such as cloning) where you
     * want to turn notification off temporarily.
     *
     * @param flag  the new value of the flag.
     */
    public void setNotify(boolean flag) {
        this.notify = flag;
    }

    /**
     * Returns true if the title can assume the specified location, and false otherwise.
     *
     * @param position  the position.
     *
     * @return <code>true</code> if the title can assume the specified position.
     */
    public abstract boolean isValidPosition(int position);

    /**
     * Returns the preferred width of the title.  When a title is displayed at
     * the left or right of a chart, the chart will attempt to give the title
     * enough space for it's preferred width.
     *
     * @param g2  the graphics device.
     *
     * @return the preferred width of the title.
     */
    public abstract double getPreferredWidth(Graphics2D g2);

    /**
     * Returns the preferred height of the title.  When a title is displayed at
     * the top or bottom of a chart, the chart will attempt to give the title
     * enough space for it's preferred height.
     *
     * @param g2  the graphics device.
     *
     * @return the preferred height of the title.
     */
    public abstract double getPreferredHeight(Graphics2D g2);

    /**
     * Draws the title on a Java 2D graphics device (such as the screen or a printer).
     *
     * @param g2  the graphics device.
     * @param titleArea  the area for drawing the title.
     */
    public abstract void draw(Graphics2D g2, Rectangle2D titleArea);

    /**
     * Returns a clone of the title.
     * <P>
     * One situation when this is useful is when editing the title properties -
     * you can edit a clone, and then it is easier to cancel the changes if
     * necessary.
     *
     * @return a clone of the title.
     *
     */
    public Object clone() {

        AbstractTitle duplicate = null;

        try {
            duplicate = (AbstractTitle) super.clone();
        }
        catch (CloneNotSupportedException e) {
            // this should never happen because Cloneable is implemented
            throw new RuntimeException("AbstractTitle.clone()");
        }

        return duplicate;

    }

    /**
     * Registers an object for notification of changes to the title.
     *
     * @param listener  the object that is being registered.
     */
    public void addChangeListener(TitleChangeListener listener) {
        this.listenerList.add(TitleChangeListener.class, listener);
    }

    /**
     * Unregisters an object for notification of changes to the chart title.
     *
     * @param listener  the object that is being unregistered.
     */
    public void removeChangeListener(TitleChangeListener listener) {
        this.listenerList.remove(TitleChangeListener.class, listener);
    }

    /**
     * Notifies all registered listeners that the chart title has changed in some way.
     *
     * @param event  an object that contains information about the change to the title.
     */
    protected void notifyListeners(TitleChangeEvent event) {

        if (this.notify) {

            Object[] listeners = this.listenerList.getListenerList();
            for (int i = listeners.length - 2; i >= 0; i -= 2) {
                if (listeners[i] == TitleChangeListener.class) {
                    ((TitleChangeListener) listeners[i + 1]).titleChanged(event);
                }
            }
        }

    }

    /**
     * Utility method for checking a horizontal alignment code.
     *
     * @param code  the alignment code.
     *
     * @return <code>true</code> if alignment is <code>LEFT|MIDDLE|RIGHT</code>.
     */
    protected static boolean isValidHorizontalAlignment(int code) {

        switch(code) {
            case AbstractTitle.LEFT:   return true;
            case AbstractTitle.MIDDLE: return true;
            case AbstractTitle.RIGHT:  return true;
            default: return false;
        }

    }

    /**
     * Utility method for checking a vertical alignment code.
     *
     * @param code  the alignment code.
     *
     * @return <code>true</code>, if alignment is <code>TOP|MIDDLE|BOTTOM</code>.
     */
    protected static boolean isValidVerticalAlignment(int code) {

        switch(code) {
            case AbstractTitle.TOP:    return true;
            case AbstractTitle.MIDDLE: return true;
            case AbstractTitle.BOTTOM: return true;
            default: return false;
        }

    }

    /**
     * Tests an object for equality with this title.
     *
     * @param obj  the object.
     *
     * @return <code>true</code> or <code>false</code>.
     */
    public boolean equals(Object obj) {

        if (obj == null) {
            return false;
        }

        if (obj == this) {
            return true;
        }

        if (obj instanceof AbstractTitle) {

            AbstractTitle t = (AbstractTitle) obj;
 //           if (super.equals(obj)) {
                boolean b0 = (this.position == t.position);
                boolean b1 = (this.horizontalAlignment == t.horizontalAlignment);
                boolean b2 = (this.verticalAlignment == t.verticalAlignment);
                boolean b3 = ObjectUtils.equal(this.spacer, t.spacer);
                boolean b4 = (this.notify == t.notify);

                return b0 && b1 && b2 && b3 && b4;
//            }
        }

        return false;

    }

    /**
     * Provides serialization support.
     *
     * @param stream  the output stream.
     *
     * @throws IOException  if there is an I/O error.
     */
    private void writeObject(ObjectOutputStream stream) throws IOException {
        stream.defaultWriteObject();
    }

    /**
     * Provides serialization support.
     *
     * @param stream  the input stream.
     *
     * @throws IOException  if there is an I/O error.
     * @throws ClassNotFoundException  if there is a classpath problem.
     */
    private void readObject(ObjectInputStream stream) throws IOException, ClassNotFoundException {
        stream.defaultReadObject();
        this.listenerList = new EventListenerList();
    }

}