Source: editor/extensions/ext-overview_window/ext-overview_window.js

/* eslint-disable max-len */
/**
 * @file ext-overview_window.js
 *
 * @license MIT
 *
 * @copyright 2013 James Sacksteder
 *
 */
import { dragmove } from './dragmove/dragmove.js';

export default {
  name: 'overview_window',
  init ({ _$ }) {
    const svgEditor = this;
    const { $id } = svgEditor.svgCanvas;
    const overviewWindowGlobals = {};

    // Define and insert the base html element.
    const propsWindowHtml =
      '<div id="overview_window_content_pane" style="width:100%; word-wrap:break-word;  display:inline-block; margin-top:20px;">' +
        '<div id="overview_window_content" style="position:relative; padding-left:15px; top:0px;">' +
          '<div style="background-color:#A0A0A0; display:inline-block; overflow:visible;">' +
            '<svg id="overviewMiniView" width="132" height="100" x="0" y="0" viewBox="0 0 4800 3600" ' +
                'xmlns="http://www.w3.org/2000/svg" ' +
                'xmlns:xlink="http://www.w3.org/1999/xlink">' +
              '<use x="0" y="0" xlink:href="#svgroot"> </use>' +
            '</svg>' +
            '<div id="overview_window_view_box" style="min-width:50px; min-height:50px; position:absolute; top:30px; left:30px; z-index:5; background-color:rgba(255,0,102,0.3);">' +
            '</div>' +
          '</div>' +
        '</div>' +
      '</div>';
    // eslint-disable-next-line no-unsanitized/method
    $id("sidepanel_content").insertAdjacentHTML( 'beforeend', propsWindowHtml );

    // Define dynamic animation of the view box.
    const updateViewBox = () => {
      const { workarea } = svgEditor;
      const portHeight = parseFloat(getComputedStyle(workarea, null).height.replace("px", ""));
      const portWidth = parseFloat(getComputedStyle(workarea, null).width.replace("px", ""));
      const portX = workarea.scrollLeft;
      const portY = workarea.scrollTop;
      const windowWidth = parseFloat(getComputedStyle($id("svgcanvas"), null).width.replace("px", ""));
      const windowHeight = parseFloat(getComputedStyle($id("svgcanvas"), null).height.replace("px", ""));
      const overviewWidth = parseFloat(getComputedStyle($id("overviewMiniView"), null).width.replace("px", ""));
      const overviewHeight = parseFloat(getComputedStyle($id("overviewMiniView"), null).height.replace("px", ""));

      const viewBoxX = portX / windowWidth * overviewWidth;
      const viewBoxY = portY / windowHeight * overviewHeight;
      const viewBoxWidth = portWidth / windowWidth * overviewWidth;
      const viewBoxHeight = portHeight / windowHeight * overviewHeight;

      $id("overview_window_view_box").style.minWidth = viewBoxWidth + 'px';
      $id("overview_window_view_box").style.minHeight = viewBoxHeight + 'px';
      $id("overview_window_view_box").style.top = viewBoxY + 'px';
      $id("overview_window_view_box").style.left = viewBoxX + 'px';
    };
    $id('workarea').addEventListener('scroll', () => {
      if (!(overviewWindowGlobals.viewBoxDragging)) {
        updateViewBox();
      }
    });
    $id('workarea').addEventListener('resize', updateViewBox);
    updateViewBox();

    // Compensate for changes in zoom and canvas size.
    const updateViewDimensions = function () {
      const viewWidth = parseFloat(getComputedStyle($id("svgroot"), null).width.replace("px", ""));
      const viewHeight = parseFloat(getComputedStyle($id("svgroot"), null).height.replace("px", ""));

      const viewX = 640;
      const viewY = 480;

      const svgWidthOld = parseFloat(getComputedStyle($id("overviewMiniView"), null).width.replace("px", ""));
      const svgHeightNew = viewHeight / viewWidth * svgWidthOld;
      $id('overviewMiniView').setAttribute('viewBox', viewX + ' ' + viewY + ' ' + viewWidth + ' ' + viewHeight);
      $id('overviewMiniView').setAttribute('height', svgHeightNew);
      updateViewBox();
    };
    updateViewDimensions();

    // Set up the overview window as a controller for the view port.
    overviewWindowGlobals.viewBoxDragging = false;
    const updateViewPortFromViewBox = function () {
      const windowWidth = parseFloat(getComputedStyle($id("svgcanvas"), null).width.replace("px", ""));
      const windowHeight = parseFloat(getComputedStyle($id("svgcanvas"), null).height.replace("px", ""));
      const overviewWidth = parseFloat(getComputedStyle($id("overviewMiniView"), null).width.replace("px", ""));
      const overviewHeight = parseFloat(getComputedStyle($id("overviewMiniView"), null).height.replace("px", ""));
      const viewBoxX = parseFloat(getComputedStyle($id("overview_window_view_box"), null).getPropertyValue('left').replace("px", ""));
      const viewBoxY = parseFloat(getComputedStyle($id("overview_window_view_box"), null).getPropertyValue('top').replace("px", ""));


      const portX = viewBoxX / overviewWidth * windowWidth;
      const portY = viewBoxY / overviewHeight * windowHeight;
      $id('workarea').scrollLeft = portX;
      $id('workarea').scrollTop = portY;
    };
    const onStart = () => {
      overviewWindowGlobals.viewBoxDragging = true;
      updateViewPortFromViewBox();
    };
    const onEnd = (el, parent, _x, _y) => {
      if((el.offsetLeft + el.offsetWidth) > parseFloat(getComputedStyle(parent, null).width.replace("px", ""))){
        el.style.left = (parseFloat(getComputedStyle(parent, null).width.replace("px", "")) - el.offsetWidth) + 'px';
      } else if(el.offsetLeft  < 0){
        el.style.left = "0px";
      }
      if((el.offsetTop + el.offsetHeight) > parseFloat(getComputedStyle(parent, null).height.replace("px", ""))){
        el.style.top = (parseFloat(getComputedStyle(parent, null).height.replace("px", "")) - el.offsetHeight) + 'px';
      } else if(el.offsetTop  < 0){
        el.style.top = "0px";
      }
      overviewWindowGlobals.viewBoxDragging = false;
      updateViewPortFromViewBox();
    };
    const onDrag = function () {
      updateViewPortFromViewBox();
    };
    const dragElem = document.querySelector("#overview_window_view_box");
    const parentElem = document.querySelector("#overviewMiniView");
    dragmove(dragElem, dragElem, parentElem, onStart, onEnd, onDrag);

    $id("overviewMiniView").addEventListener("click", (evt) => {
      // Firefox doesn't support evt.offsetX and evt.offsetY.
      const mouseX = (evt.offsetX || evt.originalEvent.layerX);
      const mouseY = (evt.offsetY || evt.originalEvent.layerY);
      const overviewWidth = parseFloat(getComputedStyle($id("overviewMiniView"), null).width.replace("px", ""));
      const overviewHeight = parseFloat(getComputedStyle($id("overviewMiniView"), null).height.replace("px", ""));
      const viewBoxWidth = parseFloat(getComputedStyle($id("overview_window_view_box"), null).getPropertyValue('min-width').replace("px", ""));
      const viewBoxHeight = parseFloat(getComputedStyle($id("overview_window_view_box"), null).getPropertyValue('min-height').replace("px", ""));

      let viewBoxX = mouseX - 0.5 * viewBoxWidth;
      let viewBoxY = mouseY - 0.5 * viewBoxHeight;
      // deal with constraints
      if (viewBoxX < 0) {
        viewBoxX = 0;
      }
      if (viewBoxY < 0) {
        viewBoxY = 0;
      }
      if (viewBoxX + viewBoxWidth > overviewWidth) {
        viewBoxX = overviewWidth - viewBoxWidth;
      }
      if (viewBoxY + viewBoxHeight > overviewHeight) {
        viewBoxY = overviewHeight - viewBoxHeight;
      }
      $id("overview_window_view_box").style.top = viewBoxY + 'px';
      $id("overview_window_view_box").style.left = viewBoxX + 'px';
      updateViewPortFromViewBox();
    });

    return {
      name: 'overview window',
      canvasUpdated: updateViewDimensions,
      workareaResized: updateViewBox
    };
  }
};