implement "scan" button

src/main/java/org/thoughtcrime/securesms/qr/QrActivity.java

@@ -12,10 +12,10 @@ import android.preference.PreferenceManager;
 import android.util.Log;
 import android.view.Menu;
 import android.view.MenuItem;
+import android.view.View;
 import android.widget.Toast;
 
 import androidx.annotation.NonNull;
-import androidx.core.view.MenuCompat;
 import androidx.fragment.app.Fragment;
 import androidx.fragment.app.FragmentManager;
 import androidx.fragment.app.FragmentStatePagerAdapter;
@@ -42,7 +42,7 @@ import org.thoughtcrime.securesms.util.ViewUtil;
 import java.io.FileNotFoundException;
 import java.io.InputStream;
 
-public class QrActivity extends BaseActionBarActivity {
+public class QrActivity extends BaseActionBarActivity implements View.OnClickListener {
 
     private final static String TAG = QrActivity.class.getSimpleName();
     private final static int REQUEST_CODE_IMAGE = 46243;
@@ -64,7 +64,7 @@ public class QrActivity extends BaseActionBarActivity {
         super.onCreate(savedInstanceState);
 
         setContentView(R.layout.activity_qr);
-        qrShowFragment = new QrShowFragment();
+        qrShowFragment = new QrShowFragment(this);
         tabLayout = ViewUtil.findById(this, R.id.tab_layout);
         viewPager = ViewUtil.findById(this, R.id.pager);
         ProfilePagerAdapter adapter = new ProfilePagerAdapter(this, getSupportFragmentManager());
@@ -216,6 +216,11 @@ public class QrActivity extends BaseActionBarActivity {
         }
     }
 
+    @Override
+    public void onClick(View v) {
+        viewPager.setCurrentItem(TAB_SCAN);
+    }
+
     private class ProfilePagerAdapter extends FragmentStatePagerAdapter {
 
         private final QrActivity activity;

src/main/java/org/thoughtcrime/securesms/qr/QrShowFragment.java

@@ -9,6 +9,7 @@ import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
 import android.view.WindowManager;
+import android.widget.Button;
 import android.widget.Toast;
 
 import androidx.annotation.NonNull;
@@ -46,6 +47,17 @@ public class QrShowFragment extends Fragment implements DcEventCenter.DcEventDel
 
     private DcContext dcContext;
 
+    private View.OnClickListener scanClicklistener;
+
+    public QrShowFragment() {
+        this(null);
+    }
+
+    public QrShowFragment(View.OnClickListener scanClicklistener) {
+        super();
+        this.scanClicklistener = scanClicklistener;
+    }
+
     @Override
     public void onCreate(Bundle bundle) {
         super.onCreate(bundle);
@@ -87,6 +99,13 @@ public class QrShowFragment extends Fragment implements DcEventCenter.DcEventDel
         }
 
         view.findViewById(R.id.share_link_button).setOnClickListener((v) -> shareInviteURL());
+        Button scanBtn = view.findViewById(R.id.scan_qr_button);
+        if (scanClicklistener != null) {
+            scanBtn.setVisibility(View.VISIBLE);
+            scanBtn.setOnClickListener(scanClicklistener);
+        } else {
+            scanBtn.setVisibility(View.GONE);
+        }
 
         return view;
     }