 this.zoomScaleValue_ +=
          ((this.lastMouseViewPos_.y - currentMouseViewPos.y) * 0.001);
      this.zoomScaleValue_ = Math.max(this.zoomScaleValue_, 0.1);

      this.drawPicture_();

      this.lastMouseViewPos_ = currentMouseViewPos;
    },

    onEndZoom_(e) {
      this.lastMouseViewPos_ = undefined;
      this.isZooming_ = false;
      e.preventDefault();
    },

    extractRelativeMousePosition_(e) {
      return {
        x: e.clientX - this.imageContainer_.offsetLeft,
        y: e.clientY - 