Im trying to implement a fragment based navigation pattern, which can be reduced to this:
<https://lh4.googleusercontent.com/-Ws0I4LcPFNA/Uf4irMURI3I/AAAAAAAAA0s/D1wYtJBCwXc/s1600/screen2.png> <https://lh4.googleusercontent.com/-4CuK_LmDSxA/Uf4iuRVg4cI/AAAAAAAAA00/ht6e2Pt1y48/s1600/sk.png> In words: There is: - Home fragment - Fragment A - Fragment B The fragments are shown in FrameLayout "content". The navigation bar is part of the activity. Workflow should be: Press back on home: Exit App. Press back on A or B: show Home. Most of it works as it should, but I have the problem that with a complex workflow like this: Start(home) - A - B - A - Back - B - Back I expect that it will show home, but instead it shows A. I think it's because the first transaction (home - A) it's in the backstack and it shows A. But I don't understand why then it works correctly in the simple cases? The code: public class MainActivity extends FragmentActivity { boolean isInHome; //a flag to control when we add fragment to the backstack or not @Overrideprotected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); //set home fragment programmatically first time FragmentTransaction transaction = getSupportFragmentManager().beginTransaction(); Fragment fragmentHome = new FragmentHome(); transaction.replace(R.id.content, fragmentHome); transaction.commit(); isInHome = true; //initialize layout Button home = (Button) findViewById(R.id.home); Button a = (Button) findViewById(R.id.a); Button b = (Button) findViewById(R.id.b); home.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { //clear complete backstack (in this case, just pop home transaction) getSupportFragmentManager().popBackStackImmediate(null, FragmentManager.POP_BACK_STACK_INCLUSIVE); //show home fragment FragmentTransaction transaction = getSupportFragmentManager().beginTransaction(); Fragment fragmentHome = new FragmentHome(); transaction.replace(R.id.content, fragmentHome); transaction.commit(); isInHome = true; } }); a.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { FragmentTransaction transaction = getSupportFragmentManager().beginTransaction(); Fragment fragmentA = new FragmentA(); transaction.replace(R.id.content, fragmentA); if (isInHome) { //add the home transaction to the backstack, such that press back on this fragment shows home again transaction.addToBackStack("home"); } transaction.commit(); isInHome = false; } }); b.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { FragmentTransaction transaction = getSupportFragmentManager().beginTransaction(); Fragment fragmentB = new FragmentB(); transaction.replace(R.id.content, fragmentB); if (isInHome) { //add the home transaction to the backstack, such that press back on this fragment shows home again transaction.addToBackStack("home"); } transaction.commit(); isInHome = false; } });} @Overridepublic void onBackPressed() { super.onBackPressed(); isInHome = true; //quick solution to update status - when press back on A or B, we are in home (and press back in home exits the app, so this doesn't matter)} } What's wrong here? Thanks in advance. -- -- You received this message because you are subscribed to the Google Groups "Android Developers" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/android-developers?hl=en --- You received this message because you are subscribed to the Google Groups "Android Developers" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/groups/opt_out.
