feat(group): Add group plugin to aggregate tasks to parent rows.

This also adds a viewChange event on tasks object raised when a task is modified in view.

Close #297

Gruntfile.js

@@ -3,7 +3,7 @@
 /*jshint undef:false */
 /*jshint camelcase:false */
 module.exports = function(grunt) {
-    var plugins = ['labels', 'table', 'tree', 'sortable', 'movable', 'drawtask', 'tooltips', 'bounds', 'progress'];
+    var plugins = ['labels', 'table', 'tree', 'groups', 'sortable', 'movable', 'drawtask', 'tooltips', 'bounds', 'progress'];
 
     var coverage = grunt.option('coverage');
 

assets/angular-gantt-plugins.css

@@ -14,6 +14,72 @@
     border-color: #FF6347;
 }
 
+.gantt-task-group {
+    position: absolute;
+
+    background: rgb(99, 136, 205);
+
+    height: 30%;
+
+    top: -25%;
+    bottom: 0;
+    margin: auto;
+}
+
+.gantt-task-group-left-main, .gantt-task-group-right-main {
+    position: absolute;
+
+    width: 12px;
+    height: 100%;
+    background: rgb(99, 136, 205);
+
+    top: 0;
+    bottom: 0;
+    margin: auto 0;
+}
+
+.gantt-task-group-left-main {
+    left: -6px;
+}
+
+.gantt-task-group-right-main {
+    right: -6px;
+}
+
+.gantt-task-group-left-symbol, .gantt-task-group-right-symbol {
+    position: absolute;
+
+    width: 0;
+    height: 50%;
+
+    top: 75%;
+    bottom: 0;
+
+    border-left: 6px solid transparent;
+    border-right: 6px solid transparent;
+    border-top: 12px solid rgb(99, 136, 205);
+}
+
+.gantt-task-group-left-symbol {
+    left: -6px;
+}
+
+.gantt-task-group-right-symbol {
+    right: -6px;
+}
+
+.gantt-task-overview {
+    height: 40%;
+    top: 40%;
+
+    -webkit-filter: grayscale(0.6);
+            filter: grayscale(0.6);
+}
+
+.gantt-task-overview .gantt-task-content {
+    display: none;
+}
+
 .gantt-labels-header {
     overflow: hidden;
 }