drawio/lib/versioning/DisabledCells.js

class DisabledCells {
  constructor() {
    this.disabledCells = new Set();
  }

  add(cell) {
    this.disabledCells.add(cell);
  }

  delete(cell) {
    this.disabledCells.delete(cell);
  }

  install(graph) {
    const self = this;
    // part #1: Intercepting mxGraph.fireMouseEvent
    const oldFireMouseEvent = graph.fireMouseEvent;
    graph.fireMouseEvent = function(evtName, me, sender) {
      if (me.state && self.disabledCells.has(me.state.cell.id)) {
        // clicked shape is disabled
        return;
      }
      oldFireMouseEvent.apply(this, arguments);
    }

    // part #2: Ignore double clicks on disabled cells
    const oldDblClick = graph.dblClick;
    graph.dblClick = function(evt, cell) {
      if (cell && self.disabledCells.has(cell.id)) {
        // clicked shape is disabled
        return;
      }
      oldDblClick.apply(this, arguments);
    }
    // part #3: Protect disabled cells from ever being selected
    const oldMxSelectionChange = mxSelectionChange; // override constructor :)
    mxSelectionChange = function(selectionModel, added, removed) {
      oldMxSelectionChange.apply(this, arguments);
      if (this.added) {
        this.added = this.added.filter(cell => !self.disabledCells.has(cell.id));
      }
    }
    mxSelectionChange.prototype = oldMxSelectionChange.prototype;
  }
}

module.exports = { DisabledCells };