Setup ScrollView with BottomNavigation in RctView

android/app/src/main/java/com/reactnativenavigation/activities/BottomTabActivity.java

@@ -5,11 +5,7 @@ import android.graphics.drawable.Drawable;
 import android.os.AsyncTask;
 import android.os.Bundle;
 import android.support.design.widget.CoordinatorLayout;
-import android.util.Log;
 import android.view.View;
-import android.view.ViewGroup;
-import android.view.ViewTreeObserver;
-import android.widget.ScrollView;
 
 import com.aurelhubert.ahbottomnavigation.AHBottomNavigation;
 import com.aurelhubert.ahbottomnavigation.AHBottomNavigationItem;
@@ -20,7 +16,6 @@ import com.reactnativenavigation.core.objects.Drawer;
 import com.reactnativenavigation.core.objects.Screen;
 import com.reactnativenavigation.utils.StyleHelper;
 import com.reactnativenavigation.views.BottomNavigation;
-import com.reactnativenavigation.views.RctView;
 import com.reactnativenavigation.views.RnnToolBar;
 import com.reactnativenavigation.views.ScreenStack;
 
@@ -48,33 +43,6 @@ public class BottomTabActivity extends BaseReactActivity implements AHBottomNavi
     private ArrayList<ScreenStack> mScreenStacks;
     private int mCurrentStackPosition = -1;
 
-    private ScrollView mScrollView;
-    private ViewTreeObserver.OnScrollChangedListener mScrollChangedListener;
-    private final View.OnAttachStateChangeListener mScrollViewStateChangeListener =
-            new View.OnAttachStateChangeListener() {
-                @Override
-                public void onViewAttachedToWindow(View v) {
-
-                }
-
-                @Override
-                public void onViewDetachedFromWindow(View detachedScrollView) {
-                    detachedScrollView.getViewTreeObserver().removeOnScrollChangedListener(mScrollChangedListener);
-                    detachedScrollView.removeOnAttachStateChangeListener(this);
-
-                    mContentFrame.post(new Runnable() {
-                        @Override
-                        public void run() {
-                            mScrollView = getScrollView(mContentFrame);
-                            if (mScrollView != null) {
-                                mScrollView.addOnAttachStateChangeListener(mScrollViewStateChangeListener);
-                                addScrollListener(mScrollView);
-                            }
-                        }
-                    });
-                }
-            };
-
     @Override
     protected void handleOnCreate() {
         super.handleOnCreate();
@@ -99,18 +67,6 @@ public class BottomTabActivity extends BaseReactActivity implements AHBottomNavi
                 setupToolbar(screens);
             }
         });
-
-        mContentFrame.setOnHierarchyChangeListener(new ViewGroup.OnHierarchyChangeListener() {
-            @Override
-            public void onChildViewAdded(View parent, View child) {
-                Log.i(TAG, "onChildViewAdded: " + child.getClass());
-            }
-
-            @Override
-            public void onChildViewRemoved(View parent, View child) {
-                Log.d(TAG, "onChildViewRemoved: " + child.getClass());
-            }
-        });
     }
 
     private void setupPages(ArrayList<Screen> screens) {
@@ -124,48 +80,6 @@ public class BottomTabActivity extends BaseReactActivity implements AHBottomNavi
         StyleHelper.updateStyles(mToolbar, initialScreen);
     }
 
-    private void setupBottomTabs(Screen initialScreen) {
-        if (initialScreen.bottomTabsHiddenOnScroll) {
-            mScrollView = getScrollView(mContentFrame);
-            if (mScrollView != null) {
-                attachStateChangeListener(mScrollView);
-                addScrollListener(mScrollView);
-            }
-        }
-    }
-
-    private void attachStateChangeListener(ScrollView scrollView) {
-        scrollView.addOnAttachStateChangeListener(mScrollViewStateChangeListener);
-    }
-
-    private void addScrollListener(final ScrollView scrollView) {
-        mScrollChangedListener = new ViewTreeObserver.OnScrollChangedListener() {
-            @Override
-            public void onScrollChanged() {
-                if (scrollView.getViewTreeObserver().isAlive()) {
-                    Log.i(TAG, "onScrollChanged: " + scrollView.getScrollY());
-                }
-            }
-        };
-        scrollView.getViewTreeObserver().addOnScrollChangedListener(mScrollChangedListener);
-    }
-
-    private ScrollView getScrollView(ViewGroup parent) {
-        for (int i = 0; i < parent.getChildCount(); i++) {
-            View child = parent.getChildAt(i);
-
-            if (child instanceof ScrollView) {
-                return (ScrollView) child;
-            }
-
-            if (child instanceof ViewGroup) {
-                return getScrollView((ViewGroup) child);
-            }
-        }
-
-        return null;
-    }
-
     @Override
     protected void onResume() {
         super.onResume();
@@ -385,18 +299,7 @@ public class BottomTabActivity extends BaseReactActivity implements AHBottomNavi
         for (int i = 0; i < screens.size(); i++) {
             final Screen screen = screens.get(i);
             ScreenStack stack = new ScreenStack(this);
-
-            if (i == 0) {
-                stack.push(screen, new RctView.OnDisplayedListener() {
-                    @Override
-                    public void onDisplayed() {
-                        setupBottomTabs(screen);
-                    }
-                });
-            } else {
-                stack.push(screen);
-            }
-
+            stack.push(screen);
             mScreenStacks.add(stack);
             AHBottomNavigationItem item = new AHBottomNavigationItem(screen.label, icons.get(screen), Color.GRAY);
             mBottomNavigation.addItem(item);

android/app/src/main/java/com/reactnativenavigation/views/RctView.java

@@ -1,7 +1,12 @@
 package com.reactnativenavigation.views;
 
 import android.os.Bundle;
+import android.util.Log;
+import android.view.View;
+import android.view.ViewGroup;
+import android.view.ViewTreeObserver;
 import android.widget.FrameLayout;
+import android.widget.ScrollView;
 
 import com.facebook.react.ReactInstanceManager;
 import com.facebook.react.ReactRootView;
@@ -14,8 +19,55 @@ import com.reactnativenavigation.utils.ReflectionUtils;
  * Created by guyc on 10/03/16.
  */
 public class RctView extends FrameLayout {
-
+    private static final String TAG = "RctView";
     private ReactRootView mReactRootView;
+    private ScrollView mScrollView;
+    private final ViewTreeObserver.OnScrollChangedListener mScrollChangedListener = new ViewTreeObserver.OnScrollChangedListener() {
+        @Override
+        public void onScrollChanged() {
+            if (mScrollView.getViewTreeObserver().isAlive()) {
+                Log.i(TAG, "onScrollChanged: " + mScrollView.getScrollY());
+            }
+        }
+    };
+    private boolean mIsScrollEventListenerRegistered = false;
+
+
+    private final View.OnAttachStateChangeListener mStateChangeListener =
+            new View.OnAttachStateChangeListener() {
+                @Override
+                public void onViewAttachedToWindow(View v) {
+                    Log.d(TAG, "onViewAttachedToWindow " + v.getClass());
+                    mScrollView = getScrollView((ViewGroup) getParent());
+
+                    if (mScrollView != null && !mIsScrollEventListenerRegistered) {
+                        Log.i(TAG, "setting scroll listener");
+                        addScrollListener();
+                    } else {
+                        Log.v(TAG, "doing nothing");
+                    }
+                }
+
+                @Override
+                public void onViewDetachedFromWindow(final View detachedView) {
+                    Log.d(TAG, "onViewDetachedFromWindow. Removing scrollChangedListener");
+                    removeScrollListener();
+
+                    post(new Runnable() {
+                        @Override
+                        public void run() {
+                            mScrollView = getScrollView((ViewGroup) getParent());
+                            if (mScrollView != null && !mIsScrollEventListenerRegistered) {
+                                Log.i(TAG, "run: setting scroll listener");
+                                mIsScrollEventListenerRegistered = true;
+                                addScrollListener();
+                            } else {
+                                Log.v(TAG, "doing nothing");
+                            }
+                        }
+                    });
+                }
+            };
 
     /**
      * Interface used to run some code when the {@link ReactRootView} is visible.
@@ -28,12 +80,26 @@ public class RctView extends FrameLayout {
     }
 
     @SuppressWarnings("unchecked")
-    public RctView(BaseReactActivity ctx, ReactInstanceManager rctInstanceManager, Screen screen,
+    public RctView(BaseReactActivity ctx, ReactInstanceManager rctInstanceManager, final Screen screen,
                    final OnDisplayedListener onDisplayedListener) {
         super(ctx);
         setLayoutParams(new FrameLayout.LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT));
 
-        mReactRootView = new RnnReactRootView(ctx, onDisplayedListener);
+        OnDisplayedListener onDisplayedListenerInternal = onDisplayedListener;
+        if (screen.bottomTabsHiddenOnScroll) {
+            onDisplayedListenerInternal = new OnDisplayedListener() {
+                @Override
+                public void onDisplayed() {
+                    if (onDisplayedListener != null) {
+                        onDisplayedListener.onDisplayed();
+                    }
+
+                    setupScrollViewWithBottomTabs();
+                }
+            };
+        }
+
+        mReactRootView = new RnnReactRootView(ctx, onDisplayedListenerInternal);
         mReactRootView.setLayoutParams(new FrameLayout.LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT));
 
         String componentName = screen.screenId;
@@ -50,12 +116,49 @@ public class RctView extends FrameLayout {
         addView(mReactRootView);
     }
 
+    private void setupScrollViewWithBottomTabs() {
+        mScrollView = getScrollView((ViewGroup) getParent());
+        if (mScrollView != null) {
+            attachStateChangeListener(mScrollView);
+            addScrollListener();
+        }
+    }
+
+    private ScrollView getScrollView(ViewGroup parent) {
+        for (int i = 0; i < parent.getChildCount(); i++) {
+            View child = parent.getChildAt(i);
+
+            if (child instanceof ScrollView) {
+                return (ScrollView) child;
+            }
+
+            if (child instanceof ViewGroup) {
+                return getScrollView((ViewGroup) child);
+            }
+        }
+
+        return null;
+    }
+
+    private void attachStateChangeListener(ScrollView scrollView) {
+        scrollView.addOnAttachStateChangeListener(mStateChangeListener);
+    }
+
+    private void addScrollListener() {
+        mScrollView.getViewTreeObserver().addOnScrollChangedListener(mScrollChangedListener);
+    }
+
+    private void removeScrollListener() {
+        mScrollView.getViewTreeObserver().removeOnScrollChangedListener(mScrollChangedListener);
+    }
+
     /**
      * Must be called before view is removed from screen, but will be added again later. Setting mAttachScheduled
      * to true will prevent the component from getting unmounted once view is detached from screen.
      */
     public void onTemporallyRemovedFromScreen() {
         // Hack in order to prevent the react view from getting unmounted
+
         ReflectionUtils.setField(mReactRootView, "mAttachScheduled", true);
     }