Increase drag margin for drawer.

Increase the margin that allows to open the drawer to prevent
accidentally starting a star swipe when trying to open the drawer.

See:
http://stackoverflow.com/questions/16988597/set-drag-margin-for-android-navigation-drawer/17802569#17802569

Author: schaal

News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/NewsReaderListActivity.java

@@ -43,6 +43,7 @@
 import android.support.design.widget.Snackbar;
 import android.support.v4.app.DialogFragment;
 import android.support.v4.view.GravityCompat;
+import android.support.v4.widget.ViewDragHelper;
 import android.support.v7.app.ActionBarDrawerToggle;
 import android.support.v4.app.FragmentActivity;
 import android.support.v4.app.FragmentManager;
@@ -56,6 +57,8 @@
 import android.widget.Toast;
 import android.widget.TextView;
 
+import java.lang.reflect.Field;
+
 import butterknife.ButterKnife;
 import butterknife.InjectView;
 import butterknife.Optional;
@@ -172,6 +175,25 @@ public void onDrawerOpened(View drawerView) {
 			};
 
 			drawerLayout.setDrawerListener(drawerToggle);
+
+            try {
+                // increase the size of the drag margin to prevent starting a star swipe when
+                // trying to open the drawer.
+                Field mDragger = drawerLayout.getClass().getDeclaredField(
+                        "mLeftDragger");
+                mDragger.setAccessible(true);
+                ViewDragHelper draggerObj = (ViewDragHelper) mDragger
+                        .get(drawerLayout);
+
+                Field mEdgeSize = draggerObj.getClass().getDeclaredField(
+                        "mEdgeSize");
+                mEdgeSize.setAccessible(true);
+                int edge = mEdgeSize.getInt(draggerObj);
+
+                mEdgeSize.setInt(draggerObj, edge * 3);
+            } catch (Exception e) {
+                e.printStackTrace();
+            }
 		}
 		setSupportActionBar(toolbar);
 		getSupportActionBar().setDisplayShowHomeEnabled(true);