Merge pull request #1 from mzorz/issue/3827-elevation-in-reader-filtered-recyclerview

fixed elevation to fulfill material design guidelines when both actionbar and toolbar are present

Author: mzorz

WordPress/src/main/java/org/wordpress/android/ui/main/WPMainActivity.java

@@ -1,9 +1,11 @@
 package org.wordpress.android.ui.main;
 
+import android.animation.ObjectAnimator;
 import android.app.Activity;
 import android.app.Fragment;
 import android.content.Intent;
 import android.os.AsyncTask;
+import android.os.Build;
 import android.os.Bundle;
 import android.os.Handler;
 import android.support.design.widget.TabLayout;
@@ -62,6 +64,7 @@ public class WPMainActivity extends Activity implements Bucket.Listener<Note> {
     private WPMainTabLayout mTabLayout;
     private WPMainTabAdapter mTabAdapter;
     private TextView mConnectionBar;
+    private int  mAppBarElevation;
 
     public static final String ARG_OPENED_FROM_PUSH = "opened_from_push";
 
@@ -126,17 +129,30 @@ public void onTabReselected(TabLayout.Tab tab) {
             }
         });
 
+        mAppBarElevation = getResources().getDimensionPixelSize(R.dimen.appbar_elevation);
+
         mViewPager.addOnPageChangeListener(new TabLayout.TabLayoutOnPageChangeListener(mTabLayout));
         mViewPager.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {
             @Override
             public void onPageSelected(int position) {
                 AppPrefs.setMainTabIndex(position);
 
                 switch (position) {
+                    case WPMainTabAdapter.TAB_MY_SITE:
+                        setTabLayoutElevation(mAppBarElevation);
+                        break;
+                    case WPMainTabAdapter.TAB_READER:
+                        setTabLayoutElevation(0);
+                    break;
+                    case WPMainTabAdapter.TAB_ME:
+                        setTabLayoutElevation(mAppBarElevation);
+                    break;
                     case WPMainTabAdapter.TAB_NOTIFS:
+                        setTabLayoutElevation(mAppBarElevation);
                         new UpdateLastSeenTask().executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR);
                         break;
                 }
+
                 trackLastVisibleTab(position, true);
             }
 
@@ -176,6 +192,19 @@ public void onPageScrolled(int position, float positionOffset, int positionOffse
         }
     }
 
+    private void setTabLayoutElevation(float newElevation){
+        if (mTabLayout == null) return;
+
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
+            float oldElevation = mTabLayout.getElevation();
+            if (oldElevation != newElevation) {
+                ObjectAnimator.ofFloat(mTabLayout, "elevation", oldElevation, newElevation)
+                        .setDuration(1000L)
+                        .start();
+            }
+        }
+    }
+
     @Override
     protected void onNewIntent(Intent intent) {
         super.onNewIntent(intent);

WordPress/src/main/res/values/dimens.xml

@@ -13,8 +13,8 @@
     <dimen name="fab_margin_tablet">24dp</dimen>
 
     <!-- http://www.google.com/design/spec/what-is-material/elevation-shadows.html#elevation-shadows-shadows -->
-    <dimen name="appbar_elevation">8dp</dimen>
-    <dimen name="filter_subbar_elevation">4dp</dimen>
+    <dimen name="appbar_elevation">4dp</dimen>
+    <dimen name="filter_subbar_elevation">@dimen/appbar_elevation</dimen>
 
     <dimen name="card_elevation">2dp</dimen>
     <dimen name="card_elevation_pressed">8dp</dimen>