DrawerLayout's item click - When is the right time to replace fragment?

Question

I\'m developing an application which uses the navigation drawer pattern (With DrawerLayout).

Each click on a drawer\'s item, replaces the fragment in the main contai

Answer 1

This is what I do to achieve an smooth transaction animation similar to Gmail app:

activity_drawer.xml

<android.support.v4.widget.DrawerLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/drawer_layout"
    android:layout_width="match_parent"
    android:layout_height="match_parent" >

    <!-- The main content view -->
    <FrameLayout
        android:id="@+id/content_frame"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

    <!-- The navigation drawer -->
    <ListView 
    android:id="@+id/left_drawer"
        android:layout_width="280dp"
        android:layout_height="match_parent"
        android:layout_gravity="left"
        android:choiceMode="singleChoice" />

</android.support.v4.widget.DrawerLayout>

DrawerActivity.java

private Fragment mContentFragment;
private Fragment mNextContentFragment;
private boolean mChangeContentFragment = false;

private Handler mHandler = new Handler();

...

@Override
public void onCreate(Bundle savedInstanceState) {
    ...

    mDrawerLayout.setDrawerListener(new DrawerListener());

    mDrawerList.setOnItemClickListener(new DrawerItemClickListener());

    ...
}

....

private class DrawerItemClickListener implements ListView.OnItemClickListener {

    @Override
    public void onItemClick(AdapterView parent, View view, int position, long id) {
        getSupportFragmentManager().beginTransaction().remove(mContentFragment).commit();

        switch (position) {
            case 0:
                mNextContentFragment = new Fragment1();
                break;

            case 1:
                mNextContentFragment = new Fragment2();
                break;

            case 2:
                mNextContentFragment = new Fragment3();
                break;
        }

        mChangeContentFragment = true;

        mDrawerList.setItemChecked(position, true);

        mHandler.postDelayed(new Runnable() {

            @Override
            public void run() {
                mDrawerLayout.closeDrawer(mDrawerList);
            }           
        }, 150);
    }
}

private class DrawerListener implements android.support.v4.widget.DrawerLayout.DrawerListener {

    @Override
    public void onDrawerClosed(View view) {
        if (mChangeContentFragment) {
             getSupportFragmentManager().beginTransaction().setTransition(FragmentTransaction.TRANSIT_FRAGMENT_OPEN).replace(R.id.content_frame, mNextContentFragment).commit();

             mContentFragment = mNextContentFragment;           
             mNextContentFragment = null;

             mChangeContentFragment = false;
         }
     }
 }

Hope that helps you! :-)