Bump version -> 2.0.0-alpha.28

This change fixes the issue with auto focusing text input fields inside native stack. Due to the fact we perform hide and show transactions in order to control back stack the hiding part would propagate visibility change event down the view hierarchy. As a result views would receive that visibility event and blur themselves resulting in textinput not getting the focus when the fragment mounts. It turns out however that for the back stack to function properly we don't need to run hide and show operation within the transaction because show is idempotent. So we change our back stack handling transaction to only call show.

Example/yarn.lock

@@ -1633,7 +1633,7 @@ combined-stream@~1.0.6:
   dependencies:
     delayed-stream "~1.0.0"
 
-commander@^2.19.0, commander@~2.20.0:
+commander@^2.19.0:
   version "2.20.0"
   resolved "https://registry.yarnpkg.com/commander/-/commander-2.20.0.tgz#d58bb2b5c1ee8f87b0d340027e9e94e222c5a422"
   integrity sha512-7j2y+40w61zy6YC2iRNpUe/NwhNyoXrYpHMrSunaMG64nRnaf96zO/KMQR4OyN/UnE5KLyEBnKHd4aG3rskjpQ==
@@ -1642,6 +1642,11 @@ commander@~2.13.0:
   version "2.13.0"
   resolved "https://registry.yarnpkg.com/commander/-/commander-2.13.0.tgz#6964bca67685df7c1f1430c584f07d7597885b9c"
 
+commander@~2.20.3:
+  version "2.20.3"
+  resolved "https://registry.yarnpkg.com/commander/-/commander-2.20.3.tgz#fd485e84c03eb4881c20722ba48035e8531aeb33"
+  integrity sha512-GpVkmM8vF2vQUkj2LvZmD35JxeJOLCwJ9cUkugyk2nuhbv3+mJvpLYYt+0+USMxE+oj+ey/lJEnhZw75x/OMcQ==
+
 commondir@^1.0.1:
   version "1.0.1"
   resolved "https://registry.yarnpkg.com/commondir/-/commondir-1.0.1.tgz#ddd800da0c66127393cca5950ea968a3aaf1253b"
@@ -2487,9 +2492,9 @@ growly@^1.3.0:
   resolved "https://registry.yarnpkg.com/growly/-/growly-1.3.0.tgz#f10748cbe76af964b7c96c93c6bcc28af120c081"
 
 handlebars@^4.0.3:
-  version "4.2.0"
-  resolved "https://registry.yarnpkg.com/handlebars/-/handlebars-4.2.0.tgz#57ce8d2175b9bbb3d8b3cf3e4217b1aec8ddcb2e"
-  integrity sha512-Kb4xn5Qh1cxAKvQnzNWZ512DhABzyFNmsaJf3OAkWNa4NkaqWcNI8Tao8Tasi0/F4JD9oyG0YxuFyvyR57d+Gw==
+  version "4.5.3"
+  resolved "https://registry.yarnpkg.com/handlebars/-/handlebars-4.5.3.tgz#5cf75bd8714f7605713511a56be7c349becb0482"
+  integrity sha512-3yPecJoJHK/4c6aZhSvxOyG4vJKDshV36VHp0iVCDVh7o9w2vwi3NSnL2MMPj3YdduqaBcu7cGbggJQM0br9xA==
   dependencies:
     neo-async "^2.6.0"
     optimist "^0.6.1"
@@ -4806,7 +4811,7 @@ react-native-safe-area-view@^0.14.1:
     debounce "^1.2.0"
 
 "react-native-screens@file:..":
-  version "2.0.0-alpha.3"
+  version "2.0.0-alpha.22"
   dependencies:
     debounce "^1.2.0"
 
@@ -5761,11 +5766,11 @@ uglify-es@^3.1.9:
     source-map "~0.6.1"
 
 uglify-js@^3.1.4:
-  version "3.6.0"
-  resolved "https://registry.yarnpkg.com/uglify-js/-/uglify-js-3.6.0.tgz#704681345c53a8b2079fb6cec294b05ead242ff5"
-  integrity sha512-W+jrUHJr3DXKhrsS7NUVxn3zqMOFn0hL/Ei6v0anCIMoKC93TjcflTagwIHLW7SfMFfiQuktQyFVCFHGUE0+yg==
+  version "3.7.3"
+  resolved "https://registry.yarnpkg.com/uglify-js/-/uglify-js-3.7.3.tgz#f918fce9182f466d5140f24bb0ff35c2d32dcc6a"
+  integrity sha512-7tINm46/3puUA4hCkKYo4Xdts+JDaVC9ZPRcG8Xw9R4nhO/gZgUM3TENq8IF4Vatk8qCig4MzP/c8G4u2BkVQg==
   dependencies:
-    commander "~2.20.0"
+    commander "~2.20.3"
     source-map "~0.6.1"
 
 ultron@1.0.x:

README.md

@@ -100,12 +100,12 @@ To do that react-native-screens provides you with two components documented belo
 ### `<ScreenContainer/>`
 
 This component is a container for one or more `Screen` components.
-It does not accept other component types are direct children.
-The role of container is to control which of its children screens should be attached to the view hierarchy.
-It does that by monitoring `active` property of each of its children.
-It it possible to have as many `active` children as you'd like but in order for the component to be the most efficient we should keep the number of active screens to the minimum.
-In a case of stack navigator or tabs navigator we only want to have one active screen (the top most view on a stack or the selected tab).
-Then for the time of transitioning between views we may want to activate a second screen for the duration of transition, and then go back to just one active screen.
+It does not accept other component types as direct children.
+The role of the container is to control which of its children screens should be attached to the view hierarchy.
+It does that by monitoring the `active` property of each of its children.
+It is possible to have as many `active` children as you'd like but in order for the component to be the most efficient we should keep the number of active screens to a minimum.
+In a case of a stack navigator or tabs navigator we only want to have one active screen (the top most view on a stack or the selected tab).
+While transitioning between views we may want to activate a second screen for the duration of the transition, and then go back to just one active screen.
 
 ### `<Screen/>`
 
@@ -127,7 +127,7 @@ Otherwise the views will be attached as long as the parent container is attached
 
 ### `<ScreenStack>`
 
-Screen stack component expects one or more `Screen` components as direct children and renders them in a platform native stack container (for iOS it is `UINavigationController` and for Android inside `Fragment` container). For `Screen` components placed as children of `ScteenStack` the `active` property is ignored and instead the screen that corresponds to the last child is rendered as active. All type of updates done to the list of children are acceptable, when the top element is exchanged the container will use platform default (unless customized) animation to transition between screens.
+Screen stack component expects one or more `Screen` components as direct children and renders them in a platform native stack container (for iOS it is `UINavigationController` and for Android inside `Fragment` container). For `Screen` components placed as children of `ScreenStack` the `active` property is ignored and instead the screen that corresponds to the last child is rendered as active. All type of updates done to the list of children are acceptable, when the top element is exchanged the container will use platform default (unless customized) animation to transition between screens.
 
 `StackScreen` extends the capabilities of `Screen` component to allow additional customizations and to make it possible to handle events such as using hardware back or back gesture to dismiss the top screen. Below is the list of additional properties that can be used for `Screen` component:
 

android/src/main/java/com/swmansion/rnscreens/ScreenAppearEvent.java

@@ -0,0 +1,30 @@
+package com.swmansion.rnscreens;
+
+import com.facebook.react.bridge.Arguments;
+import com.facebook.react.uimanager.events.Event;
+import com.facebook.react.uimanager.events.RCTEventEmitter;
+
+public class ScreenAppearEvent extends Event<ScreenAppearEvent> {
+
+  public static final String EVENT_NAME = "topAppear";
+
+  public ScreenAppearEvent(int viewId) {
+    super(viewId);
+  }
+
+  @Override
+  public String getEventName() {
+    return EVENT_NAME;
+  }
+
+  @Override
+  public short getCoalescingKey() {
+    // All events for a given view can be coalesced.
+    return 0;
+  }
+
+  @Override
+  public void dispatch(RCTEventEmitter rctEventEmitter) {
+    rctEventEmitter.receiveEvent(getViewTag(), getEventName(), Arguments.createMap());
+  }
+}

android/src/main/java/com/swmansion/rnscreens/ScreenContainer.java

@@ -2,6 +2,7 @@ package com.swmansion.rnscreens;
 
 import android.content.Context;
 import android.content.ContextWrapper;
+import android.view.View;
 import android.view.ViewGroup;
 import android.view.ViewParent;
 
@@ -22,10 +23,14 @@ public class ScreenContainer<T extends ScreenFragment> extends ViewGroup {
 
   protected final ArrayList<T> mScreenFragments = new ArrayList<>();
   private final Set<ScreenFragment> mActiveScreenFragments = new HashSet<>();
+  private final ArrayList<Runnable> mAfterTransitionRunnables = new ArrayList<>(1);
 
+  protected @Nullable FragmentManager mFragmentManager;
   private @Nullable FragmentTransaction mCurrentTransaction;
+  private @Nullable FragmentTransaction mProcessingTransaction;
   private boolean mNeedUpdate;
   private boolean mIsAttached;
+  private boolean mIsTransitioning;
   private boolean mLayoutEnqueued = false;
 
   private final ChoreographerCompat.FrameCallback mFrameCallback = new ChoreographerCompat.FrameCallback() {
@@ -100,6 +105,44 @@ public class ScreenContainer<T extends ScreenFragment> extends ViewGroup {
     markUpdated();
   }
 
+  protected void removeAllScreens() {
+    for (int i = 0, size = mScreenFragments.size(); i < size; i++) {
+      mScreenFragments.get(i).getScreen().setContainer(null);
+    }
+    mScreenFragments.clear();
+    markUpdated();
+  }
+
+  @Override
+  public void startViewTransition(View view) {
+    super.startViewTransition(view);
+    mIsTransitioning = true;
+  }
+
+  @Override
+  public void endViewTransition(View view) {
+    super.endViewTransition(view);
+    if (mIsTransitioning) {
+      mIsTransitioning = false;
+      notifyTransitionFinished();
+    }
+  }
+
+  public boolean isTransitioning() {
+    return mIsTransitioning || mProcessingTransaction != null;
+  }
+
+  public void postAfterTransition(Runnable runnable) {
+    mAfterTransitionRunnables.add(runnable);
+  }
+
+  protected void notifyTransitionFinished() {
+    for (int i = 0, size = mAfterTransitionRunnables.size(); i < size; i++) {
+      mAfterTransitionRunnables.get(i).run();
+    }
+    mAfterTransitionRunnables.clear();
+  }
+
   protected int getScreenCount() {
     return mScreenFragments.size();
   }
@@ -108,11 +151,18 @@ public class ScreenContainer<T extends ScreenFragment> extends ViewGroup {
     return mScreenFragments.get(index).getScreen();
   }
 
-  protected final FragmentActivity findRootFragmentActivity() {
+  private FragmentManager findFragmentManager() {
     ViewParent parent = this;
-    while (!(parent instanceof ReactRootView) && parent.getParent() != null) {
+    // We traverse view hierarchy up until we find screen parent or a root view
+    while (!(parent instanceof ReactRootView || parent instanceof Screen) && parent.getParent() != null) {
       parent = parent.getParent();
     }
+    // If parent is of type Screen it means we are inside a nested fragment structure.
+    // Otherwise we expect to connect directly with root view and get root fragment manager
+    if (parent instanceof Screen) {
+      return ((Screen) parent).getFragment().getChildFragmentManager();
+    }
+
     // we expect top level view to be of type ReactRootView, this isn't really necessary but in order
     // to find root view we test if parent is null. This could potentially happen also when the view
     // is detached from the hierarchy and that test would not correctly indicate the root view. So
@@ -131,16 +181,12 @@ public class ScreenContainer<T extends ScreenFragment> extends ViewGroup {
       throw new IllegalStateException(
               "In order to use RNScreens components your app's activity need to extend ReactFragmentActivity or ReactCompatActivity");
     }
-    return (FragmentActivity) context;
-  }
-
-  protected FragmentManager getFragmentManager() {
-    return findRootFragmentActivity().getSupportFragmentManager();
+    return ((FragmentActivity) context).getSupportFragmentManager();
   }
 
   protected FragmentTransaction getOrCreateTransaction() {
     if (mCurrentTransaction == null) {
-      mCurrentTransaction = getFragmentManager().beginTransaction();
+      mCurrentTransaction = mFragmentManager.beginTransaction();
       mCurrentTransaction.setReorderingAllowed(true);
     }
     return mCurrentTransaction;
@@ -148,6 +194,19 @@ public class ScreenContainer<T extends ScreenFragment> extends ViewGroup {
 
   protected void tryCommitTransaction() {
     if (mCurrentTransaction != null) {
+      final FragmentTransaction transaction = mCurrentTransaction;
+      mProcessingTransaction = transaction;
+      mProcessingTransaction.runOnCommit(new Runnable() {
+        @Override
+        public void run() {
+         if (mProcessingTransaction == transaction) {
+           // we need to take into account that commit is initiated with some other transaction while
+           // the previous one is still processing. In this case mProcessingTransaction gets overwritten
+           // and we don't want to set it to null until the second transaction is finished.
+           mProcessingTransaction = null;
+         }
+        }
+      });
       mCurrentTransaction.commitAllowingStateLoss();
       mCurrentTransaction = null;
     }
@@ -173,10 +232,16 @@ public class ScreenContainer<T extends ScreenFragment> extends ViewGroup {
     return screenFragment.getScreen().isActive();
   }
 
+  protected boolean hasScreen(ScreenFragment screenFragment) {
+    return mScreenFragments.contains(screenFragment);
+  }
+
   @Override
   protected void onAttachedToWindow() {
     super.onAttachedToWindow();
     mIsAttached = true;
+    mNeedUpdate = true;
+    mFragmentManager = findFragmentManager();
     updateIfNeeded();
   }
 
@@ -184,6 +249,14 @@ public class ScreenContainer<T extends ScreenFragment> extends ViewGroup {
   protected void onDetachedFromWindow() {
     super.onDetachedFromWindow();
     mIsAttached = false;
+
+    // fragment manager is destroyed so we can't do anything with it anymore
+    mFragmentManager = null;
+    // so we don't add the same screen twice after re-attach
+    removeAllViews();
+    mActiveScreenFragments.clear();
+    // after re-attach we'll update the screen and add views again
+    markUpdated();
   }
 
   @Override

android/src/main/java/com/swmansion/rnscreens/ScreenContainerViewManager.java

@@ -34,6 +34,11 @@ public class ScreenContainerViewManager extends ViewGroupManager<ScreenContainer
     parent.removeScreenAt(index);
   }
 
+  @Override
+  public void removeAllViews(ScreenContainer parent) {
+    parent.removeAllScreens();
+  }
+
   @Override
   public int getChildCount(ScreenContainer parent) {
     return parent.getScreenCount();

android/src/main/java/com/swmansion/rnscreens/ScreenFragment.java

@@ -7,12 +7,10 @@ import android.view.View;
 import android.view.ViewGroup;
 
 import androidx.annotation.Nullable;
-import androidx.appcompat.widget.Toolbar;
 import androidx.fragment.app.Fragment;
 
 import com.facebook.react.bridge.ReactContext;
 import com.facebook.react.uimanager.UIManagerModule;
-import com.facebook.react.uimanager.events.EventDispatcher;
 
 public class ScreenFragment extends Fragment {
 
@@ -39,12 +37,39 @@ public class ScreenFragment extends Fragment {
     return mScreenView;
   }
 
-  @Override
-  public void onDestroy() {
-    super.onDestroy();
+  private void dispatchOnAppear() {
     ((ReactContext) mScreenView.getContext())
             .getNativeModule(UIManagerModule.class)
             .getEventDispatcher()
-            .dispatchEvent(new ScreenDismissedEvent(mScreenView.getId()));
+            .dispatchEvent(new ScreenAppearEvent(mScreenView.getId()));
+  }
+
+  @Override
+  public void onCreate(@Nullable Bundle savedInstanceState) {
+    super.onCreate(savedInstanceState);
+    ScreenContainer container = mScreenView.getContainer();
+    if (container.isTransitioning()) {
+      container.postAfterTransition(new Runnable() {
+        @Override
+        public void run() {
+          dispatchOnAppear();
+        }
+      });
+    } else {
+      dispatchOnAppear();
+    }
+  }
+
+  @Override
+  public void onDestroy() {
+    super.onDestroy();
+    ScreenContainer container = mScreenView.getContainer();
+    if (container == null || !container.hasScreen(this)) {
+      // we only send dismissed even when the screen has been removed from its container
+      ((ReactContext) mScreenView.getContext())
+              .getNativeModule(UIManagerModule.class)
+              .getEventDispatcher()
+              .dispatchEvent(new ScreenDismissedEvent(mScreenView.getId()));
+    }
   }
 }

android/src/main/java/com/swmansion/rnscreens/ScreenStack.java

@@ -2,6 +2,7 @@ package com.swmansion.rnscreens;
 
 import android.content.Context;
 
+import androidx.fragment.app.Fragment;
 import androidx.fragment.app.FragmentManager;
 import androidx.fragment.app.FragmentTransaction;
 
@@ -21,7 +22,7 @@ public class ScreenStack extends ScreenContainer<ScreenStackFragment> {
   private final FragmentManager.OnBackStackChangedListener mBackStackListener = new FragmentManager.OnBackStackChangedListener() {
     @Override
     public void onBackStackChanged() {
-      if (getFragmentManager().getBackStackEntryCount() == 0) {
+      if (mFragmentManager.getBackStackEntryCount() == 0) {
         // when back stack entry count hits 0 it means the user's navigated back using hw back
         // button. As the "fake" transaction we installed on the back stack does nothing we need
         // to handle back navigation on our own.
@@ -30,6 +31,15 @@ public class ScreenStack extends ScreenContainer<ScreenStackFragment> {
     }
   };
 
+  private final FragmentManager.FragmentLifecycleCallbacks mLifecycleCallbacks = new FragmentManager.FragmentLifecycleCallbacks() {
+    @Override
+    public void onFragmentResumed(FragmentManager fm, Fragment f) {
+      if (mTopScreen == f) {
+        setupBackHandlerIfNeeded(mTopScreen);
+      }
+    }
+  };
+
   public ScreenStack(Context context) {
     super(context);
   }
@@ -60,17 +70,24 @@ public class ScreenStack extends ScreenContainer<ScreenStackFragment> {
 
   @Override
   protected void onDetachedFromWindow() {
+    if (mFragmentManager != null) {
+      mFragmentManager.removeOnBackStackChangedListener(mBackStackListener);
+      mFragmentManager.unregisterFragmentLifecycleCallbacks(mLifecycleCallbacks);
+      if (!mFragmentManager.isStateSaved()) {
+        // state save means that the container where fragment manager was installed has been unmounted.
+        // This could happen as a result of dismissing nested stack. In such a case we don't need to
+        // reset back stack as it'd result in a crash caused by the fact the fragment manager is no
+        // longer attached.
+        mFragmentManager.popBackStack(BACK_STACK_TAG, FragmentManager.POP_BACK_STACK_INCLUSIVE);
+      }
+    }
     super.onDetachedFromWindow();
-    getFragmentManager().removeOnBackStackChangedListener(mBackStackListener);
-    getFragmentManager().popBackStack(BACK_STACK_TAG, FragmentManager.POP_BACK_STACK_INCLUSIVE);
   }
 
   @Override
   protected void onAttachedToWindow() {
     super.onAttachedToWindow();
-    if (mTopScreen != null) {
-      setupBackHandlerIfNeeded(mTopScreen);
-    }
+    mFragmentManager.registerFragmentLifecycleCallbacks(mLifecycleCallbacks, false);
   }
 
   @Override
@@ -80,6 +97,17 @@ public class ScreenStack extends ScreenContainer<ScreenStackFragment> {
     super.removeScreenAt(index);
   }
 
+  @Override
+  protected void removeAllScreens() {
+    mDismissed.clear();
+    super.removeAllScreens();
+  }
+
+  @Override
+  protected boolean hasScreen(ScreenFragment screenFragment) {
+    return super.hasScreen(screenFragment) && !mDismissed.contains(screenFragment);
+  }
+
   @Override
   protected void onUpdate() {
     // remove all screens previously on stack
@@ -88,7 +116,11 @@ public class ScreenStack extends ScreenContainer<ScreenStackFragment> {
         getOrCreateTransaction().remove(screen);
       }
     }
-    ScreenStackFragment newTop = null;
+
+    // When going back from a nested stack with a single screen on it, we may hit an edge case
+    // when all screens are dismissed and no screen is to be displayed on top. We need to gracefully
+    // handle the case of newTop being NULL, which happens in several places below
+    ScreenStackFragment newTop = null; // newTop is nullable, see the above comment ^
     ScreenStackFragment belowTop = null; // this is only set if newTop has TRANSPARENT_MODAL presentation mode
 
     for (int i = mScreenFragments.size() - 1; i >= 0; i--) {
@@ -106,28 +138,26 @@ public class ScreenStack extends ScreenContainer<ScreenStackFragment> {
       }
     }
 
-
     for (ScreenStackFragment screen : mScreenFragments) {
-      // add all new views that weren't on stack before
-      if (!mStack.contains(screen) && !mDismissed.contains(screen)) {
-        getOrCreateTransaction().add(getId(), screen);
-      }
       // detach all screens that should not be visible
       if (screen != newTop && screen != belowTop && !mDismissed.contains(screen)) {
-        getOrCreateTransaction().hide(screen);
+        getOrCreateTransaction().remove(screen);
       }
     }
     // attach "below top" screen if set
-    if (belowTop != null) {
+    if (belowTop != null && !belowTop.isAdded()) {
       final ScreenStackFragment top = newTop;
-      getOrCreateTransaction().show(belowTop).runOnCommit(new Runnable() {
+      getOrCreateTransaction().add(getId(), belowTop).runOnCommit(new Runnable() {
         @Override
         public void run() {
           top.getScreen().bringToFront();
         }
       });
     }
-    getOrCreateTransaction().show(newTop);
+
+    if (newTop != null && !newTop.isAdded()) {
+      getOrCreateTransaction().add(getId(), newTop);
+    }
 
     if (!mStack.contains(newTop)) {
       // if new top screen wasn't on stack we do "open animation" so long it is not the very first screen on stack
@@ -165,7 +195,9 @@ public class ScreenStack extends ScreenContainer<ScreenStackFragment> {
 
     tryCommitTransaction();
 
-    setupBackHandlerIfNeeded(mTopScreen);
+    if (mTopScreen != null) {
+      setupBackHandlerIfNeeded(mTopScreen);
+    }
 
     for (ScreenStackFragment screen : mStack) {
       screen.onStackUpdate();
@@ -192,8 +224,14 @@ public class ScreenStack extends ScreenContainer<ScreenStackFragment> {
    * that case we want the parent navigator or activity handler to take over.
    */
   private void setupBackHandlerIfNeeded(ScreenStackFragment topScreen) {
-    getFragmentManager().removeOnBackStackChangedListener(mBackStackListener);
-    getFragmentManager().popBackStack(BACK_STACK_TAG, FragmentManager.POP_BACK_STACK_INCLUSIVE);
+    if (!mTopScreen.isResumed()) {
+      // if the top fragment is not in a resumed state, adding back stack transaction would throw.
+      // In such a case we skip installing back handler and use FragmentLifecycleCallbacks to get
+      // notified when it gets resumed so that we can install the handler.
+      return;
+    }
+    mFragmentManager.removeOnBackStackChangedListener(mBackStackListener);
+    mFragmentManager.popBackStack(BACK_STACK_TAG, FragmentManager.POP_BACK_STACK_INCLUSIVE);
     ScreenStackFragment firstScreen = null;
     for (int i = 0, size = mStack.size(); i < size; i++) {
       ScreenStackFragment screen = mStack.get(i);
@@ -203,13 +241,13 @@ public class ScreenStack extends ScreenContainer<ScreenStackFragment> {
       }
     }
     if (topScreen != firstScreen && topScreen.isDismissable()) {
-      getFragmentManager()
+      mFragmentManager
               .beginTransaction()
-              .hide(topScreen)
               .show(topScreen)
               .addToBackStack(BACK_STACK_TAG)
+              .setPrimaryNavigationFragment(topScreen)
               .commitAllowingStateLoss();
-      getFragmentManager().addOnBackStackChangedListener(mBackStackListener);
+      mFragmentManager.addOnBackStackChangedListener(mBackStackListener);
     }
   }
 }

android/src/main/java/com/swmansion/rnscreens/ScreenStackFragment.java

@@ -22,6 +22,7 @@ public class ScreenStackFragment extends ScreenFragment {
   private AppBarLayout mAppBarLayout;
   private Toolbar mToolbar;
   private boolean mShadowHidden;
+  private CoordinatorLayout mScreenRootView;
 
   @SuppressLint("ValidFragment")
   public ScreenStackFragment(Screen screenView) {
@@ -59,10 +60,7 @@ public class ScreenStackFragment extends ScreenFragment {
     }
   }
 
-  @Override
-  public View onCreateView(LayoutInflater inflater,
-                           @Nullable ViewGroup container,
-                           @Nullable Bundle savedInstanceState) {
+  private CoordinatorLayout configureView() {
     CoordinatorLayout view = new CoordinatorLayout(getContext());
     CoordinatorLayout.LayoutParams params = new CoordinatorLayout.LayoutParams(
             LinearLayout.LayoutParams.MATCH_PARENT, LinearLayout.LayoutParams.MATCH_PARENT);
@@ -87,6 +85,17 @@ public class ScreenStackFragment extends ScreenFragment {
     return view;
   }
 
+  @Override
+  public View onCreateView(LayoutInflater inflater,
+                           @Nullable ViewGroup container,
+                           @Nullable Bundle savedInstanceState) {
+    if (mScreenRootView == null) {
+      mScreenRootView = configureView();
+    }
+
+    return mScreenRootView;
+  }
+
   public boolean isDismissable() {
     View child = mScreenView.getChildAt(0);
     if (child instanceof ScreenStackHeaderConfig) {

android/src/main/java/com/swmansion/rnscreens/ScreenStackHeaderConfig.java

@@ -8,6 +8,7 @@ import android.view.Gravity;
 import android.view.View;
 import android.view.ViewGroup;
 import android.view.ViewParent;
+import android.widget.ImageView;
 import android.widget.TextView;
 
 import androidx.appcompat.app.ActionBar;
@@ -15,21 +16,24 @@ import androidx.appcompat.app.AppCompatActivity;
 import androidx.appcompat.widget.Toolbar;
 import androidx.fragment.app.Fragment;
 
+import com.facebook.react.bridge.JSApplicationIllegalArgumentException;
 import com.facebook.react.views.text.ReactFontManager;
 
+import java.util.ArrayList;
+
 public class ScreenStackHeaderConfig extends ViewGroup {
 
-  private final ScreenStackHeaderSubview mConfigSubviews[] = new ScreenStackHeaderSubview[3];
-  private int mSubviewsCount = 0;
+  private final ArrayList<ScreenStackHeaderSubview> mConfigSubviews = new ArrayList<>(3);
   private String mTitle;
   private int mTitleColor;
   private String mTitleFontFamily;
-  private int mTitleFontSize;
+  private float mTitleFontSize;
   private int mBackgroundColor;
   private boolean mIsHidden;
   private boolean mGestureEnabled = true;
   private boolean mIsBackButtonHidden;
   private boolean mIsShadowHidden;
+  private boolean mDestroyed;
   private int mTintColor;
   private final Toolbar mToolbar;
 
@@ -47,6 +51,10 @@ public class ScreenStackHeaderConfig extends ViewGroup {
     setVisibility(View.GONE);
 
     mToolbar = new Toolbar(context);
+    // reset content insets to be 0 to allow react position custom navbar views. Note that this does
+    // not affect platform native back button as toolbar does not apply left inset when navigation
+    // button is specified
+    mToolbar.setContentInsetsAbsolute(0, 0);
 
     // set primary color as background by default
     TypedValue tv = new TypedValue();
@@ -60,6 +68,10 @@ public class ScreenStackHeaderConfig extends ViewGroup {
     // no-op
   }
 
+  public void destroy() {
+    mDestroyed = true;
+  }
+
   @Override
   protected void onAttachedToWindow() {
     super.onAttachedToWindow();
@@ -113,7 +125,7 @@ public class ScreenStackHeaderConfig extends ViewGroup {
     boolean isRoot = stack == null ? true : stack.getRootScreen() == parent;
     boolean isTop = stack == null ? true : stack.getTopScreen() == parent;
 
-    if (!mIsAttachedToWindow || !isTop) {
+    if (!mIsAttachedToWindow || !isTop || mDestroyed) {
       return;
     }
 
@@ -174,10 +186,26 @@ public class ScreenStackHeaderConfig extends ViewGroup {
     }
 
     // subviews
-    for (int i = 0; i < mSubviewsCount; i++) {
-      ScreenStackHeaderSubview view = mConfigSubviews[i];
+    for (int i = mToolbar.getChildCount() - 1; i >= 0; i--) {
+      if (mToolbar.getChildAt(i) instanceof ScreenStackHeaderSubview) {
+        mToolbar.removeViewAt(i);
+      }
+    }
+    for (int i = 0, size = mConfigSubviews.size(); i < size; i++) {
+      ScreenStackHeaderSubview view = mConfigSubviews.get(i);
       ScreenStackHeaderSubview.Type type = view.getType();
 
+      if (type == ScreenStackHeaderSubview.Type.BACK) {
+        // we special case BACK button header config type as we don't add it as a view into toolbar
+        // but instead just copy the drawable from imageview that's added as a first child to it.
+        View firstChild = view.getChildAt(0);
+        if (!(firstChild instanceof ImageView)) {
+          throw new JSApplicationIllegalArgumentException("Back button header config view should have Image as first child");
+        }
+        actionBar.setHomeAsUpIndicator(((ImageView) firstChild).getDrawable());
+        continue;
+      }
+
       Toolbar.LayoutParams params =
               new Toolbar.LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.MATCH_PARENT);
 
@@ -201,39 +229,36 @@ public class ScreenStackHeaderConfig extends ViewGroup {
       }
 
       view.setLayoutParams(params);
-      if (view.getParent() == null) {
-        mToolbar.addView(view);
-      }
+      mToolbar.addView(view);
     }
   }
 
   private void maybeUpdate() {
-    if (getParent() != null) {
+    if (getParent() != null && !mDestroyed) {
       onUpdate();
     }
   }
 
   public ScreenStackHeaderSubview getConfigSubview(int index) {
-    return mConfigSubviews[index];
+    return mConfigSubviews.get(index);
   }
 
   public int getConfigSubviewsCount() {
-    return mSubviewsCount;
+    return mConfigSubviews.size();
   }
 
   public void removeConfigSubview(int index) {
-    if (mConfigSubviews[index] != null) {
-      mSubviewsCount--;
-    }
-    mConfigSubviews[index] = null;
+    mConfigSubviews.remove(index);
+    maybeUpdate();
+  }
+
+  public void removeAllConfigSubviews() {
+    mConfigSubviews.clear();
     maybeUpdate();
   }
 
   public void addConfigSubview(ScreenStackHeaderSubview child, int index) {
-    if (mConfigSubviews[index] == null) {
-      mSubviewsCount++;
-    }
-    mConfigSubviews[index] = child;
+    mConfigSubviews.add(index, child);
     maybeUpdate();
   }
 
@@ -258,7 +283,7 @@ public class ScreenStackHeaderConfig extends ViewGroup {
     mTitleFontFamily = titleFontFamily;
   }
 
-  public void setTitleFontSize(int titleFontSize) {
+  public void setTitleFontSize(float titleFontSize) {
     mTitleFontSize = titleFontSize;
   }
 

android/src/main/java/com/swmansion/rnscreens/ScreenStackHeaderConfigViewManager.java

@@ -4,11 +4,12 @@ import android.view.View;
 
 import com.facebook.react.bridge.JSApplicationCausedNativeException;
 import com.facebook.react.module.annotations.ReactModule;
-import com.facebook.react.uimanager.PixelUtil;
 import com.facebook.react.uimanager.ThemedReactContext;
 import com.facebook.react.uimanager.ViewGroupManager;
 import com.facebook.react.uimanager.annotations.ReactProp;
 
+import javax.annotation.Nonnull;
+
 @ReactModule(name = ScreenStackHeaderConfigViewManager.REACT_CLASS)
 public class ScreenStackHeaderConfigViewManager extends ViewGroupManager<ScreenStackHeaderConfig> {
 
@@ -32,6 +33,16 @@ public class ScreenStackHeaderConfigViewManager extends ViewGroupManager<ScreenS
     parent.addConfigSubview((ScreenStackHeaderSubview) child, index);
   }
 
+  @Override
+  public void onDropViewInstance(@Nonnull ScreenStackHeaderConfig view) {
+    view.destroy();
+  }
+
+  @Override
+  public void removeAllViews(ScreenStackHeaderConfig parent) {
+    parent.removeAllConfigSubviews();
+  }
+
   @Override
   public void removeViewAt(ScreenStackHeaderConfig parent, int index) {
     parent.removeConfigSubview(index);
@@ -69,8 +80,8 @@ public class ScreenStackHeaderConfigViewManager extends ViewGroupManager<ScreenS
   }
 
   @ReactProp(name = "titleFontSize")
-  public void setTitleFontSize(ScreenStackHeaderConfig config, double titleFontSizeSP) {
-    config.setTitleFontSize((int) PixelUtil.toPixelFromSP(titleFontSizeSP));
+  public void setTitleFontSize(ScreenStackHeaderConfig config, float titleFontSize) {
+    config.setTitleFontSize(titleFontSize);
   }
 
   @ReactProp(name = "titleColor", customType = "Color")

android/src/main/java/com/swmansion/rnscreens/ScreenStackHeaderSubview.java

@@ -18,7 +18,8 @@ public class ScreenStackHeaderSubview extends ReactViewGroup {
     LEFT,
     CENTER,
     TITLE,
-    RIGHT
+    RIGHT,
+    BACK
   }
 
   private int mReactWidth, mReactHeight;

android/src/main/java/com/swmansion/rnscreens/ScreenStackHeaderSubviewManager.java

@@ -47,6 +47,8 @@ public class ScreenStackHeaderSubviewManager extends ReactViewManager {
       view.setType(ScreenStackHeaderSubview.Type.TITLE);
     } else if ("right".equals(type)) {
       view.setType(ScreenStackHeaderSubview.Type.RIGHT);
+    } else if ("back".equals(type)) {
+      view.setType(ScreenStackHeaderSubview.Type.BACK);
     }
   }
 }

android/src/main/java/com/swmansion/rnscreens/ScreenViewManager.java

@@ -62,6 +62,8 @@ public class ScreenViewManager extends ViewGroupManager<Screen> {
   public Map getExportedCustomDirectEventTypeConstants() {
     return MapBuilder.of(
             ScreenDismissedEvent.EVENT_NAME,
-            MapBuilder.of("registrationName", "onDismissed"));
+            MapBuilder.of("registrationName", "onDismissed"),
+            ScreenAppearEvent.EVENT_NAME,
+            MapBuilder.of("registrationName", "onAppear"));
   }
 }

createNativeStackNavigator.js

@@ -4,7 +4,6 @@ import {
   StackRouter,
   SceneView,
   StackActions,
-  NavigationActions,
   createNavigator,
 } from '@react-navigation/core';
 import { createKeyboardAwareNavigator } from '@react-navigation/native';
@@ -13,6 +12,7 @@ import {
   ScreenStack,
   Screen,
   ScreenStackHeaderConfig,
+  ScreenStackHeaderBackButtonImage,
   ScreenStackHeaderLeftView,
   ScreenStackHeaderRightView,
   ScreenStackHeaderTitleView,
@@ -27,14 +27,14 @@ function renderComponentOrThunk(componentOrThunk, props) {
 
 class StackView extends React.Component {
   _removeScene = route => {
-    const { navigation } = this.props;
-    navigation.dispatch(
-      NavigationActions.back({
-        key: route.key,
-        immediate: true,
-      })
+    this.props.navigation.dispatch(StackActions.pop({ key: route.key }));
+  };
+
+  _onSceneFocus = (route, descriptor) => {
+    descriptor.options && descriptor.options.onAppear && descriptor.options.onAppear()
+    this.props.navigation.dispatch(
+      StackActions.completeTransition({ toChildKey: route.key })
     );
-    navigation.dispatch(StackActions.completeTransition());
   };
 
   _renderHeaderConfig = (index, route, descriptor) => {
@@ -48,6 +48,7 @@ class StackView extends React.Component {
       headerTitleStyle,
       headerBackTitleStyle,
       headerBackTitle,
+      headerBackTitleVisible,
       headerTintColor,
       gestureEnabled,
       largeTitle,
@@ -69,7 +70,7 @@ class StackView extends React.Component {
       titleFontFamily: headerTitleStyle && headerTitleStyle.fontFamily,
       titleColor: headerTintColor,
       titleFontSize: headerTitleStyle && headerTitleStyle.fontSize,
-      backTitle: headerBackTitle,
+      backTitle: headerBackTitleVisible === false ? '' : headerBackTitle,
       backTitleFontFamily:
         headerBackTitleStyle && headerBackTitleStyle.fontFamily,
       backTitleFontSize: headerBackTitleStyle && headerBackTitleStyle.fontSize,
@@ -94,6 +95,15 @@ class StackView extends React.Component {
 
     const children = [];
 
+    if (options.backButtonImage) {
+      children.push(
+        <ScreenStackHeaderBackButtonImage
+          key="backImage"
+          source={options.backButtonImage}
+        />
+      );
+    }
+
     if (options.headerLeft !== undefined) {
       children.push(
         <ScreenStackHeaderLeftView key="left">
@@ -154,21 +164,34 @@ class StackView extends React.Component {
   };
 
   _renderScene = (index, route, descriptor) => {
-    const { navigation, getComponent } = descriptor;
+    const { navigation, getComponent, options } = descriptor;
     const { mode, transparentCard } = this.props.navigationConfig;
     const SceneComponent = getComponent();
 
     let stackPresentation = 'push';
-    if (mode === 'modal') {
-      stackPresentation = transparentCard ? 'transparentModal' : 'modal';
+    if (mode === 'modal' || mode === 'containedModal') {
+      stackPresentation = mode;
+      if (transparentCard || options.cardTransparent) {
+        stackPresentation =
+          mode === 'containedModal'
+            ? 'containedTransparentModal'
+            : 'transparentModal';
+      }
+    }
+
+    let stackAnimation = options.stackAnimation;
+    if (options.animationEnabled === false) {
+      stackAnimation = 'none';
     }
 
     const { screenProps } = this.props;
     return (
       <Screen
         key={`screen_${route.key}`}
-        style={StyleSheet.absoluteFill}
+        style={options.cardStyle}
+        stackAnimation={stackAnimation}
         stackPresentation={stackPresentation}
+        onAppear={() => this._onSceneFocus(route, descriptor)}
         onDismissed={() => this._removeScene(route)}>
         {this._renderHeaderConfig(index, route, descriptor)}
         <SceneView
@@ -199,7 +222,6 @@ const styles = StyleSheet.create({
 
 function createStackNavigator(routeConfigMap, stackConfig = {}) {
   const router = StackRouter(routeConfigMap, stackConfig);
-
   // Create a navigator with StackView as the view
   let Navigator = createNavigator(StackView, router, stackConfig);
   // if (!stackConfig.disableKeyboardHandling) {

ios/RNSScreen.h

@@ -39,6 +39,7 @@ typedef NS_ENUM(NSInteger, RNSScreenStackAnimation) {
 
 @interface RNSScreenView : RCTView
 
+@property (nonatomic, copy) RCTDirectEventBlock onAppear;
 @property (nonatomic, copy) RCTDirectEventBlock onDismissed;
 @property (weak, nonatomic) UIView<RNSScreenContainerDelegate> *reactSuperview;
 @property (nonatomic, retain) UIViewController *controller;

ios/RNSScreen.m

@@ -33,6 +33,9 @@
 
 - (void)reactSetFrame:(CGRect)frame
 {
+  if (_active) {
+    [super reactSetFrame:frame];
+  }
   // ignore setFrame call from react, the frame of this view
   // is controlled by the UIViewController it is contained in
 }
@@ -135,6 +138,17 @@
   }
 }
 
+- (void)notifyAppear
+{
+  if (self.onAppear) {
+    dispatch_async(dispatch_get_main_queue(), ^{
+      if (self.onAppear) {
+        self.onAppear(nil);
+      }
+    });
+  }
+}
+
 - (BOOL)isMountedUnderScreenOrReactRoot
 {
   for (UIView *parent = self.superview; parent != nil; parent = parent.superview) {
@@ -235,6 +249,12 @@
   }
 }
 
+- (void)viewDidAppear:(BOOL)animated
+{
+  [super viewDidAppear:animated];
+  [((RNSScreenView *)self.view) notifyAppear];
+}
+
 - (void)notifyFinishTransitioning
 {
   [_previousFirstResponder becomeFirstResponder];
@@ -258,6 +278,7 @@ RCT_EXPORT_MODULE()
 RCT_EXPORT_VIEW_PROPERTY(active, BOOL)
 RCT_EXPORT_VIEW_PROPERTY(stackPresentation, RNSScreenStackPresentation)
 RCT_EXPORT_VIEW_PROPERTY(stackAnimation, RNSScreenStackAnimation)
+RCT_EXPORT_VIEW_PROPERTY(onAppear, RCTDirectEventBlock);
 RCT_EXPORT_VIEW_PROPERTY(onDismissed, RCTDirectEventBlock);
 
 - (UIView *)view

ios/RNSScreenStack.h

@@ -2,7 +2,7 @@
 #import <React/RCTUIManagerObserverCoordinator.h>
 #import "RNSScreenContainer.h"
 
-@interface RNSScreenStackView : UIView <RNSScreenContainerDelegate>
+@interface RNSScreenStackView : UIView <RNSScreenContainerDelegate, RCTInvalidating>
 
 - (void)markChildUpdated;
 - (void)didUpdateChildren;

ios/RNSScreenStack.m

@@ -22,6 +22,7 @@
   NSMutableArray<RNSScreenView *> *_reactSubviews;
   NSMutableSet<RNSScreenView *> *_dismissedScreens;
   NSMutableArray<UIViewController *> *_presentedModals;
+  __weak UIViewController* recentPopped;
   __weak RNSScreenStackManager *_manager;
 }
 
@@ -69,6 +70,10 @@
       [_dismissedScreens addObject:[_reactSubviews objectAtIndex:i - 1]];
     }
   }
+  if (recentPopped != nil) {
+    recentPopped.view = nil;
+    recentPopped = nil;
+  }
 }
 
 - (id<UIViewControllerAnimatedTransitioning>)navigationController:(UINavigationController *)navigationController animationControllerForOperation:(UINavigationControllerOperation)operation fromViewController:(UIViewController *)fromVC toViewController:(UIViewController *)toVC
@@ -77,7 +82,8 @@
   if (operation == UINavigationControllerOperationPush) {
     screen = (RNSScreenView *) toVC.view;
   } else if (operation == UINavigationControllerOperationPop) {
-   screen = (RNSScreenView *) fromVC.view;
+    screen = (RNSScreenView *) fromVC.view;
+    recentPopped = fromVC;
   }
   if (screen != nil && (screen.stackAnimation == RNSScreenStackAnimationFade || screen.stackAnimation == RNSScreenStackAnimationNone)) {
     return  [[RNSScreenStackAnimator alloc] initWithOperation:operation];
@@ -96,7 +102,16 @@
   RCTRootContentView *rootView = (RCTRootContentView *)parent;
   [rootView.touchHandler cancel];
 
-  return _controller.viewControllers.count > 1;
+  UIView *topView = _controller.viewControllers.lastObject.view;
+  RNSScreenStackHeaderConfig *config = nil;
+  for (UIView *subview in topView.reactSubviews) {
+    if ([subview isKindOfClass:[RNSScreenStackHeaderConfig class]]) {
+      config = (RNSScreenStackHeaderConfig*) subview;
+      break;
+    }
+  }
+
+  return _controller.viewControllers.count > 1 && (config == nil || config.gestureEnabled);
 }
 
 - (void)markChildUpdated
@@ -137,41 +152,65 @@
 
 - (void)setModalViewControllers:(NSArray<UIViewController *> *)controllers
 {
+  // when there is no change we return immediately. This check is important because sometime we may
+  // accidently trigger modal dismiss if we don't verify to run the below code only when an actual
+  // change in the list of presented modal was made.
+  if ([_presentedModals isEqualToArray:controllers]) {
+    return;
+  }
+
   NSMutableArray<UIViewController *> *newControllers = [NSMutableArray arrayWithArray:controllers];
   [newControllers removeObjectsInArray:_presentedModals];
 
-  NSMutableArray<UIViewController *> *controllersToRemove = [NSMutableArray arrayWithArray:_presentedModals];
-  [controllersToRemove removeObjectsInArray:controllers];
-
-  // presenting new controllers
-  for (UIViewController *newController in newControllers) {
-    [_presentedModals addObject:newController];
-    if (_controller.presentedViewController != nil) {
-      [_controller.presentedViewController presentViewController:newController animated:YES completion:nil];
+  // find bottom-most controller that should stay on the stack for the duration of transition
+  NSUInteger changeRootIndex = 0;
+  UIViewController *changeRootController = _controller;
+  for (NSUInteger i = 0; i < MIN(_presentedModals.count, controllers.count); i++) {
+    if (_presentedModals[i] == controllers[i]) {
+      changeRootController = controllers[i];
+      changeRootIndex = i + 1;
     } else {
-      [_controller presentViewController:newController animated:YES completion:nil];
+      break;
     }
   }
 
-  // hiding old controllers
-  for (UIViewController *controller in [controllersToRemove reverseObjectEnumerator]) {
-    [_presentedModals removeObject:controller];
-    if (controller.presentedViewController != nil) {
-      UIViewController *restore = controller.presentedViewController;
-      UIViewController *parent = controller.presentingViewController;
-      [controller dismissViewControllerAnimated:NO completion:^{
-        [parent dismissViewControllerAnimated:NO completion:^{
-          [parent presentViewController:restore animated:NO completion:nil];
-        }];
-      }];
-    } else {
-      [controller.presentingViewController dismissViewControllerAnimated:YES completion:nil];
+  // we verify that controllers added on top of changeRootIndex are all new. Unfortunately modal
+  // VCs cannot be reshuffled (there are some visual glitches when we try to dismiss then show as
+  // even non-animated dismissal has delay and updates the screen several times)
+  for (NSUInteger i = changeRootIndex; i < controllers.count; i++) {
+    if ([_presentedModals containsObject:controllers[i]]) {
+      RCTAssert(false, @"Modally presented controllers are being reshuffled, this is not allowed");
     }
   }
+
+  void (^finish)(void) = ^{
+    UIViewController *previous = changeRootController;
+    for (NSUInteger i = changeRootIndex; i < controllers.count; i++) {
+      UIViewController *next = controllers[i];
+      [previous presentViewController:next
+                             animated:(i == controllers.count - 1)
+                             completion:nil];
+      previous = next;
+    }
+  };
+
+  if (changeRootController.presentedViewController) {
+    [changeRootController
+     dismissViewControllerAnimated:(changeRootIndex == controllers.count)
+     completion:finish];
+  } else {
+    finish();
+  }
+  [_presentedModals setArray:controllers];
 }
 
 - (void)setPushViewControllers:(NSArray<UIViewController *> *)controllers
 {
+  // when there is no change we return immediately
+  if ([_controller.viewControllers isEqualToArray:controllers]) {
+    return;
+  }
+
   UIViewController *top = controllers.lastObject;
   UIViewController *lastTop = _controller.viewControllers.lastObject;
 
@@ -181,7 +220,7 @@
   // controller is still there
   BOOL firstTimePush = ![lastTop isKindOfClass:[RNSScreen class]];
 
-  BOOL shouldAnimate = !firstTimePush && ((RNSScreenView *) lastTop.view).stackAnimation != RNSScreenStackAnimationNone;
+  BOOL shouldAnimate = !firstTimePush && ((RNSScreenView *) lastTop.view).stackAnimation != RNSScreenStackAnimationNone && !_controller.presentedViewController;
 
   if (firstTimePush) {
     // nothing pushed yet
@@ -244,12 +283,18 @@
   _controller.view.frame = self.bounds;
 }
 
+- (void)invalidate
+{
+  for (UIViewController *controller in _presentedModals) {
+    [controller dismissViewControllerAnimated:NO completion:nil];
+  }
+  [_presentedModals removeAllObjects];
+}
+
 - (void)dismissOnReload
 {
   dispatch_async(dispatch_get_main_queue(), ^{
-    for (UIViewController *controller in self->_presentedModals) {
-      [controller dismissViewControllerAnimated:NO completion:nil];
-    }
+    [self invalidate];
   });
 }
 

ios/RNSScreenStackHeaderConfig.h

@@ -34,6 +34,7 @@
 @end
 
 typedef NS_ENUM(NSInteger, RNSScreenStackHeaderSubviewType) {
+  RNSScreenStackHeaderSubviewTypeBackButton,
   RNSScreenStackHeaderSubviewTypeLeft,
   RNSScreenStackHeaderSubviewTypeRight,
   RNSScreenStackHeaderSubviewTypeTitle,

ios/RNSScreenStackHeaderConfig.m

@@ -5,6 +5,20 @@
 #import <React/RCTUIManager.h>
 #import <React/RCTUIManagerUtils.h>
 #import <React/RCTShadowView.h>
+#import <React/RCTImageLoader.h>
+#import <React/RCTImageView.h>
+#import <React/RCTImageSource.h>
+
+// Some RN private method hacking below. Couldn't figure out better way to access image data
+// of a given RCTImageView. See more comments in the code section processing SubviewTypeBackButton
+@interface RCTImageView (Private)
+- (UIImage*)image;
+@end
+
+@interface RCTImageLoader (Private)
+- (id<RCTImageCache>)imageCache;
+@end
+
 
 @interface RNSScreenHeaderItemMeasurements : NSObject
 @property (nonatomic, readonly) CGSize headerSize;
@@ -30,6 +44,7 @@
 
 @interface RNSScreenStackHeaderSubview : UIView
 
+@property (nonatomic, weak) RCTBridge *bridge;
 @property (nonatomic, weak) UIView *reactSuperview;
 @property (nonatomic) RNSScreenStackHeaderSubviewType type;
 
@@ -150,6 +165,15 @@
         [navbar setLargeTitleTextAttributes:largeAttrs];
       }
     }
+
+    UIImage *backButtonImage = [self loadBackButtonImageInViewController:vc withConfig:config];
+    if (backButtonImage) {
+      navbar.backIndicatorImage = backButtonImage;
+      navbar.backIndicatorTransitionMaskImage = backButtonImage;
+    } else if (navbar.backIndicatorImage) {
+      navbar.backIndicatorImage = nil;
+      navbar.backIndicatorTransitionMaskImage = nil;
+    }
   }
 }
 
@@ -164,6 +188,59 @@
   }
 }
 
++ (UIImage*)loadBackButtonImageInViewController:(UIViewController *)vc
+                                     withConfig:(RNSScreenStackHeaderConfig *)config
+{
+  BOOL hasBackButtonImage = NO;
+  for (RNSScreenStackHeaderSubview *subview in config.reactSubviews) {
+    if (subview.type == RNSScreenStackHeaderSubviewTypeBackButton && subview.subviews.count > 0) {
+      hasBackButtonImage = YES;
+      RCTImageView *imageView = subview.subviews[0];
+      UIImage *image = imageView.image;
+      // IMPORTANT!!!
+      // image can be nil in DEV MODE ONLY
+      //
+      // It is so, because in dev mode images are loaded over HTTP from the packager. In that case
+      // we first check if image is already loaded in cache and if it is, we take it from cache and
+      // display immediately. Otherwise we wait for the transition to finish and retry updating
+      // header config.
+      // Unfortunately due to some problems in UIKit we cannot update the image while the screen
+      // transition is ongoing. This results in the settings being reset after the transition is done
+      // to the state from before the transition.
+      if (image == nil) {
+        // in DEV MODE we try to load from cache (we use private API for that as it is not exposed
+        // publically in headers).
+        RCTImageSource *source = imageView.imageSources[0];
+        image = [subview.bridge.imageLoader.imageCache
+                 imageForUrl:source.request.URL.absoluteString
+                 size:source.size
+                 scale:source.scale
+                 resizeMode:imageView.resizeMode];
+      }
+      if (image == nil) {
+        // This will be triggered if the image is not in the cache yet. What we do is we wait until
+        // the end of transition and run header config updates again. We could potentially wait for
+        // image on load to trigger, but that would require even more private method hacking.
+        if (vc.transitionCoordinator) {
+          [vc.transitionCoordinator animateAlongsideTransition:^(id<UIViewControllerTransitionCoordinatorContext>  _Nonnull context) {
+            // nothing, we just want completion
+          } completion:^(id<UIViewControllerTransitionCoordinatorContext>  _Nonnull context) {
+            // in order for new back button image to be loaded we need to trigger another change
+            // in back button props that'd make UIKit redraw the button. Otherwise the changes are
+            // not reflected. Here we change back button visibility which is then immediately restored
+            vc.navigationItem.hidesBackButton = YES;
+            [config updateViewControllerIfNeeded];
+          }];
+        }
+        return [UIImage new];
+      } else {
+        return image;
+      }
+    }
+  }
+  return nil;
+}
+
 + (void)willShowViewController:(UIViewController *)vc withConfig:(RNSScreenStackHeaderConfig *)config
 {
   [self updateViewController:vc withConfig:config];
@@ -190,7 +267,6 @@
   }
 
   [navctr setNavigationBarHidden:shouldHide animated:YES];
-  navctr.interactivePopGestureRecognizer.enabled = config.gestureEnabled;
 #ifdef __IPHONE_13_0
   if (@available(iOS 13.0, *)) {
     vc.modalInPresentation = !config.gestureEnabled;
@@ -201,7 +277,6 @@
   }
 
   navitem.title = config.title;
-  navitem.hidesBackButton = config.hideBackButton;
   if (config.backTitle != nil) {
     prevItem.backBarButtonItem = [[UIBarButtonItem alloc]
                                   initWithTitle:config.backTitle
@@ -290,11 +365,22 @@
       appearance.largeTitleTextAttributes = largeAttrs;
     }
 
+    UIImage *backButtonImage = [self loadBackButtonImageInViewController:vc withConfig:config];
+    if (backButtonImage) {
+      [appearance setBackIndicatorImage:backButtonImage transitionMaskImage:backButtonImage];
+    } else if (appearance.backIndicatorImage) {
+      [appearance setBackIndicatorImage:nil transitionMaskImage:nil];
+    }
+
     navitem.standardAppearance = appearance;
     navitem.compactAppearance = appearance;
     navitem.scrollEdgeAppearance = appearance;
   }
 #endif
+  navitem.hidesBackButton = config.hideBackButton;
+  navitem.leftBarButtonItem = nil;
+  navitem.rightBarButtonItem = nil;
+  navitem.titleView = nil;
   for (RNSScreenStackHeaderSubview *subview in config.reactSubviews) {
     switch (subview.type) {
       case RNSScreenStackHeaderSubviewTypeLeft: {
@@ -375,6 +461,7 @@ RCT_EXPORT_VIEW_PROPERTY(gestureEnabled, BOOL)
 @implementation RCTConvert (RNSScreenStackHeader)
 
 RCT_ENUM_CONVERTER(RNSScreenStackHeaderSubviewType, (@{
+   @"back": @(RNSScreenStackHeaderSubviewTypeBackButton),
    @"left": @(RNSScreenStackHeaderSubviewTypeLeft),
    @"right": @(RNSScreenStackHeaderSubviewTypeRight),
    @"title": @(RNSScreenStackHeaderSubviewTypeTitle),
@@ -383,9 +470,7 @@ RCT_ENUM_CONVERTER(RNSScreenStackHeaderSubviewType, (@{
 
 @end
 
-@implementation RNSScreenStackHeaderSubview {
-  __weak RCTBridge *_bridge;
-}
+@implementation RNSScreenStackHeaderSubview
 
 - (instancetype)initWithBridge:(RCTBridge *)bridge
 {

package.json

@@ -1,6 +1,6 @@
 {
   "name": "react-native-screens",
-  "version": "2.0.0-alpha.12",
+  "version": "2.0.0-alpha.28",
   "description": "First incomplete navigation solution for your react-native app.",
   "scripts": {
     "start": "node node_modules/react-native/local-cli/cli.js start",

src/screens.d.ts

@@ -3,21 +3,140 @@
 
 declare module 'react-native-screens' {
   import { ComponentClass } from 'react';
-  import { ViewProps, Animated } from 'react-native';
+  import { ViewProps, Animated, NativeSyntheticEvent, NativeTouchEvent, ImageProps } from 'react-native';
 
   export function useScreens(shouldUseScreens?: boolean): void;
   export function enableScreens(shouldEnableScreens?: boolean): void;
   export function screensEnabled(): boolean;
 
+  export type StackPresentationTypes = 'push' | 'modal' | 'transparentModal';
+  export type StackAnimationTypes = 'default' | 'fade' | 'flip' | 'none';
+
   export interface ScreenProps extends ViewProps {
     active?: 0 | 1 | Animated.AnimatedInterpolation;
     onComponentRef?: (view: any) => void;
+    children?: React.ReactNode;
+    onAppear?: (e: NativeSyntheticEvent<NativeTouchEvent>) => void;
+    /**
+     *@description A callback that gets called when the current screen is dismissed by hardware back (on Android) or dismiss gesture (swipe back or down). The callback takes no arguments.
+     */
+    onDismissed?: (e: NativeSyntheticEvent<NativeTouchEvent>) => void;
+    /**
+     * @type "push" – the new screen will be pushed onto a stack which on iOS means that the default animation will be slide from the side, the animation on Android may vary depending on the OS version and theme.
+     * @type "modal" – the new screen will be presented modally. In addition this allow for a nested stack to be rendered inside such screens
+     * @type "transparentModal" – the new screen will be presented modally but in addition the second to last screen will remain attached to the stack container such that if the top screen is non opaque the content below can still be seen. If "modal" is used instead the below screen will get unmounted as soon as the transition ends.
+     */
+    stackPresentation: StackPresentationTypes;
+    /**
+     *@description Allows for the customization of how the given screen should appear/dissapear when pushed or popped at the top of the stack. The followin values are currently supported:
+     *  @type "default" – uses a platform default animation
+     *  @type "fade" – fades screen in or out
+     *  @type "flip" – flips the screen, requires stackPresentation: "modal" (iOS only)
+     *  @type "none" – the screen appears/dissapears without an animation
+     */
+    stackAnimation?: StackAnimationTypes;
   }
-  export const Screen: ComponentClass<ScreenProps>;
+
 
   export type ScreenContainerProps = ViewProps;
-  export const ScreenContainer: ComponentClass<ScreenContainerProps>;
+  
+  export interface ScreenStackProps extends ViewProps {
+    transitioning?: number;
+    progress?: number;
+  }
 
+  export interface ScreenStackHeaderConfigProps extends ViewProps {
+    /**
+     *@description String that representing screen title that will get rendered in the middle section of the header. On iOS the title is centered on the header while on Android it is aligned to the left and placed next to back button (if one is present).
+     */
+    title?: string;
+    /**
+     *@description When set to true the header will be hidden while the parent Screen is on the top of the stack. The default value is false.
+     */
+    hidden?: boolean;
+    /**
+     *@description Controls the color of items rendered on the header. This includes back icon, back text (iOS only) and title text. If you want the title to have different color use titleColor property.
+     */
+    color?: string;
+    /**
+     *@description Customize font family to be used for the title.
+     */
+    titleFontFamily?: string;
+    /**
+     *@description Customize the size of the font to be used for the title.
+     */
+    titleFontSize?: number;
+    /**
+     *@description Allows for setting text color of the title.
+     */
+    titleColor?: string;
+    /**
+     *@description Controlls the color of the navigation header.
+     */
+    backgroundColor?: string;
+    /**
+     * @description Boolean that allows for disabling drop shadow under navigation header. The default value is true.
+     */
+    hideShadow?: boolean;
+    /**
+     * @description If set to true the back button will not be rendered as a part of navigation header.
+     */
+    hideBackButton?: boolean;
+    /**
+     * @description When set to false the back swipe gesture will be disabled when the parent Screen is on top of the stack. The default value is true.
+     */
+    gestureEnabled?: boolean;
+    /**
+     * @host (iOS only)
+     * @description When set to true, it makes native navigation bar on iOS semi transparent with blur effect. It is a common way of presenting navigation bar introduced in iOS 11. The default value is false
+     */
+    translucent?: boolean;
+    /**
+     * @host (iOS only)
+     * @description Allows for controlling the string to be rendered next to back button. By default iOS uses the title of the previous screen.
+     */
+    backTitle?: string;
+    /**
+     * @host (iOS only)
+     * @description Allows for customizing font family to be used for back button title on iOS.
+     */
+    backTitleFontFamily?: string;
+    /**
+     * @host (iOS only)
+     * @description Allows for customizing font size to be used for back button title on iOS.
+     */
+    backTitleFontSize?: number;
+    /**
+     * @host (iOS only)
+     * @description When set to true it makes the title display using the large title effect.
+     */
+    largeTitle?: boolean;
+    /**
+     * @host (iOS only)
+     * @description Customize font family to be used for the large title.
+     */
+    largeTitleFontFamily?: string;
+    /**
+     * @host (iOS only)
+     * @description Customize the size of the font to be used for the large title.
+     */
+    largeTitleFontSize?: number;
+    /**
+     * Pass HeaderLeft, HeaderRight and HeaderTitle
+     */
+    children?: React.ReactNode;
+  }
+
+  export const Screen: ComponentClass<ScreenProps>;
+  export const ScreenContainer: ComponentClass<ScreenContainerProps>;
   export const NativeScreen: ComponentClass<ScreenProps>;
   export const NativeScreenContainer: ComponentClass<ScreenContainerProps>;
+  export const ScreenStack: ComponentClass<ScreenStackProps>;
+  export const ScreenStackHeaderBackButtonImage: ComponentClass<ImageProps>;
+  export const ScreenStackHeaderLeftView: ComponentClass<ViewProps>;
+  export const ScreenStackHeaderRightView: ComponentClass<ViewProps>;
+  export const ScreenStackHeaderTitleView: ComponentClass<ViewProps>;
+  export const ScreenStackHeaderConfig: ComponentClass<
+    ScreenStackHeaderConfigProps
+  >;
 }

src/screens.native.js

@@ -4,6 +4,7 @@ import {
   requireNativeComponent,
   View,
   UIManager,
+  Image,
   StyleSheet,
 } from 'react-native';
 import { version } from 'react-native/Libraries/Core/ReactNativeVersion';
@@ -146,6 +147,14 @@ const styles = StyleSheet.create({
   },
 });
 
+const ScreenStackHeaderBackButtonImage = props => (
+  <ScreensNativeModules.NativeScreenStackHeaderSubview
+    type="back"
+    style={styles.headerSubview}>
+    <Image resizeMode="center" fadeDuration={0} {...props} />
+  </ScreensNativeModules.NativeScreenStackHeaderSubview>
+);
+
 const ScreenStackHeaderRightView = props => (
   <ScreensNativeModules.NativeScreenStackHeaderSubview
     {...props}
@@ -198,6 +207,7 @@ module.exports = {
   get ScreenStackHeaderSubview() {
     return ScreensNativeModules.NativeScreenStackHeaderSubview;
   },
+  ScreenStackHeaderBackButtonImage,
   ScreenStackHeaderRightView,
   ScreenStackHeaderLeftView,
   ScreenStackHeaderTitleView,

yarn.lock

@@ -1741,10 +1741,10 @@ commander@~2.13.0:
   version "2.13.0"
   resolved "https://registry.yarnpkg.com/commander/-/commander-2.13.0.tgz#6964bca67685df7c1f1430c584f07d7597885b9c"
 
-commander@~2.20.0:
-  version "2.20.0"
-  resolved "https://registry.yarnpkg.com/commander/-/commander-2.20.0.tgz#d58bb2b5c1ee8f87b0d340027e9e94e222c5a422"
-  integrity sha512-7j2y+40w61zy6YC2iRNpUe/NwhNyoXrYpHMrSunaMG64nRnaf96zO/KMQR4OyN/UnE5KLyEBnKHd4aG3rskjpQ==
+commander@~2.20.3:
+  version "2.20.3"
+  resolved "https://registry.yarnpkg.com/commander/-/commander-2.20.3.tgz#fd485e84c03eb4881c20722ba48035e8531aeb33"
+  integrity sha512-GpVkmM8vF2vQUkj2LvZmD35JxeJOLCwJ9cUkugyk2nuhbv3+mJvpLYYt+0+USMxE+oj+ey/lJEnhZw75x/OMcQ==
 
 commondir@^1.0.1:
   version "1.0.1"
@@ -2765,9 +2765,9 @@ growly@^1.3.0:
   resolved "https://registry.yarnpkg.com/growly/-/growly-1.3.0.tgz#f10748cbe76af964b7c96c93c6bcc28af120c081"
 
 handlebars@^4.0.3:
-  version "4.1.2"
-  resolved "https://registry.yarnpkg.com/handlebars/-/handlebars-4.1.2.tgz#b6b37c1ced0306b221e094fc7aca3ec23b131b67"
-  integrity sha512-nvfrjqvt9xQ8Z/w0ijewdD/vvWDTOweBUm96NTr66Wfvo1mJenBLwcYmPs3TIBP5ruzYGD7Hx/DaM9RmhroGPw==
+  version "4.5.3"
+  resolved "https://registry.yarnpkg.com/handlebars/-/handlebars-4.5.3.tgz#5cf75bd8714f7605713511a56be7c349becb0482"
+  integrity sha512-3yPecJoJHK/4c6aZhSvxOyG4vJKDshV36VHp0iVCDVh7o9w2vwi3NSnL2MMPj3YdduqaBcu7cGbggJQM0br9xA==
   dependencies:
     neo-async "^2.6.0"
     optimist "^0.6.1"
@@ -5855,11 +5855,11 @@ uglify-es@^3.1.9:
     source-map "~0.6.1"
 
 uglify-js@^3.1.4:
-  version "3.6.0"
-  resolved "https://registry.yarnpkg.com/uglify-js/-/uglify-js-3.6.0.tgz#704681345c53a8b2079fb6cec294b05ead242ff5"
-  integrity sha512-W+jrUHJr3DXKhrsS7NUVxn3zqMOFn0hL/Ei6v0anCIMoKC93TjcflTagwIHLW7SfMFfiQuktQyFVCFHGUE0+yg==
+  version "3.7.3"
+  resolved "https://registry.yarnpkg.com/uglify-js/-/uglify-js-3.7.3.tgz#f918fce9182f466d5140f24bb0ff35c2d32dcc6a"
+  integrity sha512-7tINm46/3puUA4hCkKYo4Xdts+JDaVC9ZPRcG8Xw9R4nhO/gZgUM3TENq8IF4Vatk8qCig4MzP/c8G4u2BkVQg==
   dependencies:
-    commander "~2.20.0"
+    commander "~2.20.3"
     source-map "~0.6.1"
 
 ultron@1.0.x: