First of all, sorry for my english.
I'm trying to make a custom 'day picker' dialog on my preference screen. I got the codes from Android Developer site and from Stackoverflow.
The dialog works 'well', it saves and loads the value (the layout contains a NumberPicker and a TextView). The problem is: the dialog disappears upon device rotation.
I have read several posts on this forum and other sites, but no luck. Can you help me ? I've spent hours so far to finding the issue, but I can't see how to solve it. Thanks.
The code:
package hu.test.android.demo.ui;
import hu.test.android.demo.AMdtApplication;
import hu.test.android.demo.R;
import android.content.Context;
import android.content.res.TypedArray;
import android.os.Parcel;
import android.os.Parcelable;
import android.preference.DialogPreference;
import android.util.AttributeSet;
import android.view.View;
import android.widget.NumberPicker;
public class DayPreference extends DialogPreference {
private NumberPicker picker = null;
private static int day;
public static int getDay () {
return day;
}
public DayPreference(Context ctxt, AttributeSet attrs) {
super(ctxt, attrs);
setDialogLayoutResource(R.layout.day_preference);
setPositiveButtonText (TestApplication.getContext().getResources().getString( R.string.save ));
setNegativeButtonText (TestApplication.getContext().getResources().getString( R.string.cancel ));
}
@Override
protected void onBindDialogView(View v) {
super.onBindDialogView (v);
picker = (NumberPicker) v.findViewById (R.id.day_preference_number_picker);
picker.setMinValue (1);
picker.setMaxValue (30);
picker.setValue (day);
}
@Override
protected void onDialogClosed(boolean positiveResult) {
super.onDialogClosed(positiveResult);
if (positiveResult) {
if (callChangeListener (day)) {
day = picker.getValue();
persistInt (day);
}
setSummary(getSummary());
}
}
@Override
protected Object onGetDefaultValue(TypedArray a, int index) {
return (a.getString(index));
}
@Override
protected void onSetInitialValue(boolean restoreValue, Object defaultValue) {
if (restoreValue) {
if (defaultValue == null) {
day = getPersistedInt (30);
}
else {
day = getPersistedInt ((Integer) defaultValue);
}
}
else {
day = (Integer) defaultValue;
}
setSummary (getSummary());
}
@Override
public CharSequence getSummary() {
return String.valueOf ( day ) + " " + TestApplication.getContext().getResources().getString( R.string.label_day );
}
// state save & restore
@Override
protected Parcelable onSaveInstanceState () {
final Parcelable superState = super.onSaveInstanceState();
if (isPersistent()) {
return superState;
}
final SavedState myState = new SavedState (superState);
myState.value = day;
return myState;
}
@Override
protected void onRestoreInstanceState (Parcelable state) {
if (state == null || !state.getClass().equals(SavedState.class)) {
super.onRestoreInstanceState(state);
return;
}
SavedState myState = (SavedState) state;
super.onRestoreInstanceState(myState.getSuperState());
// set the value to the picker
picker.setValue (myState.value);
}
private static class SavedState extends BaseSavedState {
public int value;
public SavedState (Parcelable superState) {
super(superState);
}
public SavedState (Parcel source) {
super(source);
value = source.readInt();
}
@Override
public void writeToParcel(Parcel dest, int flags) {
super.writeToParcel(dest, flags);
dest.writeInt(value);
}
// Standard creator object using an instance of this class
@SuppressWarnings( "unused" )
public static final Parcelable.Creator <SavedState> CREATOR = new Parcelable.Creator <SavedState> () {
public SavedState createFromParcel(Parcel in) {
return new SavedState(in);
}
public SavedState[] newArray (int size) {
return new SavedState[size];
}
};
}
}
UPDATE:
Please note that the below solution is just a quick hack(and is not a recommended approach), proper solution would be to persist values during onSaveInstanceState and then getting those values after your activity is recreated.
This post is a must read to gracefully handle configuration changes.
ORIGINAL ANSWER:
Maybe this will help, add this line inside the relevant activity tag in your manifest file:
android:configChanges="orientation|screenSize"
This will ensure that onCreate is not called when the screen rotates, you say to the android OS, hey i will be handling the rotation stuff myself for this activity you don't need to start over from onCreate.