Is it necessary to add toolSelectedCallback feature?

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Description

There is the method that pointNearTool and toolSelectedCallback that I can only select the tool by mousedown near the handle, but I want to select the tool by mousedown inner the measurement by the pointInnerTool setted by myself. So I changed the mouseDown.js:

  const annotationToolsWithPointInnerClick = activeAndPassiveTools.filter(
    tool => {
      const toolState = getToolState(element, tool.name);
      const isInnerPoint = 
        toolState &&
        toolState.data &&
        tool.pointInnerTool &&
        toolState.data.some(data =>
          tool.pointInnerTool(element, data, coords, 'mouse')
        );
      return isInnerPoint;
    }
  );
  if (annotationToolsWithPointInnerClick.length > 0) {
    const firstToolInnerPoint = annotationToolsWithPointInnerClick[0];
    const toolState = getToolState(element, firstToolInnerPoint.name);
    const firstAnnotationInnerPoint = toolState.data.find(data => 
      firstToolInnerPoint.pointInnerTool(element, data, coords)
    );

    if (firstAnnotationInnerPoint && firstToolInnerPoint.innerSelectedCallback) {
      firstToolInnerPoint.innerSelectedCallback(
        evt,
        firstAnnotationInnerPoint,
        'mouse'
      );
      return;
    }
  }

I Have add my custom feature in my version(forked from the official), @dannyrb If you think it’s necessary to add it , I will create PR.

[xingbofeng]

Just to play devil’s advocate, how would you intend to deal with the case of drawing one region inside the other in this pointInnerTool mode?

e.g.:

As the passive functionality of the first ROI would grab the event and you would instead start moving the ROI.

@JamesAPetts I’m not consider this problem,now i just choose the first annotation of the array.I need to consider it.

Thanks for the suggestion of @dannyrb ,i will talk about this suggestion with our doctors, now i think it’s not necessary to add this feature, maybe.Thanks!

[dannyrb]

It’s cool to see other people playing around in the listeners/dispatchers ^_^

Tools that implement pointNearTool are basically saying that, if this is true, I want to handle the incoming event, and I want to do it in the library standard way of dragging all handles (unless I’ve overridden the default behavior).

Do you see pointInnerTool being used for behavior other than dragging all annotation handles? Do you have any practical real world examples of different behavior we might want to use when this is true? Is this behavior that should be a default implementation for innerSelectedCallback on BaseAnnotationTool?

To me, the biggest questions/risks are:

• pointInnerTool has a higher chance of multiple tools reporting back true
  • Improved concepts of annotations depth/layers so we can determine which tool should handle events
  • Pushing annotations up/down layers may require a new annotation::selected state
• Should there be a default behavior? Or some canned strategies that can be set with flags?

CC: @JamesAPetts

Thanks for the suggestion, @xingbofeng! It’s really encouraging to get feedback and feature requests for this part of the library.