Add test gesture config

Author: iveysaur

src/components/slider/test-gesture-config.ts

@@ -0,0 +1,41 @@
+import {Injectable} from '@angular/core';
+import {MdGestureConfig} from '../../core/gestures/MdGestureConfig';
+// import {MdGestureConfig} from '@angular2-material/core/gestures/MdGestureConfig';
+
+/**
+ * To test the dragging behavior on the slider, we need to be able to access the hammer instances
+ * to emit events for a drag.
+ *
+ */
+@Injectable()
+export class TestGestureConfig extends MdGestureConfig {
+  /**
+   * A map of Hammer instances to element.
+   * Used to emit events over instances for an element.
+   */
+  hammerInstances: Map<HTMLElement, HammerManager[]> = new Map<HTMLElement, HammerManager[]>();
+
+  /**
+   * Create a mapping of Hammer instances to element so that events can be emitted during testing.
+   */
+  buildHammer(element: HTMLElement) {
+    let mc = super.buildHammer(element);
+
+    if (!this.hammerInstances.get(element)) {
+      this.hammerInstances.set(element, [mc]);
+    } else {
+      this.hammerInstances.get(element).push(mc);
+    }
+
+    return mc;
+  }
+
+  /**
+   * Hammer creates a new instance for every listener so we need to apply our event on all instances
+   * to hit the correct listener.
+   */
+  emitEventForElement(eventType: string, element: HTMLElement, eventData: Object) {
+    let instances = this.hammerInstances.get(element);
+    instances.forEach(instance => instance.emit(eventType, eventData));
+  }
+}