3.11 Add fully functional units setting

Author: sdspikes

app/src/main/java/com/example/android/sunshine/app/ForecastFragment.java

@@ -145,7 +145,15 @@ private String getReadableDateString(long time){
         /**
          * Prepare the weather high/lows for presentation.
          */
-        private String formatHighLows(double high, double low) {
+        private String formatHighLows(double high, double low, String unitType) {
+
+            if (unitType.equals(getString(R.string.pref_units_imperial))) {
+                high = (high * 1.8) + 32;
+                low = (low * 1.8) + 32;
+            } else if (!unitType.equals(getString(R.string.pref_units_metric))) {
+                Log.d(LOG_TAG, "Unit type not found: " + unitType);
+            }
+
             // For presentation, assume the user doesn't care about tenths of a degree.
             long roundedHigh = Math.round(high);
             long roundedLow = Math.round(low);
@@ -193,6 +201,18 @@ private String[] getWeatherDataFromJson(String forecastJsonStr, int numDays)
             dayTime = new Time();
 
             String[] resultStrs = new String[numDays];
+
+            // Data is fetched in Celsius by default.
+            // If user prefers to see in Fahrenheit, convert the values here.
+            // We do this rather than fetching in Fahrenheit so that the user can
+            // change this option without us having to re-fetch the data once
+            // we start storing the values in a database.
+            SharedPreferences sharedPrefs =
+                    PreferenceManager.getDefaultSharedPreferences(getActivity());
+            String unitType = sharedPrefs.getString(
+                    getString(R.string.pref_units_key),
+                    getString(R.string.pref_units_metric));
+
             for(int i = 0; i < weatherArray.length(); i++) {
                 // For now, using the format "Day, description, hi/low"
                 String day;
@@ -220,7 +240,7 @@ private String[] getWeatherDataFromJson(String forecastJsonStr, int numDays)
                 double high = temperatureObject.getDouble(OWM_MAX);
                 double low = temperatureObject.getDouble(OWM_MIN);
 
-                highAndLow = formatHighLows(high, low);
+                highAndLow = formatHighLows(high, low, unitType);
                 resultStrs[i] = day + " - " + description + " - " + highAndLow;
             }
             return resultStrs;

app/src/main/java/com/example/android/sunshine/app/SettingsActivity.java

@@ -41,6 +41,7 @@ public void onCreate(Bundle savedInstanceState) {
         // For all preferences, attach an OnPreferenceChangeListener so the UI summary can be
         // updated when the preference changes.
         bindPreferenceSummaryToValue(findPreference(getString(R.string.pref_location_key)));
+        bindPreferenceSummaryToValue(findPreference(getString(R.string.pref_units_key)));
     }
 
     /**

app/src/main/res/values/arrays.xml

@@ -0,0 +1,13 @@
+<?xml version="1.0" encoding="utf-8"?>
+<resources>
+
+    <string-array name="pref_units_options">
+        <item>@string/pref_units_label_metric</item>
+        <item>@string/pref_units_label_imperial</item>
+    </string-array>
+
+    <string-array name="pref_units_values">
+        <item>@string/pref_units_metric</item>
+        <item>@string/pref_units_imperial</item>
+    </string-array>
+</resources>

app/src/main/res/values/strings.xml

@@ -28,4 +28,22 @@
     <!-- Default postal code for location preference [CHAR LIMIT=NONE] -->
     <string name="pref_location_default" translatable="false">94043</string>
 
+    <!-- Label for the temperature units preference [CHAR LIMIT=30] -->
+    <string name="pref_units_label">Temperature Units</string>
+
+    <!-- Label for metric option in temperature unit preference [CHAR LIMIT=25] -->
+    <string name="pref_units_label_metric">Metric</string>
+
+    <!-- Label for imperial option in temperature unit preference [CHAR LIMIT=25] -->
+    <string name="pref_units_label_imperial">Imperial</string>
+
+    <!-- Key name for temperature unit preference in SharedPreferences [CHAR LIMIT=NONE] -->
+    <string name="pref_units_key" translatable="false">units</string>
+
+    <!-- Value in SharedPreferences for metric temperature unit option [CHAR LIMIT=NONE] -->
+    <string name="pref_units_metric" translatable="false">metric</string>
+
+    <!-- Value in SharedPreferences for imperial temperature unit option [CHAR LIMIT=NONE] -->
+    <string name="pref_units_imperial" translatable="false">imperial</string>
+
 </resources>

app/src/main/res/xml/pref_general.xml

@@ -10,4 +10,11 @@
         android:inputType="text"
         android:singleLine="true" />
 
+    <ListPreference
+        android:title="@string/pref_units_label"
+        android:key="@string/pref_units_key"
+        android:defaultValue="@string/pref_units_metric"
+        android:entryValues="@array/pref_units_values"
+        android:entries="@array/pref_units_options" />
+
 </PreferenceScreen>