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 /* This Source Code Form is subject to the terms of the Mozilla Public

  * License, v. 2.0. If a copy of the MPL was not distributed with this

  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

 package org.mozilla.gecko.preferences;

 import org.mozilla.gecko.R;

 import android.app.AlertDialog;

 import android.content.Context;

 import android.content.DialogInterface;

 import android.content.res.Resources;

 import android.preference.Preference;

 import android.view.View;

 import android.widget.TextView;

 /**

  * Represents an element in a <code>CustomListCategory</code> preference menu.

  * This preference con display a dialog when clicked, and also supports

  * being set as a default item within the preference list category.

  */

 public abstract class CustomListPreference extends Preference implements View.OnLongClickListener {

     protected String LOGTAG = "CustomListPreference";

     // Indices of the buttons of the Dialog.

     public static final int INDEX_SET_DEFAULT_BUTTON = 0;

     // Dialog item labels.

     private String[] mDialogItems;

     // Dialog displayed when this element is tapped.

     protected AlertDialog mDialog;

     // Cache label to avoid repeated use of the resource system.

     protected final String LABEL_IS_DEFAULT;

     protected final String LABEL_SET_AS_DEFAULT;

     protected final String LABEL_REMOVE;

     protected boolean mIsDefault;

     // Enclosing parent category that contains this preference.

     protected final CustomListCategory mParentCategory;

     /**

      * Create a preference object to represent a list preference that is attached to

      * a category.

      *

      * @param context The activity context we operate under.

      * @param parentCategory The PreferenceCategory this object exists within.

      */

     public CustomListPreference(Context context, CustomListCategory parentCategory) {

         super(context);

         mParentCategory = parentCategory;

         setLayoutResource(getPreferenceLayoutResource());

         setOnPreferenceClickListener(new OnPreferenceClickListener() {

             @Override

             public boolean onPreferenceClick(Preference preference) {

                 CustomListPreference sPref = (CustomListPreference) preference;

                 sPref.showDialog();

                 return true;

             }

         });

         Resources res = getContext().getResources();

         // Fetch these strings now, instead of every time we ever want to relabel a button.

         LABEL_IS_DEFAULT = res.getString(R.string.pref_default);

         LABEL_SET_AS_DEFAULT = res.getString(R.string.pref_dialog_set_default);

         LABEL_REMOVE = res.getString(R.string.pref_dialog_remove);

     }

     /**

      * Returns the Android resource id for the layout.

      */

     protected abstract int getPreferenceLayoutResource();

     /**

      * Set whether this object's UI should display this as the default item.

      * Note: This must be called from the UI thread because it touches the view hierarchy.

      *

      * To ensure proper ordering, this method should only be called after this Preference

      * is added to the PreferenceCategory.

      *

      * @param isDefault Flag indicating if this represents the default list item.

      */

     public void setIsDefault(boolean isDefault) {

         mIsDefault = isDefault;

         if (isDefault) {

             setOrder(0);

             setSummary(LABEL_IS_DEFAULT);

         } else {

             setOrder(1);

             setSummary("");

         }

     }

     private String[] getCachedDialogItems() {

         if (mDialogItems == null) {

             mDialogItems = createDialogItems();

         }

         return mDialogItems;

     }

     /**

      * Returns the strings to be displayed in the dialog.

      */

     abstract protected String[] createDialogItems();

     /**

      * Display a dialog for this preference, when the preference is clicked.

      */

     public void showDialog() {

         final AlertDialog.Builder builder = new AlertDialog.Builder(getContext());

         builder.setTitle(getTitle().toString());

         builder.setItems(getCachedDialogItems(), new DialogInterface.OnClickListener() {

             // Forward relevant events to the container class for handling.

             @Override

             public void onClick(DialogInterface dialog, int indexClicked) {

                 hideDialog();

                 onDialogIndexClicked(indexClicked);

             }

         });

         configureDialogBuilder(builder);

         // We have to construct the dialog itself on the UI thread.

         mDialog = builder.create();

         mDialog.setOnShowListener(new DialogInterface.OnShowListener() {

             // Called when the dialog is shown (so we're finally able to manipulate button enabledness).

             @Override

             public void onShow(DialogInterface dialog) {

                 configureShownDialog();

             }

         });

         mDialog.show();

     }

     /**

      * (Optional) Configure the AlertDialog builder.

      */

     protected void configureDialogBuilder(AlertDialog.Builder builder) {

         return;

     }

     abstract protected void onDialogIndexClicked(int index);

     /**

      * Disables buttons in the shown AlertDialog as required. The button elements are not created

      * until after show is called, so this method has to be called from the onShowListener above.

      * @see this.showDialog

      */

     protected void configureShownDialog() {

         // If this is already the default list item, disable the button for setting this as the default.

         final TextView defaultButton = (TextView) mDialog.getListView().getChildAt(INDEX_SET_DEFAULT_BUTTON);

         if (mIsDefault) {

             defaultButton.setEnabled(false);

             // Failure to unregister this listener leads to tapping the button dismissing the dialog

             // without doing anything.

             defaultButton.setOnClickListener(null);

         }

     }

     /**

      * Hide the dialog we previously created, if any.

      */

     public void hideDialog() {

         if (mDialog != null && mDialog.isShowing()) {

             mDialog.dismiss();

         }

     }

     @Override

     public boolean onLongClick(View view) {

         // Show the preference dialog on long-press.

         showDialog();

         return true;

     }

 }