1 /* 2 * Copyright (C) 2007 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package com.example.android.skeletonapp; 18 19 import android.app.Activity; 20 import android.os.Bundle; 21 import android.view.KeyEvent; 22 import android.view.Menu; 23 import android.view.MenuItem; 24 import android.view.View; 25 import android.view.View.OnClickListener; 26 import android.widget.Button; 27 import android.widget.EditText; 28 29 /** 30 * This class provides a basic demonstration of how to write an Android 31 * activity. Inside of its window, it places a single view: an EditText that 32 * displays and edits some internal text. 33 */ 34 public class SkeletonActivity extends Activity { 35 36 static final private int BACK_ID = Menu.FIRST; 37 static final private int CLEAR_ID = Menu.FIRST + 1; 38 39 private EditText mEditor; 40 SkeletonActivity()41 public SkeletonActivity() { 42 } 43 44 /** Called with the activity is first created. */ 45 @Override onCreate(Bundle savedInstanceState)46 public void onCreate(Bundle savedInstanceState) { 47 super.onCreate(savedInstanceState); 48 49 // Inflate our UI from its XML layout description. 50 setContentView(R.layout.skeleton_activity); 51 52 // Find the text editor view inside the layout, because we 53 // want to do various programmatic things with it. 54 mEditor = (EditText) findViewById(R.id.editor); 55 56 // Hook up button presses to the appropriate event handler. 57 ((Button) findViewById(R.id.back)).setOnClickListener(mBackListener); 58 ((Button) findViewById(R.id.clear)).setOnClickListener(mClearListener); 59 60 mEditor.setText(getText(R.string.main_label)); 61 } 62 63 /** 64 * Called when the activity is about to start interacting with the user. 65 */ 66 @Override onResume()67 protected void onResume() { 68 super.onResume(); 69 } 70 71 /** 72 * Called when your activity's options menu needs to be created. 73 */ 74 @Override onCreateOptionsMenu(Menu menu)75 public boolean onCreateOptionsMenu(Menu menu) { 76 super.onCreateOptionsMenu(menu); 77 78 // We are going to create two menus. Note that we assign them 79 // unique integer IDs, labels from our string resources, and 80 // given them shortcuts. 81 menu.add(0, BACK_ID, 0, R.string.back).setShortcut('0', 'b'); 82 menu.add(0, CLEAR_ID, 0, R.string.clear).setShortcut('1', 'c'); 83 84 return true; 85 } 86 87 /** 88 * Called right before your activity's option menu is displayed. 89 */ 90 @Override onPrepareOptionsMenu(Menu menu)91 public boolean onPrepareOptionsMenu(Menu menu) { 92 super.onPrepareOptionsMenu(menu); 93 94 // Before showing the menu, we need to decide whether the clear 95 // item is enabled depending on whether there is text to clear. 96 menu.findItem(CLEAR_ID).setVisible(mEditor.getText().length() > 0); 97 98 return true; 99 } 100 101 /** 102 * Called when a menu item is selected. 103 */ 104 @Override onOptionsItemSelected(MenuItem item)105 public boolean onOptionsItemSelected(MenuItem item) { 106 switch (item.getItemId()) { 107 case BACK_ID: 108 finish(); 109 return true; 110 case CLEAR_ID: 111 mEditor.setText(""); 112 return true; 113 } 114 115 return super.onOptionsItemSelected(item); 116 } 117 118 /** 119 * A call-back for when the user presses the back button. 120 */ 121 OnClickListener mBackListener = new OnClickListener() { 122 public void onClick(View v) { 123 finish(); 124 } 125 }; 126 127 /** 128 * A call-back for when the user presses the clear button. 129 */ 130 OnClickListener mClearListener = new OnClickListener() { 131 public void onClick(View v) { 132 mEditor.setText(""); 133 } 134 }; 135 } 136