abstractgroupstrategy.java

利用它可以做出非常漂亮的swt界面,包含的组件有PShelf Plist

package com.swtplus.widgets.group;

import org.eclipse.swt.SWT;
import org.eclipse.swt.events.ControlEvent;
import org.eclipse.swt.events.ControlListener;
import org.eclipse.swt.events.KeyEvent;
import org.eclipse.swt.events.KeyListener;
import org.eclipse.swt.events.MouseEvent;
import org.eclipse.swt.events.MouseListener;
import org.eclipse.swt.events.MouseMoveListener;
import org.eclipse.swt.events.MouseTrackListener;
import org.eclipse.swt.graphics.Color;
import org.eclipse.swt.graphics.GC;
import org.eclipse.swt.graphics.Rectangle;
import org.eclipse.swt.widgets.Event;
import org.eclipse.swt.widgets.Listener;

import com.swtplus.widgets.PGroup;
import com.swtplus.widgets.toggle.IToggleStrategy;

/**
 * AbstractGroupStrategy is a convenient starting point for all IGroupStrategy's.
 * <P>
 * The AbstractGroupStrategy handles most behavior for you.  All that is required
 * of extending classes, is to implement painting and sizing.
 *
 * @author chris
 */
public abstract class AbstractGroupStrategy implements IGroupStrategy{

	
	private PGroup group;

    private IToggleStrategy toggleStrategy;
	private boolean expanded = true;
	private boolean hoveringOnToggle = false;
	
	
    private int fontHeight = 0;
    private int textWidth = 0;
	private int titleHeight = 0;
    
    //used for hand cursor
    private Rectangle activeBounds = new Rectangle(0,0,0,0);
    

    /**
     * Default constructor
     * 
     * @param style
     */
    public AbstractGroupStrategy(int style) {
    }
	
	/**
	 * Constructs the strategy with the given toggle strategy and style.
	 * 
	 * @param t
	 * @param style
	 */
	public AbstractGroupStrategy(IToggleStrategy t, int style){
		this.toggleStrategy = t;
	}

    /* (non-Javadoc)
     * @see com.swtplus.widgets.IGroupStrategy#initialize(com.swtplus.widgets.PGroup)
     */
    public void initialize(PGroup g){
    	group = g;
		
		group.addControlListener(new ControlListener(){
			public void controlMoved(ControlEvent arg0) {
			}
			public void controlResized(ControlEvent arg0) {
				activeBounds = computeActiveBounds();
			}});
		
    	if (toggleStrategy != null) {     
            
            group.addMouseTrackListener(new MouseTrackListener(){
                public void mouseEnter(MouseEvent e) {
                }
                public void mouseExit(MouseEvent e) {                  
                    AbstractGroupStrategy.this.group.setCursor(null);
					if (hoveringOnToggle = true){
						hoveringOnToggle = false;
						group.redraw();
					}
					hoveringOnToggle = false;
                }
                public void mouseHover(MouseEvent e) {
                }});
            
            group.addMouseMoveListener(new MouseMoveListener(){
                public void mouseMove(MouseEvent e) {
					boolean newHoveringOnToggle = false;
					boolean showHand = false;
					
					if (activeBounds.intersects(e.x,e.y,1,1)){
						showHand = true;
					}
					if (toggleStrategy != null){
						Rectangle r = new Rectangle(toggleStrategy.getLocation().x,toggleStrategy.getLocation().y,toggleStrategy.getSize().x,toggleStrategy.getSize().y);
						if (r.intersects(e.x,e.y,1,1)){
							newHoveringOnToggle = true;
							showHand = true;
						}
					}

					if (newHoveringOnToggle != hoveringOnToggle){
						hoveringOnToggle = newHoveringOnToggle;
						group.redraw();
					}
					if (showHand){
						AbstractGroupStrategy.this.group.setCursor(AbstractGroupStrategy.this.group.getDisplay().getSystemCursor(SWT.CURSOR_HAND));
					} else {
						AbstractGroupStrategy.this.group.setCursor(null);
					}
                }
                });
            
            group.addMouseListener(new MouseListener(){
                public void mouseDoubleClick(MouseEvent e) {
                }
                public void mouseDown(MouseEvent e) {
					Rectangle r = new Rectangle(toggleStrategy.getLocation().x,toggleStrategy.getLocation().y,toggleStrategy.getSize().x,toggleStrategy.getSize().y);
					if (activeBounds.intersects(e.x,e.y,1,1) || r.intersects(e.x,e.y,1,1)){
                        AbstractGroupStrategy.this.group.setExpanded(!AbstractGroupStrategy.this.group.isExpanded());
						AbstractGroupStrategy.this.getGroup().getBody().setFocus();
                    }
                }
                public void mouseUp(MouseEvent e) {
                }});
            
            
            
            group.addListener (SWT.Traverse, new Listener () {
        		public void handleEvent (Event e) {
        			switch (e.detail) {
        				/* Do tab group traversal */
        				case SWT.TRAVERSE_ESCAPE:
        				case SWT.TRAVERSE_RETURN:
        				case SWT.TRAVERSE_TAB_NEXT:	
        				case SWT.TRAVERSE_TAB_PREVIOUS:
        				case SWT.TRAVERSE_PAGE_NEXT:	
        				case SWT.TRAVERSE_PAGE_PREVIOUS:
        					e.doit = true;
        					break;
        			}
        		}
        	});
        	
            group.addListener (SWT.FocusIn, new Listener () {
        		public void handleEvent (Event e) {
        			group.redraw();
        		}
        	});
            group.addListener (SWT.FocusOut, new Listener () {
        		public void handleEvent (Event e) {
        			group.redraw();
        		}
        	});

            group.addKeyListener(new KeyListener(){
                public void keyPressed(KeyEvent e) {
                    if (e.character == ' ' || e.character == '\r'){
                        AbstractGroupStrategy.this.group.setExpanded(!AbstractGroupStrategy.this.group.isExpanded());
                    }
                }
                public void keyReleased(KeyEvent e) {
                }});
       
    	}
        
        
       
        
        fontChanged();
        titleHeight = computeTitleHeight();
		activeBounds = computeActiveBounds();
    }

	/* (non-Javadoc)
	 * @see com.swtplus.widgets.IGroupStrategy#paint(org.eclipse.swt.graphics.GC)
	 */
	public void paint(GC gc){
		Color back = gc.getBackground();
		Color fore = gc.getForeground();
		paintGroup(gc);
		gc.setBackground(back);
		gc.setForeground(fore);
		paintToggle(gc);
	}
	
    /**
     * Paints the actual group widget.  This method is to be implemented by 
     * extending classes.  
     * 
     * @param gc
     */
    public abstract void paintGroup(GC gc);
    
	/**
	 * Paints the toggle on top of the group.  Not intended to be implemented
	 * in extending classes.
	 * 
	 * @param gc
	 */
	public void paintToggle(GC gc){
		if (getToggleStrategy() != null){
			getToggleStrategy().paint(getGroup(),gc,isExpanded(),getGroup().isFocusControl(),hoveringOnToggle);
		}
	}
	
    /* (non-Javadoc)
     * @see com.swtplus.widgets.IGroupStrategy#resize(org.eclipse.swt.events.ControlEvent)
     */
    public abstract void resize(ControlEvent e);
    
    /**
     * Returns the height of the title area of the PGroup.  This is the area
     * where the PGroup's decoration is expected to be drawn.  This method is 
     * not technically necessary but is provided for convenience.  The height
     * of this title area is typically used throughout many methods including
     * painting and resizing.  Therefore calculating this height ahead of time
     * is beneficial.  This method is called whenever any property that might
     * affect the title height is affected (i.e. font, image, text).
     * 
     * @return
     */
    public abstract int computeTitleHeight();
    
    /**
     * Returns the active area.  The active area is the area where the mouse will
     * change to a hand cursor and the user will be able to expand/collapse the
     * PGroup.  This area and behavior are in addition to the toggle.  
     * 
     * @return
     */
    public abstract Rectangle computeActiveBounds();
    
    /* (non-Javadoc)
     * @see com.swtplus.widgets.IGroupStrategy#isExpanded()
     */
    public boolean isExpanded() {
        return expanded;
    }


    /* (non-Javadoc)
     * @see com.swtplus.widgets.IGroupStrategy#setExpanded(boolean)
     */
    public void setExpanded(boolean expanded) {
		this.expanded = expanded;
		getGroup().getBody().setVisible(expanded);
        group.redraw();
        group.getParent().layout();
        group.redraw();
    }
    
    
	/**
	 * @return Returns the PGroup.
	 */
	public PGroup getGroup() {
		return group;
	}
	
	/**
	 * Returns the height (in pixels) of the PGroup's font.
	 * 
	 * @return the height (in pixels) of the PGroup's font
	 */
	protected int getFontHeight() {
		return fontHeight;
	}

	/**
	 * Returns the width (in pixels) of the PGroup's text.  This is the
	 * full string, not a truncated string relative to the PGroup's size.
	 * 
	 * @return
	 */
	public int getTextWidth() {
		return textWidth;
	}

	/**
	 * @return Returns the toggleStrategy.
	 */
	public IToggleStrategy getToggleStrategy() {
		return toggleStrategy;
	}

	/* (non-Javadoc)
	 * @see com.swtplus.widgets.IGroupStrategy#fontChanged()
	 */
	public void fontChanged() {
        GC gc = new GC(group);
        fontHeight = gc.getFontMetrics().getHeight();
        gc.dispose();
		
		titleHeight = computeTitleHeight();
		activeBounds = computeActiveBounds();
	}

	/* (non-Javadoc)
	 * @see com.swtplus.widgets.IGroupStrategy#imageChanged()
	 */
	public void imageChanged() {
		// TODO Auto-generated method stub
		
		titleHeight = computeTitleHeight();
		activeBounds = computeActiveBounds();		
	}

	/* (non-Javadoc)
	 * @see com.swtplus.widgets.IGroupStrategy#textChanged()
	 */
	public void textChanged() {
        GC gc = new GC(group);
        textWidth = gc.textExtent(group.getText()).x;
        gc.dispose();
	
		titleHeight = computeTitleHeight();
		activeBounds = computeActiveBounds();
	}

	/**
	 * @return Returns the titleHeight.
	 */
	public int getTitleHeight() {
		return titleHeight;
	}
	

	/**
	 * @param titleHeight The titleHeight to set.
	 */
	public void setTitleHeight(int titleHeight) {
		this.titleHeight = titleHeight;
	}
	
	
	
	
	
	
}