Saturday, 27 September 2014

DAY 8 : REMEMBER SYNTAX TO CALL AN ACTION IN ACTIVITY

HELLO BUDDS!!!

WELCOME BACK HERE!!!

I HAVE SOLUTION FOR ALL THE ACTIONS WHICH WILL BE CALL IN ACTIVIT'Y/IES!!!
1. Register Activity : [AndroidManifest.xml]
            <activity android:name=".SecondActivity" android:label="@string/app_name">

      </activity>

2. Create An Intent : [<activityClassNAme.java>]
      startActivity(new Intent("second"));

3. Button: [<activityClassNAme.java>]
            Button mybtn=(Button)findViewById(R.id.button);

4. ClickListener:[<activityClassNAme.java>]
      1. after "extends Activity" "implements OnClickListene"
     
      2. mybtn.setOnClickListener(this);
      // outside function & inside activity class
      public void onClick(View v) {
            startActivity(new Intent("second"));     
      }

5. SecondActivity:[<activityClassNAme.java>]
            @Override
            protected void onCreate(Bundle savedInstanceState) {
                        super.onCreate(savedInstanceState);
                        setContentView(R.layout.second);
            }

6. ListView:
            1.  import android.app.ListActivity;
      2. extends ListActivity{  //not Activity this time
      3. String str[]={"One","Two"};
          setListAdapter(new ArrayAdapter<String>(this,           R.layout.main,R.id.label,str));
      4. [in "main.xml" at "res->layout->"]
            <TextView  …..
             /TextView>

7. Toast
      Toast.makeText(this,”Your Message”,Toast.Length_Short).show();

8. Alert
      AlertDialog.Builder alert = new AlertDialog.Builder(AlertDemoActivity.this);
      alert.setTitle("My Alert of Tsunami");
      alert.setMessage("No need to worry about Tsunami. It's Safe.");
      alert.setIcon(R.drawable.geekslab_icon);
      alert.show();


All the codes can be found in given applications

Wednesday, 17 September 2014

DAY 7 : ANDROID SDK - Android Sample Apps

The Android SDK includes many sample apps that can help you learn Android by inspecting how different APIs are used to build a mobile application. These sample apps are available for download through the Android SDK Manager. Learn how to easily create Eclipse projects around these sample apps, compile them, and use them in your own projects.

Part 0: Getting Started

This tutorial is for the Java developer just getting started learning Android app development, who is familiar with Eclipse, and who has installed the Android SDK with the Android Developer Plugin for Eclipse. 

Step 1: Download the Android Samples

The Android SDK Samples can be downloaded using the Android SDK Manager. The samples are organized by the API Level they were designed for, and can be downloaded under the label "Samples for SDK". On a related note, the Google API add-on downloads tend to come with samples specifically to illustrate their usage.
As you're aware, the Android SDK Manager downloads samples into a directory under your SDK installation. You could use these to start the project. You could even copy them out so you don't modify the originals. But, that's not how we're going to do it! There’s a better way!

Step 2: Start the Sample Project Wizard

In Eclipse, choose File > New > Other..., then expand the Android folder, and choose "Android Sample Project".

Step 3: Pick a Build Target

Next, you'll be presented with a list of build targets. What you see here is directly related to which API Level samples you have installed through the Android SDK Manager. What you see in our screenshot is probably overkill. Few will want to target Android 1.1 (Really).

You can only choose one build target for your project. To follow along, choose Android 4.1, Android Open Source Project, which is API Level 16.

Step 4: Pick a Sample Project

On the next screen, you'll be shown a variety of compatible sample projects to choose from. Projects that end in "> tests" are JUnit test projects that match up to a primary project. They are less interesting for the beginner, so stick to non-test projects for now.
Pick a sample project, then type in a name if you'd like to change it. Changing the name is useful if you've already created the sample project once and want to create a new version within the sample Eclipse workspace. To continue following along, pick ApiDemos. We're naming it "ApiDemo 4.1" so as not to confuse it with other ApiDemos samples from other SDK versions.

Step 5: Explore a Sample Project
Your new project will now show up in Eclipse. You can look through its files, packages, and the structure of the sample app. The ApiDemos sample app is particularly big, as it has sample code to demonstrate almost every core Android API.

Step 6: Launch a Sample Project

Let's compile and launch our new sample project on the emulator. First, start your emulator and wait for it to fully launch (forget how this works? See here...)
Next, choose Run > Run Configurations...

Double-click on Android Application (or right-click and choose New). On the first tab, choose the Browse... button, pick your new sample project, and click OK.



Now fill in the Name field. We usually name our Run Configurations with the project name to avoid confusion but you can name it whatever you like. Run and Debug Configurations have different options such that you could want multiple configurations for a single project.


On the Target tab, check the radio button for "Always prompt to pick device." Take note of some of the other Run Configuration options, like the network speed and latency; we're not going to use any of these options right now but it’s worth knowing where they are.


Now click the Run button. You should get the Android Device Chooser dialog now. This dialog will display any currently connected Android devices and running emulator instances in the top section, as well as offer the option of launching a new emulator instance via a compatible AVD configuration on-the-fly.




Pick the emulator you already have running and click the OK button. You'll see something like, "Uploading ApiDemo 4.1.apk onto device 'emulator-5554'" in the Eclipse console while the binary is being copied to the emulator and installed. After a moment, the ApiDemos sample app will launch within the emulator.

Tip: If the app doesn't launch, but instead you see an error such as "Re-installation failed due to different application signatures", then you need to uninstall an existing version. ApiDemos sometimes exists on otherwise clean emulator images. Forcefully uninstall the previous version by using the adb command-line tool with the following options: "adb -e uninstall com.example.android.apis"

Step 7: Try More Sample Apps

Now that you know how to create an Eclipse project for and run an Android SDK sample app, you can create any that you'd like. Remember that each API may have a different set of sample apps. Explore them. For example, here's an image of the Weather List Widget sample app:

Step 8: Try Samples on Your Device

Connect your Android phone or tablet up to your development machine . Your device will appear in the Android Device Chooser whenever you try to launch your app via its Run Configuration. As long as the app’s API target meets the API level version requirements for the sample app, you should be able to load it and run it in just the same as the emulator.

Conclusion

You've learned how to create projects out of the sample apps through a few simple steps in Eclipse. You've also learned how to run them on the emulator and even your own Android devices! You're well on your way to Android development. What kinds of apps are you looking forward to creating? Which sample app was your favorite? Let us know in the comments!
IF YOU WANT MORE EXAMPLE/SAMPLE THEN EMail me : Rakshitshah1994@gmail.com

I have 50+ samples made on Eclipse IDE @ just $2

Tuesday, 16 September 2014

DAY 6 : Build A Custom Launcher on Android

Introduction
In its most basic form, a launcher is an application that does the following:
  • it represents the home screen of a device
  • it lists and launches applications that are installed on the device
In other words, it is the application that shows up when you press the home button. Unless you've already installed a custom launcher, you are currently using the default launcher that comes with your Android installation. A lot of device manufacturers have their own default, custom launchers that conform to their proprietary look and feel, for example, Samsung TouchWiz and HTC Sense.
In this tutorial, we are going to create a simple launcher with a basic user interface. It will have two screens:
  • a home screen showing the device's wallpaper
  • a screen showing the icons and details of the applications installed on the device.
1. Requirements
You need to have the following installed and configured on your development machine:
  • Android SDK and platform tools
  • Eclipse IDE 3.7.2 or higher with the ADT plugin
  • an emulator or Android device running Android 2.2 or higher
You can download the SDK and platform tools the Android developer portal.
2. Project Setup
Launch Eclipse and create a new Android application project. I'm naming the application SimpleLauncher, but you can name it anything you want. Make sure you use a unique package. The lowest SDK version our launcher supports is Froyo and the target SDK is Jelly Bean.

  • Since we don't want to create an Activity, deselect Create Activity. Click Finish to continue. 

3. Project Manifest
The next step is modifying the AndroidManifest.xml file by adding two activities. The first Activity displays the home screen. Let's name it HomeActivity as shown below.
<activity
    android:name="ah.hathi.simplelauncher.HomeActivity"
    android:label="Simple Launcher Home"
    android:theme="@android:style/Theme.Wallpaper.NoTitleBar.Fullscreen"
    android:launchMode="singleTask"
    android:stateNotNeeded="true"
    >
    <intent-filter>
      <action android:name="android.intent.action.MAIN" />
      <category android:name="android.intent.category.HOME" />
      <category android:name="android.intent.category.DEFAULT" />
    </intent-filter>        
</activity>


By adding the categories android.intent.category.HOME andandroid.intent.category.DEFAULT to the intent-filter group, the associatedActivity behaves like a launcher and shows up as an option when you press the device's home button.
We also need to set the launchMode to singleTask to make sure that only one instance of this Activity is held by the system at any time. To show the user's wallpaper, set the theme to Theme.Wallpaper.NoTitleBar.FullScreen.
The second Activity we need to add displays the applications that are installed on the user's device. It's also responsible for launching applications. We don't need any special configuration for this Activity. Name it AppsListActivity.
<activity
    android:name="ah.hathi.simplelauncher.AppsListActivity"
    android:theme="@android:style/Theme.NoTitleBar.Fullscreen"
    >           
</activity>
4. Activity Layouts
Create an XML file for the HomeActivity class in the project's res/layout folder and name it activity_home.xml. The layout has a single Button that responds to click events. Clicking the button takes the user from the home screen to the list of applications.

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".HomeActivity" >
    <Button
        android:id="@+id/apps_button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentRight="true"
        android:layout_alignParentTop="true"
        android:layout_marginRight="10dp"
        android:layout_marginTop="10dp"
        android:text="Show Apps"
        android:onClick="showApps"
        />
</RelativeLayout>


Next, create an XML file for the AppsListActivity class in the project's res/layoutfolder and name it activity_apps_list.xml. The layout contains a ListView that takes up the entire screen.

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >
     
    <ListView
        android:id="@+id/apps_list"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        >       
    </ListView>   
</LinearLayout>

Finally, create a third XML file in the same location and name it list_item.xml. This file defines the layout of an item in the ListView. Each list view item represents an application installed on the user's device. It shows the application's icon, label, and package name. We display the application icon using an ImageView instance and TextView instances for the label and package name.

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:padding="10dp"
    >
    <ImageView
        android:id="@+id/item_app_icon"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_centerVertical="true"       
        />
     
    <TextView
        android:id="@+id/item_app_label"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
android:layout_toRightOf="@+id/item_app_icon"
        android:paddingLeft="10dp"
        />
    <TextView
        android:id="@+id/item_app_name"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@+id/item_app_label"
        android:layout_toRightOf="@+id/item_app_icon"
        android:paddingLeft="10dp"
        />
     
</RelativeLayout>
5. Implementing the Activity Classes
HomeActivity
With the layouts of the application created, it's time to create the two Activityclasses. When creating the two classes, make sure the name of each class matches the one you specified in the project's manifest file earlier.
Create a new class named HomeActivity and set android.app.Activity as its superclass.
package ah.hathi.simplelauncher;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
public class HomeActivity extends Activity {
     
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_home);
    }
     
    public void showApps(View v){
        Intent i = new Intent(this, AppsListActivity.class);
        startActivity(i);
    }
}

In the class's onCreate method, we invoke setContentView, passing in the layout we created earlier. You may remember that we added a button to the activity_home layout that triggers a method named showApps. We now need to implement that method in the HomeActivity class. The implementation is pretty simple, we create an Intent for the AppsListActivity class and start it.
AppsListActivity 
Create another Activity class named AppsListActivity and set android.app.Activity as its superclass. In the class's onCreate method, we invoke setContentView, passing in the activity_apps_list layout we created earlier.
package ah.hathi.simplelauncher;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
public class AppsListActivity extends Activity {
     
    @Override
    protected void onCreate(Bundle savedInstanceState) {   
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_apps_list);
    }
         
}

Even though our launcher isn't finished yet, you can save and run your application at this point. When you press the device's home button, you should see a pop-up asking you which launcher you'd like to use.


  • If you choose Simple Launcher Home, you should see your new home screen with a single button in the top right corner of the screen. You should also see your device's current wallpaper.


Go back to Eclipse and create a class named AppDetail that will contain the details of an application, its package name, label, and application icon. The interface is pretty basic as you can see below.
package ah.hathi.simplelauncher;
import android.graphics.drawable.Drawable;
public class AppDetail {
        CharSequence label;
        CharSequence name;
        Drawable icon;
}

6. Fetching Applications
In the loadApps method of the AppsListActivity class, we use thequeryIntentActivities method of the PackageManager class to fetch all the Intentsthat have a category of Intent.CATEGORY_LAUNCHER. The query returns a list of the applications that can be launched by a launcher. We loop through the results of the query and add each item to a list named apps. Take a look at the following code snippet for clarification.
private PackageManager manager;
private List<AppDetail> apps;
private void loadApps(){
    manager = getPackageManager();
    apps = new ArrayList<AppDetail>();
     
    Intent i = new Intent(Intent.ACTION_MAIN, null);
    i.addCategory(Intent.CATEGORY_LAUNCHER);
     
    List<ResolveInfo> availableActivities = manager.queryIntentActivities(i, 0);
    for(ResolveInfo ri:availableActivities){
       AppDetail app = new AppDetail();
        app.label = ri.loadLabel(manager);
        app.name = ri.activityInfo.packageName;
     app.icon = ri.activityInfo.loadIcon(manager);
               apps.add(app);
    }
}
7. Displaying the List of Applications
With the apps variable containing all the details we need, we can show the list of applications using the ListView class. We create a simple ArrayAdapter and override its getView method to render the list's items. We then associate theListView with the adapter.
private ListView list;   
private void loadListView(){
    list = (ListView)findViewById(R.id.apps_list);
  
    ArrayAdapter<AppDetail> adapter = new ArrayAdapter<AppDetail>(this,
            R.layout.list_item,
            apps) {
        @Override
        public View getView(int position, View convertView, ViewGroup parent) {
            if(convertView == null){
                convertView = getLayoutInflater().inflate(R.layout.list_item, null);
            }
             
            ImageView appIcon = (ImageView)convertView.findViewById(R.id.item_app_icon);
            appIcon.setImageDrawable(apps.get(position).icon);
             
            TextView appLabel = (TextView)convertView.findViewById(R.id.item_app_label);
            appLabel.setText(apps.get(position).label);
             
            TextView appName = (TextView)convertView.findViewById(R.id.item_app_name);
            appName.setText(apps.get(position).name);
             
            return convertView;
        }
    };
list.setAdapter(adapter);          
}

8. Listening for Clicks
When the user clicks an item in the ListView, the corresponding application should be launched by our launcher. We use the getLaunchIntentForPackage method of the PackageManager class to create an Intent with which we start the application. Take a look at the following code snippet.
private void addClickListener(){       
    list.setOnItemClickListener(new AdapterView.OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> av, View v, int pos,
                long id) {
            Intent i = manager.getLaunchIntentForPackage(apps.get(pos).name.toString());
            AppsListActivity.this.startActivity(i);
        }
    });
}

9. Putting It All Together
To make everything work together, we need to invoke loadApps, loadListView, andaddClickListener in the onCreate method of the AppsListActivity class as shown below.
protected void onCreate(Bundle savedInstanceState) {   
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_apps_list);
     
    loadApps();
    loadListView();
addClickListener();
}
Build and run your application once more to see the result. You should now be able to see the applications that can be launched when you click the button on the home screen of our launcher. Click on an item to launch the corresponding application.
Conclusion
You now have your own custom launcher. It's very basic, but you can add all the customizations you want. If you want to dig deeper into custom launchers, I encourage you to take a look at the sample applications on the Android Developer Portal.

  

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