like selecting a point with mouse

[dabid]

hello, I need to eliminate points of graphic with mouse and wanted to know like selecting the points


thanks

[michael75]

hello dabid,

afaik selecting points is not implemented in jfreechart but if u are interested in doing so, have a look at how the crosshairs can lock on data. this might be a good starting point to understand how things work inside jfreechart.

cu,
michael

[Guest]

oK. thanks michael

[david.gilbert]

Try the addChartMouseListener() method in the ChartPanel class and look through the events generated by this mechanism. You can use this to determine when a data point is clicked - after that, you need to write your own code to do something with that information (e.g. delete an item from the dataset).

[vani_hegde]

David,
with this, we can only detect if the mouse is moved over or clicked on a data point.
I want to findout if the mouse is clicked anywhere on the series irrespective of just the data points and adding a chartmouselistener, i could detect only the data points. What do i need to do if i want to know the mouse clicks at points other than data points also?

thanks,
vani

[david.gilbert]

See this thread:

http://www.jfree.org/phpBB2/viewtopic.php?t=14854

[Guest]

As you can see in the linked thread, you just need to translate the mouse click into a chart coordinate ...

After that, what you want to do with it is quite free ; you can for example look for the closest data point and consider it as selected ...

[vani_hegde]

Yes, i got the point where the mouse was clicked, it was quite straight forward. But my question is how can i find out the nearest data point and how to determine which series that point belongs to.

I have multiple series in my chart and when the mouse is clicked, i want to know which is the series that is nearer to that mouse click area. How to do this???

Please help

[Cdr]

Here's a piece of code you could use ... I need to do something familiar.

I don't pretend it's the most efficient way though.

Code: Select all

	public void mousePressed(MouseEvent e){
		// get the chart coordinates for the mouse click
		Point2D p = ChartUtils.screenToChart(panel,e.getPoint());
		
		// try to locate the closest data point in the (first dataset of the) panel
		double min_dist = Double.MAX_VALUE; 
		double x_min=0,y_min=0 ;
		XYDataset set = panel.getChart().getXYPlot().getDataset();
		for (int i=0;i<set.getSeriesCount();i++) {
			for (int j=0;j<set.getItemCount(i);j++) {
				// evaluate the distance
				double dist = p.distance(set.getXValue(i,j),set.getYValue(i,j));
				if(dist<min_dist){
					min_dist = dist ;
					x_min = set.getXValue(i,j) ;
					y_min = set.getYValue(i,j) ;
				}
			}
		}
		
// do whatever you like with the point after
		System.out.println("("+x_min+","+y_min+")");
	}

The screenToChart method is my own, and converts a mouseclick into chart coordinates; i guess you did that already so I didn't join the code.

From there on, you can get the closest point or its series/dataset (i and j), and add your own code to handle the closest point (delete ?).

Good luck,
Cédric.

[Cdr]

you can also make use of

Code: Select all

double x_min = panel.getChart().getXYPlot().getDomainCrosshairValue() ;
double y_min = panel.getChart().getXYPlot().getRangeCrosshairValue() ;

after setting the crosshair to lock on data

Code: Select all

			panel.getChart().getXYPlot().setDomainCrosshairVisible(true);
			panel.getChart().getXYPlot().setDomainCrosshairLockedOnData(true);
			panel.getChart().getXYPlot().setRangeCrosshairVisible(true);
			panel.getChart().getXYPlot().setRangeCrosshairLockedOnData(true);