Creating an intent by clicking a item in a PreferenceFragment

Question

I want to create a PreferenceFragment in android. There should be an item that allows the usere to import his old database into the app. Before I found the PreferenceFragment I used my own SettingsFragment, but as this seems to be better(and for everything else exxept this it is atm) I tried using this.

My Problem is that I used startActivityForResult with an intent to get the file and import the database. This was called with a buttonclick. In the new Preference Fragment I don't really have a way to get clicks.

Here is my Settings.xml:

<?xml version="1.0" encoding="utf-8"?>
<PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android">


    <com.myContainer.myApp.helper.ImportDatabaseSettingsDialog
        android:id="@+id/database1"
        android:key="import_database"
        android:title="@string/importDatabaseFromDB" />

    <SwitchPreference
        android:key="pref_beta"
        android:title="@string/enableBeta"
        android:summary="@string/enableBetaSummary"
        android:defaultValue="false" />

    <Preference
        android:id="@+id/database2"
    android:key="import_database"
    android:title="@string/importDatabaseFromDB" />

    <ListPreference
        android:id="@+id/database3"
        android:key="import_database"
        android:title="@string/importDatabaseFromDB" />


</PreferenceScreen>

The idead I had

a) I tried to get OnClickListeners

@Override
public void onViewCreated(View view, @Nullable Bundle savedInstanceState) {
    super.onViewCreated(view, savedInstanceState);

    View data1 = mSettingsFragmentView.findViewById(R.id.database1);
    View data2 = mSettingsFragmentView.findViewById(R.id.database2);
    View data3 =  mSettingsFragmentView.findViewById(R.id.database3);

    data1.setOnClickListener(this);
    data2.setOnClickListener(this);
    data3.setOnClickListener(this);
}

I get this: Attempt to invoke virtual method 'void android.view.View.setOnClickListener(android.view.View$OnClickListener)' on a null object reference

So I can't get the items from settings.xml I guess.

b) The other Idea I had was using a DialogPreference. I use the same settings.xml as above.

package com.pi314.mylife.helper;

import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.net.Uri;
import android.preference.DialogPreference;
import android.util.AttributeSet;
import android.util.Log;
import android.widget.Toast;

import com.pi314.mylife.R;

import static android.app.PendingIntent.getActivity;
import static android.support.v4.app.ActivityCompat.startActivityForResult;

/**
 * Created  on 20.09.2015.
 */
public class ImportDatabaseSettingsDialog extends DialogPreference {

    private static final int SELECT_DATABASEFILE = 1;

    public ImportDatabaseSettingsDialog(Context context, AttributeSet attrs) {
        super(context, attrs);

        //setDialogLayoutResource(R.layout.numberpicker_dialog);
        setDialogMessage(R.string.ARE_YOU_SURE_YOU_WANT_IMPORT);
        setPositiveButtonText(android.R.string.ok);
        setNegativeButtonText(android.R.string.cancel);

        setDialogIcon(null);
    }


    @Override
    protected void onDialogClosed(boolean positiveResult) {
        super.onDialogClosed(positiveResult);

        if (positiveResult) {

            Log.d("ml Settings", "importing database");
            Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
            intent.setType("*/*");
            intent.addCategory(Intent.CATEGORY_OPENABLE);
            Intent finalIntent = Intent.createChooser(intent, "Select databasefile");
            startActivityForResult(finalIntent, SELECT_DATABASEFILE);
        }
    }


}

But I can't use startActivityForResult as I don't have an Acitivity in my DialogPreference.

c) The best way I could think would just be to have an item like in that opens the intent when clicking

The closest I found help I found was this. It doesn't sound like a great way and si also 3 years old and I don't really get how get the DialogPreference Object in my settings class:

startactivityforresult from dialogpreference (non activity)

Helpfull links:

http://developer.android.com/reference/android/preference/DialogPreference.html

http://developer.android.com/guide/topics/ui/settings.html

Answer 1

I solved it myself. So here is the solution, if someone is interested. I now use Preferences in settings.xml and created onPreferenceClickListener in my fragment.

settings.xml:

<Preference
    android:key="export_database"
    android:summary="@string/exportDatabasefileSummary"
    android:title="@string/exportDatabasefile" />

<Preference
    android:key="import_database"
    android:summary="@string/importDatabaseFromDBSummary"
    android:title="@string/importDatabaseFromDB" />

Fragment:

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    // Load the preferences from an XML resource
    addPreferencesFromResource(R.xml.settings);

    Preference preferenceImportDatabase = findPreference("import_database");
    preferenceImportDatabase.setOnPreferenceClickListener(new Preference.OnPreferenceClickListener() {
        @Override
        public boolean onPreferenceClick(Preference preference) {
            importDatabaseFromDB();
            return false;
        }
    });

    Preference preferenceExportDatabase = findPreference("export_database");
    preferenceExportDatabase.setOnPreferenceClickListener(new Preference.OnPreferenceClickListener() {
        @Override
        public boolean onPreferenceClick(Preference preference) {
            exportDatabasefile();
            return false;
        }
    });
}