Develop Reference

Button savedInstanceState and onRestoreInstanceState

Saving the State of Drawable xml Button.
private boolean mJam;
private button mSwitch;
private static final String KEY_ENABLE = "KEY_ENABLE";
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if( null == savedInstanceState ) {
mJam = false;
} else {
mJam = savedInstanceState.getBoolean(KEY_ENABLE);
}
button_layout();
}
#Override
protected void onSaveInstanceState(Bundle outState) {
outState.putBoolean(KEY_ENABLE, mJam);
outState.putBoolean(KEY_ENABLE, mSwitch.isSelected()); // Saving the state of the
super.onSaveInstanceState(outState);
}
#Override
protected void onRestoreInstanceState(Bundle savedInstanceState) {
mSwitch.setSelected(savedInstanceState.getBoolean(KEY_ENABLE));
mJam = savedInstanceState.getBoolean(KEY_ENABLE);
super.onRestoreInstanceState(savedInstanceState);
}
Note: If you don't want to use ScreenSize in Android manifest, This code can be used,
If you want to do it Manually, then go for this one.
P.S: setting Screen Size in Manifest, never go to onCreate if the Orientation Change, It Just saved all the instance and display as it is, when
Android orientation Change.

How to save fragment state with annotations?

I have a little project, one activity and two fragment. I have started from the "Bottom Navigation Activity" sample on a new projet.
The I use the Android Annotations (https://github.com/androidannotations/androidannotations/wiki) for injecting my fragment, It display correctly but when I rotate, I loose all my information and the app display the first fragment, even if I displayed the second one. I tried to save my data, from an edit text with a Bundle object, in the "onSaveInstanceState" method, I get back it in the "onActivityCreated" or in the "onCreate" method but after their method were re-call and my data desappear.
I don't know how to save which fragment was displayed and how re-displayed it with the android annotations.
In my Activity class I have those methods :
#Override
protected void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
}
#Override
protected void onRestoreInstanceState(Bundle savedInstanceState) {
super.onRestoreInstanceState(savedInstanceState);
}
And in my main fragments :
#Override
public void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
if(dpdEditText != null){
rttNumberTemp = rttEditText.getText().toString();
outState.putString("rttNumberTemp", rttNumberTemp);
}
}
#Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
Log.d(Tag, "onActivityCreated");
if(savedInstanceState != null){
Log.d(Tag, "onActivityCreated if");
updateEditText(rttEditText,savedInstanceState.getString("rttNumberTemp"));
}
}
So my question is how can I save my fragment, and its data and which fragment is displayed ?

I finally find my mistake. In my main activity I have the following method :
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
So the program call the view by the injection and call it again with the setContentView. So I update the method like that :
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}

Save Instance Variable values through Android Activity Life Cycle

I use an intent to start another activity to display data in an ArrayList.
After pressing the back button in the action bar, the values of the array list are lost.
How do I fix this?
The code I'm currently using:
#Override
public void onSaveInstanceState(Bundle savedInstanceState) {
super.onSaveInstanceState(savedInstanceState);
savedInstanceState.putStringArrayList(X_COORDINATE, dataX);
savedInstanceState.putStringArrayList(Y_COORDINATE, dataX);
}
#Override
public void onRestoreInstanceState(Bundle savedInstanceState) {
super.onRestoreInstanceState(savedInstanceState);
dataX=savedInstanceState.getStringArrayList(X_COORDINATE);
dataY=savedInstanceState.getStringArrayList(Y_COORDINATE);
}
The first method is how I put my arraylists in to the Bundle, and the second method is how I restore it.

try this:
protected void onSaveInstanceState(Bundle savedInstanceState) {
super.onSaveInstanceState(savedInstanceState);
savedInstanceState.putStringArrayList(X_COORDINATE, dataX);
}
And restore the values in onCreate():
public void onCreate(Bundle savedInstanceState) {
if (savedInstanceState!= null){
dataX=savedInstanceState.getStringArrayList(X_COORDINATE);
}
}

saving ArrayList in the bundle savedInstanceState

the ArrayList is defined on class level.
these are my savedInstance methods:
#Override
protected void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
outState.putStringArrayList("savedList", list);
}
#Override
protected void onRestoreInstanceState(Bundle savedInstanceState) {
super.onRestoreInstanceState(savedInstanceState);
list=savedInstanceState.getStringArrayList("savedList");
}
but still, when i change orientation the ArrayList is blank

When you use onRestoreInstanceState() to restore state, its called after onStart() so you update your list with the saved state after you define your adapter. Your best option is to restore the list in onCreate() the same way you do it on onRestoreInstanceState(). You can also redefine the adapter or call notifyDataSetChanged().

TextView textviewname;
String textname;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//declare the ui like this
textviewname = (TextView) findViewById(R.id.textviewid);
if(savedInstanceState==null){
//the first time the activity was created
//do the normal flow of the code
//Example:getting the intent data for(savedList)or processing it
Intent i = getIntent();
textname = i.getStringExtra("savetext");
//or textname="name_data";
}else{
//this is called when orientation change occur
//get the savedata
list=savedInstanceState.getStringArrayList("savedList");
textname=savedInstanceState.getString("savetext");
}
textviewname.setText(textname);
}
#Override
protected void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
//saving data when orientation change trigger
//saving data before ondestroy happens
//onSaveInstanceState is called before going to another activity or orientation change
outState.putStringArrayList("savedList", list);
outState.putString("savetext", textname);
//all imnportant data saved and can be restored
}
#Override
protected void onRestoreInstanceState(Bundle savedInstanceState) {
super.onRestoreInstanceState(savedInstanceState);
//this is only called after ondestroy-> oncreate occur
list=savedInstanceState.getStringArrayList("savedList");
textname=savedInstanceState.getString("savetext");
//oncreate->onSaveInstanceState->ondestroy->oncreate->onRestoreInstanceState
}

try to use
list.addAll(savedInstanceState.getStringArrayList("savedList"));
instead
list=savedInstanceState.getStringArrayList("savedList");

how to store values and retrieve it when the orientation changes?

I have checked many posts, and as per that I have done coding for the orientation change. When orientation changes, the problem is I am not able to retrieve the entered values inside TextViews. Can anyone plz tell where did I go wrong?
Coding:
In manifest file for the corresponding activity I added:
android:configChanges="orientation|keyboardHidden"
In activity, I added the following methods:
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.home_screen);
//Initialized the widgets
}
#Override
public void onConfigurationChanged(Configuration newConfig) {
super.onConfigurationChanged(newConfig);
//have written separate layout files for portrait and landscape
setContentView(R.layout.home_screen);
//Initialized the widgets again
retrieveSavedState(); //sets the TextViews again
}
#Override
protected void onPause() {
super.onPause();
saveState(); //save the TextView values
}
#Override
protected void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
saveState();
}
#Override
protected void onResume() {
super.onResume();
retrieveSavedState();
}

#Override
public Object onRetainNonConfigurationInstance()
{
final MyDataObject data = collectMyLoadedData();
return data;
}
the above method can be used to save any object to save data...
#Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
final MyDataObject data = (MyDataObject) getLastNonConfigurationInstance();
if (data == null) {
data = loadMyData();
}
...
}
and u can retreive that object in the onCreate() which will we called when orientation changes.. after reading data from that object you can use it where ever you want..
http://developer.android.com/guide/topics/resources/runtime-changes.html
http://developer.android.com/guide/topics/resources/runtime-changes.html
other mechanisms are also there but this is the best way for my knowledge.. you can also use shared preferences to store and retrieve data...
http://saigeethamn.blogspot.com/2009/10/shared-preferences-android-developer.html