Add setPageWithoutAnimation

Summary: In some cases it's desirable to set the page in the ViewPager without animating it -- we have this in ScrollView with `scrollWithoutAnimationTo`. This PR adds `setPageWithoutAnimation` on ViewPager.

cc ide kmagiera
Closes facebook#3621

Reviewed By: svcscm

Differential Revision: D2652056

Pulled By: mkonicek

fb-gh-sync-id: 6f1f38558c41ffdd863c0ebb2f046c75b5c0392c

Examples/UIExplorer/ViewPagerAndroidExample.android.js

@@ -96,23 +96,39 @@ var ViewPagerAndroidExample = React.createClass({
     description: 'Container that allows to flip left and right between child views.'
   },
   getInitialState: function() {
-    return {page: 0, progress: {position: 0, offset: 0}};
+    return {
+      page: 0,
+      animationsAreEnabled: true,
+      progress: {
+        position: 0,
+        offset: 0,
+      },
+    };
   },
+
   onPageSelected: function(e) {
     this.setState({page: e.nativeEvent.position});
   },
+
   onPageScroll: function(e) {
     this.setState({progress: e.nativeEvent});
   },
+
   move: function(delta) {
     var page = this.state.page + delta;
-    this.viewPager && this.viewPager.setPage(page);
-    this.setState({page});
+    this.go(page);
   },
+
   go: function(page) {
-    this.viewPager && this.viewPager.setPage(page);
+    if (this.state.animationsAreEnabled) {
+      this.viewPager.setPage(page);
+    } else {
+      this.viewPager.setPageWithoutAnimation(page);
+    }
+
     this.setState({page});
   },
+
   render: function() {
     var pages = [];
     for (var i = 0; i < PAGES; i++) {
@@ -131,7 +147,7 @@ var ViewPagerAndroidExample = React.createClass({
        </View>
       );
     }
-    var page = this.state.page;
+    var { page, animationsAreEnabled } = this.state;
     return (
       <View style={styles.container}>
         <ViewPagerAndroid
@@ -142,6 +158,19 @@ var ViewPagerAndroidExample = React.createClass({
           ref={viewPager => { this.viewPager = viewPager; }}>
           {pages}
         </ViewPagerAndroid>
+        <View style={styles.buttons}>
+          { animationsAreEnabled ?
+            <Button
+              text="Turn off animations"
+              enabled={true}
+              onPress={() => this.setState({animationsAreEnabled: false})}
+            /> :
+            <Button
+              text="Turn animations back on"
+              enabled={true}
+              onPress={() => this.setState({animationsAreEnabled: true})}
+            /> }
+        </View>
         <View style={styles.buttons}>
           <Button text="Start" enabled={page > 0} onPress={() => this.go(0)}/>
           <Button text="Prev" enabled={page > 0} onPress={() => this.move(-1)}/>

Libraries/Components/ViewPager/ViewPagerAndroid.android.js

@@ -2,24 +2,24 @@
  * Copyright 2004-present Facebook. All Rights Reserved.
  *
  * @providesModule ViewPagerAndroid
+ * @flow
  */
 'use strict';
 
+var NativeModules = require('NativeModules');
 var NativeMethodsMixin = require('NativeMethodsMixin');
 var React = require('React');
 var ReactElement = require('ReactElement');
 var ReactNativeViewAttributes = require('ReactNativeViewAttributes');
 var ReactPropTypes = require('ReactPropTypes');
 
+var RCTUIManager = NativeModules.UIManager;
+
 var createReactNativeComponentClass = require('createReactNativeComponentClass');
 var dismissKeyboard = require('dismissKeyboard');
 
 var VIEWPAGER_REF = 'viewPager';
 
-var ViewPagerValidAttributes = {
-  selectedPage: true,
-};
-
 /**
  * Container that allows to flip left and right between child views. Each
  * child view of the `ViewPagerAndroid` will be treated as a separate page
@@ -97,17 +97,17 @@ var ViewPagerAndroid = React.createClass({
     ]),
   },
 
-  getInitialState: function() {
-    return {
-      selectedPage: this.props.initialPage,
-    };
+  componentDidMount: function() {
+    if (this.props.initialPage) {
+      this.setPageWithoutAnimation(this.props.initialPage);
+    }
   },
 
-  getInnerViewNode: function() {
+  getInnerViewNode: function(): ReactComponent {
     return this.refs[VIEWPAGER_REF].getInnerViewNode();
   },
 
-  _childrenWithOverridenStyle: function() {
+  _childrenWithOverridenStyle: function(): Array {
     // Override styles so that each page will fill the parent. Native component
     // will handle positioning of elements, so it's not important to offset
     // them correctly.
@@ -134,34 +134,51 @@ var ViewPagerAndroid = React.createClass({
       return ReactElement.createElement(child.type, newProps);
     });
   },
-  _onPageScroll: function(event) {
+
+  _onPageScroll: function(e: Event) {
     if (this.props.onPageScroll) {
-      this.props.onPageScroll(event);
+      this.props.onPageScroll(e);
     }
     if (this.props.keyboardDismissMode === 'on-drag') {
       dismissKeyboard();
     }
   },
-  _onPageSelected: function(event) {
-    var selectedPage = event.nativeEvent.position;
-    this.setState({
-      selectedPage,
-    });
+
+  _onPageSelected: function(e: Event) {
     if (this.props.onPageSelected) {
-      this.props.onPageSelected(event);
+      this.props.onPageSelected(e);
     }
   },
-  setPage: function(selectedPage) {
-    this.setState({
-      selectedPage,
-    });
+
+  /**
+   * A helper function to scroll to a specific page in the ViewPager.
+   * The transition between pages will be animated.
+   */
+  setPage: function(selectedPage: number) {
+    RCTUIManager.dispatchViewManagerCommand(
+      React.findNodeHandle(this),
+      RCTUIManager.AndroidViewPager.Commands.setPage,
+      [selectedPage],
+    );
   },
+
+  /**
+   * A helper function to scroll to a specific page in the ViewPager.
+   * The transition between pages will be *not* be animated.
+   */
+  setPageWithoutAnimation: function(selectedPage: number) {
+    RCTUIManager.dispatchViewManagerCommand(
+      React.findNodeHandle(this),
+      RCTUIManager.AndroidViewPager.Commands.setPageWithoutAnimation,
+      [selectedPage],
+    );
+  },
+
   render: function() {
     return (
       <NativeAndroidViewPager
         ref={VIEWPAGER_REF}
         style={this.props.style}
-        selectedPage={this.state.selectedPage}
         onPageScroll={this._onPageScroll}
         onPageSelected={this._onPageSelected}
         children={this._childrenWithOverridenStyle()}
@@ -171,10 +188,7 @@ var ViewPagerAndroid = React.createClass({
 });
 
 var NativeAndroidViewPager = createReactNativeComponentClass({
-  validAttributes: {
-    ...ReactNativeViewAttributes.UIView,
-    ...ViewPagerValidAttributes,
-  },
+  validAttributes: ReactNativeViewAttributes.UIView,
   uiViewClassName: 'AndroidViewPager',
 });
 

ReactAndroid/src/main/java/com/facebook/react/views/viewpager/ReactViewPager.java

@@ -133,6 +133,12 @@ public boolean onInterceptTouchEvent(MotionEvent ev) {
     return false;
   }
 
+  public void setCurrentItemFromJs(int item, boolean animated) {
+    mIsCurrentItemFromJs = true;
+    setCurrentItem(item, animated);
+    mIsCurrentItemFromJs = false;
+  }
+
   /*package*/ void addViewToAdapter(View child, int index) {
     getAdapter().addView(child, index);
   }
@@ -148,10 +154,4 @@ public boolean onInterceptTouchEvent(MotionEvent ev) {
   /*package*/ View getViewFromAdapter(int index) {
     return getAdapter().getViewAt(index);
   }
-
-  /*package*/ void setCurrentItemFromJs(int item) {
-    mIsCurrentItemFromJs = true;
-    setCurrentItem(item);
-    mIsCurrentItemFromJs = false;
-  }
 }

ReactAndroid/src/main/java/com/facebook/react/views/viewpager/ReactViewPagerManager.java

@@ -13,18 +13,24 @@
 
 import android.view.View;
 
+import com.facebook.infer.annotation.Assertions;
+import com.facebook.react.bridge.ReadableArray;
 import com.facebook.react.common.MapBuilder;
-import com.facebook.react.uimanager.ReactProp;
 import com.facebook.react.uimanager.ThemedReactContext;
 import com.facebook.react.uimanager.ViewGroupManager;
 
+import javax.annotation.Nullable;
+
 /**
  * Instance of {@link ViewManager} that provides native {@link ViewPager} view.
  */
 public class ReactViewPagerManager extends ViewGroupManager<ReactViewPager> {
 
   private static final String REACT_CLASS = "AndroidViewPager";
 
+  public static final int COMMAND_SET_PAGE = 1;
+  public static final int COMMAND_SET_PAGE_WITHOUT_ANIMATION = 2;
+
   @Override
   public String getName() {
     return REACT_CLASS;
@@ -35,12 +41,6 @@ protected ReactViewPager createViewInstance(ThemedReactContext reactContext) {
     return new ReactViewPager(reactContext);
   }
 
-  @ReactProp(name = "selectedPage")
-  public void setSelectedPage(ReactViewPager view, int page) {
-    // TODO(8496821): Handle selectedPage property cleanup correctly, now defaults to 0
-    view.setCurrentItemFromJs(page);
-  }
-
   @Override
   public boolean needsCustomLayoutForChildren() {
     return true;
@@ -54,6 +54,39 @@ public Map getExportedCustomDirectEventTypeConstants() {
     );
   }
 
+  @Override
+  public Map<String,Integer> getCommandsMap() {
+    return MapBuilder.of(
+        "setPage",
+        COMMAND_SET_PAGE,
+        "setPageWithoutAnimation",
+        COMMAND_SET_PAGE_WITHOUT_ANIMATION);
+  }
+
+  @Override
+  public void receiveCommand(
+      ReactViewPager viewPager,
+      int commandType,
+      @Nullable ReadableArray args) {
+    Assertions.assertNotNull(viewPager);
+    Assertions.assertNotNull(args);
+    switch (commandType) {
+      case COMMAND_SET_PAGE: {
+        viewPager.setCurrentItemFromJs(args.getInt(0), true);
+        return;
+      }
+      case COMMAND_SET_PAGE_WITHOUT_ANIMATION: {
+        viewPager.setCurrentItemFromJs(args.getInt(0), false);
+        return;
+      }
+      default:
+        throw new IllegalArgumentException(String.format(
+            "Unsupported command %d received by %s.",
+            commandType,
+            getClass().getSimpleName()));
+    }
+  }
+
   @Override
   public void addView(ReactViewPager parent, View child, int index) {
     parent.addViewToAdapter(child, index);