better Keyabord event utils

Reviewed By: shergin

Differential Revision: D6639418

fbshipit-source-id: ef973cfebb94325579525bdcd3990737fe576ef8

Libraries/Components/Keyboard/Keyboard.js

@@ -11,6 +11,7 @@
  */
 'use strict';
 
+const LayoutAnimation = require('LayoutAnimation');
 const invariant = require('fbjs/lib/invariant');
 const NativeEventEmitter = require('NativeEventEmitter');
 const KeyboardObserver = require('NativeModules').KeyboardObserver;
@@ -25,16 +26,18 @@ type KeyboardEventName =
   | 'keyboardWillChangeFrame'
   | 'keyboardDidChangeFrame';
 
-type KeyboardEventData = {
-  endCoordinates: {
-    width: number,
-    height: number,
-    screenX: number,
-    screenY: number,
-  },
-};
+export type KeyboardEvent = {|
+  +duration?: number,
+  +easing?: string,
+  +endCoordinates: {|
+    +width: number,
+    +height: number,
+    +screenX: number,
+    +screenY: number,
+  |},
+|};
 
-type KeyboardEventListener = (e: KeyboardEventData) => void;
+type KeyboardEventListener = (e: KeyboardEvent) => void;
 
 // The following object exists for documentation purposes
 // Actual work happens in
@@ -134,11 +137,31 @@ let Keyboard = {
    */
   dismiss() {
     invariant(false, 'Dummy method used for documentation');
-  }
+  },
+
+  /**
+   * Useful for syncing TextInput (or other keyboard accessory view) size of
+   * position changes with keyboard movements.
+   */
+  scheduleLayoutAnimation(event: KeyboardEvent) {
+    invariant(false, 'Dummy method used for documentation');
+  },
 };
 
 // Throw away the dummy object and reassign it to original module
 Keyboard = KeyboardEventEmitter;
 Keyboard.dismiss = dismissKeyboard;
+Keyboard.scheduleLayoutAnimation = function(event: KeyboardEvent) {
+  const {duration, easing} = event;
+  if (duration) {
+    LayoutAnimation.configureNext({
+      duration: duration,
+      update: {
+        duration: duration,
+        type: (easing && LayoutAnimation.Types[easing]) || 'keyboard',
+      },
+    });
+  }
+};
 
 module.exports = Keyboard;