choicegroup.java

j2me polish学习的经典代码

				throw new IllegalArgumentException("invalid choiceType [" + choiceType + "] - IMPLICIT=" + Choice.IMPLICIT + ".");
			//#else
				//# throw new IllegalArgumentException();
			//#endif
		}
		this.choiceType = choiceType;
		for (int i = 0; i < items.length; i++) {
			ChoiceItem item = items[i];
			append( item );
		}
	}
	
	/**
	 * Builds an array of <code>ChoiceItems</code> out of
	 * an array of <code>String</code>s and <code>Image</code>s,
	 * specifying the <code>choiceType</code> and <code>style</code>
	 * common to any <code>ChoiceItem</code> in the resulting array.
	 * 
	 * @param stringElements set of strings specifying the string parts of the ChoiceGroup elements
	 * @param imageElements set of images specifying the image parts of the ChoiceGroup elements
	 * @param choiceType EXCLUSIVE, MULTIPLE, or POPUP
	 * @param style The CSS style for this item
	 * @return an aray of choice items
	 * @throws NullPointerException if stringElements is null or if the stringElements array contains any null elements
	 * @throws IllegalArgumentException if the imageElements array is non-null and has a different length from the stringElements array
	 * @see Choice#EXCLUSIVE
	 * @see Choice#MULTIPLE
	 * @see Choice#IMPLICIT
	 * @see Choice#POPUP
	 */
	protected static ChoiceItem[] buildChoiceItems(String[] stringElements, Image[] imageElements, int choiceType, Style style)
	{
		//#ifndef polish.skipArgumentCheck
			if (imageElements != null && imageElements.length != stringElements.length) {
				//#ifdef polish.verboseDebug
					throw new IllegalArgumentException("imageElements need to have the same length as the stringElements.");
				//#else
					//# throw new IllegalArgumentException();
				//#endif
			}
		//#endif
		ChoiceItem[] items = new ChoiceItem[stringElements.length];
		for (int i = 0; i < stringElements.length; ++i) {
			Image img = null;
			if (imageElements != null) {
				img = imageElements[i];
			}
			items[i] = new ChoiceItem( stringElements[i], img, choiceType, style );
		}
		return items;
	}
	
	//#ifdef polish.usePopupItem
	/**
	 * Creates or returns the default image for popup groups.
	 * 
	 * @return the default popup image
	 */
	protected Image createPopupImage() {
		if (popupImage == null) {
			popupImage = Image.createImage( 9, 12 );
			Graphics g = popupImage.getGraphics();
			g.setColor( this.popupBackgroundColor );
			g.fillRect(0, 0, 10, 13 );
			g.setColor( this.popupColor );
			g.drawLine(0, 0, 9, 0 );
			g.drawLine( 3, 3, 3, 9 );
			g.drawLine( 4, 3, 4, 10 );
			g.drawLine( 5, 3, 5, 9 );
			g.drawLine( 2, 8, 6, 8 );	
			g.drawLine( 1, 7, 7, 7 );	
		}
		return popupImage;
	}
	//#endif

	/**
	 * Gets the <code>String</code> part of the element referenced by
	 * <code>elementNum</code>.
	 * 
	 * @param elementNum the index of the element to be queried
	 * @return the string part of the element
	 * @throws IndexOutOfBoundsException if elementNum is invalid
	 * @see Choice#getString(int) in interface Choice
	 * @see #getImage(int)
	 */
	public String getString(int elementNum)
	{
		ChoiceItem item = (ChoiceItem) this.itemsList.get( elementNum );
		return item.getText();
	}

	/**
	 * Gets the <code>Image</code> part of the element referenced by
	 * <code>elementNum</code>.
	 * 
	 * @param elementNum the number of the element to be queried
	 * @return the image part of the element, or null if there is no image
	 * @throws IndexOutOfBoundsException if elementNum is invalid
	 * @see Choice#getImage(int) in interface Choice
	 * @see #getString(int)
	 */
	public Image getImage(int elementNum)
	{
		ChoiceItem item = (ChoiceItem) this.itemsList.get( elementNum );
		return item.getImage();
	}

	/**
	 * Gets the <code>ChoiceItem</code> of the element referenced by
	 * <code>elementNum</code>.
	 *
	 * @param elementNum the number of the element to be queried
	 * @return the ChoiceItem of the element
	 * @throws IndexOutOfBoundsException if elementNum is invalid
	 */
	public ChoiceItem getItem( int elementNum )
	{
		return (ChoiceItem)this.itemsList.get( elementNum );
	}

	/**
	 * Appends an element to the <code>ChoiceGroup</code>.
	 * 
	 * @param stringPart the string part of the element to be added
	 * @param imagePart the image part of the element to be added, or null if there is no image part
	 * @return the assigned index of the element
	 * @throws NullPointerException if stringPart is null
	 * @see Choice#append( String, Image) in interface Choice
	 */
	public int append( String stringPart, Image imagePart)
	{
		return append( stringPart, imagePart, null );
	}
	
	/**
	 * Appends an element to the <code>ChoiceGroup</code>.
	 * 
	 * @param stringPart the string part of the element to be added
	 * @param imagePart the image part of the element to be added, or null if there is no image part
	 * @param elementStyle the style for the appended ChoiceItem
	 * @return the assigned index of the element
	 * @throws NullPointerException if stringPart is null
	 * @see Choice#append( String, Image) in interface Choice
	 */
	public int append( String stringPart, Image imagePart, Style elementStyle )
	{
		ChoiceItem item = new ChoiceItem( stringPart, imagePart, this.choiceType, elementStyle );
		return append( item, elementStyle );
	}
	
	/**
	 * Appends a ChoiceItem to this choice group.
	 * 
	 * @param item the item
	 * @return the assigned index of the element
	 */
	public int append( ChoiceItem item ) {
		return append( item, null );
	}
	/**
	 * Appends a ChoiceItem to this choice group.
	 * 
	 * @param item the item
	 * @param elementStyle the style of the item, ignored when null
	 * @return the assigned index of the element
	 */
	public int append( ChoiceItem item, Style elementStyle ) {
		add( item );
		if ( elementStyle != null ) {
			item.setStyle( elementStyle );
		}
		//#ifdef polish.usePopupItem
			if (this.isPopup && this.isPopupClosed && this.selectedIndex == -1) {
				this.popupItem.setText( item.text );
				this.selectedIndex = 0;
			}
		//#endif
		return this.itemsList.size() - 1;
	}

	/**
	 * Inserts an element into the <code>ChoiceGroup</code> just prior to
	 * the element specified.
	 * 
	 * @param elementNum the index of the element where insertion is to occur
	 * @param stringPart the string part of the element to be inserted
	 * @param imagePart the image part of the element to be inserted, or null if there is no image part
	 * @throws IndexOutOfBoundsException if elementNum is invalid
	 * @throws NullPointerException if stringPart is null
	 * @see Choice#insert(int, String, Image)  in interface Choice
	 */
	public void insert(int elementNum, String stringPart, Image imagePart)
	{
		insert( elementNum, stringPart, imagePart, null );
	}

	/**
	 * Inserts an element into the <code>ChoiceGroup</code> just prior to
	 * the element specified.
	 * 
	 * @param elementNum the index of the element where insertion is to occur
	 * @param stringPart the string part of the element to be inserted
	 * @param imagePart the image part of the element to be inserted, or null if there is no image part
	 * @param elementStyle the style for the inserted ChoiceItem
	 * @throws IndexOutOfBoundsException if elementNum is invalid
	 * @throws NullPointerException if stringPart is null
	 * @see Choice#insert(int, String, Image)  in interface Choice
	 */
	public void insert(int elementNum, String stringPart, Image imagePart, Style elementStyle)
	{
		ChoiceItem item = new ChoiceItem( stringPart, imagePart, this.choiceType, elementStyle );
		add(elementNum, item);
	}

	/**
	 * Inserts an element into the <code>ChoiceGroup</code> just prior to
	 * the element specified.
	 * 
	 * @param elementNum the index of the element where insertion is to occur
	 * @param item ChoiceItem of the element to be inserted
	 * @throws IndexOutOfBoundsException if elementNum is invalid
	 */
	public void insert(int elementNum, ChoiceItem item)
	{
		add(elementNum, item);
	}

	/**
	 * Sets the <code>String</code> and <code>Image</code> parts of the
	 * element referenced by <code>elementNum</code>,
	 * replacing the previous contents of the element.
	 * 
	 * @param elementNum - the index of the element to be set
	 * @param stringPart - the string part of the new element
	 * @param imagePart - the image part of the element, or null if there is no image part
	 * @throws IndexOutOfBoundsException - if elementNum is invalid
	 * @throws NullPointerException - if stringPart is null
	 * @see Choice#set(int, String, Image) in interface Choice
	 */
	public void set(int elementNum, String stringPart, Image imagePart)
	{
		set( elementNum, stringPart, imagePart, null );
	}

	/**
	 * Sets the <code>String</code> and <code>Image</code> parts of the
	 * element referenced by <code>elementNum</code>,
	 * replacing the previous contents of the element.
	 * 
	 * @param elementNum the index of the element to be set
	 * @param stringPart the string part of the new element
	 * @param imagePart the image part of the element, or null if there is no image part
	 * @param elementStyle the style for the new list element.
	 * @throws IndexOutOfBoundsException if elementNum is invalid
	 * @throws NullPointerException if stringPart is null
	 * @see Choice#set(int, String, Image) in interface Choice
	 */
	public void set(int elementNum, String stringPart, Image imagePart, Style elementStyle )
	{
		ChoiceItem item = (ChoiceItem) this.itemsList.get( elementNum );
		item.setText( stringPart );
		if (imagePart != null) {
			item.setImage(imagePart);
		}
		if (elementStyle != null) {
			item.setStyle(elementStyle);
		}
		
		//#if polish.i18n.useDynamicTranslations
//		if (elementNum == this.focusedIndex) {
//				if (this.selectCommand == List.SELECT_COMMAND ) {
//					String selectLabel = Locale.get("polish.command.select");
//					if ( selectLabel != List.SELECT_COMMAND.getLabel()) {
//						List.SELECT_COMMAND = new Command( selectLabel, Command.ITEM, 3 );
//						removeCommand(this.selectCommand);
//						this.selectCommand = List.SELECT_COMMAND;
//						addCommand( this.selectCommand );
//					}
//				}
//		}
		//#endif

		if (this.isInitialised) {
			this.isInitialised = false;
			repaint();
		}
	}

	/**
	 * Sets the <code>ChoiceItem</code> of the
	 * element referenced by <code>elementNum</code>,
	 * replacing the previous one.
	 * 
	 * @param elementNum the index of the element to be set
	 * @param item the ChoiceItem of the new element
	 * @throws IndexOutOfBoundsException if elementNum is invalid
	 */
	public void set(int elementNum, ChoiceItem item )
	{
		delete( elementNum );
		add( elementNum, item );
		if (this.isInitialised) {
			this.isInitialised = false;
			repaint();
		}
	}

	/**
	 * Deletes the element referenced by <code>elementNum</code>.
	 * 
	 * @param elementNum the index of the element to be deleted
	 * @throws IndexOutOfBoundsException if elementNum is invalid
	 * @see Choice#delete(int) in interface Choice
	 */
	public void delete(int elementNum)
	{
		remove(elementNum);
		//#ifdef polish.usePopupItem
			if (this.isPopup) {
				if (this.selectedIndex == elementNum ) {
					if (this.itemsList.size() > 0) {
						this.selectedIndex = -1;
						if (this.isPopupClosed) {
							setSelectedIndex( 0, true );
						}
					} else {
						this.selectedIndex = -1;
					}
				} else if ( elementNum < this.selectedIndex ) {
					this.selectedIndex--;
				}
			} else {
		//#endif
			if (this.selectedIndex == elementNum ) {
				this.selectedIndex = -1;
			} else if (elementNum < this.selectedIndex) {
				this.selectedIndex--;
			}
		//#ifdef polish.usePopupItem
			}
		//#endif
	}

	/**
	 * Deletes all elements from this <code>ChoiceGroup</code>.
	 * 
	 * @see Choice#deleteAll() in interface Choice
	 */
	public void deleteAll()
	{
		clear();
		this.selectedIndex = -1;
	}

	
	/**
	 * Gets a boolean value indicating whether this element is selected.
	 * 
	 * @param elementNum the index of the element to be queried
	 * @return selection state of the element
	 * @throws IndexOutOfBoundsException if elementNum is invalid
	 * @see Choice#isSelected(int) in interface Choice
	 */
	public boolean isSelected(int elementNum)
	{
		ChoiceItem item = (ChoiceItem) this.itemsList.get( elementNum );
		return item.isSelected;
	}

	/**
	 * Returns the index number of an element in the
	 * <code>ChoiceGroup</code> that is
	 * selected. For <code>ChoiceGroup</code> objects of type
	 * <code>EXCLUSIVE</code> and <code>POPUP</code>
	 * there is at most one element selected, so
	 * this method is useful for determining the user's choice.
	 * Returns <code>-1</code> if
	 * there are no elements in the <code>ChoiceGroup</code>.
	 * 
	 * <p>For <code>ChoiceGroup</code> objects of type
	 * <code>MULTIPLE</code>, this always
	 * returns <code>-1</code> because no
	 * single value can in general represent the state of such a
	 * <code>ChoiceGroup</code>.
	 * To get the complete state of a <code>MULTIPLE</code>
	 * <code>Choice</code>, see <A HREF="../../../javax/microedition/lcdui/ChoiceGroup.html#getSelectedFlags(boolean[])"><CODE>getSelectedFlags</CODE></A>.</p>
	 * 
	 * @return index of selected element, or -1 if none
	 * @see Choice#getSelectedIndex() in interface Choice
	 * @see #setSelectedIndex(int, boolean)
	 */
	public int getSelectedIndex()
	{
		if (this.isMultiple || this.itemsList.size() == 0) {
			return -1;
		} else if (this.isImplicit) {
			return this.focusedIndex;
		} else {
			return this.selectedIndex;
		}
	}

	/**
	 * Queries the state of a <code>ChoiceGroup</code> and returns the state of
	 * all elements in the
	 * boolean array
	 * <code>selectedArray_return</code>. <strong>Note:</strong> this
	 * is a result parameter.
	 * It must be at least as long as the size
	 * of the <code>ChoiceGroup</code> as returned by <code>size()</code>.
	 * If the array is longer, the extra
	 * elements are set to <code>false</code>.
	 * 
	 * <p>For <code>ChoiceGroup</code> objects of type
	 * <code>MULTIPLE</code>, any
	 * number of elements may be selected and set to true in the result
	 * array.  For <code>ChoiceGroup</code> objects of type
	 * <code>EXCLUSIVE</code> and <code>POPUP</code>
	 * exactly one element will be selected, unless there are
	 * zero elements in the <code>ChoiceGroup</code>. </p>
	 * 
	 * @param selectedArray_return array to contain the results
	 * @return the number of selected elements in the ChoiceGroup
	 * @throws IllegalArgumentException if selectedArray_return is shorter than the size of the ChoiceGroup
	 * @throws NullPointerException if selectedArray_return is null
	 * @see Choice#getSelectedFlags(boolean[]) in interface Choice
	 * @see #setSelectedFlags(boolean[])
	 */