Add dismissModal method to Android

Also changed the structure used to store Modals
from a Map based on navigatorId to a stack.
Reason for the change is that screens can be
pushed only to the topmost Modal.

android/app/src/main/java/com/reactnativenavigation/controllers/ModalController.java

 import com.reactnativenavigation.utils.RefUtils;
 
 import java.lang.ref.WeakReference;
-import java.util.HashMap;
-import java.util.Iterator;
-import java.util.Map;
+import java.util.Stack;
 
 /**
  * Created by guyc on 06/05/16.
 public class ModalController {
     private static ModalController sInstance;
 
-    private final Map<String, WeakReference<RnnModal>> mModals;
+    private final Stack<WeakReference<RnnModal>> mModals;
 
     private ModalController() {
-        mModals = new HashMap<>();
+        mModals = new Stack<>();
     }
 
     public static synchronized ModalController getInstance() {
         return sInstance;
     }
 
-    public void add(RnnModal modal, String navigatorId) {
-        mModals.put(navigatorId, new WeakReference<>(modal));
+    public void add(RnnModal modal) {
+        mModals.add(new WeakReference<>(modal));
     }
 
     public boolean isModalDisplayed() {
         return mModals.size() != 0;
     }
 
-    public boolean isModalDisplayed(String navigatorId) {
-        return mModals.size() != 0 && mModals.containsKey(navigatorId);
+    @Nullable
+    public RnnModal get() {
+        return isModalDisplayed() ? RefUtils.get(mModals.peek()) : null;
     }
 
-    @Nullable
-    public RnnModal get(String navigatorId) {
-        if (mModals.containsKey(navigatorId)) {
-            return RefUtils.get(mModals.get(navigatorId));
+    public void remove() {
+        if (isModalDisplayed()) {
+            mModals.pop();
         }
-
-        return null;
     }
 
-    public void remove(String navigatorId) {
-        if (mModals.containsKey(navigatorId)) {
-            mModals.remove(navigatorId);
+    public void dismissAllModals() {
+        while (isModalDisplayed()) {
+            dismissModal();
         }
     }
 
-    public void dismissAllModals() {
-        Iterator<String> iterator = mModals.keySet().iterator();
-        while (iterator.hasNext()) {
-            WeakReference<RnnModal> ref = mModals.get(iterator.next());
-            RnnModal modal = RefUtils.get(ref);
-            if (modal != null) {
-                modal.dismiss();
-            }
+    public void dismissModal() {
+        WeakReference<RnnModal> ref = mModals.pop();
+        RnnModal modal = RefUtils.get(ref);
+        if (modal != null) {
+            modal.dismiss();
         }
     }
 }

android/app/src/main/java/com/reactnativenavigation/modal/RnnModal.java

     public RnnModal(BaseReactActivity context, Screen screen) {
         super(context, R.style.Modal);
         mScreen = screen;
-        ModalController.getInstance().add(this, screen.navigatorId);
+        ModalController.getInstance().add(this);
         init(context);
     }
 
         if (mScreenStack.getStackSize() > 1) {
             mScreenStack.pop();
         } else {
-            ModalController.getInstance().remove(mScreen.navigatorId);
+            ModalController.getInstance().remove();
             super.onBackPressed();
         }
     }
 
     @Override
     public void onDismiss(DialogInterface dialog) {
-        ModalController.getInstance().remove(mScreen.navigatorId);
+        ModalController.getInstance().remove();
     }
 }

android/app/src/main/java/com/reactnativenavigation/modules/RctActivityModule.java

             return;
         }
 
-        // First, check is the screen should be displayed in a Modal
+        // First, check if the screen should be pushed to a Modal
         ModalController modalController = ModalController.getInstance();
-        if (modalController.isModalDisplayed(screen.navigatorId)) {
-            final RnnModal modal = modalController.get(screen.navigatorId);
+        if (modalController.isModalDisplayed()) {
+            final RnnModal modal = modalController.get();
             if (modal != null) {
                 context.runOnUiThread(new Runnable() {
                     @Override
 
         // First, check if the screen should be popped from a Modal
         ModalController modalController = ModalController.getInstance();
-        if (modalController.isModalDisplayed(navigatorId)) {
-            final RnnModal modal = modalController.get(navigatorId);
+        if (modalController.isModalDisplayed()) {
+            final RnnModal modal = modalController.get();
             if (modal != null) {
                 context.runOnUiThread(new Runnable() {
                     @Override
         });
         }
     }
+
+
+    /**
+     * Dismisses the top modal (the last modal pushed).
+     */
+    @ReactMethod
+    public void dismissModal() {
+        ModalController modalController = ModalController.getInstance();
+        if (modalController.isModalDisplayed()) {
+            modalController.dismissModal();
+        }
+    }
 }

example-redux/src/screens/PushedScreen.js

           <Text style={styles.button}>Pop Screen</Text>
         </TouchableOpacity>
 
+        <TouchableOpacity onPress={ this.onShowModalPress.bind(this) }>
+          <Text style={styles.button}>Modal Screen</Text>
+        </TouchableOpacity>
+
+        <TouchableOpacity onPress={ this.onDismissModal.bind(this) }>
+          <Text style={styles.button}>Dismiss modal</Text>
+        </TouchableOpacity>
+
+
+        <TouchableOpacity onPress={ this.onDismissAllModalsPress.bind(this) }>
+          <Text style={styles.button}>Dismiss all modals</Text>
+        </TouchableOpacity>
+
         <TextInput style={{height: 40, borderColor: 'gray', borderWidth: 1}}/>
 
       </View>
     );
   }
+
   onIncrementPress() {
     this.props.dispatch(counterActions.increment());
   }
+
   onPushPress() {
     this.props.navigator.push({
       title: "More",
       screen: "example.PushedScreen"
     });
   }
+
   onPopPress() {
     this.props.navigator.pop();
   }
+
+  onShowModalPress() {
+    this.props.navigator.showModal({
+      title: "Modal Screen",
+      screen: "example.PushedScreen"
+    });
+  }
+
+  onDismissAllModalsPress() {
+    this.props.navigator.dismissAllModals();
+  }
+
+  onDismissModal() {
+    this.props.navigator.dismissModal();
+  }
 }
 
 const styles = StyleSheet.create({

src/platformSpecific.android.js

   RctActivity.showModal(params);
 }
 
+function dismissModal() {
+  RctActivity.dismissModal();
+}
+
 function dismissAllModals(params) {
   RctActivity.dismissAllModals(params.animationType);
 }
   navigatorPush,
   navigatorPop,
   showModal,
+  dismissModal,
   dismissAllModals
 }

src/platformSpecific.ios.js

           passProps={passProps}
           style={navigatorStyle}
           leftButtons={navigatorButtons.leftButtons}
-          rightButtons={navigatorButtons.rightButtons}
-        />
+          rightButtons={navigatorButtons.rightButtons}/>
       );
     }
   });