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