Listen preference change and transfer boolean in checkbox to MainActivity

Question

I have 2 file:

control_preferences.xml:`

<PreferenceCategory
    android:title="@string/control_category">


    <CheckBoxPreference
        android:title="Debug Information ON/OFF"
        android:defaultValue="false"
        android:summary="Show debug information when ON"
        android:key="checkboxPref" />

</PreferenceCategory>

`

SettingsActivity.java:

package com.sample;

import android.content.SharedPreferences;
import android.os.Bundle;
import android.preference.CheckBoxPreference;
import android.preference.Preference;
import android.preference.PreferenceActivity;
import android.preference.PreferenceFragment;
import android.preference.PreferenceManager;
import android.util.Log;
import android.widget.Toast;



public class SettingsActivity extends PreferenceActivity implements SharedPreferences.OnSharedPreferenceChangeListener {


    public static final String KEY_PREF_DEBUG = "checkboxPref";



    @Override
    public void onSharedPreferenceChanged(SharedPreferences sharedPreferences,
                                          String key) {
        if (key.equals(KEY_PREF_DEBUG)) {
            Toast.makeText(getApplicationContext(), "CLICK",
                    Toast.LENGTH_SHORT).show();
        }
    }





    @Override
    public void onBuildHeaders(List<Header> target) {
        loadHeadersFromResource(R.xml.preference_headers, target);
    }


    public static class ControlPrefsFragment extends PreferenceFragment {
        @Override
        public void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);

            // load the preferences from an XML resource
            addPreferencesFromResource(R.xml.fragmented_control_preferences);
        }
    }}

I have 2 questions:

1. Why when selecting or deselecting Checkbox Toast doesn't display?
2. How to store in SharedPreferences boolean from this CheckBox and later read this boolean in MainActivity.

Answer 1

1) Why when selecting or deselecting Checkbox Toast doesn't display?

Add below lines in on resume of your activity

SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(this);
prefs.registerOnSharedPreferenceChangeListener(prefs);

2)How to store in SharedPreferences boolean from this CheckBox and later read this boolean in MainActivity? Use below code to get value

    SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(this);
prefs.getBoolean("key_value_given_in_preference_xml_file") 

Answer 2

Use this instead of implementing interface

checkboxPref = (CheckBoxPreference) getPreferenceScreen().findPreference(your_key);

checkboxPref.setOnPreferenceChangeListener(new Preference.OnPreferenceChangeListener() 
{

     @Override
     public boolean onPreferenceChange(Preference preference, Object newValue) 
     {

          YOUR CODE                    

          return false;
     }
});

Answer 3

@Jawegiel

I insert this to:

public static class ControlPrefsFragment extends PreferenceFragment {
        @Override
        public void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);

            // load the preferences from an XML resource
            addPreferencesFromResource(R.xml.fragmented_control_preferences);

            final CheckBoxPreference checkboxPref = (CheckBoxPreference) getPreferenceManager().findPreference("checkboxPref");


            checkboxPref.setOnPreferenceChangeListener(new Preference.OnPreferenceChangeListener()
            {

                @Override
                public boolean onPreferenceChange(Preference preference, Object newValue)
                {

                    Toast.makeText(getActivity().getApplicationContext(), "CLICK",
                            Toast.LENGTH_SHORT).show();

                    return false;
                }
            });
        }
    }

and it works :)

Thank you both :)

Answer 4

@Jawegiel

what if I would use Toast like "Debug: " + "boolean from this actually changed checkbox" In MainActivity i read this boolean through code:

SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(getApplication‌​Context());
 boolean check = prefs.getBoolean("checkboxPref",false);

How read this boolean in in SettingsActivity same like in MainActivity?

I try through this code:

checkboxPref.setOnPreferenceChangeListener(new Preference.OnPreferenceChangeListener()
            {

                @Override
                public boolean onPreferenceChange(Preference preference, Object newValue)
                {
                    boolean check = checkboxPref.getSharedPreferences().getBoolean("checkboxPref",false);
                    Toast.makeText(getActivity().getApplicationContext(), "Debug " + check,
                            Toast.LENGTH_SHORT).show();

                    return false;
                }
            });

But now I can't unclick Checkbox or click if false :d