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      1 /*
      2  * Copyright 2013 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 package com.example.android.activityinstrumentation;
     18 
     19 import android.app.Activity;
     20 import android.content.SharedPreferences;
     21 import android.os.Bundle;
     22 import android.preference.PreferenceManager;
     23 import android.view.View;
     24 import android.widget.AdapterView;
     25 import android.widget.ArrayAdapter;
     26 import android.widget.Spinner;
     27 
     28 import java.util.ArrayList;
     29 import java.util.Arrays;
     30 
     31 /**
     32  * Basic activity with a spinner. The spinner should persist its position to disk every time a
     33  * new selection is made.
     34  */
     35 public class MainActivity extends Activity {
     36 
     37     /** Shared preferences key: Holds spinner position. Must not be negative. */
     38     private static final String PREF_SPINNER_POS = "spinner_pos";
     39     /** Magic constant to indicate that no value is stored for PREF_SPINNER_POS. */
     40     private static final int PREF_SPINNER_VALUE_ISNULL = -1;
     41     /** Values for display in spinner. */
     42     private static final String[] SPINNER_VALUES = new String[] {
     43             "Select Weather...", "Sunny", "Partly Cloudy", "Cloudy", "Rain", "Snow", "Hurricane"};
     44 
     45     // Constants representing each of the options in SPINNER_VALUES. Declared package-private
     46     // so that they can be accessed from our test suite.
     47     static final int WEATHER_NOSELECTION = 0;
     48     static final int WEATHER_SUNNY = 1;
     49     static final int WEATHER_PARTLY_CLOUDY = 2;
     50     static final int WEATHER_CLOUDY = 3;
     51     static final int WEATHER_RAIN = 4;
     52     static final int WEATHER_SNOW = 5;
     53     static final int WEATHER_HURRICANE = 6;
     54 
     55     /** Handle to default shared preferences for this activity. */
     56     private SharedPreferences mPrefs;
     57     /** Handle to the spinner in this Activity's layout. */
     58     private Spinner mSpinner;
     59 
     60     /**
     61      * Setup activity state.
     62      *
     63      * @param savedInstanceState
     64      */
     65     @Override
     66     protected void onCreate(Bundle savedInstanceState) {
     67         super.onCreate(savedInstanceState);
     68 
     69         // Inflate UI from res/layout/activity_main.xml
     70         setContentView(R.layout.sample_main);
     71 
     72         // Get handle to default shared preferences for this activity
     73         mPrefs = PreferenceManager.getDefaultSharedPreferences(MainActivity.this);
     74 
     75         // Populate spinner with sample values from an array
     76         mSpinner = (Spinner) findViewById(R.id.spinner);
     77         mSpinner.setAdapter(
     78                 new ArrayAdapter<String>(
     79                         this,                                                   // Context
     80                         android.R.layout.simple_list_item_1,                    // Layout
     81                         new ArrayList<String>(Arrays.asList(SPINNER_VALUES))    // Data source
     82                 ));
     83 
     84         // Read in a sample value, if it's not set.
     85         int selection = mPrefs.getInt(PREF_SPINNER_POS, PREF_SPINNER_VALUE_ISNULL);
     86         if (selection != PREF_SPINNER_VALUE_ISNULL) {
     87             mSpinner.setSelection(selection);
     88         }
     89 
     90         // Callback to persist spinner data whenever a new value is selected. This will be the
     91         // focus of our sample unit test.
     92         mSpinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
     93 
     94             // The methods below commit the ID of the currently selected item in the spinner
     95             // to disk, using a SharedPreferences file.
     96             //
     97             // Note: A common mistake here is to forget to call .commit(). Try removing this
     98             // statement and running the tests to watch them fail.
     99             @Override
    100             public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
    101                 mPrefs.edit().putInt(PREF_SPINNER_POS, position).commit();
    102             }
    103 
    104             @Override
    105             public void onNothingSelected(AdapterView<?> parent) {
    106                 mPrefs.edit().remove(PREF_SPINNER_POS).commit();
    107             }
    108         });
    109     }
    110 }
    111