feat(tabs): more touchActive features

ionic/components/tabs/tabs.ts

@@ -217,15 +217,36 @@ export class Tabs extends Ion {
 
   /**
    * @private
-   * "Touch" the active tab, either going back to the root view of the tab
-   * or scrolling the tab to the top
+   * "Touch" the active tab, going back to the root view of the tab
+   * or optionally letting the tab handle the event
    */
   touchActive(tab) {
+    let active = tab.getActive();
+
+    if(!active) {
+      return Promise.resolve();
+    }
+
+    let instance = active.instance;
+
+    // If they have a custom tab selected handler, call it
+    if(instance.tabSelected) {
+      return instance.tabSelected();
+    }
+
+    // If we're a few pages deep, pop to root
     if (tab.length() > 1) {
       // Pop to the root view
       return tab.popToRoot();
     }
 
+    // Otherwise, if the page we're on is not our real root, reset it to our
+    // default root type
+    if(tab.root != active.componentType) {
+      return tab.setRoot(tab.root);
+    }
+
+    // And failing all of that, we do something safe and secure
     return Promise.resolve();
   }