Home | History | Annotate | Download | only in app 
      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.apis.app;
     18 
     19 // Need the following import to get access to the app resources, since this
     20 // class is in a sub-package.
     21 import com.example.android.apis.R;
     22 
     23 import android.app.Activity;
     24 import android.content.Intent;
     25 import android.os.Bundle;
     26 import android.view.View;
     27 import android.view.View.OnClickListener;
     28 import android.widget.Button;
     29 
     30 
     31 /**
     32  * <p>Example of removing yourself from the history stack after forwarding to
     33  * another activity. This can be useful, for example, to implement
     34     a confirmation dialog before the user goes on to another activity -- once the
     35     user has confirmed this operation, they should not see the dialog again if they
     36 go back from it.</p>
     37 
     38 <p>Note that another way to implement a confirmation dialog would be as
     39 an activity that returns a result to its caller.  Either approach can be
     40 useful depending on how it makes sense to structure the application.</p>
     41 
     42 <h4>Demo</h4>
     43 App/Activity/Receive Result
     44 
     45 <h4>Source files</h4>
     46 <table class="LinkTable">
     47         <tr>
     48             <td class="LinkColumn">src/com.example.android.apis/app/Forwarding.java</td>
     49             <td class="DescrColumn">Forwards the user to another activity when its button is pressed</td>
     50         </tr>
     51         <tr>
     52             <td class="LinkColumn">/res/any/layout/forwarding.xml</td>
     53             <td class="DescrColumn">Defines contents of the Forwarding screen</td>
     54         </tr>
     55 </table>
     56  */
     57 public class Forwarding extends Activity
     58 {
     59     @Override
     60 	protected void onCreate(Bundle savedInstanceState)
     61     {
     62         super.onCreate(savedInstanceState);
     63 
     64         setContentView(R.layout.forwarding);
     65 
     66         // Watch for button clicks.
     67         Button goButton = (Button)findViewById(R.id.go);
     68         goButton.setOnClickListener(mGoListener);
     69     }
     70 
     71     private OnClickListener mGoListener = new OnClickListener()
     72     {
     73         public void onClick(View v)
     74         {
     75             // Here we start the next activity, and then call finish()
     76             // so that our own will stop running and be removed from the
     77             // history stack.
     78             Intent intent = new Intent();
     79             intent.setClass(Forwarding.this, ForwardTarget.class);
     80             startActivity(intent);
     81             finish();
     82         }
     83     };
     84 }
     85 
     86