Android: Change top app bar color on scroll

Source/Android/app/src/main/java/org/dolphinemu/dolphinemu/activities/ConvertActivity.java

@@ -8,6 +8,7 @@ import android.os.Bundle;
 
 import androidx.appcompat.app.AppCompatActivity;
 
+import com.google.android.material.appbar.AppBarLayout;
 import com.google.android.material.appbar.CollapsingToolbarLayout;
 import com.google.android.material.appbar.MaterialToolbar;
 
@@ -50,6 +51,9 @@ public class ConvertActivity extends AppCompatActivity
     ctb.setTitle(getString(R.string.convert_convert));
     setSupportActionBar(tb);
     getSupportActionBar().setDisplayHomeAsUpEnabled(true);
+
+    AppBarLayout appBarLayout = findViewById(R.id.appbar_convert);
+    ThemeHelper.enableScrollTint(tb, appBarLayout, this);
   }
 
   @Override

Source/Android/app/src/main/java/org/dolphinemu/dolphinemu/activities/UserDataActivity.java

@@ -17,6 +17,8 @@ import androidx.annotation.Nullable;
 import androidx.appcompat.app.AppCompatActivity;
 import androidx.appcompat.widget.Toolbar;
 
+import com.google.android.material.appbar.AppBarLayout;
+import com.google.android.material.appbar.MaterialToolbar;
 import com.google.android.material.dialog.MaterialAlertDialogBuilder;
 
 import org.dolphinemu.dolphinemu.R;
@@ -85,9 +87,12 @@ public class UserDataActivity extends AppCompatActivity
 
     buttonExportUserData.setOnClickListener(view -> exportUserData());
 
-    Toolbar tb = findViewById(R.id.toolbar_user_data);
+    MaterialToolbar tb = findViewById(R.id.toolbar_user_data);
     setSupportActionBar(tb);
     getSupportActionBar().setDisplayHomeAsUpEnabled(true);
+
+    AppBarLayout appBarLayout = findViewById(R.id.appbar_user_data);
+    ThemeHelper.enableScrollTint(tb, appBarLayout, this);
   }
 
   @Override

Source/Android/app/src/main/java/org/dolphinemu/dolphinemu/features/riivolution/ui/RiivolutionBootActivity.java

@@ -12,6 +12,7 @@ import androidx.appcompat.app.AppCompatActivity;
 import androidx.recyclerview.widget.LinearLayoutManager;
 import androidx.recyclerview.widget.RecyclerView;
 
+import com.google.android.material.appbar.AppBarLayout;
 import com.google.android.material.appbar.CollapsingToolbarLayout;
 import com.google.android.material.appbar.MaterialToolbar;
 
@@ -86,6 +87,9 @@ public class RiivolutionBootActivity extends AppCompatActivity
     ctb.setTitle(getString(R.string.riivolution_riivolution));
     setSupportActionBar(tb);
     getSupportActionBar().setDisplayHomeAsUpEnabled(true);
+
+    AppBarLayout appBarLayout = findViewById(R.id.appbar_riivolution);
+    ThemeHelper.enableScrollTint(tb, appBarLayout, this);
   }
 
   @Override

Source/Android/app/src/main/java/org/dolphinemu/dolphinemu/features/settings/ui/SettingsActivity.java

@@ -14,11 +14,12 @@ import android.widget.Toast;
 import androidx.annotation.NonNull;
 import androidx.appcompat.app.AlertDialog;
 import androidx.appcompat.app.AppCompatActivity;
-import androidx.appcompat.widget.Toolbar;
 import androidx.fragment.app.FragmentTransaction;
 import androidx.lifecycle.ViewModelProvider;
 
+import com.google.android.material.appbar.AppBarLayout;
 import com.google.android.material.appbar.CollapsingToolbarLayout;
+import com.google.android.material.appbar.MaterialToolbar;
 import com.google.android.material.dialog.MaterialAlertDialogBuilder;
 
 import org.dolphinemu.dolphinemu.NativeLibrary;
@@ -88,10 +89,13 @@ public final class SettingsActivity extends AppCompatActivity implements Setting
     mPresenter = new SettingsActivityPresenter(this, getSettings());
     mPresenter.onCreate(savedInstanceState, menuTag, gameID, revision, isWii, this);
 
-    Toolbar tb = findViewById(R.id.toolbar_settings);
+    MaterialToolbar tb = findViewById(R.id.toolbar_settings);
     mToolbarLayout = findViewById(R.id.toolbar_settings_layout);
     setSupportActionBar(tb);
     getSupportActionBar().setDisplayHomeAsUpEnabled(true);
+
+    AppBarLayout appBarLayout = findViewById(R.id.appbar_settings);
+    ThemeHelper.enableScrollTint(tb, appBarLayout, this);
   }
 
   @Override

Source/Android/app/src/main/java/org/dolphinemu/dolphinemu/utils/ThemeHelper.java

@@ -6,6 +6,12 @@ import android.content.res.Configuration;
 import android.os.Build;
 import android.preference.PreferenceManager;
 
+import androidx.annotation.ColorInt;
+
+import com.google.android.material.appbar.AppBarLayout;
+import com.google.android.material.appbar.MaterialToolbar;
+import com.google.android.material.color.MaterialColors;
+
 import org.dolphinemu.dolphinemu.R;
 import org.dolphinemu.dolphinemu.ui.main.ThemeProvider;
 
@@ -104,4 +110,37 @@ public class ThemeHelper
       activity.recreate();
     }
   }
+
+  private static void setStatusBarColor(@ColorInt int color, Activity activity)
+  {
+    if (Build.VERSION.SDK_INT < Build.VERSION_CODES.M)
+    {
+      activity.getWindow()
+              .setStatusBarColor(activity.getResources().getColor(android.R.color.black));
+    }
+    else
+    {
+      activity.getWindow().setStatusBarColor(color);
+    }
+  }
+
+  public static void enableScrollTint(MaterialToolbar toolbar, AppBarLayout appBarLayout,
+          Activity activity)
+  {
+    appBarLayout.addOnOffsetChangedListener((layout, verticalOffset) ->
+    {
+      if (-verticalOffset >= (layout.getTotalScrollRange() / 2))
+      {
+        @ColorInt int color = MaterialColors.getColor(toolbar, R.attr.colorSurfaceVariant);
+        toolbar.setBackgroundColor(color);
+        setStatusBarColor(color, activity);
+      }
+      else
+      {
+        @ColorInt int color = MaterialColors.getColor(toolbar, R.attr.colorSurface);
+        toolbar.setBackgroundColor(color);
+        setStatusBarColor(color, activity);
+      }
+    });
+  }
 }

Source/Android/app/src/main/res/layout/activity_cheats.xml

@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
-<androidx.coordinatorlayout.widget.CoordinatorLayout
+<androidx.coordinatorlayout.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
-    xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
     android:id="@+id/coordinator_main"
     android:layout_width="match_parent"
     android:layout_height="match_parent">
@@ -9,7 +9,8 @@
         android:id="@+id/appbar_cheats"
         android:layout_width="match_parent"
         android:layout_height="wrap_content"
-        android:layout_alignParentTop="true">
+        android:layout_alignParentTop="true"
+        app:elevation="0dp">
 
         <com.google.android.material.appbar.MaterialToolbar
             android:id="@+id/toolbar_cheats"

Source/Android/app/src/main/res/layout/activity_main.xml

@@ -9,7 +9,8 @@
     <com.google.android.material.appbar.AppBarLayout
         android:id="@+id/appbar_main"
         android:layout_width="match_parent"
-        android:layout_height="wrap_content">
+        android:layout_height="wrap_content"
+        app:elevation="0dp">
 
         <com.google.android.material.appbar.MaterialToolbar
             android:id="@+id/toolbar_main"

Source/Android/app/src/main/res/layout/activity_settings.xml

@@ -10,7 +10,8 @@
         android:id="@+id/appbar_settings"
         android:layout_width="match_parent"
         android:layout_height="wrap_content"
-        android:layout_alignParentTop="true">
+        android:layout_alignParentTop="true"
+        app:elevation="0dp">
 
         <com.google.android.material.appbar.CollapsingToolbarLayout
             style="?attr/collapsingToolbarLayoutMediumStyle"