show label when user mouseOver ValueMarker in jFreeChart

Question

Right now i a JFreeChart line graph. I want to add marker to mark some events. I have added the markers. The problem is that the marker labels have started to overlap. I want to solve this by only showing the marker label if the user mouse over's the marker line. How can i capture the mouseover event?

Marker tempMarker = new ValueMarker(hour.getFirstMillisecond());        
tempMarker.setPaint(Color.BLACK); 
tempMarker.setLabelAnchor(RectangleAnchor.TOP_LEFT);
tempMarker.setLabelTextAnchor(TextAnchor.TOP_RIGHT);

//instead of this i want a mouseoverlistner and then show the label
tempMarker.setLabel("Event Name");

code for mouse over

chartPanel.addChartMouseListener(new ChartMouseListener() {
    @Override
    public void chartMouseClicked(ChartMouseEvent event) {
        //do something on mouse click
    }

    @Override
    public void chartMouseMoved(ChartMouseEvent event) {
        System.out.println("Entity Type: " + event.getEntity());
    }
});

When i mouse over the Marker objects a ChartEntity is sent to the chartMouseMoved. This is the same as when i mouse over other non filled portions of the chart.

You can capture the mouseover with a `ChartMouseListener` (example: http://stackoverflow.com/questions/21172794/jfreechart-dispay-mouse-coordinates-near-to-mouse-as-hints-on-mouse-move), but perhaps you would be satisfied with a tooltip? (example: http://stackoverflow.com/questions/6766223/jfreechart-create-tooltip-in-chartpanel) — Eric Leibenguth, Oct 01 '15 at 10:05
@Eric the `ChartMouseListener` does not capture mouse events over the ValueMarker. Tried it already. Markers are added to the plot and the chartmouselistener is on the chart object — codeNinja, Oct 01 '15 at 11:13
The `ChartMouseListener` should be capturing all the events happening within the chart. Can you post what you have tried? How about addind/removing the markers dynamically when detecting the mouse over a particular entity? — Eric Leibenguth, Oct 01 '15 at 11:54
@Eric i have updated my question with the chartMouseListner code. Basically i have tested with it already and it does not provide any way to identify that the mouse is over a Marker. — codeNinja, Oct 01 '15 at 18:42

score 2 · Accepted Answer · edited Oct 02 '15 at 08:24

It's not really possible to do this. I got help from @paradoxoff in this thread on the jfree forum. Here is how I achieved it.

Download the Annotation files from Click here
You only need the org.jfree.chart.annotations folder. Add it to your project.

Replace the Marker with Annotations with this code below

XYDomainValueAnnotation tempMarker = new XYDomainValueAnnotation();
tempMarker.setValue(hour.getFirstMillisecond());

//set the color of the lines
switch (priority) {
    case Constants.HIGH_IMPORTANCE:
        tempMarker.setPaint(Color.RED);
        break;
    case Constants.LOW_IMPORTANCE:
        tempMarker.setPaint(Color.GREEN);
        break;
    default:
        tempMarker.setPaint(Color.BLACK);
}

// dont set the label
//tempMarker.setLabel("Event Name");

//set the Tool Tip which will display when you mouse over.
tempMarker.setToolTipText("Annotation");

//format everything
tempMarker.setStroke(new BasicStroke(5.0f));        
tempMarker.setLabelTextAnchor(TextAnchor.TOP_LEFT);
tempMarker.setLabelAnchor(RectangleAnchor.TOP_LEFT);
tempMarker.setRotationAnchor(TextAnchor.TOP_LEFT);

//add the annotation lines
plot.addAnnotation(tempMarker);

When you mouse over the annotation lines the tooltip will appear.

show label when user mouseOver ValueMarker in jFreeChart

1 Answers1