Hu Uli, thanks for trying the patch and for the feedback.
uvoigt wrote:
Combined plots seems to be not supported yet
I just discovered that the logic to detect zoom and pan events is broken for subplots. I will need to change the order of checks in the mousePressed method and to first check whether the mouse event occured within the area of a ZoomableEntity and then whether it occurs within the data area. At present, it is the other way round. With the present order, it will not be possible to reach ZoomableEntities that are within the data area.
uvoigt wrote:
When zooming with the mouse on a single axis the mouse movement should only be evaluated in x direction for domain axes and y direction for range axes. This matters for the zoom out detection triggered by a negative sized mouse movement.
If the ZoomableEntity is in fact an instance of ValueAxisEntity, you are definitely right. If the ZoomableEntity is of another type, the behaviour described may or may not the desired or intuitive one. I see two approaches to this issue:
1. In the mouseDragged method, check whether the ZoomableEntity is an instance of ValueAxisEntity, and if yes, check its positions realtive to the data area and draw the zoom rectangle accordingly.
2. Delegate the calculation of the zooom rectangle to the ZoomableEntity. Personally, I prefer the second approach, as this would allow to add further ZoomableEntities without having to teach ChartPanel how to draw an appropriate zoom rectangle.
uvoigt wrote:Can you explain a situation where it is reasonable to use the isGloballyPannable/Zoomable flag?
I find it more understandable to have an isSingleAxisPannable/Zoomable flag of the ChartPanel (or Chart?) instead. At the moment it is possible to set all isGlobally* flags to false (the defaults), set the setXXPannable/Zoomable flags to true. It is then possible to create the zoom window with the mouse within the plot but nothing happens. Zooming on the axis works.
One use case is the visualization of the response of a process over time which is dependent on some process variables. In such a case, the process variables (which are defined by a user and changed in a controlled way in regular intervals) are rerpesented by separate datasets and plotted on secondary y axes. The "outcome" of the process and the time are plotted on the primary y and on the x axis, respectively. In such a case, it is highly desirable, to leave the ranges for the y axes showing the process parameters constant and only zoom/pan the axes for the time and the process outcome.
But you are right that the behaviour during a zoom action if all axes have the globalXXXable flags set to false is irritating. I will change the isDomain/RangePannable/Zoomable methods of XYPlot and CategoryPlot to not directly return true or false, but to check the respective globalXXX flags of their domain and range axes and return a more appropriate flag.
Regarding the behaviour that you observed for the MultipleAxisDemo4: I will need to check that, but I think that this probably comes from the frequent change of the tick unit and variable lengths of the tick marks.
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