Demonstrates how fragments can participate in the options menu. : Menu « UI « Android

1. Android
2. UI
3. Menu

Demonstrates how fragments can participate in the options menu.

  
/*
 * Copyright (C) 2010 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.example.android.apis.app;

import com.example.android.apis.R;

import android.app.Activity;
import android.app.Fragment;
import android.app.FragmentManager;
import android.app.FragmentTransaction;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.CheckBox;

/**
 * Demonstrates how fragments can participate in the options menu.
 */
public class FragmentMenu extends Activity {
    Fragment mFragment1;
    Fragment mFragment2;
    CheckBox mCheckBox1;
    CheckBox mCheckBox2;

    // Update fragment visibility when check boxes are changed.
    final OnClickListener mClickListener = new OnClickListener() {
        public void onClick(View v) {
            updateFragmentVisibility();
        }
    };

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.fragment_menu);
        
        // Make sure the two menu fragments are created.
        FragmentManager fm = getFragmentManager();
        FragmentTransaction ft = fm.beginTransaction();
        mFragment1 = fm.findFragmentByTag("f1");
        if (mFragment1 == null) {
            mFragment1 = new MenuFragment();
            ft.add(mFragment1, "f1");
        }
        mFragment2 = fm.findFragmentByTag("f2");
        if (mFragment2 == null) {
            mFragment2 = new Menu2Fragment();
            ft.add(mFragment2, "f2");
        }
        ft.commit();
        
        // Watch check box clicks.
        mCheckBox1 = (CheckBox)findViewById(R.id.menu1);
        mCheckBox1.setOnClickListener(mClickListener);
        mCheckBox2 = (CheckBox)findViewById(R.id.menu2);
        mCheckBox2.setOnClickListener(mClickListener);
        
        // Make sure fragments start out with correct visibility.
        updateFragmentVisibility();
    }

    @Override
    protected void onRestoreInstanceState(Bundle savedInstanceState) {
        super.onRestoreInstanceState(savedInstanceState);
        // Make sure fragments are updated after check box view state is restored.
        updateFragmentVisibility();
    }

    // Update fragment visibility based on current check box state.
    void updateFragmentVisibility() {
        FragmentTransaction ft = getFragmentManager().beginTransaction();
        if (mCheckBox1.isChecked()) ft.show(mFragment1);
        else ft.hide(mFragment1);
        if (mCheckBox2.isChecked()) ft.show(mFragment2);
        else ft.hide(mFragment2);
        ft.commit();
    }

    /**
     * A fragment that displays a menu.  This fragment happens to not
     * have a UI (it does not implement onCreateView), but it could also
     * have one if it wanted.
     */
    public static class MenuFragment extends Fragment {

        @Override
        public void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setHasOptionsMenu(true);
        }

        @Override
        public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
            menu.add("Menu 1a").setShowAsAction(MenuItem.SHOW_AS_ACTION_IF_ROOM);
            menu.add("Menu 1b").setShowAsAction(MenuItem.SHOW_AS_ACTION_IF_ROOM);
        }
    }

    /**
     * Second fragment with a menu.
     */
    public static class Menu2Fragment extends Fragment {

        @Override
        public void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setHasOptionsMenu(true);
        }

        @Override
        public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
            menu.add("Menu 2").setShowAsAction(MenuItem.SHOW_AS_ACTION_IF_ROOM);
        }
    }
}

//fragment_menu.xml

<?xml version="1.0" encoding="utf-8"?>
<!-- Copyright (C) 2010 The Android Open Source Project

     Licensed under the Apache License, Version 2.0 (the "License");
     you may not use this file except in compliance with the License.
     You may obtain a copy of the License at
  
          http://www.apache.org/licenses/LICENSE-2.0
  
     Unless required by applicable law or agreed to in writing, software
     distributed under the License is distributed on an "AS IS" BASIS,
     WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     See the License for the specific language governing permissions and
     limitations under the License.
-->

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:padding="8dp">

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:textAppearance="?android:attr/textAppearanceMedium"
        android:text="@string/fragment_menu_msg" />

    <CheckBox android:id="@+id/menu1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:checked="true"
        android:text="@string/fragment1menu">
    </CheckBox>
    
    <CheckBox android:id="@+id/menu2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:checked="true"
        android:text="@string/fragment2menu">
    </CheckBox>
    
</LinearLayout>

   
    
  

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