Add / Remove Nodes in FreehandRoi Tool

Prerequisites

• Latest
• Are you reporting to the correct repository?
• No related issues, one of them got me no answers.

Description

I would like to know, if there is a possibility to add or remove nodes after the tool has been closed. I am thinking of it as getting the coords from the mouse, and on click, check the tool state and if there is an existing node, remove it (causes error) and re-render the state, and if there is no node, then add it and as well re-render the state.

Expected behavior:

When adding or removing nodes from a rendered tool, be able to add or remove this information from the tool state’s object and re-render the tool state to update the view with/without the selected nodes.

Actual behavior:

After removing or adding a node from the tool state’s object, changing the lines coordinates and re-rendering, after a click or movement the tool crashes stating Undefined is not an object.

As usual, thanks in advance.

[HoAnhVan]

export const undoFreehandPoint = (toolName, enableElement) => {
  if (!toolName || !enableElement) return;
  try {
    const tool = cornerstoneTools.getToolForElement(enableElement, toolName);
    const activeDrawing = (tool || {})._activeDrawingToolReference;
    if (
      activeDrawing &&
      activeDrawing.handles &&
      (activeDrawing.handles.points || []).length > 1
    ) {
      const configuration = tool._configuration;

      if (configuration.currentHandle > 1) {
        const len = activeDrawing.handles.points.length;
        activeDrawing.handles.points.length = len - 1;
        activeDrawing.handles.points[len - 2].lines = [];
        configuration.currentHandle = configuration.currentHandle - 1;
        cornerstone.updateImage(enableElement);
      }
    }
  } catch (error) {
    console.log(error);
  }
};

[pzehle]

@dannyrb thanks for your response. What I am currently doing as an example on my project is:

Every time I mark a point with the Freehand tool, I am saving the state of the tool in React’s state. At any moment, I can press ‘cmd + z’ and the last node will get deleted from the state, with the following code:

undoPoint = () => {
	var markings = cornerstoneTools.getToolState(this.element, 'FreehandRoi');
	var data = markings.data[0];
	if(data.handles.points.length === 1) {
		return false;
	} else {
		data.handles.points.pop();
		let latestPoint = data.handles.points.length - 1;
		data.handles.points[latestPoint].lines = [];
		cornerstoneTools.clearToolState(this.element, 'FreehandRoi');
		cornerstoneTools.addToolState(this.element, 'FreehandRoi', data);
		cornerstone.updateImage(this.element);
	}
}

I am removing the last available node’s lines array as the last node should not have lines, AFAIK. This all works correctly, but after continuing with the marking, the next point I mark makes my application crash and output the following error:

cornerstoneTools.js:32070 Uncaught TypeError: Cannot read property 'lines' of undefined
    at FreehandRoiTool._addPoint (cornerstoneTools.js:32070)
    at FreehandRoiTool._drawingMouseDownCallback (cornerstoneTools.js:31756)
    at triggerEvent (cornerstoneTools.js:48197)
    at HTMLDivElement.mouseDown (cornerstoneTools.js:8356)
_addPoint @ cornerstoneTools.js:32070
_drawingMouseDownCallback @ cornerstoneTools.js:31756
triggerEvent @ cornerstoneTools.js:48197
mouseDown @ cornerstoneTools.js:8356
cornerstoneTools.js:32070 Uncaught TypeError: Cannot read property 'lines' of undefined
    at FreehandRoiTool._addPoint (cornerstoneTools.js:32070)
    at FreehandRoiTool._addPointPencilMode (cornerstoneTools.js:32106)
    at FreehandRoiTool._drawingDrag (cornerstoneTools.js:31685)
    at FreehandRoiTool._drawingMouseDragCallback (cornerstoneTools.js:31656)
    at triggerEvent (cornerstoneTools.js:48197)
    at HTMLDocument.onMouseMove (cornerstoneTools.js:8398)

When comparing two objects, the first being an object being generated as I mark lesions, and the second object being the object output after the undo function, they seem exactly the same. I don’t really know if internally there is a points or lines counter on the cornerstoneTools’ object or something that is making this error appear after removing a node from the array.

I am putting here a small vide as an example of the things I described above.

I hope this can make my issue clearer. Thanks again.