move Undo button to the top

app/src/main/java/com/simplemobiletools/gallery/Utils.java

@@ -6,6 +6,7 @@ import android.content.pm.PackageManager;
 import android.content.res.Resources;
 import android.support.v4.content.ContextCompat;
 import android.support.v7.app.ActionBar;
+import android.util.TypedValue;
 import android.view.View;
 import android.view.Window;
 import android.widget.Toast;
@@ -19,12 +20,28 @@ public class Utils {
         Toast.makeText(context, context.getResources().getString(resId), Toast.LENGTH_SHORT).show();
     }
 
+    public static int getActionBarHeight(Context context, Resources res) {
+        final TypedValue tv = new TypedValue();
+        int height = 0;
+        if (context.getTheme().resolveAttribute(android.R.attr.actionBarSize, tv, true)) {
+            height = TypedValue.complexToDimensionPixelSize(tv.data, res.getDisplayMetrics());
+        }
+        return height;
+    }
+
+    public static int getStatusBarHeight(Resources res) {
+        int id = res.getIdentifier("status_bar_height", "dimen", "android");
+        if (id > 0) {
+            return res.getDimensionPixelSize(id);
+        }
+        return 0;
+    }
+
     public static int getNavBarHeight(Resources res) {
         int id = res.getIdentifier("navigation_bar_height", "dimen", "android");
         if (id > 0) {
             return res.getDimensionPixelSize(id);
         }
-
         return 0;
     }
 

app/src/main/java/com/simplemobiletools/gallery/activities/ViewPagerActivity.java

@@ -343,18 +343,15 @@ public class ViewPagerActivity extends AppCompatActivity
 
     private void addUndoMargin() {
         final Resources res = getResources();
-        final int height = Utils.getNavBarHeight(res);
         final RelativeLayout.LayoutParams params = (RelativeLayout.LayoutParams) undoBtn.getLayoutParams();
+        final int topMargin = Utils.getStatusBarHeight(res) + Utils.getActionBarHeight(getApplicationContext(), res);
         int rightMargin = params.rightMargin;
-        int bottomMargin = params.bottomMargin;
 
-        if (getResources().getConfiguration().orientation == Configuration.ORIENTATION_PORTRAIT) {
-            bottomMargin = height;
-        } else {
-            rightMargin = height;
+        if (getResources().getConfiguration().orientation != Configuration.ORIENTATION_PORTRAIT) {
+            rightMargin += Utils.getNavBarHeight(res);
         }
 
-        params.setMargins(params.leftMargin, params.topMargin, rightMargin, bottomMargin);
+        params.setMargins(params.leftMargin, topMargin, rightMargin, params.bottomMargin);
     }
 
     @Override

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

@@ -13,10 +13,10 @@
 
     <ImageView
         android:id="@+id/undo_delete"
-        android:layout_width="64dp"
-        android:layout_height="64dp"
-        android:layout_alignParentBottom="true"
+        android:layout_width="56dp"
+        android:layout_height="56dp"
         android:layout_alignParentRight="true"
+        android:layout_alignParentTop="true"
         android:padding="@dimen/undo_padding"
         android:src="@mipmap/undo"
         android:visibility="gone"/>