Lifecycle of an Android Application

In most cases, every Android application runs in its own Linux process. This process is created for the application when some of its code needs to be run, and will remain running until it is no longer needed and the system needs to reclaim its memory for use by other applications.

An important and unusual feature of Android is that an application process's lifetime is not directly controlled by the application itself. Instead, it is determined by the system through a combination of the parts of the application that the system knows are running, how important these things are to the user, and how much overall memory is available in the system.

It is important that application developers understand how different application components (in particular Activity, Service, and IntentReceiver) impact the lifetime of the application's process. Not using these components correctly can result in the system killing the application's process while it is doing important work.

A common example of a process lifecycle bug is an IntentReceiver that starts a thread when it receives an Intent in its onReceiveIntent() method, and then returns from the function. Once it returns, the system considers that IntentReceiver to be no longer active, and thus its hosting process no longer needed (unless other application components are active in it). Thus, it may kill the process at any time to reclaim memory, terminating the spawned thread that is running in it. The solution to this problem is to start a Service from the IntentReceiver, so the system knows that there is still active work being done in the process.

To determine which processes should be killed when low on memory, Android places them into an "importance hierarchy" based on the components running in them and the state of those components. These are, in order of importance:

   1. A foreground process is one holding an Activity at the top of the screen that the user is interacting with (its onResume() method has been called) or an IntentReceiver that is currently running (its onReceiveIntent() method is executing). There will only ever be a few such processes in the system, and these will only be killed as a last resort if memory is so low that not even these processes can continue to run. Generally at this point the device has reached a memory paging state, so this action is required in order to keep the user interface responsive.

   2. A visible process is one holding an Activity that is visible to the user on-screen but not in the foreground (its onPause() method has been called). This may occur, for example, if the foreground activity has been displayed with a dialog appearance that allows the previous activity to be seen behind it. Such a process is considered extremely important and will not be killed unless doing so is required to keep all foreground processes running.

   3. A service process is one holding a Service that has been started with the startService() method. Though these processes are not directly visible to the user, they are generally doing things that the user cares about (such as background mp3 playback or background network data upload or download), so the system will always keep such processes running unless there is not enough memory to retain all foreground and visible process.

   4. A background process is one holding an Activity that is not currently visible to the user (its onStop() method has been called). These processes have no direct impact on the user experience. Provided they implement their activity lifecycle correctly (see Activity for more details), the system can kill such processes at any time to reclaim memory for one of the three previous processes types. Usually there are many of these processes running, so they are kept in an LRU list to ensure the process that was most recently seen by the user is the last to be killed when running low on memory.

   5.An empty process is one that doesn't hold any active application components. The only reason to keep such a process around is as a cache to improve startup time the next time a component of its application needs to run. As such, the system will often kill these processes in order to balance overall system resources between these empty cached processes and the underlying kernel caches.

When deciding how to classify a process, the system picks the most important level of all the components currently active in the process. See the Activity, Service, and IntentReceiver documentation for more detail on how each of these components contribute to the overall lifecycle of a process. The documentation for each of these classes describes in more detail how they impact the overall lifecycle of their application.

Andriod 2D Graphics - Drawing Pad Sample

In this aritcle shows how to use onDraw() method and create a simple drawing program. The only significant files are Draw activity and the DrawView. You should see a black screen and be able to draw on it with your finger.

This activity creates the DrawView and sets it as activity's main content. It also sets the borderless window.

MainActivity.java
public class MainActivity extends Activity {
    DrawView drawView;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,WindowManager.LayoutParams.FLAG_FULLSCREEN);
        requestWindowFeature(Window.FEATURE_NO_TITLE);
        drawView = new DrawView(this);
        setContentView(drawView);
        drawView.requestFocus();
    }

    // DrawView is a view. It listens to mouse click events and draws a point at the point that it was clicked on.
   public class DrawView extends View implements OnTouchListener {
        List<Point> points = new ArrayList<Point>();
        Paint paint = new Paint();
        public DrawView(Context context) {
        super(context);
        setFocusable(true);
        setFocusableInTouchMode(true);
        this.setOnTouchListener(this);
        paint.setColor(Color.WHITE);
        paint.setAntiAlias(true);
        }

    @Override
    public void onDraw(Canvas canvas) {
        for (Point point : points) {
            canvas.drawCircle(point.x, point.y, 5, paint);
        }
    }

    public boolean onTouch(View view, MotionEvent event) {
        Point point = new Point();
        point.x = event.getX();
        point.y = event.getY();
        points.add(point);
        invalidate();
        return true;
    }
}
    class Point {
        float x, y;
        @Override
        public String toString() {
        return x + ", " + y;
        }
    }
}

Custom ContextMenu using PopupWindow Sample

Here we are creating a  custom contextmenu using PopupWindow in android. A simple PopUpWindow can be created using the following steps.
   1)A layout XML  which describes the View that will be rendered within a PopUpWindow  has to be created.
   2)Invoke the PopUpWindow by inflating the layout XML,  and assign appropriate  “parent view”  to  the pop-up.

Popup_example.xml:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:padding="10dip" android:layout_width="fill_parent"
android:layout_height="wrap_content" >
    <TextView android:layout_width="fill_parent"
    android:layout_height="wrap_content" android:layout_marginTop="10dip" android:text="Test Pop-Up"/>
</LinearLayout>

Java Code:
    LayoutInflater inflater = (LayoutInflater)
    this.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    PopupWindow pw = new PopupWindow(
    inflater.inflate(R.layout.popup_example, null, false),  100,  100,    true);
    // The code below assumes that the root container has an id called 'main'
    pw.showAtLocation(this.findViewById(R.id.main), Gravity.CENTER, 0, 0); 

How to Dismiss the PopUp Window?

Declare the necessary variables:

         private PopupWindow Popup;
       //how much time your popup window should appear
        private static final int POPUP_DISMISS_DELAY = 4000
       private DismissPopup mDismissPopup = new DismissPopup();


Class for dismissing the PopUp Window
Create a class which helps in dismissing the window automatically after the specified time:
class DismissPopup implements Runnable {
  public void run() {
      // Protect against null-pointer exceptions
      if (mPopup != null) {
          mPopup.dismiss();
      }
  }
}

Code Snippet:
Popup = new PopupWindow(this.getViewInflate()
                  .inflate(R.layout.main1,null,null),0,0);  
Popup.setOutsideTouchable(false);
Popup.setTouchInterceptor(new OnTouchListener() {

public boolean onTouch(View v, MotionEvent event) {
return false;
}});

Popup.showAtLocation(this.findViewById(R.id.main2),Gravity.BOTTOM, 20, 20);

youractivity.postDelayed(mDismissPopup, POPUP_DISMISS_DELAY);

2D graphics with Effects

In this article help us to set the different type of effect in the drawable.

Effects

Shadow Effect
This draws a shadow layer below the main layer, with the specified offset and color, and blur radius.


MaskFilterEffect
MaskFilter is the base class for object that perform transformations on an alpha-channel mask before drawing it. A subclass of MaskFilter may be installed into a Paint. Blur and emboss are implemented as subclasses of MaskFilter.

Sample Implementation:
Blur Filter
paint.setMaskFilter(new BlurMaskFilter(15, Blur.INNER));
paint.setMaskFilter(new BlurMaskFilter(15, Blur.OUTER));
paint.setMaskFilter(new BlurMaskFilter(15, Blur.SOLID));
paint.setMaskFilter(new BlurMaskFilter(15, Blur.NORMAL));

Emboss Filter
paint.setMaskFilter(new EmbossMaskFilter(new float[] { 1, 1, 1 },0.4f, 10, 8.2f));

Shader Effect
Shader is the based class for objects that return horizontal spans of colors during drawing. A subclass of Shader is installed in a Paint calling paint.setShader(shader). After that any object (other than a bitmap) that is drawn with that paint will get its color(s) from the shader.

Shader Sample Implementation:
LinearGradient
paint.setShader(new LinearGradient(8f, 80f, 30f, 20f, Color.RED,Color.WHITE, Shader.TileMode.MIRROR));

RadialGradient
paint.setShader(new RadialGradient(8f, 80f, 90f, Color.RED,Color.WHITE, Shader.TileMode.MIRROR));

SweepGradient
paint.setShader(new SweepGradient(80, 80, Color.RED, Color.WHITE));



Sample Apps
Layout : main.xml
<?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="fill_parent">

<LinearLayout android:id="@+id/ImageView01" android:layout_height="150dip" android:layout_width="150dip"
android:layout_gravity="center"></LinearLayout>
<LinearLayout android:id="@+id/LinearLayout01" android:layout_width="wrap_content" android:layout_height="wrap_content"
android:layout_gravity="center">
<Button android:text="Draw Cicle" android:id="@+id/circle"
android:layout_height="wrap_content" android:layout_gravity="center"
android:layout_width="85dip" android:gravity="center"></Button>
<Button android:text="Anti Alias" android:id="@+id/antialias"
android:layout_height="wrap_content" android:layout_gravity="center"
android:layout_width="85dip" android:gravity="center"></Button>
<Button android:text="Shadow" android:id="@+id/shadow"
android:layout_height="wrap_content" android:layout_gravity="center"
android:layout_width="85dip" android:gravity="center"></Button>
</LinearLayout>

<LinearLayout android:id="@+id/LinearLayout01"
android:layout_width="wrap_content" android:layout_height="wrap_content"
android:layout_gravity="center">
<Button android:text="Blur Effect - 1" android:id="@+id/blur1"
android:layout_height="wrap_content" android:layout_gravity="center"
android:layout_width="85dip" android:gravity="center"></Button>
<Button android:text="Blur Effect - 2" android:id="@+id/blur2"
android:layout_height="wrap_content" android:layout_gravity="center"
android:layout_width="85dip" android:gravity="center"></Button>
<Button android:text="Blur Effect - 3" android:id="@+id/blur3"
android:layout_height="wrap_content" android:layout_gravity="center"
android:layout_width="85dip" android:gravity="center"></Button>
</LinearLayout>

<LinearLayout android:id="@+id/LinearLayout01"
android:layout_width="wrap_content" android:layout_height="wrap_content"
android:layout_gravity="center">
<Button android:text="Blur Effect - 4" android:id="@+id/blur4"
android:layout_height="wrap_content" android:layout_gravity="center"
android:layout_width="85dip" android:gravity="center"></Button>
<Button android:text="Emboss" android:id="@+id/emboss"
android:layout_height="wrap_content" android:layout_gravity="center"
android:layout_width="85dip" android:gravity="center"></Button>
</LinearLayout>

<LinearLayout android:id="@+id/LinearLayout01"
android:layout_width="wrap_content" android:layout_height="wrap_content"
android:layout_gravity="center">
<Button android:text="Sweep" android:id="@+id/sweep"
android:layout_height="wrap_content" android:layout_gravity="center"
android:layout_width="85dip" android:gravity="center"></Button>
<Button android:text="Linear" android:id="@+id/linear"
android:layout_height="wrap_content" android:layout_gravity="center"
android:layout_width="85dip" android:gravity="center"></Button>
<Button android:text="Radial" android:id="@+id/radial"
android:layout_height="wrap_content" android:layout_gravity="center"
android:layout_width="85dip" android:gravity="center"></Button>
</LinearLayout>
</LinearLayout>


MainActivity.java

public class MainActivity extends Activity implements OnClickListener {

LinearLayout imageView;
Button circle, antialias, shadow, blur1, blur2, blur3, blur4, emboss,
sweep, radial, linear;

@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
imageView = (LinearLayout) findViewById(R.id.ImageView01);
circle = (Button) findViewById(R.id.circle);
antialias = (Button) findViewById(R.id.antialias);
shadow = (Button) findViewById(R.id.shadow);
blur1 = (Button) findViewById(R.id.blur1);
blur2 = (Button) findViewById(R.id.blur2);
blur3 = (Button) findViewById(R.id.blur3);
blur4 = (Button) findViewById(R.id.blur4);

emboss = (Button) findViewById(R.id.emboss);
sweep = (Button) findViewById(R.id.sweep);
linear = (Button) findViewById(R.id.linear);
radial = (Button) findViewById(R.id.radial);

circle.setOnClickListener(this);
antialias.setOnClickListener(this);
shadow.setOnClickListener(this);
blur1.setOnClickListener(this);
blur2.setOnClickListener(this);
blur3.setOnClickListener(this);
blur4.setOnClickListener(this);
emboss.setOnClickListener(this);
sweep.setOnClickListener(this);
linear.setOnClickListener(this);
radial.setOnClickListener(this);

}

@Override
public void onClick(View v) {
imageView.removeAllViews();
switch (v.getId()) {
case R.id.circle:
imageView.addView(new DrawView(MainActivity.this));
break;
case R.id.antialias:
imageView.addView(new DrawView(MainActivity.this).getAntiAlias());
break;
case R.id.shadow:
imageView
.addView(new DrawView(MainActivity.this).getShadowEffect());
break;
case R.id.blur1:
imageView.addView(new DrawView(MainActivity.this)
.getBlurMaskFitler(1));
break;
case R.id.blur2:
imageView.addView(new DrawView(MainActivity.this)
.getBlurMaskFitler(2));
break;
case R.id.blur3:
imageView.addView(new DrawView(MainActivity.this)
.getBlurMaskFitler(3));
break;

case R.id.blur4:
imageView.addView(new DrawView(MainActivity.this)
.getBlurMaskFitler(4));
break;
case R.id.emboss:
imageView.addView(new DrawView(MainActivity.this)
.getEmbossMaskFilter());
break;
case R.id.sweep:
imageView.addView(new DrawView(MainActivity.this)
.getSweepShaderEffect());
break;
case R.id.linear:
imageView.addView(new DrawView(MainActivity.this)
.getLinearShaderEffect());
break;
case R.id.radial:
imageView.addView(new DrawView(MainActivity.this)
.getRadialShaderEffect());
break;

}

}

public class DrawView extends View {
Paint paint = new Paint();
Context c;
final float xPos = 80, yPos = 80, radius = 40;

public DrawView(Context context) {
super(context);
c = context;
paint.setColor(Color.WHITE);
invalidate();
}

private View getAntiAlias() {

paint.setAntiAlias(true);
return this;
}

private View getShadowEffect() {
paint.setAntiAlias(true);
paint.setShadowLayer(10, 10, 5, Color.RED);
return this;
}

private View getBlurMaskFitler(int type) {
invalidate();
paint.setAntiAlias(true);
switch (type) {
case 1:
paint.setMaskFilter(new BlurMaskFilter(15, Blur.INNER));
break;
case 2:
paint.setMaskFilter(new BlurMaskFilter(15, Blur.OUTER));
break;
case 3:
paint.setMaskFilter(new BlurMaskFilter(15, Blur.SOLID));
break;
case 4:
paint.setMaskFilter(new BlurMaskFilter(15, Blur.NORMAL));
break;
}
return this;
}

private View getEmbossMaskFilter() {
paint.setAntiAlias(true);
paint.setMaskFilter(new EmbossMaskFilter(new float[] { 1, 1, 1 },
0.4f, 10, 8.2f));
return this;
}

private View getSweepShaderEffect() {
paint.setAntiAlias(true);
paint.setShader(new SweepGradient(80, 80, Color.RED, Color.WHITE));
return this;
}

private View getRadialShaderEffect() {
paint.setAntiAlias(true);
paint.setShader(new RadialGradient(8f, 80f, 90f, Color.RED,
Color.WHITE, Shader.TileMode.MIRROR));
return this;
}

private View getLinearShaderEffect() {
paint.setAntiAlias(true);
paint.setShader(new LinearGradient(8f, 80f, 30f, 20f, Color.RED,
Color.WHITE, Shader.TileMode.MIRROR));
return this;
}

@Override
public void onDraw(Canvas canvas) {
canvas.drawCircle(xPos, yPos, radius, paint);
}
}
}

Android 2D Graphics Example

This example shows how to use onDraw() method and create a simple drawing program. The only significant files are Draw activity and the DrawView.

MainActivity.java
public class MainActivity extends Activity { 
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);      
        DrawView drawView = new DrawView(this);
        setContentView(drawView);
        drawView.requestFocus();
    }
}


public class DrawView extends View {
    Paint paint = new Paint();
    Context c;
    public DrawView(Context context) {
        super(context);
        c= context;    
        paint.setColor(Color.WHITE);
        paint.setAntiAlias(true);
    }

    @Override
   public void onDraw(Canvas canvas) {
            canvas.drawCircle(100, 100, 50, paint);
    }
}
}

Custom ROM For Galaxy Mini Chocobread v2.2

Hello every body .. now i want share tutorial custom rom for galaxy mini, it is my first custom rom in share about tutorial for android. And this time i share Chocobread mini v2.2 for galaxy that have actually been released long enough, yesterday I've managed to test by myself. made by the team chocodev one of them is my friend named Nizar and one college with me. Hopefully when when he wants to share his knowledge on how to create your own custom rom. you can just see how it looks below

Chocobread is a custom rom for galaxy mini from the stock rom 2.3.x (Gingerbread), with many changes of customization, additional features and performance. Everyone can use, modify, and create your own rom using the kernel and the base of this rom

Advantages of chocobread custom rom:

• There is abl Indonesian language in the search for a lot of people (in my country) haha: p
• include a2sdGUI
  kernel-806mhz
• Smooth and efficient batrenya
• Based gingerbread 2.3.6
• -New kernel 2.6.35.14 (21 Governor + 7 i/o scheduler, SFB, cgroups, support EXT,SWAP,FAT filesystem, Fix battery drain, Default SmartassV2 & SIO, TUN & CIFS compiled, Overclock up to 844mhz, UV (on progress)).
• Toucwiz30Launcher with 5 dock, 5x3 app drawer, list mode, and enable landscape mode.
• Scrolling cache and volume step.
• 14 Statusbar toogle and battery bar.
• Chocobread Parts.
• Elegance Style Theme.
• Old market.
• Gapps updated (without maps and market).
• Fix RTL and Multyread Fonts.
• 9 Lockscreen (Settings->Display->Unlock screen).
• 100% deodexed files.
• Reboot, Recovery and Screenshot shortcut on Power Menu.
• Adhoc wifi.
• Data Monitor (Settings -> Wireless and networks -> Data monitor).
• Pre-Rooted.
• App2sd darktremor.
• New apps : Droidvpn, Cifs Manager, RealCalc, File Manager, No-frills CPU, Superuser, Walkman, 2SDGUI, and Terminal.

download chocobread v2.2

how to install chocobread custom rom:

-base: 2.3.4

-must have installed clockworkmod recovery, see tutorial install clockworkmod recovery

-install a custom rom file through recovery mode, do not forget to wipe and cache the data well after finished install chocobread then wipe data and cache again

-if already completed select reboot system now

note:

-if there are problems please wipe the data n the new cache cr reinstall it.

-to activate the partition a2sdGUI please dlu micro sd mini galaxy, I recommend using ext2, create swap with size 50mb linux just do not need much

ok that for tutorial change custom rom galaxy mini to chocobread.. see you in next tutorial for android.