Added extraHeight prop (#32)

Author: alvaromb

lib/KeyboardAwareMixin.js

@@ -6,16 +6,19 @@ import TimerMixin from 'react-timer-mixin'
 
 const _KAM_DEFAULT_TAB_BAR_HEIGHT = 49
 const _KAM_KEYBOARD_OPENING_TIME = 250
+const _KAM_EXTRA_HEIGHT = 75
 
 const KeyboardAwareMixin = {
   mixins: [TimerMixin],
   propTypes: {
-    enableAutoAutomaticScroll: PropTypes.bool
+    enableAutoAutomaticScroll: PropTypes.bool,
+    extraHeight: PropTypes.number,
   },
 
   getDefaultProps: function () {
     return {
         enableAutoAutomaticScroll: true,
+        extraHeight: _KAM_EXTRA_HEIGHT,
     }
   },
 
@@ -87,7 +90,7 @@ const KeyboardAwareMixin = {
   /**
    * @param extraHeight: takes an extra height in consideration.
    */
-  scrollToFocusedInput: function (reactNode: Object, extraHeight: number = _KAM_DEFAULT_TAB_BAR_HEIGHT) {
+  scrollToFocusedInput: function (reactNode: Object, extraHeight: number = this.props.extraHeight) {
     const scrollView = this.refs._rnkasv_keyboardView.getScrollResponder()
     this.setTimeout(() => {
       scrollView.scrollResponderScrollNativeHandleToKeyboard(
@@ -96,7 +99,7 @@ const KeyboardAwareMixin = {
     }, _KAM_KEYBOARD_OPENING_TIME)
   },
 
-  scrollToFocusedInputWithNodeHandle: function (nodeID: number, extraHeight: number = _KAM_DEFAULT_TAB_BAR_HEIGHT) {
+  scrollToFocusedInputWithNodeHandle: function (nodeID: number, extraHeight: number = this.props.extraHeight) {
     const reactNode = ReactNative.findNodeHandle(nodeID)
     this.scrollToFocusedInput(reactNode, extraHeight)
   },