Issue mozilla-mobile#1664 - Add navigation overlay toolbar-push behavior

app/src/main/java/org/mozilla/tv/firefox/navigationoverlay/NavigationOverlayBehavior.kt

@@ -0,0 +1,58 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+package org.mozilla.tv.firefox.navigationoverlay
+
+import android.content.Context
+import android.support.design.widget.CoordinatorLayout
+import android.support.v4.widget.NestedScrollView
+import android.util.AttributeSet
+import android.view.View
+import android.widget.LinearLayout
+import org.mozilla.tv.firefox.R
+
+class NavigationOverlayBehavior(context: Context, attrs: AttributeSet) : CoordinatorLayout.Behavior<LinearLayout>(context, attrs) {
+    var toolbarHeight = 0
+
+    override fun onLayoutChild(parent: CoordinatorLayout, child: LinearLayout, layoutDirection: Int): Boolean {
+        toolbarHeight = child.measuredHeight
+        return super.onLayoutChild(parent, child, layoutDirection)
+    }
+
+    override fun onStartNestedScroll(
+        coordinatorLayout: CoordinatorLayout,
+        child: LinearLayout,
+        directTargetChild: View,
+        target: View,
+        axes: Int,
+        type: Int
+    ): Boolean {
+        return true
+    }
+
+    override fun onNestedScroll(
+        coordinatorLayout: CoordinatorLayout,
+        child: LinearLayout,
+        target: View,
+        dxConsumed: Int,
+        dyConsumed: Int,
+        dxUnconsumed: Int,
+        dyUnconsumed: Int,
+        type: Int
+    ) {
+        if (target is NestedScrollView) {
+            val overlayBottomContainer = (target.findViewById<LinearLayout>(R.id.overlayBottomHalf))
+            val containerPosArray = intArrayOf(0, 0)
+            overlayBottomContainer.getLocationOnScreen(containerPosArray)
+
+            val containerTop = containerPosArray[1]
+            if (containerTop < toolbarHeight) {
+                child.y = 1.0f * (containerTop - toolbarHeight)
+            } else {
+                child.y = 0f
+            }
+        }
+        super.onNestedScroll(coordinatorLayout, child, target, dxConsumed, dyConsumed, dxUnconsumed, dyUnconsumed, type)
+    }
+}

app/src/main/res/layout/fragment_navigation_overlay.xml

@@ -3,6 +3,7 @@
    - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
 <android.support.design.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:tools="http://schemas.android.com/tools"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
     android:id="@+id/overlayScrollView"
     android:layout_width="match_parent"
     android:layout_height="match_parent"
@@ -26,6 +27,7 @@
                 android:layout_height="412dp"/>
 
             <LinearLayout
+                android:id="@+id/overlayBottomHalf"
                 android:layout_width="match_parent"
                 android:layout_height="wrap_content"
                 android:orientation="vertical"
@@ -60,6 +62,7 @@
         android:layout_height="wrap_content"
         android:paddingTop="27dp"
         android:background="@color/browser_overlay_background"
+        app:layout_behavior="org.mozilla.tv.firefox.navigationoverlay.NavigationOverlayBehavior"
         android:orientation="vertical">
 
         <LinearLayout