Fix screen container layout on Android. (#217)

This is a similar fix to the one already merged in #215 but for Android this time. We change default screen container to layout its direct children without using flexbox. This is to follow the same pattern as with native stack container.

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

@@ -26,21 +26,45 @@ public class ScreenContainer<T extends ScreenFragment> extends ViewGroup {
   private @Nullable FragmentTransaction mCurrentTransaction;
   private boolean mNeedUpdate;
   private boolean mIsAttached;
+  private boolean mLayoutEnqueued = false;
 
-  private ChoreographerCompat.FrameCallback mFrameCallback = new ChoreographerCompat.FrameCallback() {
+  private final ChoreographerCompat.FrameCallback mFrameCallback = new ChoreographerCompat.FrameCallback() {
     @Override
     public void doFrame(long frameTimeNanos) {
       updateIfNeeded();
     }
   };
 
+  private final Runnable mLayoutRunnable = new Runnable() {
+    @Override
+    public void run() {
+      mLayoutEnqueued = false;
+      measure(
+              MeasureSpec.makeMeasureSpec(getWidth(), MeasureSpec.EXACTLY),
+              MeasureSpec.makeMeasureSpec(getHeight(), MeasureSpec.EXACTLY));
+      layout(getLeft(), getTop(), getRight(), getBottom());
+    }
+  };
+
   public ScreenContainer(Context context) {
     super(context);
   }
 
   @Override
-  protected void onLayout(boolean b, int i, int i1, int i2, int i3) {
-    // no-op
+  protected void onLayout(boolean changed, int l, int t, int r, int b) {
+    for (int i = 0, size = getChildCount(); i < size; i++) {
+      getChildAt(i).layout(0, 0, getWidth(), getHeight());
+    }
+  }
+
+  @Override
+  public void requestLayout() {
+    super.requestLayout();
+
+    if (!mLayoutEnqueued) {
+      mLayoutEnqueued = true;
+      post(mLayoutRunnable);
+    }
   }
 
   protected void markUpdated() {
@@ -162,6 +186,14 @@ public class ScreenContainer<T extends ScreenFragment> extends ViewGroup {
     mIsAttached = false;
   }
 
+  @Override
+  protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
+    super.onMeasure(widthMeasureSpec, heightMeasureSpec);
+    for (int i = 0, size = getChildCount(); i < size; i++) {
+      getChildAt(i).measure(widthMeasureSpec, heightMeasureSpec);
+    }
+  }
+
   private void updateIfNeeded() {
     if (!mNeedUpdate || !mIsAttached) {
       return;

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

@@ -43,4 +43,9 @@ public class ScreenContainerViewManager extends ViewGroupManager<ScreenContainer
   public View getChildAt(ScreenContainer parent, int index) {
     return parent.getScreenAt(index);
   }
+
+  @Override
+  public boolean needsCustomLayoutForChildren() {
+    return true;
+  }
 }

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

@@ -17,7 +17,6 @@ public class ScreenStack extends ScreenContainer<ScreenStackFragment> {
   private final Set<ScreenStackFragment> mDismissed = new HashSet<>();
 
   private ScreenStackFragment mTopScreen = null;
-  private boolean mLayoutEnqueued = false;
 
   private final FragmentManager.OnBackStackChangedListener mBackStackListener = new FragmentManager.OnBackStackChangedListener() {
     @Override
@@ -59,48 +58,12 @@ public class ScreenStack extends ScreenContainer<ScreenStackFragment> {
     return new ScreenStackFragment(screen);
   }
 
-  @Override
-  protected void onLayout(boolean changed, int l, int t, int r, int b) {
-    for (int i = 0, size = getChildCount(); i < size; i++) {
-      getChildAt(i).layout(0, 0, getWidth(), getHeight());
-    }
-  }
-
-  @Override
-  protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
-    super.onMeasure(widthMeasureSpec, heightMeasureSpec);
-    for (int i = 0, size = getChildCount(); i < size; i++) {
-      getChildAt(i).measure(widthMeasureSpec, heightMeasureSpec);
-    }
-  }
-
   @Override
   protected void onDetachedFromWindow() {
     super.onDetachedFromWindow();
     getFragmentManager().removeOnBackStackChangedListener(mBackStackListener);
   }
 
-  private final Runnable mLayoutRunnable = new Runnable() {
-    @Override
-    public void run() {
-      mLayoutEnqueued = false;
-      measure(
-              MeasureSpec.makeMeasureSpec(getWidth(), MeasureSpec.EXACTLY),
-              MeasureSpec.makeMeasureSpec(getHeight(), MeasureSpec.EXACTLY));
-      layout(getLeft(), getTop(), getRight(), getBottom());
-    }
-  };
-
-  @Override
-  public void requestLayout() {
-    super.requestLayout();
-
-    if (!mLayoutEnqueued) {
-      mLayoutEnqueued = true;
-      post(mLayoutRunnable);
-    }
-  }
-
   @Override
   protected void removeScreenAt(int index) {
     Screen toBeRemoved = getScreenAt(index);