Collapsing react view header with top tabs

Add expendOnTopTabChange style property which defaults to true. Setting it to false

android/app/src/main/java/com/reactnativenavigation/params/CollapsingTopBarParams.java

     public int reactViewHeight;
     public StyleParams.Color scrimColor;
     public CollapseBehaviour collapseBehaviour;
+    public boolean expendOnTopTabChange;
 
     public boolean hasBackgroundImage() {
         return imageUri != null;

android/app/src/main/java/com/reactnativenavigation/params/parsers/CollapsingTopBarParamsParser.java

         result.imageUri = params.getString("collapsingToolBarImage", null);
         result.reactViewId = params.getString("collapsingToolBarComponent", null);
         result.reactViewHeight = params.getInt("collapsingToolBarComponentHeight");
+        result.expendOnTopTabChange = params.getBoolean("expendCollapsingToolBarOnTopTabChange");
         result.scrimColor = getColor(params, "collapsingToolBarCollapsedColor", new StyleParams.Color(Color.WHITE));
         result.collapseBehaviour = getCollapseBehaviour();
         return result;

android/app/src/main/java/com/reactnativenavigation/screens/CollapsingViewPagerScreen.java

     protected ViewPager createViewPager(Context context) {
         CollapsingViewPager viewPager = new CollapsingViewPager(context);
         if (screenParams.styleParams.drawScreenBelowTopBar) {
-            viewPager.setViewMeasurer(new CollapsingViewMeasurer((CollapsingTopBar) topBar, this));
+            viewPager.setViewMeasurer(new CollapsingViewMeasurer((CollapsingTopBar) topBar, this, styleParams));
         }
         return viewPager;
     }
     public void onEvent(Event event) {
         super.onEvent(event);
         if (ViewPagerScreenScrollStartEvent.TYPE.equals(event.getType()) || ViewPagerScreenChangedEvent.TYPE.equals(event.getType())) {
-            ((CollapsingView) topBar).collapse(new CollapseAmount(CollapseCalculator.Direction.Down));
-            ((CollapsingView) viewPager).collapse(new CollapseAmount(CollapseCalculator.Direction.Down));
+            if (screenParams.styleParams.collapsingTopBarParams.expendOnTopTabChange) {
+                ((CollapsingView) topBar).collapse(new CollapseAmount(CollapseCalculator.Direction.Down));
+                ((CollapsingView) viewPager).collapse(new CollapseAmount(CollapseCalculator.Direction.Down));
+            }
         }
     }
 

android/app/src/main/java/com/reactnativenavigation/views/collapsingToolbar/CollapseAmount.java

         return amount != null || this != None;
     }
 
+    boolean hasExactAmount() {
+        return amount != null;
+    }
+
     public boolean collapseToTop() {
         return direction == CollapseCalculator.Direction.Up;
     }

android/app/src/main/java/com/reactnativenavigation/views/collapsingToolbar/CollapsingTitleBar.java

         }
     }
 
-    public void collapse(float collapse) {
+    public void collapse(CollapseAmount amount) {
+        if (amount.hasExactAmount()) {
+            collapse(amount.get());
+        }
+    }
+
+    private void collapse(float collapse) {
         if (params.hasBackgroundImage()) {
             title.setTranslationY(0);
             title.collapseBy(collapse);

android/app/src/main/java/com/reactnativenavigation/views/collapsingToolbar/CollapsingTopBar.java

     public void collapse(CollapseAmount amount) {
         viewCollapser.collapse(amount);
         if (titleBar instanceof CollapsingTitleBar) {
-            ((CollapsingTitleBar) titleBar).collapse(amount.get());
+            ((CollapsingTitleBar) titleBar).collapse(amount);
         }
         if (collapsingTopBarBackground != null) {
             collapsingTopBarBackground.collapse(amount.get());
     }
 
     public int getCollapsedHeight() {
-        if (params.hasBackgroundImage()) {
+        if (topTabs != null) {
+            return topTabs.getHeight();
+        } else if (params.hasBackgroundImage()) {
             return topBarHeight;
         } else if (params.hasReactView()) {
             return topBarHeight;
-        } else if (topTabs != null) {
-            return topTabs.getHeight();
         } else {
             return titleBar.getHeight();
         }

android/app/src/main/java/com/reactnativenavigation/views/collapsingToolbar/CollapsingViewMeasurer.java

 import com.reactnativenavigation.views.utils.ViewMeasurer;
 
 public class CollapsingViewMeasurer extends ViewMeasurer {
-
     int collapsedTopBarHeight;
     private float finalCollapseValue;
     int screenHeight;
     int bottomTabsHeight = 0;
-    boolean bottomTabsHidden;
+    protected StyleParams styleParams;
 
-    public CollapsingViewMeasurer(CollapsingTopBar topBar, Screen screen, StyleParams styleParams) {
-        this(topBar, screen);
-        bottomTabsHidden = styleParams.bottomTabsHidden;
+    public CollapsingViewMeasurer(final CollapsingTopBar topBar, final Screen collapsingSingleScreen, StyleParams styleParams) {
+        this.styleParams = styleParams;
         bottomTabsHeight = (int) ViewUtils.convertDpToPixel(56);
-    }
-
-    public CollapsingViewMeasurer(final CollapsingTopBar topBar, final Screen collapsingSingleScreen) {
         ViewUtils.runOnPreDraw(topBar, new Runnable() {
             @Override
             public void run() {
 
     @Override
     public int getMeasuredHeight(int heightMeasureSpec) {
-        return screenHeight - collapsedTopBarHeight + (bottomTabsHidden ? bottomTabsHeight : 0);
+        int height = screenHeight - collapsedTopBarHeight;
+        if (styleParams.bottomTabsHidden) {
+            height += bottomTabsHeight;
+        }
+        return height;
     }
 }

android/app/src/main/java/com/reactnativenavigation/views/collapsingToolbar/CollapsingViewPagerContentViewMeasurer.java

 
     @Override
     public int getMeasuredHeight(int heightMeasureSpec) {
-        return screenHeight - collapsedTopBarHeight - (bottomTabsHidden ? 0 : bottomTabsHeight);
+        int height = screenHeight - collapsedTopBarHeight;
+//        if (styleParams.bottomTabsHidden) {
+            height -= bottomTabsHeight;
+//        }
+        return height;
     }
 }

src/deprecated/platformSpecificDeprecated.android.js

     collapsingToolBarComponent: originalStyleObject.collapsingToolBarComponent,
     collapsingToolBarComponentHeight: originalStyleObject.collapsingToolBarComponentHeight,
     collapsingToolBarCollapsedColor: processColor(originalStyleObject.collapsingToolBarCollapsedColor),
+    expendCollapsingToolBarOnTopTabChange: originalStyleObject.expendCollapsingToolBarOnTopTabChange,
     titleBarHidden: originalStyleObject.navBarHidden,
     titleBarHideOnScroll: originalStyleObject.navBarHideOnScroll,
     titleBarTitleColor: processColor(originalStyleObject.navBarTextColor),
       ret.collapsingToolBarImage = collapsingToolBarImage.uri;
     }
   }
+  if (_.isUndefined(ret.expendCollapsingToolBarOnTopTabChange)) {
+    ret.expendCollapsingToolBarOnTopTabChange = true;
+  }
   return ret;
 }