[VIDEO-Tut] Building an Contact-Caller App in Minutes

plusminus · by **plusminus** » Thu Nov 15, 2007 5:08 pm

Building a Conact-List Caller Application

What is this: This tutorial shows how to create a ListActivity-Application, where your contact list is loaded to the List-Based View and when you click one of the contacts an Intent is sent to call that person.
What you learn: You will learn how easy it is, to create Intents and how to use ListActivities.

:idea:

Designed/Tested with sdk-version: m5-rc14

Difficulty: 1 of 5

What it will look like:

And this video shows you how to accomplish it:

Here is the source-code created during the video-tutorial:
File: HelloAndroid.java @ package: org.anddev.android.hello

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package org.anddev.android.hello;
 
import android.app.ListActivity;
import android.content.ContentUris;
import android.content.Intent;
import android.database.Cursor;
import android.os.Bundle;
import android.provider.Contacts.People;
import android.view.View;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.SimpleCursorAdapter;
 
public class HelloAndroid extends ListActivity {
   
     private ListAdapter mAdapter;
     
      /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle icicle) {
        super.onCreate(icicle);
        Cursor c = getContentResolver().query(People.CONTENT_URI, null, null, null, null);
        startManagingCursor(c);
       
        String[] columns = new String[]{People.NAME}; // Comment
        int[] names = new int[]{R.id.row_entry};
       
        mAdapter = new SimpleCursorAdapter(this, R.layout.main, c, columns, names);
       
        this.setListAdapter(mAdapter);
    }
   
    @Override
    protected void onListItemClick(ListView l, View v, int position, long id){
     super.onListItemClick(l, v, position, id);
     
     Intent i = new Intent(Intent.CALL_ACTION);
     
     Cursor c = (Cursor) mAdapter.getItem(position);
     long phoneID = c.getLong(c.getColumnIndex(People.PREFERRED_PHONE_ID));
     
     i.setData(ContentUris.withAppendedId(
          android.provider.Contacts.Phones.CONTENT_URI, phoneID));
     
     this.startActivity(i);
    }
}
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Main.xml @ folder: res.layout

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<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="horizontal"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    >
<TextView  
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:text="Name: "
    />
<TextView  
    android:id="@+id/row_entry"
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    />
</LinearLayout>
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AndroidManifest.xml @ root-folder

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<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="org.anddev.android.hello">
    <uses-permission android:name="android.permission.READ_CONTACTS"/>
    <uses-permission android:name="android.permission.CALL_PHONE"/>
    <application android:icon="@drawable/icon">
        <activity android:name=".HelloAndroid" android:label="@string/app_name">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>
</manifest> 
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Regards,
plusminus

Marek · by **Marek** » Thu Nov 15, 2007 8:26 pm

Nice one. Thanks for posting the tutorial.

mrocket · by **mrocket** » Thu Nov 15, 2007 11:23 pm

Huh, i like these tutorials, got so many pictures and comments!

Even I can understand them :roll:

Cya...

Mark · by **Mark** » Fri Nov 16, 2007 4:56 pm

I really like this style of tutorials.

: ) good~

atr · by **atr** » Mon Nov 19, 2007 11:40 am

i know the tutorial is really easy. I get it run, but there are no names, no numbers. it's just white blank display. I done copy paste the exact same source code. any idea? did i miss something?
thank you for suggestion.

plusminus · by **plusminus** » Mon Nov 19, 2007 3:11 pm

atr wrote:i know the tutorial is really easy. I get it run, but there are no names, no numbers. it's just white blank display. I done copy paste the exact same source code. any idea? did i miss something?
thank you for suggestion.

Hi atr,

seems like you didn't add contacts in the emulator, i wondered too on my first try.
Simply select the Contacts-Icon in the Home-Window (the very first with the mountain in the background) and add some Contacts there.

Think that helped...?

Regards,
plusminus

atr · by **atr** » Tue Nov 20, 2007 1:22 pm

Yep its done! Thank you

Ghalya · by **Ghalya** » Mon Feb 11, 2008 8:22 pm

Hi Mr. PLusMiuns,

Thx for ur nice tutorial when I implement it everything go smoothly UNTIL I decide to change the GUI in order to understand the ActivityList and how the ListAdapter work.

See this is the idea to improve the prototype

So based on that, I change the main.xml file to:

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<?xml version="1.0" encoding="utf-8"?> 
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 
    android:orientation="vertical" 
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content" 
    > 
 
<TextView  id="@+id/row_entry" 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    />
<TextView  id="@+id/location" 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
       android:visibility="gone" />
<TextView  id="@+id/number" 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
   android:foreground="#7B7C7D"
      android:visibility="gone" 
    / 
</LinearLayout>
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And change the onCreate method in the java file to:

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    @Override 
    public void onCreate(Bundle icicle) { 
        super.onCreate(icicle); 
        
        Cursor c = getContentResolver().query(People.CONTENT_URI, null, null, null, null); 
        startManagingCursor(c); 
        
        String[] columns = new String[]{People.NAME,People.USER_STATUS, People.NUMBER};
        int[] names = new int[]{R.id.row_entry,R.id.location,R.id.number}; 
  
        mAdapter = new SimpleCursorAdapter(this, R.layout.main, c, columns,names ); 
        
        this.setListAdapter(mAdapter);        
    }    
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Notice I got problem in getting the correct value for contact location.

Also I override onKeyDown and onKeyUp method to implement on select item. I know by using set visiabilty I can make it. But the problem I dunno how to get the specific view from ListAdapter in order to change it. I tried getitem(), findViewbyID and many other ways, but all failed >.<

Therefore, I counting in you to help me in solving this issue. It may seem easy to u, cause u already knowledgeable enough with this platform =P

Thanks in advance.

Best Regards,
Ghalya

code · by **code** » Mon Feb 11, 2008 9:59 pm

First, thanks Mr. PLusMiuns for this tutorial, it works fine with me and I learned from it

Regarding the problem that was posted by Ms. Ghalya, I tried to find a solution for it. Here is what I have added to your code:

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               @Override
        public boolean onKeyDown(int keyCode, KeyEvent event) {
                if (selectedTV != null)
                        selectedTV.setVisibility(View.GONE);
 
                View vv = this.getListView().getSelectedView();
                TextView tv = (TextView) vv.findViewById(R.id.number);
                tv.setVisibility(View.VISIBLE);
                selectedTV = tv;
                return true;
        }
 
 
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BUT :( I do not know how to do that for the selected list item when the application starts. I tried many ways to get the first list item, but it always give me NullPointerException

Am a beginner in Android, so could someone tell me how can I get the selected list item when the application start??

plusminus · by **plusminus** » Mon Feb 11, 2008 10:13 pm

Hello code,

did you place your tries behind this line:

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this.setListAdapter(mAdapter);
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I haven't tested it, but it still could not work, because perhaps we just set the Adapter and when when code returns from the onCreate to whatever is above (we cannot know, because the sources are not open

) the List gets filled.

Regards,
plusminus

code · by **code** » Mon Feb 11, 2008 10:43 pm

Yes all my tries were placed after this line

So, where could I place it??

Ghalya · by **Ghalya** » Tue Feb 12, 2008 12:30 pm

thx CODE for ur solution

plusminus · by **plusminus** » Tue Feb 12, 2008 1:47 pm

Hello code,

perhaps a bit delayed, when application is fully created, i.e. using a

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new Handler().postDelayed(Runnable r, long ms)
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Regards,
plusminus

code · by **code** » Tue Feb 12, 2008 3:07 pm

I tried what you suggest plusminus, and this here where I added it:

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                                this.setListAdapter(mAdapter);
 
                new Handler().postDelayed(null, 100000);
 
                View vv = (View) this.getListView().getSelectedView();
 
                TextView tv = (TextView) vv.findViewById(R.id.row_entry);
 
                tv.setVisibility(View.VISIBLE); selectedTV = tv;
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but the same exception

NullPointer

Did I added the delay in wrong way?? or in worng place??

Thanks plusminus for your help

regards,
code

plusminus · by **plusminus** » Tue Feb 12, 2008 3:32 pm

Hello code,

sorry I should have specified further. I meant like this:

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                new Handler().postDelayed(new Runnable(){
 
                        @Override
 
                        public void run() {
 
                                /* Create an Intent that will start the Menu-Activity. */
 
                                Intent mainIntent = new Intent(Splash.this,Menu.class);
 
                                Splash.this.startActivity(mainIntent);
 
                                Splash.this.finish();
 
                        }
 
                }, SPLASH_DISPLAY_LENGHT);
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it will cause the GUI-Thread to execute the Runnable after X milliseconds.

Regards,
plusminus

[VIDEO-Tut] Building an Contact-Caller App in Minutes

[VIDEO-Tut] Building an Contact-Caller App in Minutes

I like it.

Names won't display

Re: Names won't display

Done

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