Fixed issue #321

app/build.gradle

@@ -66,3 +66,7 @@ dependencies {
     implementation 'com.squareup.picasso:picasso:2.5.2'
     implementation 'com.eftimoff:android-viewpager-transformers:1.0.1@aar'
 }
+
+preBuild.dependsOn('checkstyle')
+assemble.dependsOn('lint')
+check.dependsOn('checkstyle')

app/src/main/java/swati4star/createpdf/activity/MainActivity.java

@@ -3,6 +3,7 @@
 import android.content.Intent;
 import android.net.Uri;
 import android.os.Bundle;
+import android.os.Handler;
 import android.support.annotation.NonNull;
 import android.support.design.widget.NavigationView;
 import android.support.v4.app.Fragment;
@@ -14,6 +15,7 @@
 import android.support.v7.app.AppCompatActivity;
 import android.support.v7.widget.Toolbar;
 import android.view.MenuItem;
+import android.widget.Toast;
 
 import java.util.ArrayList;
 
@@ -45,6 +47,9 @@ public class MainActivity extends AppCompatActivity
     private FeedbackUtils mFeedbackUtils;
     private NavigationView mNavigationView;
 
+    private boolean mDoubleBackToExitPressedOnce = false;
+
+
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
@@ -170,8 +175,38 @@ public void onBackPressed() {
         if (drawer.isDrawerOpen(GravityCompat.START)) {
             drawer.closeDrawer(GravityCompat.START);
         } else {
+            if (getCurrentFragment() instanceof ImageToPdfFragment) {
+                checkDoubleBackPress();
+            } else {
+                Fragment fragment = new ImageToPdfFragment();
+                getSupportFragmentManager().beginTransaction().replace(R.id.content, fragment).commit();
+                setDefaultMenuSelected(0);
+            }
+        }
+    }
+
+    private void checkDoubleBackPress() {
+        if (mDoubleBackToExitPressedOnce) {
             super.onBackPressed();
+            return;
         }
+
+        this.mDoubleBackToExitPressedOnce = true;
+        Toast.makeText(this, R.string.confirm_exit_message, Toast.LENGTH_SHORT).show();
+
+        new Handler().postDelayed(new Runnable() {
+
+            @Override
+            public void run() {
+                mDoubleBackToExitPressedOnce = false;
+            }
+        }, 1500);
+    }
+
+    Fragment getCurrentFragment() {
+        Fragment currentFragment = getSupportFragmentManager()
+                .findFragmentById(R.id.content);
+        return currentFragment;
     }
 
     @Override

app/src/main/res/values-es/strings.xml

@@ -246,6 +246,8 @@
     <string name="image_rearranging_options">Image Rearranging Options</string>
     <string name="filter_file_name">%s_%s.jpg</string>
     <string name="reset">Reset</string>
+
+    <string name="confirm_exit_message">Presione de nuevo para salir</string>
     <string name="border">Add Image Border</string>
     <string name="enable_doodle_effect">Enable Doodle Effect</string>
     <string name="disable_doodle_effect">Disable Doodle Effect</string>

app/src/main/res/values-fr/strings.xml

@@ -247,6 +247,8 @@
     <string name="image_rearranging_options">Image Rearranging Options</string>
     <string name="filter_file_name">%s_%s.jpg</string>
     <string name="reset">Reset</string>
+
+    <string name="confirm_exit_message">Appuyez à nouveau pour quitter</string>
     <string name="border">Add Image Border</string>
     <string name="enable_doodle_effect">Enable Doodle Effect</string>
     <string name="disable_doodle_effect">Disable Doodle Effect</string>

app/src/main/res/values-ja/strings.xml

@@ -245,6 +245,8 @@
     <string name="image_rearranging_options">Image Rearranging Options</string>
     <string name="filter_file_name">%s_%s.jpg</string>
     <string name="reset">Reset</string>
+
+    <string name="confirm_exit_message">もう一度戻ると終了します。</string>
     <string name="border">Add Image Border</string>
     <string name="enable_doodle_effect">Enable Doodle Effect</string>
     <string name="disable_doodle_effect">Disable Doodle Effect</string>

app/src/main/res/values/strings.xml

@@ -304,6 +304,9 @@
     <string name="image_rearranging_options">Image Rearranging Options</string>
     <string name="filter_file_name">%s_%s.jpg</string>
     <string name="reset">Reset</string>
+
+    <string name="confirm_exit_message">Press back again to exit</string>
+
     <string name="border">Add Image Border</string>
     <string name="enable_doodle_effect">Enable Doodle Effect</string>
     <string name="disable_doodle_effect">Disable Doodle Effect</string>