item.java

来自「This is a resource based on j2me embedde」· Java 代码 · 共 1,133 行 · 第 1/3 页

    public final static int LAYOUT_RIGHT = 2;

    /**
     * A layout directive indicating that this <code>Item</code> should have a
     * horizontally centered layout.
     *
     * <P>Value <code>3</code> is assigned to <code>LAYOUT_CENTER</code>.</P>
     */
    public final static int LAYOUT_CENTER = 3;

    /**
     * A layout directive indicating that this <code>Item</code> should have a
     * top-aligned layout.
     *
     * <P>Value <code>0x10</code> is assigned to <code>LAYOUT_TOP</code>.</P>
     */
    public final static int LAYOUT_TOP = 0x10;

    /**
     * A layout directive indicating that this <code>Item</code> should have a
     * bottom-aligned layout.
     *
     * <P>Value <code>0x20</code> is assigned to <code>LAYOUT_BOTTOM</code>.</P>
     */
    public final static int LAYOUT_BOTTOM = 0x20;

    /**
     * A layout directive indicating that this <code>Item</code> should have a
     * vertically centered layout.
     *
     * <P>Value <code>0x30</code> is assigned to 
     * <code>LAYOUT_VCENTER</code>.</P>
     */
    public final static int LAYOUT_VCENTER = 0x30;

    /**
     * A layout directive indicating that this <code>Item</code> 
     * should be placed at the beginning of a new line or row.
     *
     * <P>Value <code>0x100</code> is assigned to 
     * <code>LAYOUT_NEWLINE_BEFORE</code>.</P>
     */
    public final static int LAYOUT_NEWLINE_BEFORE = 0x100;

    /**
     * A layout directive indicating that this <code>Item</code>
     * should the last on its line or row, and that the next
     * <code>Item</code> (if any) in the container
     * should be placed on a new line or row.
     *
     * <P>Value <code>0x200</code> is assigned to 
     * <code>LAYOUT_NEWLINE_AFTER</code>.</P>
     */
    public final static int LAYOUT_NEWLINE_AFTER = 0x200;

    /**
     * A layout directive indicating that this <code>Item's</code>
     * width may be reduced to its minimum width.
     *
     *<P>Value <code>0x400</code> is assigned to <code>LAYOUT_SHRINK</code></P>
     */
    public final static int LAYOUT_SHRINK = 0x400;

    /**
     * A layout directive indicating that this <code>Item's</code> 
     * width may be increased to fill available space.
     *
     *<P>Value <code>0x800</code> is assigned to <code>LAYOUT_EXPAND</code>.</P>
     */
    public final static int LAYOUT_EXPAND = 0x800;

    /**
     * A layout directive indicating that this <code>Item's</code>
     * height may be reduced to its minimum height.
     *
     * <P>Value <code>0x1000</code> is assigned to
     * <code>LAYOUT_VSHRINK</code>.</P>
     */
    public final static int LAYOUT_VSHRINK = 0x1000;

    /**
     * A layout directive indicating that this <code>Item's</code> 
     * height may be increased to fill available space.
     *
     * <P>Value <code>0x2000</code> is assigned to 
     * <code>LAYOUT_VEXPAND</code>.</P>
     */
    public final static int LAYOUT_VEXPAND = 0x2000;

    /**
     * A layout directive indicating that new MIDP layout
     * rules are in effect for this <code>Item</code>.  If this
     * bit is clear, indicates that MIDP 1.0 layout behavior
     * applies to this <code>Item</code>.
     *
     * <P>Value <code>0x4000</code> is assigned to
     * <code>LAYOUT_2</code>.</P>
     * 
     */
    public static final int LAYOUT_2 = 0x4000;

    /**
     * An appearance mode value indicating that the <code>Item</code> is to have
     * a normal appearance.
     *
     * <P>Value <code>0</code> is assigned to <code>PLAIN</code>.</P>
     */
    public final static int PLAIN = 0;

    /**
     * An appearance mode value indicating that the <code>Item</code>
     * is to appear as a hyperlink.
     * <P>Value <code>1</code> is assigned to <code>HYPERLINK</code>.</P>
     */
    public final static int HYPERLINK = 1;

    /**
     * An appearance mode value indicating that the <code>Item</code>
     * is to appear as a button.
     * <P>Value <code>2</code> is assigned to <code>BUTTON</code>.</P>
     */
    public final static int BUTTON = 2;


// ************************************************************
//  Static initializer, constructor
// ************************************************************

    /**
     * Creates a new item with a given label.
     *
     * @param label the label string; null is allowed
     */
    Item(String label) {
        // SYNC NOTE: probably safe, but since subclasses can't lock
        // around their call to super(), we'll lock it here
        synchronized (Display.LCDUILock) {
            this.label = label;
        }
    }

// ************************************************************
//  public methods
// ************************************************************

    /**
     * Sets the label of the <code>Item</code>. If <code>label</code>
     * is <code>null</code>, specifies that this item has no label.
     * 
     * <p>It is illegal to call this method if this <code>Item</code>
     * is contained within  an <code>Alert</code>.</p>
     * 
     * @param label the label string
     * @throws IllegalStateException if this <code>Item</code> is contained 
     * within an <code>Alert</code>
     * @see #getLabel
     */
    public void setLabel(String label) {
        synchronized (Display.LCDUILock) {
            if (label != this.label && 
	        (label == null || !label.equals(this.label))) {
                this.label = label;
                itemLF.lSetLabel(label);
            }
        }
    }
    
    /**
     * Gets the label of this <code>Item</code> object.
     * @return the label string
     * @see #setLabel
     */
    public String getLabel() {
        // SYNC NOTE: return of atomic value, no locking necessary
        return label;
    }

    /**
     * Gets the layout directives used for placing the item.
     * @return a combination of layout directive values
     * @see #setLayout
     */
    public int getLayout() {
        // SYNC NOTE: return of atomic value, no locking necessary
        return layout;
    }

    /**
     * Sets the layout directives for this item.
     *
     * <p>It is illegal to call this method if this <code>Item</code> 
     * is contained within an <code>Alert</code>.</p>
     * 
     * @param layout a combination of layout directive values for this item
     * @throws IllegalArgumentException if the value of layout is not a
     * bit-wise OR combination of layout directives
     * @throws IllegalStateException if this <code>Item</code> is
     * contained within an <code>Alert</code>
     * @see #getLayout
     */
    public void setLayout(int layout) {
        synchronized (Display.LCDUILock) {
            int oldLayout = this.layout;
            setLayoutImpl(layout);
            if (oldLayout != this.layout) {
                itemLF.lSetLayout(layout);
            }
        }
    }

    /**
     * Adds a context sensitive <code>Command</code> to the item.
     * The semantic type of
     * <code>Command</code> should be <code>ITEM</code>. The implementation
     * will present the command
     * only when the item is active, for example, highlighted.
     * <p>
     * If the added command is already in the item (tested by comparing the
     * object references), the method has no effect. If the item is
     * actually visible on the display, and this call affects the set of
     * visible commands, the implementation should update the display as soon
     * as it is feasible to do so.
     *
     * <p>It is illegal to call this method if this <code>Item</code>
     * is contained within an <code>Alert</code>.</p>
     *
     * @param cmd the command to be added
     * @throws IllegalStateException if this <code>Item</code> is contained
     * within an <code>Alert</code>
     * @throws NullPointerException if cmd is <code>null</code>
     */
    public void addCommand(Command cmd) {
        synchronized (Display.LCDUILock) {
            addCommandImpl(cmd);
        }
    }

    /**
     * Removes the context sensitive command from item. If the command is not
     * in the <code>Item</code> (tested by comparing the object references),
     * the method has
     * no effect. If the <code>Item</code> is actually visible on the display, 
     * and this  call
     * affects the set of visible commands, the implementation should update
     * the display as soon as it is feasible to do so.
     *
     *
     * If the command to be removed happens to be the default command,
     * the command is removed and the default command on this Item is
     * set to <code>null</code>.
     *
     * The following code:
     * <CODE> <pre>
     *     // Command c is the default command on Item item
     *     item.removeCommand(c);
     * </pre> </CODE>
     * is equivalent to the following code:
     * <CODE> <pre>
     *     // Command c is the default command on Item item
     *     item.setDefaultCommand(null);
     *     item.removeCommand(c);
     * </pre> </CODE>
     *
     *
     * @param cmd the command to be removed
     */
    public void removeCommand(Command cmd) {
        synchronized (Display.LCDUILock) {
            removeCommandImpl(cmd);
        }
    }

    /**
     * Sets a listener for <code>Commands</code> to this <code>Item</code>,
     * replacing any previous
     * <code>ItemCommandListener</code>. A <code>null</code> reference
     * is allowed and has the effect of
     * removing any existing listener.
     *
     * <p>It is illegal to call this method if this <code>Item</code>
     * is contained within an <code>Alert</code>.</p>
     *
     * @param l the new listener, or <code>null</code>.
     * @throws IllegalStateException if this <code>Item</code> is contained
     * within an <code>Alert</code>
     */
    public void setItemCommandListener(ItemCommandListener l) {
        synchronized (Display.LCDUILock) {
            commandListener = l;
        }
    }

    /**
     * Gets the preferred width of this <code>Item</code>.  
     * If the application has locked
     * the width to a specific value, this method returns that value.
     * Otherwise, the return value is computed based on the 
     * <code>Item's</code> contents,
     * possibly with respect to the <code>Item's</code> preferred height 
     * if it is locked.
     * See <a href="#sizes">Item Sizes</a> for a complete discussion.
     *
     * @return the preferred width of the Item
     * @see #getPreferredHeight
     * @see #setPreferredSize
     */
    public int getPreferredWidth() {
	synchronized (Display.LCDUILock) {
	    if (lockedWidth != -1) {
		return lockedWidth;
	    } else { 
		return itemLF.lGetPreferredWidth(lockedHeight);
	    }
	}
    }

    /**
     * Gets the preferred height of this <code>Item</code>.  
     * If the application has locked
     * the height to a specific value, this method returns that value.
     * Otherwise, the return value is computed based on the 
     * <code>Item's</code> contents,
     * possibly with respect to the <code>Item's</code> preferred 
     * width if it is locked.
     * See <a href="#sizes">Item Sizes</a> for a complete discussion.
     *
     * @return the preferred height of the <code>Item</code>
     * @see #getPreferredWidth
     * @see #setPreferredSize
     */
    public int getPreferredHeight() {
	synchronized (Display.LCDUILock) {
	    if (lockedHeight != -1) {
		return lockedHeight;
	    } else {
		return itemLF.lGetPreferredHeight(lockedWidth);
	    }
	}
    }

    /**
     * Sets the preferred width and height for this <code>Item</code>.
     * Values for width and height less than <code>-1</code> are illegal.
     * If the width is between zero and the minimum width, inclusive,
     * the minimum width is used instead.
     * If the height is between zero and the minimum height, inclusive,
     * the minimum height is used instead.
     *
     * <p>Supplying a width or height value greater than the minimum width or 
     * height <em>locks</em> that dimension to the supplied
     * value.  The implementation may silently enforce a maximum dimension for 
     * an <code>Item</code> based on factors such as the screen size. 
     * Supplying a value of
     * <code>-1</code> for the width or height unlocks that dimension.
     * See <a href="#sizes">Item Sizes</a> for a complete discussion.</p>
     * 
     * <p>It is illegal to call this method if this <code>Item</code> 
     * is contained within  an <code>Alert</code>.</p>
     * 
     * @param width the value to which the width should be locked, or
     * <code>-1</code> to unlock
     * @param height the value to which the height should be locked, or 
     * <code>-1</code> to unlock
     * @throws IllegalArgumentException if width or height is less than 
     * <code>-1</code>
     * @throws IllegalStateException if this <code>Item</code> is contained
     * within an <code>Alert</code>
     * @see #getPreferredHeight
     * @see #getPreferredWidth
     */
    public void setPreferredSize(int width, int height) {
        if (width < -1 || height < -1) {
            throw new IllegalArgumentException();
        }

        synchronized (Display.LCDUILock) {

            if (owner != null && owner instanceof Alert) {