Refactor: Split out ListGroupPreference

Split out the implementation of a string-list preference from
CustomExtraKeysPreference.

Allows to share the implementation with future preferences.

3 files changed, 216 insertions, 144 deletions

diff --git a/srcs/juloo.keyboard2/CustomExtraKeysPreference.java b/srcs/juloo.keyboard2/CustomExtraKeysPreference.java
index 668e6f1..7bbc449 100644
--- a/srcs/juloo.keyboard2/CustomExtraKeysPreference.java
+++ b/srcs/juloo.keyboard2/CustomExtraKeysPreference.java
@@ -17,161 +17,45 @@ import org.json.JSONException;
 
 /** Allows to enter custom keys to be added to the keyboard. This shows up at
     the top of the "Add keys to the keyboard" option. */
-public class CustomExtraKeysPreference extends PreferenceCategory
+public class CustomExtraKeysPreference extends ListGroupPreference
 {
   /** This pref stores a list of strings encoded as JSON. */
-  static String KEY = "custom_extra_keys";
-
-  boolean _attached = false;
-  /** Mutable. This is the list of the key strings, not the key names. */
-  List<String> _keys;
+  static final String KEY = "custom_extra_keys";
 
   public CustomExtraKeysPreference(Context context, AttributeSet attrs)
   {
     super(context, attrs);
     setKey(KEY);
-    setOrderingAsAdded(true);
-    _keys = new ArrayList<String>();
   }
 
   public static List<KeyValue> get(SharedPreferences prefs)
   {
     List<KeyValue> kvs = new ArrayList<KeyValue>();
-    String inp = prefs.getString(KEY, null);
-    if (inp != null)
-      for (String key_name : load_from_string(inp))
-        kvs.add(KeyValue.makeStringKey(key_name));
-    return kvs;
-  }
-
-  @Override
-  protected void onSetInitialValue(boolean restoreValue, Object defaultValue)
-  {
-    if (restoreValue)
+    List<String> key_names = load_from_preferences(KEY, prefs, null);
+    if (key_names != null)
     {
-      String persisted = getPersistedString(null);
-      if (persisted != null)
-        set_keys(load_from_string(persisted), false);
+      for (String key_name : key_names)
+        kvs.add(KeyValue.makeStringKey(key_name));
     }
-    else if (defaultValue != null)
-      set_keys(load_from_string((String)defaultValue), false);
+    return kvs;
   }
 
   @Override
-  protected void onAttachedToActivity()
-  {
-    super.onAttachedToActivity();
-    if (_attached)
-      return;
-    _attached = true;
-    reattach();
-  }
-
-  void reattach()
-  {
-    removeAll();
-    for (String k : _keys)
-      addPreference(this.new CustomExtraKey(getContext(), k));
-    addPreference(this.new AddButton(getContext()));
-  }
-
-  void set_keys(List<String> v, boolean persist)
-  {
-    _keys = v;
-    reattach();
-    if (persist)
-      persistString(save_to_string(_keys));
-  }
-
-  void add_key(String k)
-  {
-    _keys.add(k);
-    set_keys(_keys, true);
-  }
-
-  void remove_key(String k)
-  {
-    _keys.remove(k);
-    set_keys(_keys, true);
-  }
-
-  static String save_to_string(List<String> keys)
-  {
-    return (new JSONArray(keys)).toString();
-  }
-
-  static List<String> load_from_string(String inp)
-  {
-    List<String> keys = new ArrayList<String>();
-    try
-    {
-      JSONArray arr = new JSONArray(inp);
-      for (int i = 0; i < arr.length(); i++)
-        keys.add(arr.getString(i));
-    }
-    catch (JSONException e)
-    {
-      Logs.err_load_custom_extra_keys(e);
-    }
-    return keys;
-  }
-
-  /** A preference with no key that is only intended to be rendered. */
-  final class CustomExtraKey extends Preference implements View.OnClickListener
-  {
-    String _key;
-
-    public CustomExtraKey(Context ctx, String key)
-    {
-      super(ctx);
-      _key = key;
-      setTitle(key);
-      setPersistent(false);
-      setWidgetLayoutResource(R.layout.custom_extra_key_widget);
-    }
-
-    /** Remove-button listener. */
-    @Override
-    public void onClick(View _v)
-    {
-      CustomExtraKeysPreference.this.remove_key(_key);
-    }
-
-    @Override
-    protected View onCreateView(ViewGroup parent)
-    {
-      View v = super.onCreateView(parent);
-      v.findViewById(R.id.btn_custom_extra_key_remove).setOnClickListener(this);
-      return v;
-    }
-  }
-
-  final class AddButton extends Preference
-  {
-    public AddButton(Context ctx)
-    {
-      super(ctx);
-      setPersistent(false);
-      setLayoutResource(R.layout.custom_extra_key_add);
-    }
-
-    @Override
-    protected void onClick()
-    {
-      new AlertDialog.Builder(getContext())
-        .setView(R.layout.custom_extra_key_add_dialog)
-        .setPositiveButton(android.R.string.ok, new DialogInterface.OnClickListener(){
-          public void onClick(DialogInterface dialog, int which)
-          {
-            EditText input = (EditText)((AlertDialog)dialog).findViewById(R.id.key_name);
-            String k = input.getText().toString();
-            if (!k.equals(""))
-              CustomExtraKeysPreference.this.add_key(k);
-          }
-        })
-        .setNegativeButton(android.R.string.cancel, null)
-        .setIcon(android.R.drawable.ic_dialog_alert)
-        .show();
-    }
+  void select(final SelectionCallback callback)
+  {
+    new AlertDialog.Builder(getContext())
+      .setView(R.layout.custom_extra_key_add_dialog)
+      .setPositiveButton(android.R.string.ok, new DialogInterface.OnClickListener(){
+        public void onClick(DialogInterface dialog, int which)
+        {
+          EditText input = (EditText)((AlertDialog)dialog).findViewById(R.id.key_name);
+          final String k = input.getText().toString();
+          if (!k.equals(""))
+            callback.select(k);
+        }
+      })
+    .setNegativeButton(android.R.string.cancel, null)
+      .setIcon(android.R.drawable.ic_dialog_alert)
+      .show();
   }
 }
diff --git a/srcs/juloo.keyboard2/ListGroupPreference.java b/srcs/juloo.keyboard2/ListGroupPreference.java
new file mode 100644
index 0000000..b7f2259
--- /dev/null
+++ b/srcs/juloo.keyboard2/ListGroupPreference.java
@@ -0,0 +1,193 @@
+package juloo.keyboard2;
+
+import android.content.Context;
+import android.content.SharedPreferences;
+import android.preference.Preference;
+import android.preference.PreferenceGroup;
+import android.util.AttributeSet;
+import android.view.View;
+import android.view.ViewGroup;
+import java.util.ArrayList;
+import java.util.List;
+import org.json.JSONArray;
+import org.json.JSONException;
+
+/** A list of preferences where the users can add items to the end and modify
+    and remove items. Backed by a string list. Implement user selection in
+    [select()]. */
+public abstract class ListGroupPreference extends PreferenceGroup
+{
+  boolean _attached = false;
+  List<String> _values;
+
+  public ListGroupPreference(Context context, AttributeSet attrs)
+  {
+    super(context, attrs);
+    setOrderingAsAdded(true);
+    setLayoutResource(R.layout.pref_listgroup_group);
+    _values = new ArrayList<String>();
+  }
+
+  /** Overrideable */
+
+  /** The label to display on the item for a given value. */
+  String label_of_value(String value, int i)
+  {
+    return value;
+  }
+
+  /** Called when an item is added or modified. Returns [null] to cancel the
+      action. */
+  abstract void select(SelectionCallback callback);
+
+  /** Load/save utils */
+
+  /** Read a value saved by preference from a [SharedPreferences] object.
+      Returns [null] on error. */
+  static List<String> load_from_preferences(String key,
+      SharedPreferences prefs, List<String> def)
+  {
+    String s = prefs.getString(key, null);
+    return (s != null) ? load_from_string(s) : def;
+  }
+
+  /** Decode a list of string previously encoded with [save_to_string]. Returns
+      [null] on error. */
+  static List<String> load_from_string(String inp)
+  {
+    try
+    {
+      List<String> l = new ArrayList<String>();
+      JSONArray arr = new JSONArray(inp);
+      for (int i = 0; i < arr.length(); i++)
+        l.add(arr.getString(i));
+      return l;
+    }
+    catch (JSONException e)
+    {
+      return null;
+    }
+  }
+
+  /** Encode a list of string so it can be passed to
+      [Preference.persistString()]. Decode with [load_from_string]. */
+  static String save_to_string(List<String> l)
+  {
+    return (new JSONArray(l)).toString();
+  }
+
+  /** Protected API */
+
+  /** Set the values. If [persist] is [true], persist into the store. */
+  void set_values(List<String> vs, boolean persist)
+  {
+    _values = vs;
+    reattach();
+    if (persist)
+      persistString(save_to_string(vs));
+  }
+
+  void add_item(String v)
+  {
+    _values.add(v);
+    set_values(_values, true);
+  }
+
+  void remove_item(String v)
+  {
+    _values.remove(v);
+    set_values(_values, true);
+  }
+
+  /** Internal */
+
+  @Override
+  protected void onSetInitialValue(boolean restoreValue, Object defaultValue)
+  {
+    String input = (restoreValue) ? getPersistedString(null) : (String)defaultValue;
+    if (input != null)
+    {
+      List<String> values = load_from_string(input);
+      if (values != null)
+        set_values(values, false);
+    }
+  }
+
+  @Override
+  protected void onAttachedToActivity()
+  {
+    super.onAttachedToActivity();
+    if (_attached)
+      return;
+    _attached = true;
+    reattach();
+  }
+
+  void reattach()
+  {
+    removeAll();
+    int i = 0;
+    for (String v : _values)
+    {
+      Item item = this.new Item(getContext(), v);
+      item.setTitle(label_of_value(v, i));
+      addPreference(item);
+      i++;
+    }
+    addPreference(this.new AddButton(getContext()));
+  }
+
+  class Item extends Preference
+  {
+    final String _value;
+
+    public Item(Context ctx, String value)
+    {
+      super(ctx);
+      _value = value;
+      setPersistent(false);
+      setWidgetLayoutResource(R.layout.pref_listgroup_item_widget);
+    }
+
+    @Override
+    protected View onCreateView(ViewGroup parent)
+    {
+      View v = super.onCreateView(parent);
+      v.findViewById(R.id.pref_listgroup_remove_btn)
+        .setOnClickListener(new View.OnClickListener() {
+          @Override
+          public void onClick(View _v)
+          {
+            remove_item(_value);
+          }
+        });
+      return v;
+    }
+  }
+
+  final class AddButton extends Preference
+  {
+    public AddButton(Context ctx)
+    {
+      super(ctx);
+      setPersistent(false);
+      setLayoutResource(R.layout.pref_listgroup_add_btn);
+    }
+
+    @Override
+    protected void onClick()
+    {
+      select(new SelectionCallback() {
+        public void select(String value)
+        {
+          add_item(value);
+        }
+      });
+    }
+  }
+
+  public interface SelectionCallback
+  {
+    public void select(String value);
+  }
+}
diff --git a/srcs/juloo.keyboard2/Logs.java b/srcs/juloo.keyboard2/Logs.java
index ee44e21..c214296 100644
--- a/srcs/juloo.keyboard2/Logs.java
+++ b/srcs/juloo.keyboard2/Logs.java
@@ -26,9 +26,4 @@ public final class Logs
     _debug_logs.println("swapEnterActionKey: "+conf.swapEnterActionKey);
     _debug_logs.println("actionLabel: "+conf.actionLabel);
   }
-
-  public static void err_load_custom_extra_keys(JSONException e)
-  {
-    Log.e(TAG, "Failed to read custom extra keys from preferences", e);
-  }
 }