#Description:  DrawerLayoutEdgeToggle is library that adds visible handle to the DrawerLayout. It allows you to slide the handle to open/close the DrawerLayout, or use click event to open/close the DrawerLayout. It is independent of the ActionBar home indicator as it is seen in ActionBarDrawerToggle.  #Usage: 1. Import the library project and set it to your project.  <pre><code>boolean keepShadowOnHandle = true; mDrawerToggle = new DrawerLayoutEdgeToggle(this, mDrawerLayout, R.drawable.drawer_open, R.drawable.drawer_close,Gravity.LEFT, keepShadowOnHandle){                  @Override                 public void onDrawerClosed(View arg0) {                     super.onDrawerClosed(arg0); //must call super                 }                  @Override                 public void onDrawerOpened(View arg0) {                     super.onDrawerOpened(arg0); //must call super                 }                  @Override                 public void onDrawerSlide(View arg0, float slideOffset) {                     super.onDrawerSlide(arg0, slideOffset); //must call super                  }};     mDrawerLayout.setDrawerListener(mDrawerToggle);. </code></pre>