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

/**
 * @file ext-shapes.js
 *
 * @license MIT
 *
 * @copyright 2010 Christian Tzurcanu, 2010 Alexis Deveria
 *
 */
const name = 'shapes'

const loadExtensionTranslation = async function (svgEditor) {
  let translationModule
  const lang = svgEditor.configObj.pref('lang')
  try {
    translationModule = await import(`./locale/${lang}.js`)
  } catch (_error) {
    console.warn(`Missing translation (${lang}) for ${name} - using 'en'`)
    translationModule = await import('./locale/en.js')
  }
  svgEditor.i18next.addResourceBundle(lang, name, translationModule.default)
}

export default {
  name,
  async init () {
    const svgEditor = this
    const canv = svgEditor.svgCanvas
    const { $id, $click } = canv
    const svgroot = canv.getSvgRoot()
    let lastBBox = {}
    await loadExtensionTranslation(svgEditor)

    const modeId = 'shapelib'
    const startClientPos = {}

    let curShape
    let startX
    let startY

    return {
      callback () {
        if ($id('tool_shapelib') === null) {
          const buttonTemplate = `
          <se-explorerbutton id="tool_shapelib" title="${svgEditor.i18next.t(`${name}:buttons.0.title`)}" lib="./extensions/ext-shapes/shapelib/"
          src="shapelib.svg"></se-explorerbutton>
          `
          canv.insertChildAtIndex($id('tools_left'), buttonTemplate, 9)
          $click($id('tool_shapelib'), () => {
            if (this.leftPanel.updateLeftPanel('tool_shapelib')) {
              canv.setMode(modeId)
            }
          })
        }
      },
      mouseDown (opts) {
        const mode = canv.getMode()
        if (mode !== modeId) { return undefined }

        const currentD = document.getElementById('tool_shapelib').dataset.draw
        startX = opts.start_x
        const x = startX
        startY = opts.start_y
        const y = startY
        const curStyle = canv.getStyle()

        startClientPos.x = opts.event.clientX
        startClientPos.y = opts.event.clientY

        curShape = canv.addSVGElementsFromJson({
          element: 'path',
          curStyles: true,
          attr: {
            d: currentD,
            id: canv.getNextId(),
            opacity: curStyle.opacity / 2,
            style: 'pointer-events:none'
          }
        })

        curShape.setAttribute('transform', 'translate(' + x + ',' + y + ') scale(0.005) translate(' + -x + ',' + -y + ')')

        canv.recalculateDimensions(curShape)

        lastBBox = curShape.getBBox()

        return {
          started: true
        }
      },
      mouseMove (opts) {
        const mode = canv.getMode()
        if (mode !== modeId) { return }

        const zoom = canv.getZoom()
        const evt = opts.event

        const x = opts.mouse_x / zoom
        const y = opts.mouse_y / zoom

        const tlist = curShape.transform.baseVal
        const box = curShape.getBBox()
        const left = box.x; const top = box.y

        const newbox = {
          x: Math.min(startX, x),
          y: Math.min(startY, y),
          width: Math.abs(x - startX),
          height: Math.abs(y - startY)
        }

        let sx = (newbox.width / lastBBox.width) || 1
        let sy = (newbox.height / lastBBox.height) || 1

        // Not perfect, but mostly works...
        let tx = 0
        if (x < startX) {
          tx = lastBBox.width
        }
        let ty = 0
        if (y < startY) {
          ty = lastBBox.height
        }

        // update the transform list with translate,scale,translate
        const translateOrigin = svgroot.createSVGTransform()
        const scale = svgroot.createSVGTransform()
        const translateBack = svgroot.createSVGTransform()

        translateOrigin.setTranslate(-(left + tx), -(top + ty))
        if (!evt.shiftKey) {
          const max = Math.min(Math.abs(sx), Math.abs(sy))

          sx = max * (sx < 0 ? -1 : 1)
          sy = max * (sy < 0 ? -1 : 1)
        }
        scale.setScale(sx, sy)

        translateBack.setTranslate(left + tx, top + ty)
        tlist.appendItem(translateBack)
        tlist.appendItem(scale)
        tlist.appendItem(translateOrigin)

        canv.recalculateDimensions(curShape)

        lastBBox = curShape.getBBox()
      },
      mouseUp (opts) {
        const mode = canv.getMode()
        if (mode !== modeId) { return undefined }

        const keepObject = (opts.event.clientX !== startClientPos.x && opts.event.clientY !== startClientPos.y)

        return {
          keep: keepObject,
          element: curShape,
          started: false
        }
      }
    }
  }
}