Refine design for preference package

src/main/scala/be/mygod/preference/DialogPreferencePlus.scala

@@ -0,0 +1,8 @@
+package be.mygod.preference
+
+import android.app.DialogFragment
+import android.support.v7.preference.DialogPreference
+
+trait DialogPreferencePlus extends DialogPreference {
+  def createDialog(): DialogFragment
+}

src/main/scala/be/mygod/preference/EditTextPreference.scala

@@ -11,10 +11,12 @@ import android.util.AttributeSet
   * Based on: https://github.com/Gericop/Android-Support-Preference-V7-Fix/tree/master/app/src/main/java/android/support/v7/preference
   */
 class EditTextPreference(context: Context, attrs: AttributeSet = null) extends Parent(context, attrs)
-  with SummaryPreference {
+  with DialogPreferencePlus with SummaryPreference {
   val editText = new AppCompatEditText(context, attrs)
   editText.setId(android.R.id.edit)
 
+  override def createDialog() = new EditTextPreferenceDialogFragment()
+
   override protected def getSummaryValue = {
     var text = getText
     if (text == null) text = ""

src/main/scala/be/mygod/preference/NumberPickerPreference.scala

@@ -9,7 +9,7 @@ import android.widget.NumberPicker
 import com.github.shadowsocks.R
 
 class NumberPickerPreference(private val context: Context, attrs: AttributeSet = null)
-  extends DialogPreference(context, attrs) with SummaryPreference {
+  extends DialogPreference(context, attrs) with DialogPreferencePlus with SummaryPreference {
   private[preference] val picker = new NumberPicker(new ContextThemeWrapper(context, R.style.NumberPickerStyle))
   private var value: Int = _
 
@@ -20,6 +20,8 @@ class NumberPickerPreference(private val context: Context, attrs: AttributeSet =
     a.recycle
   }
 
+  override def createDialog() = new NumberPickerPreferenceDialogFragment()
+
   def getValue = value
   def getMin = if (picker == null) 0 else picker.getMinValue
   def getMax = picker.getMaxValue

src/main/scala/be/mygod/preference/PreferenceFragment.scala

@@ -3,7 +3,7 @@ package be.mygod.preference
 import android.app.DialogFragment
 import android.os.Bundle
 import android.support.v14.preference.{PreferenceFragment => Base}
-import android.support.v7.preference.PreferenceScreen
+import android.support.v7.preference.{Preference, PreferenceScreen}
 import android.view.{LayoutInflater, ViewGroup}
 
 abstract class PreferenceFragment extends Base {
@@ -20,6 +20,11 @@ abstract class PreferenceFragment extends Base {
       .commitAllowingStateLoss()
   }
 
+  override def onDisplayPreferenceDialog(preference: Preference) = preference match {
+    case dpp: DialogPreferencePlus => displayPreferenceDialog(preference.getKey, dpp.createDialog())
+    case _ => super.onDisplayPreferenceDialog(preference)
+  }
+
   override protected def onCreateAdapter(screen: PreferenceScreen) = new PreferenceGroupAdapter(screen)
 
   override def onResume {

src/main/scala/com/github/shadowsocks/ShadowsocksSettings.scala

@@ -203,12 +203,8 @@ class ShadowsocksSettings extends PreferenceFragment with OnSharedPreferenceChan
     })
   }
 
-  override def onDisplayPreferenceDialog(preference: Preference) = preference match {
-    case _: EditTextPreference => displayPreferenceDialog(preference.getKey,
-      if (preference.getKey == Key.kcpcli) new KcpCliPreferenceDialogFragment()
-      else new EditTextPreferenceDialogFragment())
-    case _: NumberPickerPreference =>
-      displayPreferenceDialog(preference.getKey, new NumberPickerPreferenceDialogFragment())
+  override def onDisplayPreferenceDialog(preference: Preference) = preference.getKey match {
+    case Key.kcpcli => displayPreferenceDialog (Key.kcpcli, new KcpCliPreferenceDialogFragment () )
     case _ => super.onDisplayPreferenceDialog(preference)
   }