The EditButton of my app in Android Studio can be edited but once you have edited the texts it will not save when you exit the window. What to do?
public class BellPepperActivity extends AppCompatActivity {
TextView bpTextView;
AlertDialog dialog;
EditText editText;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_bell_pepper);
bpTextView = (TextView) findViewById(R.id.bpTextView);
dialog = new AlertDialog.Builder(this).create();
editText = new EditText(this);
dialog.setTitle("BELL PEPPER");
dialog.setView(editText);
dialog.setButton(DialogInterface.BUTTON_POSITIVE, "SAVE", new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialog, int which) {
bpTextView.setText(editText.getText());
}
});
bpTextView.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
editText.setText(bpTextView.getText());
dialog.show();
}
});
}
}
By window, I assume you Activity (the AppCompatActivity that you have created). To maintain state in Activities you have to learn about the activity lifecycle. Basically when you leave you have to save the instance state:
// invoked when the activity may be temporarily destroyed, save the instance state here
#Override
public void onSaveInstanceState(Bundle outState) {
outState.putString(TEXT_VIEW_KEY, editText.getText());
// call superclass to save any view hierarchy
super.onSaveInstanceState(outState);
}
and when you restore the state you do the same:
// This callback is called only when there is a saved instance previously saved using
// onSaveInstanceState(). We restore some state in onCreate() while we can optionally restore
// other state here, possibly usable after onStart() has completed.
// The savedInstanceState Bundle is same as the one used in onCreate().
#Override
public void onRestoreInstanceState(Bundle savedInstanceState) {
editText.setText(savedInstanceState.getString(TEXT_VIEW_KEY));
}
Obviously you have to create a TEXT_VIEW_KEY as private final string at the top of your class:
private static final String TEXT_VIEW_KEY = "TEXT_VIEW_KEY";
Untested, but that should work for you now. For more advanced lifecycle handling learn about the Android Architecture Components, but that should wait until you understand the basic activity lifecycle in android App.
i've got a "simple" question:
How do i pass a view from an Activity to another?
In my case:
I've got a MainActivity with setContentView(R.layout.activity_main); In this activity_main i've declared a Relativelayout, whose Backgroundcolor I wanna change from another Activity, that gets its setContentView from an .xml file, where you cant find this RelativeLayout. How do i do that?
Thanks for the quick answer!
MainActivity.java
public class MainActivity extends AppCompatActivity{
#Override
protected void onRestoreInstanceState(Bundle savedInstanceState) {
super.onRestoreInstanceState(savedInstanceState);
if (savedInstanceState != null) {
//Save the text of the editText
bringer = savedInstanceState.getString("bringer");
input.setText(bringer);
//Save the Listview
content = savedInstanceState.getStringArrayList("content");
adapter = new ArrayAdapter<String>(MainActivity.this, android.R.layout.simple_list_item_1, content);
layout = (ListView) findViewById(R.id.layout);
layout.setAdapter(adapter);
}
}
#Override
public void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
outState.putStringArrayList("content", content);
outState.putStringArrayList("list", list);
bringer = input.getText().toString();
outState.putString("bringer", bringer);
}
Second Activity:
public class pop extends Activity {
back.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
//Thats where it fails, because it couldnt get the parent-
view.
finish();
}
});
sure.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
}
});
}
}
The short answer is that you can't pass a View between activities.
If you have a View in ActivityOne that you want to modify based on the user's actions in ActivityTwo, then you should have ActivityOne launch ActivityTwo using startActivityForResult().
ActivityTwo can then call the setResult() method, and ActivityOne can implement onActivityResult() to receive that info.
I am writing a program where I call multiple layouts on the same activity but then i noted that when i switch layouts, the changes made before the switch are not restored and onSavedInstanceState(Bundle outState) is not called. I have tried to manually call the method but i can't get the Bundle outState.
So the question really is: How do I get and store the current state of an activity to be recalled and/or restored at a time of my choosing?
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_contact_view);
// more code
}
#Override
public void onBackPressed() {
if (layoutId == R.layout.activity_contact_view) exit();
else if (layoutId == R.layout.main) {
Toast.makeText(NsdChatActivity.this, "Successful back button action", Toast.LENGTH_SHORT).show();
setContentView(R.layout.activity_contact_view);
refreshContactList();
}
}
And then from a seperate class
public void updateList(final int found) {
LinearLayout layxout = (LinearLayout) ((Activity)mContext).getWindow().getDecorView().findViewById(R.id.others);
TextView t = new TextView(mContext);
t.setClickable(true);
t.setText(found + ". " + activity.sNames.get(found));
t.setLayoutParams(new ViewGroup.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.WRAP_CONTENT));
t.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
//show chat view
activity.setContentView(R.layout.main);
TextView name = (TextView)activity.findViewById(R.id.clientName);
name.setText(activity.sNames.get(found).split(" \\(")[0]);
final ScrollView scroll = (ScrollView)activity.findViewById(R.id.scroll);
scroll.setOnFocusChangeListener(new View.OnFocusChangeListener() {
#Override
public void onFocusChange(View view, boolean b) {
scroll.fullScroll(View.FOCUS_DOWN);
}
});
}
});
layxout.addView(t);
}
I might be late for that but what you could do is to keep your sate as a member of the class. That way you can restore the state anytime you want.
Bundle mState;
#Override
public void onSaveInstanceState(Bundle savedInstanceState) {
// Save the state
savedInstanceState = mState;
super.onSaveInstanceState(savedInstanceState);
}
#Overrite
public void onRestoreInstanceState(Bundle savedInstance){
mState = savedInstance;
Restore();
}
public void Restore(){
//access your state and restore
}
Also you shouldn't use setContentView to switch between views it's expensive way to do it. You might want to check ViewSwitcher or ViewFlipper or someway to implement Fragments.
May be you should have a look at Application Fundamentals
Android calls onSaveInstanceState() before the activity becomes vulnerable to being destroyed by the system, but does not bother calling it when the instance is actually being destroyed by a user action (such as pressing the BACK key)
so you call multiple layouts on the same activity may not cause the above situation. For more details, you can refer to the question Android: Saving a state during Android lifecycle. Hope that helps!
I'm having some trouble with my EditText's on orientation change. For some reason they dont restore whatever was typed in them.
I have 2 classes. The main activity and the fragment which goes in the activity
Main activity:
public class MainActivity extends ActionBarActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(
setContentView(R.layout.
getFragmentManager().beginTransaction().replace(R.id.controlsBar, new AddItemFragment()).commit();
}
}
And the fragment:
public class AddItemFragment extends Fragment {
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
View view = inflater.inflate(R.layout.fragment_add_item, container, false);
EditText item = (EditText) view.findViewById(R.id.itemNameAdd);
EditText amount = (EditText) view.findViewById(R.id.itemAmount);
if (savedInstanceState != null) {
System.out.println(savedInstanceState.getString("item"));
item.setText(savedInstanceState.getString("item", ""));
amount.setText(savedInstanceState.getString("amount", ""));
}
//item.setText("SOME TEXT");
//amount.setText("SOME TEXT");
return view;
}
#Override
public void onSaveInstanceState(Bundle outState) {
EditText item = (EditText) getActivity().findViewById(R.id.itemNameAdd);
EditText amount = (EditText) getActivity().findViewById(R.id.itemAmount);
outState.putString("item", item.getText().toString());
outState.putString("amount", amount.getText().toString());
}
}
The funny thing is that the line "System.out.println(savedInstanceState.getString("item"));" prints out the correct word in the console.
And furthermore the outcommented lines where i set the text to "SOME TEXT" also works.
Its only when i set the text to savedInstanceState.getString("amount", ""), it wont work
Thank you
Try adding the line marked "<---- THIS LINE" to public void onSaveInstanceState(Bundle outState):
#Override
public void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState); // <---- THIS LINE
EditText item = (EditText) getActivity().findViewById(R.id.itemNameAdd);
EditText amount = (EditText) getActivity().findViewById(R.id.itemAmount);
outState.putString("item", item.getText().toString());
outState.putString("amount", amount.getText().toString());
}
Also, look at using onActivityCreated, and check out the resources in my comment below.
I have a Login screen which consists of 2 EditTexts for Username and Password. My requirement is that on orientation change , input data(if any) in EditText should remain as it is and a new layout should also be drawn. I have 2 layout xml files- one in layout folder and other in layout-land folder. I am trying to implement following 2 approaches but none of them is perfect:
(1) configChanges:keyboardHidden - In this approach, I don't provide "orientation" in configChanges in manifest file. So I call setContentView() method in both onCreate() and onConfigurationChanged() methods. It fulfills both my requirements. Layout is changed and input data in EditTexts also remains as it is. But it has a big problem :
When user clicks on Login button, a ProgressDialog shows until server-response is received. Now if user rotates the device while ProgressDialog is running, app crashes. It shows an Exception saying "View cannot be attached to Window." I have tried to handle it using onSaveInstanceState (which DOES get called on orientation change) but app still crashes.
(2) configChanges:orientation|keyboardHidden - In this approach, I provide "orientation" in manifest. So now I have 2 scenarios:
(a) If I call setContentView() method in both onCreate() and onConfigurationChanged(), Layout is changed accordingly but EditText data is lost.
(b) If I call setContentView() method in onCreate() , but not in onConfigurationChanged(), then EditText data is not lost but layout also not changes accordingly.
And in this approach, onSaveInstanceState() is not even called.
So I am in a really intimidating situation. Is there any solution to this problem? Please help. Thanx in advance.
By default, Edittext save their own instance when changing orientation.
Be sure that the 2 Edittexts have unique IDs and have the same IDs in both Layouts.
That way, their state should be saved and you can let Android handle the orientation change.
If you are using a fragment, be sure it has a unique ID also and you dont recreate it when recreating the Activity.
A better approach is to let android handle the orientation change. Android will automatically fetch the layout from the correct folder and display it on the screen. All you need to do is to save the input values of the edit texts in the onSaveInsanceState() method and use these saved values to initialize the edit texts in the onCreate() method.
Here is how you can achieve this:
#Override
protected void onCreate (Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.login_screen);
...
...
String userName, password;
if(savedInstanceState!=null)
{
userName = savedInstanceState.getString("user_name");
password= savedInstanceState.getString("password");
}
if(userName != null)
userNameEdtTxt.setText(userName);
if(password != null)
passEdtTxt.setText(password);
}
>
#Override
protected void onSaveInstanceState (Bundle outState)
{
outState.putString("user_name", userNameEdtTxt.getText().toString());
outState.putString("password", passEdtTxt.getText().toString());
}
Give the element an id and Android will manage it for you.
android:id="#id/anything"
in onConfigurationChanged method, first get the data of both the edit texts in global variables and then call setContentView method. Now set the saved data again into the edit texts.
There are many ways to do this. The simplest is 2(b) in your question. Mention android:configChanges="orientation|keyboardHidden|screenSize" in your manifest so that Activity doesn't get destroyed on Orientation changes.
Call setContentView() in onConfigChange(). but before calling setContentView() get the EditText data into a string and set it back after calling setContentView()
#Override
public void onConfigurationChanged(Configuration newConfig) {
super.onConfigurationChanged(newConfig);
mEditTextData = mEditText.getText().tostring();//mEditTextData is a String
//member variable
setContentView(R.layout.myLayout);
initializeViews();
}
private void initializeViews(){
mEditText = (EditText)findViewById(R.id.edittext1);
mEdiText.setText(mEditTextData);
}
The following should work and is standard to the activities and fragments
#Override
public void onSaveInstanceState (Bundle outState)
{
outState.putString("editTextData1", editText1.getText().toString());
outState.putString("editTextData2", editText2.getText().toString());
super.onSaveInstanceState(outState);
}
#Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate();
... find references to editText1, editText2
if (savedInstanceState != null)
{
editText1.setText(savedInstanceState.getString("editTextData1");
editText2.setText(savedInstanceState.getString("editTextData2");
}
}
Im restoring instance to restore values and it works fine for me :)
#Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.addtask2);
if(savedInstanceState!=null)
onRestoreInstanceState(savedInstanceState);
}
Remove android:configChanges attribute from the menifest file and let android handle the orientation change your data in edittext will automatically remain.
Now The problem you mentioned is with the progress dialog force close this is because when the orientation is changed the thread running in backgroud is trying to update the older dialog component whihc was visible. You can handle it by closing the dialog on savedinstancestate method and recalling the proceess you want to perform onRestoreInstanceState method.
Below is a sample hope it helps solving your problem:-
public class MyActivity extends Activity {
private static final String TAG = "com.example.handledataorientationchange.MainActivity";
private static ProgressDialog progressDialog;
private static Thread thread;
private static boolean isTaskRunnig;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
Log.d(TAG, "onCreate");
setContentView(R.layout.main);
Button button = (Button) findViewById(R.id.button);
button.setOnClickListener(new EditText.OnClickListener() {
#Override
public void onClick(View v) {
perform();
isTaskRunnig = true;
}
});
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
public void perform() {
Log.d(TAG, "perform");
progressDialog = android.app.ProgressDialog.show(this, null,
"Working, please wait...");
progressDialog
.setOnDismissListener(new DialogInterface.OnDismissListener() {
#Override
public void onDismiss(DialogInterface dialog) {
//isTaskRunnig = false;
}
});
thread = new Thread() {
public void run() {
Log.d(TAG, "run");
int result = 0;
try {
// Thread.sleep(5000);
for (int i = 0; i < 20000000; i++) {
}
result = 1;
isTaskRunnig = false;
} catch (Exception e) {
e.printStackTrace();
result = 0;
}
Message msg = new Message();
msg.what = result;
handler.sendMessage(msg);
};
};
thread.start();
}
// handler to update the progress dialgo while the background task is in
// progress
private static Handler handler = new Handler() {
public void handleMessage(Message msg) {
Log.d(TAG, "handleMessage");
int result = msg.what;
if (result == 1) {// if the task is completed successfully
Log.d(TAG, "Task complete");
try {
progressDialog.dismiss();
} catch (Exception e) {
e.printStackTrace();
isTaskRunnig = true;
}
}
}
};
#Override
protected void onRestoreInstanceState(Bundle savedInstanceState) {
super.onRestoreInstanceState(savedInstanceState);
Log.d(TAG, "onRestoreInstanceState" + isTaskRunnig);
if (isTaskRunnig) {
perform();
}
}
#Override
protected void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
Log.d(TAG, "onSaveInstanceState");
if (thread.isAlive()) {
thread.interrupt();
Log.d(TAG, thread.isAlive() + "");
progressDialog.dismiss();
}
}
As pointed out by Yalla T it is important to not recreate the fragment. The EditText will not lose its content if the existing fragment is reused.
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// setContentView(R.layout.activity_frame);
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
// Display the fragment as the main content.
// Do not do this. It will recreate the fragment on orientation change!
// getSupportFragmentManager().beginTransaction().replace(android.R.id.content, new Fragment_Places()).commit();
// Instead do this
String fragTag = "fragUniqueName";
FragmentManager fm = getSupportFragmentManager();
Fragment fragment = (Fragment) fm.findFragmentByTag(fragTag);
if (fragment == null)
fragment = new Fragment_XXX(); // Here your fragment
FragmentTransaction ft = fm.beginTransaction();
// ft.setCustomAnimations(R.xml.anim_slide_in_from_right, R.xml.anim_slide_out_left,
// R.xml.anim_slide_in_from_left, R.xml.anim_slide_out_right);
ft.replace(android.R.id.content, fragment, fragTag);
// ft.addToBackStack(null); // Depends on what you want to do with your back button
ft.commit();
}
Saving state = Saving (Fragment State + Activity State)
When it comes to saving the state of a Fragment during orientation change, I usually do this way.
1) Fragment State:
Save and Restore EditText value
// Saving State
#Override
public void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
outState.putString("USER_NAME", username.getText().toString());
outState.putString("PASSWORD", password.getText().toString());
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup parent, Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.user_name_fragment, parent, false);
username = (EditText) view.findViewById(R.id.username);
password = (EditText) view.findViewById(R.id.password);
// Retriving value
if (savedInstanceState != null) {
username.setText(savedInstanceState.getString("USER_NAME"));
password.setText(savedInstanceState.getString("PASSWORD"));
}
return view;
}
2) Activity State::
Create a new Instance when the activity launches for the first time
else find the old fragment using a TAG and the FragmentManager
#Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.main_activity);
fragmentManager = getSupportFragmentManager();
if(savedInstanceState==null) {
userFragment = UserNameFragment.newInstance();
fragmentManager.beginTransaction().add(R.id.profile, userFragment, "TAG").commit();
}
else {
userFragment = fragmentManager.findFragmentByTag("TAG");
}
}
You can see the the full working code HERE
Below code is work for me. Need to care two things.
Each Input Field (Edit Text or TextInputEditText) assign unique id.
Manifest activity declaration should have on configuration change attribute with below values.
android:configChanges="orientation|keyboardHidden|screenSize"
Sample activity declaration in manifest.
<activity
android:name=".screens.register.RegisterActivity"
android:configChanges="orientation|keyboardHidden|screenSize"
android:exported="true"
android:label="Registration"
android:theme="#style/AppTheme.NoActionBar" />
Sample declaration of
<com.google.android.material.textfield.TextInputLayout
android:id="#+id/inputLayout"
style="#style/Widget.MaterialComponents.TextInputLayout.OutlinedBox"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:boxCornerRadiusBottomEnd="#dimen/boxCornerRadiusDP"
app:boxCornerRadiusBottomStart="#dimen/boxCornerRadiusDP"
app:boxCornerRadiusTopEnd="#dimen/boxCornerRadiusDP"
app:boxCornerRadiusTopStart="#dimen/boxCornerRadiusDP">
<com.google.android.material.textfield.TextInputEditText
android:id="#+id/inputEditText"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:focusable="true"
android:fontFamily="#font/proxima_nova_semi_bold"
android:inputType="textCapWords"
android:lines="1"
android:textColor="#color/colorInputText"
android:textColorHint="#color/colorInputText" />
</com.google.android.material.textfield.TextInputLayout>
this may help you
if your android:targetSdkVersion="12" or less
android:configChanges="orientation|keyboardHidden">
if your android:targetSdkVersion="13" or more
android:configChanges="orientation|keyboardHidden|screenSize">