SeekBarPreference: support resetting to the default value.

android/res/layout/seekbar_preference.xml

         android:layout_height="0dp"
         android:layout_weight="1" />
 
+    <LinearLayout
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        android:layout_weight="1" >
+
+        <Button
+            android:id="@+id/resetToDefault"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:layout_gravity="bottom"
+            android:layout_weight="1"
+            android:text="@string/resetToDefault" />
+
+    </LinearLayout>
+
 </LinearLayout>

android/res/values/strings.xml

         <string name="espeak_volume">Volume</string>
         <string name="formatter_wpm">%s WPM</string>
         <string name="formatter_percentage">%s%%</string>
+        <string name="resetToDefault">Set to default</string>
 
 </resources>

android/src/com/reecedunn/espeak/SeekBarPreference.java

 import android.preference.DialogPreference;
 import android.util.AttributeSet;
 import android.view.View;
+import android.widget.Button;
 import android.widget.SeekBar;
 import android.widget.TextView;
 
     private TextView mValueText;
 
     private int mProgress = 0;
+    private int mDefaultValue = 0;
     private int mMin = 0;
     private int mMax = 100;
     private String mFormatter = "%s";
         callChangeListener(text);
     }
 
+    public void setDefaultValue(int defaultValue) {
+        mDefaultValue = defaultValue;
+    }
+
+    public int getDefaultValue() {
+        return mDefaultValue;
+    }
+
     public int getMin() {
         return mMin;
     }
         View root = super.onCreateDialogView();
         mSeekBar = (SeekBar)root.findViewById(R.id.seekBar);
         mValueText = (TextView)root.findViewById(R.id.valueText);
+
+        Button reset = (Button)root.findViewById(R.id.resetToDefault);
+        reset.setOnClickListener(new View.OnClickListener(){
+            @Override
+            public void onClick(View v)
+            {
+                mSeekBar.setProgress(getDefaultValue());
+            }
+        });
         return root;
     }
 

android/src/com/reecedunn/espeak/TtsSettingsActivity.java

 
     private static Preference createPreference(Context context, SpeechSynthesis.Parameter parameter, String key, int titleRes) {
         final String title = context.getString(titleRes);
+        final int defaultValue = parameter.getDefaultValue();
 
         final SeekBarPreference pref = new SeekBarPreference(context);
         pref.setTitle(title);
 
         pref.setMin(parameter.getMinValue());
         pref.setMax(parameter.getMaxValue());
+        pref.setDefaultValue(defaultValue);
 
         final SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(context);
         final String prefString = prefs.getString(key, null);
         if (prefString == null) {
-            pref.setProgress(parameter.getDefaultValue());
+            pref.setProgress(defaultValue);
         } else {
             pref.setProgress(Integer.parseInt(prefString));
         }