I already owe a lot of credit to a user of SO for getting me this far, but after 6+ hours of developer page reading I still cannot get this to work on an Android emulator.
I am simply trying to swap one fragment for another. What happens when the button is clicked is the initial frag animates quickly, but stays put. It only animates once and subsequent button presses do not produce subsequent animations. I don't know if that's because for some reason the onCreate code is somehow running again quickly replacing the initial frag over the "click frag" or if the issue is in the replaceFrag method itself or if something is executing incorrectly. If anyone sees the issue and could point to where it is (without a full detailed explanation), I'd be very appreciative. When I get it to work I will award that person the green check and post the solution as well.
Here is the Main_Activity:
public class MainActivity extends FragmentActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
if (findViewById(R.id.fragment_container) != null) {
if (savedInstanceState != null) {
return;
}
}
// Add the fragment to'fragment_container'
FragmentManager fm = getSupportFragmentManager();
FragmentTransaction ft = fm.beginTransaction();
Menu_Fragment fragment = new Menu_Fragment();
fragment.setArguments(getIntent().getExtras());
ft.add(R.id.fragment_container, fragment, "INITIAL_FRAG");
ft.commit();
}
public void replaceFrag(View v) {
Fragment fragment = new Click_Fragment(); //Creates a new Click_Fragment when button selected
Fragment savedFragment = null; // creates an instance of savedFragment
if (fragment != null) { //check to see if fragment was instantiated, always true
savedFragment = getSupportFragmentManager().findFragmentByTag("FB");
FragmentTransaction ft = getSupportFragmentManager().beginTransaction();
if (savedFragment != null) {//searches to see if the Click_Fragment has already been created once
ft.replace(R.id.fragment_container, savedFragment, "FB");
} else {
ft.replace(R.id.fragment_container, fragment, "FB");
}
ft.addToBackStack(null);
ft.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_OPEN);
ft.commit();
}
}
}
The button, which has its XML housed in the menu_fragment layout, has the attribute:
android:onClick="replaceFrag"
EDIT: This error appears in the SDK log when button is pressed:
mycompany.fragment_test W/OpenGLRenderer: Failed to set EGL_SWAP_BEHAVIOR on surface 0xab70a680, error=EGL_SUCCESS
Can you explain why you have both of these lines in replaceFrag():
ft.addToBackStack(null);
ft.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_OPEN);
I recommend stepping through by either debugging or using log statements to see what's happening. You might even print off the backstack at the of replaceFrag(). Additionally, I would not set replaceFrag() in XML.
Related
I have this Activity in which I replace the main fragment with a preference fragment. When I click back after looking at the preferences, I get a blank (white) area where my fragment should be. If I rotate the screen then it works just fine. Everything in my fragment appears to be ok except for it is blank. Here are my methods:
The onCreate method of the activity.
#Override
protected void onCreate(Bundle savedInstanceState) {
.....
if (savedInstanceState == null) {
getFragmentManager().beginTransaction()
.add(MAIN_CONTAINER, new MainFragment())
.commit();
}
}
The starting of the preferences fragment:
public void startPreferencesFragment() {
FragmentManager mFragmentManager = getFragmentManager();
FragmentTransaction mFragmentTransaction = mFragmentManager
.beginTransaction();
MyPreferencesFragment mPrefsFragment = new MyPreferencesFragment();
mFragmentTransaction.addToBackStack(null)
.replace(MAIN_CONTAINER, mPrefsFragment)
.commit();
}
The onBackPressed of my activity:
#Override
public void onBackPressed() {
FragmentManager fm = getFragmentManager();
if (fm.getBackStackEntryCount() > 0) {
fm.popBackStack();
return;
}else {
super.onBackPressed();
}
}
So what am I doing wrong?
Thanks.
EDIT: If I open preferences and then rotate and then press back, it all works fine.
Also I should mention that removing the onBackPressed method does not fix the issue, it just exits the app.
EDIT: Turned out to not be a problem with the fragment back stack at all. Basically my fragment has a recyclerview and that is all it has. The instance of the adapter I was setting on the recyclerview was being kept while the recyclerview itself was new when the fragment was brought back from the back stack and I was checking whether the adapter was null when setting it.
You are already adding the transaction to the backstack, there is not need to override onBackPressed(); the framework will pop the Fragment out of the stack automatically when the back button is pressed. I am pretty sure that you are "double" popping the backstack.
After struggling to make my simple fragment program work, I have not found any solution to the following: I manage two Fragments in my main activity: FragmentNeedle and FragmentPlot. Only one should appear at a time. The user has two bottons where he can select which fragment he wants to display. Also, when the FragmentPlot is showing, the user should be able to navigate back to the FragmentNeedle by pressing the back key. This is my Code:
public void onButtonPlotPressed()
{
FragmentManager manager = getSupportFragmentManager();
mPlotFragment = (PlotFragment) manager.findFragmentByTag(PlotFragment.class.getSimpleName());
if(mPlotFragment == null)
{
mPlotFragment = new PlotFragment();
FragmentTransaction ft = manager.beginTransaction();
ft.replace(R.id.main_layout_center, mPlotFragment, PlotFragment.class.getSimpleName());
ft.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_OPEN);
ft.addToBackStack(null);
ft.commit();
manager.executePendingTransactions();
}
public void OnButtonNeedlePressed()
{
FragmentManager manager = getSupportFragmentManager();
mFragmentNeedle = (FragmentNeedle) manager.findFragmentByTag(FragmentNeedle.class.getSimpleName());
FragmentTransaction ft = manager.beginTransaction();
if(mFragmentNeedle == null)
{
mFragmentNeedle= new FragmentNeedle();
ft.replace(R.id.main_layout_center, mFragmentNeedle, FragmentNeedle.class.getSimpleName());
ft.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_OPEN);
ft.commit();
manager.executePendingTransactions();
}
}
When the PlotFragment is shown, and I press back, I return to the NeedleFragment. But now when I try to change to Plot Fragment by pressing the UI button, it will keep showing the PlotFragment. If I remove the line ft.addToBackStack(), the switching between fragments works fine by pressing the buttons on the UI, but then I cannot go back with the back key. What am I doing something wrong?
you never add your FragmentNeedle to the backstack.
public void OnButtonNeedlePressed() {
mFragmentNeedle = (FragmentNeedle)manager.findFragmentByTag(FragmentNeedle.class.getSimpleName());
if(mFragmentNeedle == null) {
FragmentManager manager = getSupportFragmentManager();
mFragmentNeedle= new FragmentNeedle();
ft.replace(R.id.main_layout_center, mFragmentNeedle, FragmentNeedle.class.getSimpleName());
ft.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_OPEN);
//missing line
ft.addToBackStack(FragmentNeedle.class.getSimpleName());
ft.commit();
manager.executePendingTransactions();
}
}
I am having trouble figuring out the proper way to navigate through fragments without a pager and i am having problems during Configuration changes for screen orientation. I am using Show/Hide on the fragments to make them visible and functional but i am wondering if i should instead be using Detach/Attach. I am also having problems adding things to the back stack and i think it is also due to the use of show/hide. Is it better to use Attach/detatch or is there a way to override what the back button does to make it show/hide the last/current fragment.
The Behavior:
I have a map fragment and a List fragment along with a few others. everything starts up correctly and works initially with orientation changes. When i navigate to the list view it populates correctly but upon orientation change the list gets redrawn without the Data in it. The map view also gets redrawn and is visible behind my pager title indicator.
If anyone could please point me in right direction for solving this that would be awesome. I am suspecting that is is caused by the way that i am showing and hiding the fragments.
Here is where i create the Fragments and add them to the fragment manager. I have also shown where i show/hide fragments.
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_map_frags);
mapViewContainer = LayoutInflater.from(this)
.inflate(R.layout.map, null);
setupFragments();
showFragment(0);
}
public void setListData(String name) {
bName = name;
showFragment(1);
}
private void setupFragments() {
final FragmentManager fm = getSupportFragmentManager();
final FragmentTransaction ft = fm.beginTransaction();
mFragment1 = fm.findFragmentByTag("f1");
if (mFragment1 == null) {
mFragment1 = new MenuFragment();
ft.add(mFragment1, "f1");
ft.hide(mFragment1);
}
mMapFragment = (MapFragment) getSupportFragmentManager()
.findFragmentByTag(MapFragment.TAG);
if (mMapFragment == null) {
mMapFragment = MapFragment.newInstance(0);
ft.add(R.id.fragment_container, mMapFragment, MapFragment.TAG);
}
ft.hide(mMapFragment);
myListFragment = (ListFrag) getSupportFragmentManager()
.findFragmentByTag(ListFrag.TAG);
if (myListFragment == null) {
myListFragment = new ListFrag();
ft.add(R.id.fragment_container, myListFragment, ListFrag.TAG);
}
ft.hide(myListFragment);
frag = (frag) getSupportFragmentManager().findFragmentByTag(
frag.TAG);
if (frag == null) {
bacFrag = new frag();
ft.add(R.id.fragment_container, frag, frag.TAG);
}
ft.hide(bacFrag);
ft.commit();
}
public void showFragment(int fragIn) {
final FragmentTransaction ft = getSupportFragmentManager()
.beginTransaction();
ft.setCustomAnimations(android.R.anim.fade_in, android.R.anim.fade_out);
if (mVisible != null) {
if (mVisible == mListFragment) {
ft.remove(mListFragment);
} else {
ft.hide(mVisible);
}
}
switch (fragIn) {
case 0:
ft.show(mMapFragment);
ft.commit();
mVisible = mMapFragment;
break;
case 1:
mListFragment = (ListFragmentDisplay) getSupportFragmentManager()
.findFragmentByTag(ListFragmentDisplay.TAG);
Toast.makeText(this, "startListFrag", Toast.LENGTH_LONG).show();
if (mListFragment == null) {
mListFragment = new ListFragmentDisplay();
ft.add(R.id.fragment_container, mListFragment,
ListFragmentDisplay.TAG);
}
ft.show(mListFragment).commit();
mVisible = mListFragment;
break;
case 2:
ft.show(myfragment).commit();
mVisible = myfragment;
break;
case 3:
ft.show(frag).commit();
mVisible = frag;
break;
}
}
It's not your fault. The problem is that when the orientation changes all the Activity is Destroyed, even all the fragments added. So none of the data within it is retained.
It's not advised to use android:configChanges="orientation|keyboardHidden".
Rather, set for every fragment setRetainInstance(true) and it will work well with your current code.
If you want to have a better persistence (for example when the activity is temporarily destroyed for space issues) also remember to save the state of your fragments with onSaveInstanceState. setRetainInstance will work only when a configuration change is about to come.
I have a layout that has an EditText and a Button. I <include> it in my main layout.
I'm having a weird issue with the layout and rotation. It seems to duplicate itself when the device (physical) is rotated, messing up the text and layout.
Here it is on first open, after I add some extra garble:
DSC_0013 is in the EditText on launch of the fragment.
Then, I rotate the phone and add some different garble:
And you can see the issue pretty clearly. At first, I thought it was just the EditText messing up. But if I add enough text to make a new line:
I can see that the button gets messed up too.
I do override onSaveInstanceState, but in it I don't touch the EditText or its value, it's strictly used for something else.
What's happening and how do I fix it?
Fixed it!
Turns out it wasn't the view duplicating itself, or the EditText, or the Button. It was the entire fragment.
In my Activity's onCreate, I add the fragment to an xml layout:
private FileDetails fileDetailsFragment;
public void onCreate(Bundle savedInstanceState) {
...
FragmentManager fragmentManager = getSupportFragmentManager();
FragmentTransaction fragmentTransaction = fragmentManager
.beginTransaction();
fileDetailsFragment = new FileDetails(fileData);
fragmentTransaction.add(R.id.DetailsHolder, fileDetailsFragment);
fragmentTransaction.commit();
And onCreate was being called every time I rotated the phone (as it's meant to). So I put in a check to see if the activity is being run for the first time, and it works great.
private FileDetails fileDetailsFragment;
public void onCreate(Bundle savedInstanceState) {
...
if (savedInstanceState == null) {
FragmentManager fragmentManager = getSupportFragmentManager();
FragmentTransaction fragmentTransaction = fragmentManager
.beginTransaction();
fileDetailsFragment = new FileDetails(fileData);
fragmentTransaction.add(R.id.DetailsHolder, fileDetailsFragment);
fragmentTransaction.commit();
} else {
fileDetailsFragment = (FileDetails) getSupportFragmentManager().findFragmentById(R.id.DetailsHolder);
}
You can also setRetainedInstance(true) on your fragment, then try to get the Fragment form de FragmentManager.findFragmentById(int) or FragmentManager.findFragmentByTag(String), and if it returns null it meant you had to create a new instance of your Fragment.
private FileDetails fileDetailsFragment;
public void onCreate(Bundle savedInstanceState) {
...
FragmentManager fragmentManager = getSupportFragmentManager();
fileDetailsFragment = (FileDetails) getSupportFragmentManager().findFragmentById(R.id.DetailsHolder);
if (fileDetailsFragment == null) {
fileDetailsFragment = new FileDetails(FileData);
}
FragmentTransaction fragmentTransaction = fragmentManager
.beginTransaction();
fragmentTransaction.add(R.id.DetailsHolder, fileDetailsFragment);
fragmentTransaction.commit();
}
In some cases, the value of savedInstanceState may be null after rotation, so it is better to add another condition:
FragmentManager fragmentManager = getSupportFragmentManager();
if (savedInstanceState == null &&
fragmentManager.getFragments().size() == 0) {
FragmentTransaction fragmentTransaction = fragmentManager
.beginTransaction();
fileDetailsFragment = new FileDetails(fileData);
fragmentTransaction.add(R.id.DetailsHolder, fileDetailsFragment);
fragmentTransaction.commit();
} else {
fileDetailsFragment = (FileDetails)
getSupportFragmentManager().findFragmentById(R.id.DetailsHolder);
}
We add a general/normal Fragment programatically by doing something like:
fragmentTransaction.add(containerViewId, fragmentToAdd, fragmentTag);
and we replace a Fragment by another by doing something like:
fragmentTransaction.replace(containerViewId, newFragment, tagOfNewFragment);
But we add a DialogFragment by
dialogFramentInstance.show(fragmentManager, fragmentTag);
The question is that how should I replace this DialogFragment which has been added by the show() method?
dialogFramentInstance.show(fragmentManager, fragmentTag);
Just adds the dialog fragment to the fragment manger using an add transaction (with no container).
In order to replace fragments you'll need a container and since you don't have one your only option is to dismiss() the first one and show() the new one.
private void closeYourDialogFragment() {
FragmentTransaction ft = getSupportFragmentManager().beginTransaction();
Fragment fragmentToRemove = getSupportFragmentManager().findFragmentByTag("your_dialog_fragment");
if (fragmentToRemove != null) {
ft.remove(fragmentToRemove);
}
ft.addToBackStack(null);
ft.commit(); // or ft.commitAllowingStateLoss()
}
private void replaceYourDialogFragment() {
closeYourDialogFragment();
YourDialogFragment yourDialogFragment = new YourDialogFragment();
yourDialogFragment.show(getSupportFragmentManager(), "your_dialog_fragment");
}
Maybe you can do like this:
public void showFragment(Fragment fragment) {
if (fragment instanceof DialogFragment) {
FragmentTransaction ft = mContext.getFragmentManager().beginTransaction();
Fragment prev = mContext.getFragmentManager().findFragmentByTag("dialog");
if (prev != null) {
Log.d(TAG, "showFragment: remove prev...." + prev.getClass().getSimpleName());
ft.remove(prev);
}
mContext.getFragmentManager().executePendingTransactions();
if (!fragment.isAdded()){
ft.addToBackStack(null);
((DialogFragment) fragment).show(ft, "dialog");
} else {
Log.w(TAG, "showFragment: fragment has been added!" );
}
}
}
So this took me a lot of digging to figure out.
Dialog fragment show method only adds fragments hence if you want to replace them you have to manually remove the previous dialog fragment.
One thing to keep in mind, it is important to use the same fragmentManager used to open the initial dialog fragment. For example if you opened the first dialog fragment via an Activity (supportFragmentManager) and now using the dialog fragment fragment manager (childFragmentManager) since they do not have the same stack you wont be able to access the original dialog fragment and remove it.