Function onMouseDown

src/DataSheet.js:403–436

(i, j, e)

  }

  onMouseDown (i, j, e) {
    const isNowEditingSameCell = !isEmpty(this.state.editing) && this.state.editing.i === i && this.state.editing.j === j
    let editing = (isEmpty(this.state.editing) || this.state.editing.i !== i || this.state.editing.j !== j)
      ? {} : this.state.editing

    this._setState({
      selecting: !isNowEditingSameCell,
      start: e.shiftKey ? this.state.start : {i, j},
      end: {i, j},
      editing: editing,
      forceEdit: !!isNowEditingSameCell
    })

    var ua = window.navigator.userAgent
    var isIE = /MSIE|Trident/.test(ua)
    // Listen for Ctrl + V in case of IE
    if (isIE) {
      document.addEventListener('keydown', (e) => {
        if ((e.keyCode === 86 || e.which === 86) && e.ctrlKey) {
          this.handlePaste(e)
        }
      })
    }

    // Keep listening to mouse if user releases the mouse (dragging outside)
    document.addEventListener('mouseup', this.onMouseUp)
    // Listen for any outside mouse clicks
    document.addEventListener('mousedown', this.pageClick)

    // Cut, copy and paste event handlers
    document.addEventListener('cut', this.handleCut)
    document.addEventListener('copy', this.handleCopy)
    document.addEventListener('paste', this.handlePaste)
  }

  onMouseOver (i, j) {
    if (this.state.selecting && isEmpty(this.state.editing)) {