[added] onSelecting callback

closes #46

src/Calendar.jsx

@@ -101,6 +101,17 @@ let Calendar = React.createClass({
  */
  onSelectEvent: PropTypes.func,
 
+ /**
+ * Callback fired when dragging a selection in the Time views.
+ *
+ * Returning `false` from the handler will prevent a selection.
+ *
+ * ```js
+ * function ({ start: Date, end: Date }) : boolean
+ * ```
+ */
+ onSelecting: PropTypes.func,
+
  /**
  * An array of built-in view names to allow the calendar to display.
  *

src/DaySlot.jsx

@@ -51,6 +51,7 @@ let DaySlot = React.createClass({
  selectable: React.PropTypes.bool,
  eventOffset: React.PropTypes.number,
 
+ onSelecting: React.PropTypes.func,
  onSelectSlot: React.PropTypes.func.isRequired,
  onSelectEvent: React.PropTypes.func.isRequired
  },
@@ -193,6 +194,24 @@ let DaySlot = React.createClass({
  let node = findDOMNode(this);
  let selector = this._selector = new Selection(()=> findDOMNode(this))
 
+ let maybeSelect = (box) => {
+ let onSelecting = this.props.onSelecting
+ let current = this.state || {};
+ let state = selectionState(box);
+ let { startDate: start, endDate: end } = state;
+
+ if (onSelecting) {
+ if (
+ (dates.eq(current.startDate, start, 'minutes') &&
+ dates.eq(current.endDate, end, 'minutes')) ||
+ onSelecting({ start, end }) === false
+ )
+ return
+ }
+
+ this.setState(state)
+ }
+
  let selectionState = ({ x, y }) => {
  let { step, min, max } = this.props;
  let { top, bottom } = getBoundsForNode(node)
@@ -225,11 +244,8 @@ let DaySlot = React.createClass({
  }
  }
 
- selector.on('selecting',
- box => this.setState(selectionState(box)))
-
- selector.on('selectStart',
- box => this.setState(selectionState(box)))
+ selector.on('selecting', maybeSelect)
+ selector.on('selectStart', maybeSelect)
 
  selector
  .on('click', ({ x, y }) => {
@@ -242,8 +258,10 @@ let DaySlot = React.createClass({
 
  selector
  .on('select', () => {
- this._selectSlot(this.state)
- this.setState({ selecting: false })
+ if (this.state.selecting) {
+ this._selectSlot(this.state)
+ this.setState({ selecting: false })
+ }
  })
  },