AbstractTimeCanvas.java

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package edu.rice.cs.hpc.traceviewer.painter;

import org.eclipse.swt.SWT;
import org.eclipse.swt.events.FocusAdapter;
import org.eclipse.swt.events.FocusEvent;
import org.eclipse.swt.events.MouseEvent;
import org.eclipse.swt.events.PaintEvent;
import org.eclipse.swt.events.PaintListener;
import org.eclipse.swt.graphics.Point;
import org.eclipse.swt.graphics.Rectangle;
import org.eclipse.swt.widgets.Composite;

import edu.rice.cs.hpc.data.util.OSValidator;
import edu.rice.cs.hpc.traceviewer.data.util.Constants;



/**********************************************************************************
 * 
 * abstract class for helper information (located on the bottom of the window)
 *
 **********************************************************************************/
public abstract class AbstractTimeCanvas
extends BufferedCanvas
implements ITraceCanvas, PaintListener
{
    private ITraceCanvas.MouseState mouseState;
    
    private Point mouseDown;
    
    private Rectangle selection;
    
    protected enum RegionType {Vertical, Rectangle};
    
    final private RegionType regionType;
    
    /****************
     * Constructs a new instance of this class given its parent and a style value describing its behavior and appearance.
     *
     * @param composite
     * @param style
     ****************/
    public AbstractTimeCanvas(Composite composite, int style) {
        this(composite, style, RegionType.Vertical);
    }
    
    public AbstractTimeCanvas(Composite composite, int style, RegionType regionType) {
        super(composite);
        mouseState = ITraceCanvas.MouseState.ST_MOUSE_INIT;
        this.regionType = regionType;
    }
    
    public void init() 
    {
        if (mouseState == ITraceCanvas.MouseState.ST_MOUSE_INIT) 
        {
            addMouseListener(this);
            addMouseMoveListener(this);
            addPaintListener(this);
            
            // need to initialize mouse selection variables when we lost the focus
            //  otherwise, Eclipse will keep the variables and draw useless selected rectangles
            addFocusListener(new FocusAdapter() {
                /*
                 * (non-Javadoc)
                 * @see org.eclipse.swt.events.FocusAdapter#focusLost(org.eclipse.swt.events.FocusEvent)
                 */
                public void focusLost(FocusEvent e) {
                    AbstractTimeCanvas.this.initMouseSelection();
                }
            });
        }
        initMouseSelection();
        super.initBuffer();
    }
    
    /*****
     * initialize variables 
     */
    private void initMouseSelection()
    {
        selection = new Rectangle(0, 0, 0, 0);
        mouseState = ITraceCanvas.MouseState.ST_MOUSE_NONE;
    }
    
    @Override
    public void mouseMove(MouseEvent e) 
    {
        if (mouseState == ITraceCanvas.MouseState.ST_MOUSE_DOWN)
        {
            Point pos = new Point(e.x, e.y);
            adjustPosition(mouseDown, pos);
            
            redraw();
        }
    }

    @Override
    public void mouseDoubleClick(MouseEvent e) {}

    @Override
    public void mouseDown(MouseEvent e) 
    {
        // take into account ONLY when the button-1 is clicked and it's never been clicked before
        // the click is not right click (or modifier click on Mac)
        if (e.button == 1 && mouseState == ITraceCanvas.MouseState.ST_MOUSE_NONE 
                && (e.stateMask & SWT.MODIFIER_MASK)==0 )
        {
            mouseState = ITraceCanvas.MouseState.ST_MOUSE_DOWN;
            mouseDown = new Point(e.x,e.y);
        }
    }

    @Override
    public void mouseUp(MouseEvent e) 
    {
        if (mouseState == ITraceCanvas.MouseState.ST_MOUSE_DOWN)
        {
            Point mouseUp = new Point(e.x,e.y);
            mouseState = ITraceCanvas.MouseState.ST_MOUSE_NONE;
            
            //difference in mouse movement < 3 constitutes a "single click"
            if(Math.abs(mouseUp.x-mouseDown.x)<3 && Math.abs(mouseUp.y-mouseDown.y)<3)
            {
                changePosition(mouseDown);
            }
            else
            {
                adjustPosition(mouseDown, mouseUp);
                changeRegion(selection);
            }
            redraw();
        }
    }

    @Override
    public void paintControl(PaintEvent event) 
    {
        super.paintControl(event);
        
        //paints the selection currently being made
        if (mouseState==ITraceCanvas.MouseState.ST_MOUSE_DOWN)
        {
            // some Unix machines have no advanced graphic function
            // to render the alpha transformation.
            if (!OSValidator.isUnix()) 
            {
                event.gc.setBackground(Constants.COLOR_WHITE);
                event.gc.setAlpha(100);
                event.gc.fillRectangle( selection );
                event.gc.setAlpha(240);
    
            }           
            event.gc.setLineWidth(2);
            event.gc.setForeground(Constants.COLOR_BLACK);
            event.gc.drawRectangle(selection);
        }
    }
    
    
    private void adjustPosition(Point p1, Point p2) 
    {
        selection.x = Math.min(p1.x, p2.x);
        selection.width = Math.max(p1.x, p2.x) - selection.x;
        final Rectangle area   = getClientArea();

        switch(regionType) {
        case Rectangle:
            selection.y = Math.min(p1.y, p2.y);
            selection.height = Math.max(p1.y, p2.y) - selection.y;
            break;
        case Vertical:
            default:
            selection.y = 0;
            selection.height = area.height;
            break;
        }
    }
    
    /*************************
     * function called when there's a change of mouse click position
     * 
     * @param point
     *************************/
    protected abstract void changePosition(Point point);
    
    
    /***************************
     * function called when there's a change of selected region
     * 
     * @param left
     * @param right
     ***************************/
    protected abstract void changeRegion(Rectangle region);
}