feat: add drag and drop support (#100)

BREAKING CHANGE:

A dependency on the `angular-draggable-droppable` library has been added. System.js users will need to add this to their config:

```
'angular-draggable-droppable': 'npm:angular-draggable-droppable/dist/umd/angular-draggable-droppable.js'
```

Closes #10
Closes #102

demo/demo.component.ts

@@ -80,7 +80,8 @@ const colors: any = {
           [events]="events"
           [refresh]="refresh"
           [activeDayIsOpen]="activeDayIsOpen"
-          (dayClicked)="dayClicked($event.day)">
+          (dayClicked)="dayClicked($event.day)"
+          (eventTimesChanged)="eventTimesChanged($event)">
         </mwl-calendar-month-view>
         <mwl-calendar-week-view
           *ngSwitchCase="'week'"
@@ -139,13 +140,14 @@ export class DemoComponent {
   }, {
     start: addHours(startOfDay(new Date()), 2),
     end: new Date(),
-    title: 'A resizable event',
+    title: 'A draggable and resizable event',
     color: colors.yellow,
     actions: this.actions,
     resizable: {
       beforeStart: true,
       afterEnd: true
-    }
+    },
+    draggable: true
   }];
 
   activeDayIsOpen: boolean = true;

karma.conf.ts

@@ -80,7 +80,10 @@ module.exports = function(config) {
           }
         }),
         new FixDefaultImportPlugin()
-      ]
+      ],
+      performance: {
+        hints: false
+      }
     },
 
     remapIstanbulReporter: {

package.json

@@ -123,8 +123,9 @@
   },
   "dependencies": {
     "@ng-bootstrap/ng-bootstrap": "^1.0.0-alpha.0",
-    "angular-resizable-element": "~0.5.0",
-    "calendar-utils": "0.0.38",
+    "angular-draggable-droppable": "^0.4.0",
+    "angular-resizable-element": "^0.5.4",
+    "calendar-utils": "0.0.39",
     "date-fns": "^1.15.1"
   }
 }

scss/day-view.scss

@@ -40,6 +40,10 @@
     white-space: nowrap;
   }
 
+  .cal-draggable {
+    cursor: move;
+  }
+
   .cal-event.cal-starts-within-day {
     border-top-left-radius: 5px;
     border-top-right-radius: 5px;

scss/month-view.scss

@@ -119,6 +119,10 @@
     font-size: 1.9em;
   }
 
+  .cal-day-cell.cal-drag-over {
+    background-color: darken(#ededed, 5%) !important;
+  }
+
   .cal-open-day-events {
     padding: 15px;
     color: white;

scss/week-view.scss

@@ -39,6 +39,10 @@
     line-height: 30px;
   }
 
+  .cal-draggable {
+    cursor: move;
+  }
+
   .cal-event.cal-starts-within-week {
     border-top-left-radius: 5px;
     border-bottom-left-radius: 5px;

src/calendar.module.ts

@@ -1,6 +1,7 @@
 import { NgModule, ModuleWithProviders } from '@angular/core';
 import { CommonModule } from '@angular/common';
 import { ResizableModule } from 'angular-resizable-element';
+import { DragAndDropModule } from 'angular-draggable-droppable';
 import { CalendarDayViewComponent } from './components/day/calendarDayView.component';
 import { CalendarWeekViewComponent } from './components/week/calendarWeekView.component';
 import { CalendarMonthViewComponent } from './components/month/calendarMonthView.component';
@@ -38,8 +39,17 @@ import { CalendarDateFormatter } from './providers/calendarDateFormatter.provide
     CalendarDate,
     CalendarEventTitlePipe
   ],
-  imports: [CommonModule, ResizableModule],
-  exports: [CalendarDayViewComponent, CalendarWeekViewComponent, CalendarMonthViewComponent, CalendarDate],
+  imports: [
+    CommonModule,
+    ResizableModule,
+    DragAndDropModule
+  ],
+  exports: [
+    CalendarDayViewComponent,
+    CalendarWeekViewComponent,
+    CalendarMonthViewComponent,
+    CalendarDate
+  ],
   entryComponents: [CalendarTooltipWindowComponent]
 })
 export class CalendarModule {

src/components/day/calendarDayView.component.ts

@@ -13,14 +13,14 @@ import {
 import { getDayView, getDayViewHourGrid, CalendarEvent, DayView, DayViewHour } from 'calendar-utils';
 import { Subject } from 'rxjs/Subject';
 import { Subscription } from 'rxjs/Subscription';
-import { CalendarEventTimesChangedEvent } from './../../interfaces/calendarEventTimesChangedEvent.interface';
+import { CalendarEventTimesChangedEvent } from '../../interfaces/calendarEventTimesChangedEvent.interface';
 
 const SEGMENT_HEIGHT: number = 30;
 
 @Component({
   selector: 'mwl-calendar-day-view',
   template: `
-    <div class="cal-day-view">
+    <div class="cal-day-view" #dayViewContainer>
       <mwl-calendar-all-day-event
         *ngFor="let event of view.allDayEvents"
         [event]="event"
@@ -34,6 +34,7 @@ const SEGMENT_HEIGHT: number = 30;
             [hourSegments]="hourSegments"
             [tooltipPlacement]="tooltipPlacement"
             [eventSnapSize]="eventSnapSize"
+            [dayViewContainer]="dayViewContainer"
             (eventClicked)="eventClicked.emit({event: dayEvent.event})"
             (eventResized)="eventTimesChanged.emit($event)">
           </mwl-calendar-day-view-event>

src/components/day/calendarDayViewEvent.component.ts

@@ -1,13 +1,15 @@
-import { Component, Input, Output, EventEmitter } from '@angular/core';
+import { Component, Input, Output, EventEmitter, ChangeDetectorRef } from '@angular/core';
 import { DayViewEvent } from 'calendar-utils';
 import { ResizeEvent } from 'angular-resizable-element';
 import addMinutes from 'date-fns/add_minutes';
+import { CalendarDragHelper } from '../../providers/calendarDragHelper.provider';
 
 @Component({
   selector: 'mwl-calendar-day-view-event',
   template: `
     <div
       class="cal-event"
+      #event
       [style.marginTop.px]="dayEvent.top"
       [style.marginLeft.px]="dayEvent.left + 70"
       [style.height.px]="dayEvent.height"
@@ -16,6 +18,7 @@ import addMinutes from 'date-fns/add_minutes';
       [style.borderColor]="dayEvent.event.color.primary"
       [class.cal-starts-within-day]="!dayEvent.startsBeforeDay"
       [class.cal-ends-within-day]="!dayEvent.endsAfterDay"
+      [class.cal-draggable]="dayEvent.event.draggable"
       [ngClass]="dayEvent.event.cssClass"
       [mwlCalendarTooltip]="dayEvent.event | calendarEventTitle:'dayTooltip'"
       [tooltipPlacement]="tooltipPlacement"
@@ -24,7 +27,13 @@ import addMinutes from 'date-fns/add_minutes';
       [resizeSnapGrid]="{top: eventSnapSize, bottom: eventSnapSize}"
       (resizeStart)="resizeStarted(dayEvent, $event)"
       (resizing)="resizing(dayEvent, $event)"
-      (resizeEnd)="resizeEnded(dayEvent)">
+      (resizeEnd)="resizeEnded(dayEvent)"
+      mwlDraggable
+      [dragAxis]="{x: false, y: dayEvent.event.draggable && !currentResize}"
+      [dragSnapGrid]="{y: eventSnapSize}"
+      [validateDrag]="validateDrag"
+      (dragStart)="dragStart(event)"
+      (dragEnd)="eventDragged(dayEvent, $event.y)">
       <mwl-calendar-event-title
         [event]="dayEvent.event"
         view="day"
@@ -44,6 +53,8 @@ export class CalendarDayViewEventComponent {
 
   @Input() tooltipPlacement: string;
 
+  @Input() dayViewContainer: HTMLElement;
+
   @Output() eventClicked: EventEmitter<any> = new EventEmitter();
 
   @Output() eventResized: EventEmitter<any> = new EventEmitter();
@@ -54,6 +65,10 @@ export class CalendarDayViewEventComponent {
     edge: string
   };
 
+  validateDrag: Function;
+
+  constructor(private cdr: ChangeDetectorRef) {}
+
   resizeStarted(event: DayViewEvent, resizeEvent: ResizeEvent): void {
     this.currentResize = {
       originalTop: event.top,
@@ -93,7 +108,26 @@ export class CalendarDayViewEventComponent {
     }
 
     this.eventResized.emit({newStart, newEnd, event: dayEvent.event});
+    this.currentResize = null;
 
   }
 
+  dragStart(event: HTMLElement): void {
+    const dragHelper: CalendarDragHelper = new CalendarDragHelper(this.dayViewContainer, event);
+    this.validateDrag = ({x, y}) => dragHelper.validateDrag({x, y});
+    this.cdr.markForCheck();
+  }
+
+  eventDragged(dayEvent: DayViewEvent, draggedInPixels: number): void {
+    const segments: number = draggedInPixels / this.eventSnapSize;
+    const segmentAmountInMinutes: number = 60 / this.hourSegments;
+    const minutesMoved: number = segments * segmentAmountInMinutes;
+    const newStart: Date = addMinutes(dayEvent.event.start, minutesMoved);
+    let newEnd: Date;
+    if (dayEvent.event.end) {
+      newEnd = addMinutes(dayEvent.event.end, minutesMoved);
+    }
+    this.eventResized.emit({newStart, newEnd, event: dayEvent.event});
+  }
+
 }

src/components/month/calendarMonthCell.component.ts

@@ -9,16 +9,19 @@ import { MonthViewDay } from 'calendar-utils';
       <span class="cal-day-number">{{ day.date | calendarDate:'monthViewDayNumber':locale }}</span>
     </div>
     <div class="cal-events">
-      <span
+      <div
         class="cal-event"
         *ngFor="let event of day.events"
         [style.backgroundColor]="event.color.primary"
         [ngClass]="event?.cssClass"
         (mouseenter)="highlightDay.emit({event: event})"
         (mouseleave)="unhighlightDay.emit({event: event})"
         [mwlCalendarTooltip]="event | calendarEventTitle:'monthTooltip'"
-        [tooltipPlacement]="tooltipPlacement">
-      </span>
+        [tooltipPlacement]="tooltipPlacement"
+        mwlDraggable
+        [dropData]="{event: event}"
+        [dragAxis]="{x: event.draggable, y: event.draggable}">
+      </div>
     </div>
   `,
   host: {

src/components/month/calendarMonthView.component.ts

@@ -21,6 +21,15 @@ import {
 import { Subject } from 'rxjs/Subject';
 import { Subscription } from 'rxjs/Subscription';
 import isSameDay from 'date-fns/is_same_day';
+import setDate from 'date-fns/set_date';
+import setMonth from 'date-fns/set_month';
+import setYear from 'date-fns/set_year';
+import getDate from 'date-fns/get_date';
+import getMonth from 'date-fns/get_month';
+import getYear from 'date-fns/get_year';
+import differenceInSeconds from 'date-fns/difference_in_seconds';
+import addSeconds from 'date-fns/add_seconds';
+import { CalendarEventTimesChangedEvent } from '../../interfaces/calendarEventTimesChangedEvent.interface';
 
 @Component({
   selector: 'mwl-calendar-month-view',
@@ -36,13 +45,18 @@ import isSameDay from 'date-fns/is_same_day';
           <div class="cal-cell-row">
             <mwl-calendar-month-cell
               *ngFor="let day of view.days | slice : rowIndex : rowIndex + 7"
+              [class.cal-drag-over]="day.dragOver"
               [day]="day"
               [openDay]="openDay"
               [locale]="locale"
               [tooltipPlacement]="tooltipPlacement"
               (click)="dayClicked.emit({day: day})"
               (highlightDay)="toggleDayHighlight($event.event, true)"
-              (unhighlightDay)="toggleDayHighlight($event.event, false)">
+              (unhighlightDay)="toggleDayHighlight($event.event, false)"
+              mwlDroppable
+              (dragEnter)="day.dragOver = true"
+              (dragLeave)="day.dragOver = false"
+              (drop)="day.dragOver = false; eventDropped(day, $event.dropData.event)">
             </mwl-calendar-month-cell>
           </div>
           <mwl-calendar-open-day-events
@@ -108,6 +122,11 @@ export class CalendarMonthViewComponent implements OnChanges, OnInit, OnDestroy
    */
   @Output() eventClicked: EventEmitter<{event: CalendarEvent}> = new EventEmitter<{event: CalendarEvent}>();
 
+  /**
+   * Called when an event is dragged and dropped
+   */
+  @Output() eventTimesChanged: EventEmitter<CalendarEventTimesChangedEvent> = new EventEmitter<CalendarEventTimesChangedEvent>();
+
   /**
    * @private
    */
@@ -193,6 +212,22 @@ export class CalendarMonthViewComponent implements OnChanges, OnInit, OnDestroy
     });
   }
 
+  /**
+   * @private
+   */
+  eventDropped(day: MonthViewDay, event: CalendarEvent): void {
+    const year: number = getYear(day.date);
+    const month: number = getMonth(day.date);
+    const date: number = getDate(day.date);
+    const newStart: Date = setYear(setMonth(setDate(event.start, date), month), year);
+    let newEnd: Date;
+    if (event.end) {
+      const secondsDiff: number = differenceInSeconds(newStart, event.start);
+      newEnd = addSeconds(event.end, secondsDiff);
+    }
+    this.eventTimesChanged.emit({event, newStart, newEnd});
+  }
+
   private refreshHeader(): void {
     this.columnHeaders = getWeekViewHeader({
       viewDate: this.viewDate,

src/components/month/calendarOpenDayEvents.component.ts

@@ -16,8 +16,14 @@ import { CalendarEvent } from 'calendar-utils';
     <div class="cal-open-day-events" [@collapse] *ngIf="isOpen">
       <div
         *ngFor="let event of events"
-        [ngClass]="event?.cssClass">
-        <span class="cal-event" [style.backgroundColor]="event.color.primary"></span>
+        [ngClass]="event?.cssClass"
+        mwlDraggable
+        [dropData]="{event: event}"
+        [dragAxis]="{x: event.draggable, y: event.draggable}">
+        <span
+          class="cal-event"
+          [style.backgroundColor]="event.color.primary">
+        </span>
         <mwl-calendar-event-title
           [event]="event"
           view="month"