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Create a rectangle of selection [message #899647]

Wed, 01 August 2012 16:29

Pierrick LE DAY

Messages: 2
Registered: August 2012

Junior Member

hello,

in a chart created with the SWTChart API, i have to implement a selection rectangle to zoom on the created selection. The zoom party isn't a problem, my problem is on the creation of the rectangle with the GC API.

Here is my code

Listener listener = new Listener() {
	boolean mouseDown=false;
	boolean mouseMoved=false;
	private Integer oldX, oldY;
	final Cursor cursorCross = new Cursor(parent.getDisplay(), SWT.CURSOR_CROSS);
	final Cursor cursorNormal = new Cursor(parent.getDisplay(), SWT.CURSOR_ARROW);
	
	public void handleEvent(Event event) {
		switch (event.type) {
		case SWT.MouseDown:
			mouseDown=true;
			break;
		case SWT.MouseMove:
			if(oldX!=null && oldY!=null && mouseDown) {
				mouseMoved=true;
				parent.setCursor(cursorCross);
				GC gc= new GC(chart.getPlotArea());
				gc.setLineStyle(SWT.LINE_DOT);
				gc.setForeground(gc.getDevice().getSystemColor(SWT.COLOR_DARK_GRAY));
				gc.drawRectangle(oldX, oldY, event.x-oldX, event.y-oldY);
				gc.dispose();
			} else {
				oldX=event.x;
				oldY=event.y;
			}
			break;
		case SWT.MouseUp:
			if(mouseMoved) {
				Range range= new Range(getXAxis().getDataCoordinate(oldX),getXAxis().getDataCoordinate(event.x));
				getXAxis().setRange(range);
				range= new Range(getYAxis().getDataCoordinate(oldY),getYAxis().getDataCoordinate(event.y));
				getYAxis().setRange(range);
				chart.redraw();
				oldX=null;
				oldY=null;
				parent.setCursor(cursorNormal);
			}
			mouseMoved=false;
			mouseDown=false;
			break;
		}
	}
};
chart.getPlotArea().addListener(SWT.MouseDown, listener);
chart.getPlotArea().addListener(SWT.MouseUp, listener);
chart.getPlotArea().addListener(SWT.MouseMove, listener);

I draw a rectangle every time my mouse moves, but I want the old rectangle disappears once the new one is drawn.

Thx for the help.

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Re: Create a rectangle of selection [message #899849 is a reply to message #899647]

Thu, 02 August 2012 15:01

Grant Gayed

Messages: 2150
Registered: July 2009

Senior Member

Hi, two answers:

1. You need to do all of your drawing from an SWT.Paint callback. To
trigger one of these from your MouseMove callback invoke
redraw(theBoundsToRedraw) on chart.getPlotArea().

2. The Tracker widget may save you from having to handle these details,
see the example snippets at http://www.eclipse.org/swt/snippets/#tracker .

Grant

On 8/1/2012 12:29 PM, Pierrick LE DAY wrote:
> hello,
>
> in a chart created with the SWTChart API, i have to implement a
> selection rectangle to zoom on the created selection. The zoom party
> isn't a problem, my problem is on the creation of the rectangle with the
> GC API.
>
> Here is my code
>
> Listener listener = new Listener() {
> boolean mouseDown=false;
> boolean mouseMoved=false;
> private Integer oldX, oldY;
> final Cursor cursorCross = new Cursor(parent.getDisplay(),
> SWT.CURSOR_CROSS);
> final Cursor cursorNormal = new Cursor(parent.getDisplay(),
> SWT.CURSOR_ARROW);
>
> public void handleEvent(Event event) {
> switch (event.type) {
> case SWT.MouseDown:
> mouseDown=true;
> break;
> case SWT.MouseMove:
> if(oldX!=null && oldY!=null && mouseDown) {
> mouseMoved=true;
> parent.setCursor(cursorCross);
> GC gc= new GC(chart.getPlotArea());
> gc.setLineStyle(SWT.LINE_DOT);
>
> gc.setForeground(gc.getDevice().getSystemColor(SWT.COLOR_DARK_GRAY));
> gc.drawRectangle(oldX, oldY, event.x-oldX, event.y-oldY);
> gc.dispose();
> } else {
> oldX=event.x;
> oldY=event.y;
> }
> break;
> case SWT.MouseUp:
> if(mouseMoved) {
> Range range= new
> Range(getXAxis().getDataCoordinate(oldX),getXAxis().getDataCoordinate(event.x));
>
> getXAxis().setRange(range);
> range= new
> Range(getYAxis().getDataCoordinate(oldY),getYAxis().getDataCoordinate(event.y));
>
> getYAxis().setRange(range);
> chart.redraw();
> oldX=null;
> oldY=null;
> parent.setCursor(cursorNormal);
> }
> mouseMoved=false;
> mouseDown=false;
> break;
> }
> }
> };
> chart.getPlotArea().addListener(SWT.MouseDown, listener);
> chart.getPlotArea().addListener(SWT.MouseUp, listener);
> chart.getPlotArea().addListener(SWT.MouseMove, listener);
>
>
> I draw a rectangle every time my mouse moves, but I want the old
> rectangle disappears once the new one is drawn.
>
> Thx for the help.

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Re: Create a rectangle of selection [message #900014 is a reply to message #899849]

Fri, 03 August 2012 13:02

Pierrick LE DAY

Messages: 2
Registered: August 2012

Junior Member

Thank you for the answer, i managed to implement what i wanted with the Tracker

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Re: Create a rectangle of selection [message #1015671 is a reply to message #900014]

Fri, 01 March 2013 16:00

txas kun

Messages: 5
Registered: March 2013

Junior Member

Hello Pierrick

I am very interested in your post. I have problems to get my chart information from a selection. My purpose is to do a zoom to a LineChart but I am becoming crazy!! Do you mind sending me your code source? With the tracker I am visualizing the rectangle, but I have no idea how to get the points that are in the selection.(I have been searching some example/information to get the information of the dataset).

Thanks in advance!

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Re: Create a rectangle of selection [message #1067038 is a reply to message #1015671]

Fri, 05 July 2013 14:38

Aljoscha Steffens

Messages: 302
Registered: November 2012

Senior Member

        Listener listener = new Listener () {
        	boolean mouseDown=false;
        	Tracker tracker = null;
        	Integer width, height;
        	
    		public void handleEvent (Event event) {
    			switch (event.type) {
				case SWT.MouseDown:
					mouseDown = true;
					break;
				case SWT.MouseMove:
					int xSign=1, ySign=1;
					if( mouseDown){
						tracker = new Tracker(chart.getPlotArea(), SWT.RESIZE);
						tracker.setRectangles (new Rectangle [] {
								new Rectangle (event.x, event.y, 0, 0),
							});
						if(tracker.open()){
							width = tracker.getRectangles()[0].width;
							height = tracker.getRectangles()[0].height;
							if(tracker.getRectangles()[0].contains(event.x+1, event.y+1)){
								xSign = 1;
								ySign = 1;
							}
							else if(tracker.getRectangles()[0].contains(event.x+1, event.y-1)){
								xSign = 1;
								ySign = -1;
							}
							else if(tracker.getRectangles()[0].contains(event.x-1, event.y+1)){
								xSign = -1;
								ySign = 1;
							}
							else if(tracker.getRectangles()[0].contains(event.x-1, event.y-1)){
								xSign = -1;
								ySign = -1;
							}

						}
					

    					tracker.dispose();
    					try{


    					Range range= new Range(getXAxis().getDataCoordinate(event.x+ xSign*width),getXAxis().getDataCoordinate(event.x));
    					getXAxis().setRange(range);
    					range= new Range(getYAxis().getDataCoordinate(event.y+ySign*height),getYAxis().getDataCoordinate(event.y));
    					getYAxis().setRange(range);
    					}catch(Exception e){
    					
    					}

    					chart.redraw();
    					mouseDown = false;
        				
    				}

    			}

    		}
    	};
        
    	chart.getPlotArea().addListener(SWT.MouseMove, listener);
    	chart.getPlotArea().addListener(SWT.MouseDown, listener);

@edited: now it should work fine, even if its a stupid workaround

[Updated on: Fri, 05 July 2013 16:19]

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