begin()

in packages/miew/src/ComplexVisualEdit.js [194:265]

• 52 lines of code
• 8 McCabe index (conditional complexity)

  begin() {
    const visual = this._complexVisual;
    const selection = this._complexVisual.getSelectionGeo();

    const atoms = this._getSelectionBorderAtoms();
    if (atoms.length < 1 || atoms.length > 2) {
      logger.error('Can only edit fragments with one or two bound atoms.');
      return false;
    }

    this._fragmentBoundAtoms = atoms;

    const selectionMask = 1 << visual.getSelectionBit();

    // hide selected fragment in main model
    visual.disableSubset(selectionMask, true);

    // hide selection geo in main model
    for (let k = 0; k < selection.children.length; ++k) {
      selection.children[k].visible = false;
    }

    // create visible fragment representation to rotate
    const pivotPos = atoms[0].position.clone();

    if (atoms.length === 2) {
      pivotPos.lerp(atoms[1].position, 0.5);
    }

    this._fragmentGeo = new THREE.Group();
    visual.add(this._fragmentGeo);
    this._fragmentGeo.position.copy(pivotPos);

    this._fragmentSelectionGeo = new THREE.Group();
    selection.add(this._fragmentSelectionGeo);
    this._fragmentSelectionGeo.position.copy(pivotPos);

    const offset = pivotPos.clone();
    offset.negate();

    for (let i = 0; i < visual.children.length; ++i) {
      const g = visual.children[i];
      if (!('getSubset' in g)) {
        continue;
      }

      const vg = new THREE.Group();
      this._fragmentGeo.add(vg);

      const sg = new THREE.Group();
      this._fragmentSelectionGeo.add(sg);

      const meshes = g.getSubset(selectionMask, true);
      for (let j = 0; j < meshes.length; j++) {
        const m = meshes[j];
        vg.add(m);
        m.position.copy(offset);
      }

      const smeshes = g.getSubset(selectionMask, true);
      for (let h = 0; h < smeshes.length; h++) {
        const sm = smeshes[h];
        sg.add(sm);
        sm.position.copy(offset);
      }
    }

    gfxutils.applySelectionMaterial(this._fragmentSelectionGeo);

    this._inProgress = true;
    return true;
  }