Bug 766066 - Part 3: Open keyboard when user taps input element, not when panning. r=djf

--HG--
extra : rebase_source : 69db692037f659f47c5560b7d1f9c36179e1aa69

b2g/chrome/content/forms.js

@@ -71,6 +71,7 @@ let FormAssistant = {
       return;
 
     if (this.focusedElement) {
+      this.focusedElement.removeEventListener('click', this);
       this.focusedElement.removeEventListener('mousedown', this);
       this.focusedElement.removeEventListener('mouseup', this);
       if (!element) {
@@ -79,6 +80,7 @@ let FormAssistant = {
     }
 
     if (element) {
+      element.addEventListener('click', this);
       element.addEventListener('mousedown', this);
       element.addEventListener('mouseup', this);
     }
@@ -95,9 +97,10 @@ let FormAssistant = {
         if (this.isTextInputElement(target) && this.isIMEDisabled())
           return;
 
+        // We got input focus, but don't open the virtual keyboard unless we
+        // get a 'click' event, i.e. the user is tapping the input element.
         if (target && this.isFocusableElement(target)) {
           this.setFocusedElement(target);
-          this.showKeyboard(target);
         }
         break;
 
@@ -125,6 +128,14 @@ let FormAssistant = {
         }
         break;
 
+      case 'click':
+        // We only listen for click events on the currently focused element.
+        // Gecko fires a click event if the user "taps" an input element
+        // without dragging. This is how we differentiate tap gestures to set
+        // input focus (and open the keyboard) from simply panning the page.
+        this.showKeyboard();
+        break;
+
       case "resize":
         if (!this.isKeyboardOpened)
           return;