useNativeDriver for smoother animation in backdrop opacity and modal position

corrected various state changes, to ensure they are set before and after animations (in Animated.timing().start() callback, not the other way around)

fixed state.isAnimateBackdrop to always be true on animation start, false on end

ported hardwareAccelerated={true} back from #196 that was lost in the shuffle of merging for 1.5.0

Author: fungilation

index.js

@@ -169,47 +169,49 @@ var ModalBox = createReactClass({
    * Open animation for the backdrop, will fade in
    */
   animateBackdropOpen: function() {
-    if (this.state.isAnimateBackdrop) {
+    if (this.state.isAnimateBackdrop && this.state.animBackdrop) {
       this.state.animBackdrop.stop();
     }
+    this.setState({ isAnimateBackdrop: true });
 
     let animBackdrop = Animated.timing(
       this.state.backdropOpacity,
       {
         toValue: 1,
-        duration: this.props.animationDuration
+        duration: this.props.animationDuration,
+        easing: this.props.easing,
+        useNativeDriver: true,
       }
-    );
-
-    this.setState({
-      isAnimateBackdrop: true,
-      animBackdrop
-    }, () => {
-      this.state.animBackdrop.start();
+    ).start(() => {
+      this.setState({
+        isAnimateBackdrop: false,
+        animBackdrop
+      });
     });
   },
 
   /*
    * Close animation for the backdrop, will fade out
    */
   animateBackdropClose: function() {
-    if (this.state.isAnimateBackdrop) {
+    if (this.state.isAnimateBackdrop && this.state.animBackdrop) {
       this.state.animBackdrop.stop();
     }
+    this.setState({ isAnimateBackdrop: true });
 
     let animBackdrop = Animated.timing(
       this.state.backdropOpacity,
       {
         toValue: 0,
-        duration: this.props.animationDuration
+        duration: this.props.animationDuration,
+        easing: this.props.easing,
+        useNativeDriver: true,
       }
-    );
-
-    this.setState({
-      isAnimateBackdrop: false,
-      animBackdrop
-    }, () => {
-      this.state.animBackdrop.start();
+    ).start(() => {
+      this.setState({
+        isAnimateBackdrop: false,
+        animBackdrop
+      });
     });
   },
 
@@ -249,17 +251,15 @@ var ModalBox = createReactClass({
             toValue: positionDest,
             duration: this.props.animationDuration,
             easing: this.props.easing,
+            useNativeDriver: true,
           }
-        );
-
-        this.setState({
-          isAnimateOpen: false,
-          animOpen,
-          positionDest
-        }, () => {
-          animOpen.start(() => {
-            if (!this.state.isOpen && this.props.onOpened) this.props.onOpened();
+        ).start(() => {
+          this.setState({
+            isAnimateOpen: false,
+            animOpen,
+            positionDest
           });
+          if (this.props.onOpened) this.props.onOpened();
         });
       })
     });
@@ -293,17 +293,17 @@ var ModalBox = createReactClass({
         this.state.position,
         {
           toValue: this.props.entry === 'top' ? -this.state.containerHeight : this.state.containerHeight,
-          duration: this.props.animationDuration
+          duration: this.props.animationDuration,
+          easing: this.props.easing,
+          useNativeDriver: true,
         }
-      );
-
-      this.setState({
-        isAnimateClose: false,
-        animClose
-      }, () => {
-        animClose.start(() => {
-          if (this.props.onClosed) this.props.onClosed();
+      ).start(() => {
+        // Keyboard.dismiss();   // make this optional. Easily user defined in .onClosed() callback
+        this.setState({
+          isAnimateClose: false,
+          animClose
         });
+        if (this.props.onClosed) this.props.onClosed();
       });
     });
   },
@@ -479,6 +479,7 @@ if (!this.props.coverScreen) return content;
           }
         }}
         supportedOrientations={['landscape', 'portrait', 'portrait-upside-down']} transparent visible={visible}
+        hardwareAccelerated={true}
       >
         {content}
       </Modal>