Introduction

AbstractWidget define the API for widget. It can’t be instantiated.

widgetRep (set/get vtkWidgetRepresentation)

Set the representation of the widget. The object needs to be inherited from vtkWidgetRepresentation

parent (set/get vtkAbstractWidget)

Specifying a parent to this widget is used when creating composite widgets.

createDefaultRepresentation()

Virtual method, needs to be overrides in derived class.
It defines the representation of the widget

listenEvents()

Attaches interactor events to callbacks. Events are defined in
vtkRenderWindowInteractor.handledEvents, and callbacks need to be formatted
as handle${eventToHandle} and implemented in derived classes.
example: handleMouseMove, handleLeftButtonPress…

render()

Render the interactor.

setEnabled(bool)

Enables or disables the widget.
When the widget is enabled, then the default representation is created.

Source

index.js

import macro from 'vtk.js/Sources/macro';
import vtkInteractorObserver from 'vtk.js/Sources/Rendering/Core/InteractorObserver';

// ----------------------------------------------------------------------------
// vtkAbstractWidget methods
// ----------------------------------------------------------------------------

function vtkAbstractWidget(publicAPI, model) {
  // Set our className
  model.classHierarchy.push('vtkAbstractWidget');
  const superClass = { ...publicAPI };

  //----------------------------------------------------------------------------
  // Public API methods
  //----------------------------------------------------------------------------
  // Virtual method
  publicAPI.createDefaultRepresentation = () => {};

  //----------------------------------------------------------------------------
  publicAPI.setEnabled = (enable) => {
    if (enable === model.enabled) {
      return;
    }

    if (model.interactor) {
      const renderer = model.interactor.getCurrentRenderer();
      if (renderer && model.widgetRep) {
        renderer.removeViewProp(model.widgetRep);
      }
    }

    // Enable/disable in superclass
    superClass.setEnabled(enable);

    if (enable) {
      // Add representation to new interactor's renderer
      if (!model.interactor) {
        return;
      }
      const renderer = model.interactor.getCurrentRenderer();
      if (!renderer) {
        return;
      }
      publicAPI.createDefaultRepresentation();
      model.widgetRep.setRenderer(renderer);
      model.widgetRep.buildRepresentation();
      renderer.addViewProp(model.widgetRep);
    }
  };

  //----------------------------------------------------------------------------
  publicAPI.render = () => {
    if (!model.parent && model.interactor) {
      model.interactor.render();
    }
  };
}

// ----------------------------------------------------------------------------
// Object factory
// ----------------------------------------------------------------------------

const DEFAULT_VALUES = {
  widgetRep: null,
  parent: null,
};

// ----------------------------------------------------------------------------

export function extend(publicAPI, model, initialValues = {}) {
  Object.assign(model, DEFAULT_VALUES, initialValues);

  // Inheritance
  vtkInteractorObserver.extend(publicAPI, model, initialValues);

  // Make widgets disabled by default
  publicAPI.setEnabled(false);

  // Use a priority of 0.5, since default priority from
  // vtkInteractorObserver is 0.0.
  publicAPI.setPriority(0.5);
  macro.setGet(publicAPI, model, ['widgetRep', 'parent']);

  // Object methods
  vtkAbstractWidget(publicAPI, model);
}

// ----------------------------------------------------------------------------

export const newInstance = macro.newInstance(extend, 'vtkAbstractWidget');

// ----------------------------------------------------------------------------

export default { newInstance, extend };