Disabling default mouse behaviour

[avanidhar]

Dear All,

I am using mouseclicks to zoom into my chart. When i do a regular click with an isShiftDown() function call, the zoom in functionality works fine. But when i try to zoom out using a shift + right click combination, it does not happen. This is my sample code

Code: Select all

public void mouseClicked(MouseEvent e) {
                       
            if(e.isShiftDown())
            {
                this.chartPanel.setZoomAroundAnchor(true);
                this.chartPanel.setZoomInFactor(.5);
                this.chartPanel.zoomInRange(e.getX(), e.getY());
                this.chartPanel.zoomInDomain(e.getX(),e.getY());
                
            }
            else if(e.isMetaDown()&&e.isShiftDown()){
            
                this.chartPanel.setZoomAroundAnchor(true);
                this.chartPanel.setZoomOutFactor(.1);
                this.chartPanel.zoomOutRange(e.getX(), e.getY());
                this.chartPanel.zoomOutDomain(e.getX(),e.getY());
            }
        }

Could you guide me on how to get over this problem? How do i override default behaviour? I am new to JfreeChart and your inputs would be very valuable.

Avanidhar

[RichardWest]

This seems to be a simple code ordering problem. The if-condition is less stringent than the else-if-condition, so an event that would meet the condition of the else-if-statement would also meet the condition of the if-statement. Try changing the order of the conditions or rewrite the code to:

Code: Select all

public void mouseClicked(MouseEvent e) {
    if (e.isShiftDown()) {
        if (e.isMetaDown()) {
            this.chartPanel.setZoomAroundAnchor(true); 
            this.chartPanel.setZoomOutFactor(.1); 
            this.chartPanel.zoomOutRange(e.getX(), e.getY()); 
            this.chartPanel.zoomOutDomain(e.getX(),e.getY()); 
        }
        else {
            this.chartPanel.setZoomAroundAnchor(true); 
            this.chartPanel.setZoomInFactor(.5); 
            this.chartPanel.zoomInRange(e.getX(), e.getY()); 
            this.chartPanel.zoomInDomain(e.getX(),e.getY()); 
        }
    }
}

[avanidhar]

I tried re-ordering the code. The zoom works fine as usual. But the zoomout gives the same problem. When i do a right click with shift enabled, the zoomout fails and the default menu appears on right click. Could this be solved if I could set the default mouse behaviour to null in some way?

I tried to add zoom-in behaviour to shift+Click and zoomout behaviour to control+Click. Heres the sample code for that

Code: Select all

if(e.isShiftDown())
            {
                this.chartPanel.setZoomAroundAnchor(true);
                this.chartPanel.setZoomInFactor(.5);
                this.chartPanel.zoomInBoth(e.getX(), e.getY());
                
            }
       else if(e.isControlDown()){
            
                
                this.chartPanel.setZoomInFactor(0.2);
                this.chartPanel.zoomOutBoth(e.getX(), e.getY());
            }

Note here that i have used setZoomInFactor for controldown, even though i am zooming out. When i use setZoomOutFactor(0.2) for this, the zoomout fails. Both zoomin and zoomout seem to work by setting the ZoomInFactor. Is this usual?

[RichardWest]

I tried re-ordering the code. The zoom works fine as usual. But the zoomout gives the same problem.

The code needed to be reordered (the error was so blatent that I missed the subtler error). The problem is that isMetaDown() && isShiftDown() is not the equivalent of Shift+right-click. Using the isMetaDown() method does not determine if a click is a right click unless you are using a very strange environment. You should probably use isPopupTrigger() instead.

Note here that i have used setZoomInFactor for controldown, even though i am zooming out. When i use setZoomOutFactor(0.2) for this, the zoomout fails. Both zoomin and zoomout seem to work by setting the ZoomInFactor. Is this usual?

Zooming-out and zooming-in use the same basic zoom method based on a factor. You can zoom-out with a factor <1.0, but that is effectively a zoom-in. Conversely, you can zoom-in with a factor >1.0, but that is effectively a zoom-out. The default factors for zoom-in and zoom-out are 0.5 and 2.0 (half-size and double-size), respectively.

Since you never set the zoom-out factor in your updated code, the default value of 2.0 is used. You can prove this to yourself by changing the zoom-in factor in the else-if-statement and see that it has no affect on how the plot resizes. You can also see how this works by looking at the ChartPanel source code.