Added extraScrollHeight prop to handle elements above keyboard (#76)

* Added extraScrollHeight prop to handle elements above keyboard

* Updated README

Author: alvaromb

README.md

@@ -95,8 +95,9 @@ All the `ScrollView`/`ListView` props will be passed.
 |----------|----------|-----------------|
 | `viewIsInsideTabBar` | `boolean` | Adds an extra offset that represents the `TabBarIOS` height. |
 | `resetScrollToCoords` | `Object: {x: number, y: number}` | Coordinates that will be used to reset the scroll when the keyboard hides. |
-| `enableAutoAutomaticScroll` | `boolean` | When focus in TextInput will scroll the position, default is enabled. |
-| `extraHeight` | `number` | Adds an extra offset |
+| `enableAutoAutomaticScroll` | `boolean` | When focus in `TextInput` will scroll the position, default is enabled. |
+| `extraHeight` | `number` | Adds an extra offset when focusing the `TextInput`s. |
+| `extraScrollHeight` | `number` | Adds an extra offset to the keyboard. Useful if you want to stick elements above the keyboard. |
 
 ## License
 

lib/KeyboardAwareMixin.js

@@ -4,21 +4,23 @@ import { PropTypes } from 'react'
 import ReactNative, { TextInput, Keyboard, UIManager } from 'react-native'
 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 _KAM_DEFAULT_TAB_BAR_HEIGHT: number = 49
+const _KAM_KEYBOARD_OPENING_TIME: number = 250
+const _KAM_EXTRA_HEIGHT: number = 75
 
 const KeyboardAwareMixin = {
   mixins: [TimerMixin],
   propTypes: {
     enableAutoAutomaticScroll: PropTypes.bool,
     extraHeight: PropTypes.number,
+    extraScrollHeight: PropTypes.number,
   },
 
   getDefaultProps: function () {
     return {
-        enableAutoAutomaticScroll: true,
-        extraHeight: _KAM_EXTRA_HEIGHT,
+      enableAutoAutomaticScroll: true,
+      extraHeight: _KAM_EXTRA_HEIGHT,
+      extraScrollHeight: 0,
     }
   },
 
@@ -42,43 +44,40 @@ const KeyboardAwareMixin = {
 
   // Keyboard actions
   updateKeyboardSpace: function (frames: Object) {
-    const keyboardSpace = (this.props.viewIsInsideTabBar) ? frames.endCoordinates.height - _KAM_DEFAULT_TAB_BAR_HEIGHT : frames.endCoordinates.height
-    this.setState({
-      keyboardSpace: keyboardSpace,
-    })
+    let keyboardSpace: number = frames.endCoordinates.height + this.props.extraScrollHeight
+    if (this.props.viewIsInsideTabBar) {
+      keyboardSpace -= _KAM_DEFAULT_TAB_BAR_HEIGHT
+    }
+    this.setState({keyboardSpace})
     // Automatically scroll to focused TextInput
     if (this.props.enableAutoAutomaticScroll) {
       const currentlyFocusedField = TextInput.State.currentlyFocusedField()
       if (!currentlyFocusedField) {
         return
       }
-
       UIManager.viewIsDescendantOf(
         currentlyFocusedField,
         this.getScrollResponder().getInnerViewNode(),
         (isAncestor) => {
           if (isAncestor) {
             // Check if the TextInput will be hidden by the keyboard
             UIManager.measureInWindow(currentlyFocusedField, (x, y, width, height) => {
-              if (y + height > frames.endCoordinates.screenY) {
+              if (y + height > frames.endCoordinates.screenY - this.props.extraScrollHeight - this.props.extraHeight) {
                 this.scrollToFocusedInputWithNodeHandle(currentlyFocusedField)
               }
             })
           }
         }
       )
     }
-
     if (!this.resetCoords) {
       this.defaultResetScrollToCoords = this.position
     }
   },
 
   resetKeyboardSpace: function () {
-    const keyboardSpace = (this.props.viewIsInsideTabBar) ? _KAM_DEFAULT_TAB_BAR_HEIGHT : 0
-    this.setState({
-      keyboardSpace: keyboardSpace,
-    })
+    const keyboardSpace: number = (this.props.viewIsInsideTabBar) ? _KAM_DEFAULT_TAB_BAR_HEIGHT : 0
+    this.setState({keyboardSpace})
     // Reset scroll position after keyboard dismissal
     if (this.resetCoords) {
       this.scrollToPosition(this.resetCoords.x, this.resetCoords.y, true)
@@ -117,7 +116,7 @@ const KeyboardAwareMixin = {
 
   scrollToFocusedInputWithNodeHandle: function (nodeID: number, extraHeight: number = this.props.extraHeight) {
     const reactNode = ReactNative.findNodeHandle(nodeID)
-    this.scrollToFocusedInput(reactNode, extraHeight)
+    this.scrollToFocusedInput(reactNode, extraHeight + this.props.extraScrollHeight)
   },
 
   position: {x: 0, y: 0},