[ADDED] Back button on the actionbar.

Author: hossain-khan

app/src/main/AndroidManifest.xml

@@ -17,8 +17,12 @@
                 <category android:name="android.intent.category.LAUNCHER" />
             </intent-filter>
         </activity>
-        <activity android:name=".layoutpreview.LayoutPreviewBaseActivity" />
-        <activity android:name=".layoutpreview.LayoutVisibilityGoneActivity"></activity>
+        <activity
+            android:name=".layoutpreview.LayoutPreviewBaseActivity"
+            android:parentActivityName=".browse.MainActivity" />
+        <activity
+            android:name=".layoutpreview.LayoutVisibilityGoneActivity"
+            android:parentActivityName=".browse.MainActivity" />
     </application>
 
 </manifest>

app/src/main/java/com/hossainkhan/android/demo/layoutpreview/LayoutPreviewBaseActivity.kt

@@ -22,6 +22,7 @@ import android.net.Uri
 import android.os.Bundle
 import android.support.annotation.LayoutRes
 import android.support.customtabs.CustomTabsIntent
+import android.support.v4.app.NavUtils
 import android.support.v7.app.AppCompatActivity
 import android.view.Menu
 import android.view.MenuItem
@@ -77,6 +78,7 @@ open class LayoutPreviewBaseActivity : AppCompatActivity() {
         setContentView(layoutResourceId)
 
         supportActionBar?.title = layoutInformation.title
+        supportActionBar?.setDisplayHomeAsUpEnabled(true)
 
         showLayoutInfo(layoutInformation)
     }
@@ -149,6 +151,12 @@ open class LayoutPreviewBaseActivity : AppCompatActivity() {
                 showLayoutInfo(layoutInformation, true)
                 true
             }
+            android.R.id.home -> {
+                // Respond to the action bar's Up/Home button
+                // https://developer.android.com/training/implementing-navigation/ancestral
+                NavUtils.navigateUpFromSameTask(this)
+                return true
+            }
             else -> super.onOptionsItemSelected(item)
         }
     }