Another Glowing Windows 8 Review

Tim Edwards at PCGamesN.com does not like Windows 8. He provides plenty of detail why.



Sounds like this is not gonna pass "can my parents use it" test. I'm definitely in the wait and see camp at this point in time.

Apocalypse Not: So just Suck it up People

This month's Wired magazine has a wonderful article on the coming Apocalypse or lack of one. The story debunks many of the Apocalypse myths and memes of the last 50 years. From oil shortages and running out of energy to the horrors of overpopulation. There must be a dozen examples of "experts" who's prediction of our demise has already come and gone.



Of course the author does miss the most likely end of the world... the Zombie Apocalypse. Which we all know from video games and TV shows, is inevitable. But I guess I will cut him slack on that one. :)



So I guess we will be around for a while, better suck it up and soldier on.

A Keyboard for Messy Folks

Do you like to eat and drink while you code? Well Logitech's fully washable keyboard is for you. Spilling soda is no longer quite the problem it was.

Determine the best camera preview size

It'a example to determine the best supported camera preview size, to have the biggest preview area.

package com.example.androidcamera;

import java.io.IOException;
import java.util.List;

import android.hardware.Camera;
import android.os.Bundle;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.widget.Toast;
import android.app.Activity;

public class MainActivity extends Activity {
 
 Camera myCamera;
 SurfaceView mySurfaceView;
 SurfaceHolder mySurfaceHolder;
 boolean isPreview;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        
        isPreview = false;
        mySurfaceView = (SurfaceView)findViewById(R.id.mypreview);
        mySurfaceHolder = mySurfaceView.getHolder();
        mySurfaceHolder.addCallback(mySurfaceCallback);
        
    }
    
    SurfaceHolder.Callback mySurfaceCallback
    = new SurfaceHolder.Callback(){

  @Override
  public void surfaceChanged(SurfaceHolder holder, int format, int width,
    int height) {
   Camera.Parameters myParameters = myCamera.getParameters();
   Camera.Size myBestSize = getBestPreviewSize(width, height, myParameters);
   
   if(myBestSize != null){
    myParameters.setPreviewSize(myBestSize.width, myBestSize.height);
    myCamera.setParameters(myParameters);
    myCamera.startPreview();
    isPreview = true;
    
    Toast.makeText(getApplicationContext(), 
      "Best Size:\n" +
      String.valueOf(myBestSize.width) + " : " + String.valueOf(myBestSize.height), 
      Toast.LENGTH_LONG).show();
   }
  }

  @Override
  public void surfaceCreated(SurfaceHolder holder) {
   try {
    myCamera.setPreviewDisplay(mySurfaceHolder);
   } catch (IOException e) {
    // TODO Auto-generated catch block
    e.printStackTrace();
   }
   
  }

  @Override
  public void surfaceDestroyed(SurfaceHolder holder) {
   // TODO Auto-generated method stub
   
  }
     
    };
    
    private Camera.Size getBestPreviewSize(int width, int height, Camera.Parameters parameters){
     Camera.Size bestSize = null;
     List<Camera.Size> sizeList = parameters.getSupportedPreviewSizes();
     
     bestSize = sizeList.get(0);
     
     for(int i = 1; i < sizeList.size(); i++){
      if((sizeList.get(i).width * sizeList.get(i).height) >
        (bestSize.width * bestSize.height)){
       bestSize = sizeList.get(i);
      }
     }

     return bestSize;
    }
    
 @Override
 protected void onResume() {
  super.onResume();
  myCamera = Camera.open();
 }

 @Override
 protected void onPause() {
  
  if(isPreview){
   myCamera.stopPreview();
  }
  
  myCamera.release();
  myCamera = null;
  isPreview = false;
  
  super.onPause();
 }

}

Modify the layout to have a SurfaceView for preview.

<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" >

    <SurfaceView
        android:id="@+id/mypreview"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

</RelativeLayout>

Modify AndroidManifest.xml to add permission of "android.permission.CAMERA", and set android:screenOrientation="landscape".

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.androidcamera"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="8"
        android:targetSdkVersion="15" />
    <uses-permission android:name="android.permission.CAMERA"/>

    <application
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name=".MainActivity"
            android:label="@string/title_activity_main" 
            android:screenOrientation="landscape">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

Download the files.

Pro Android Augmented Reality (Professional Apress)

Augmented reality (AR) offers a live direct or indirect view of a physical, real-world environment, where the elements and surroundings are augmented by computer-generated sensory input such as graphics and GPS data. It makes a game more real. Your social media app puts you where want to be or go. 

Pro Android Augmented Reality walks you through the foundations of building an augmented reality application. From using various software and Android hardware sensors, such as an accelerometer or a magnetometer (compass), you'll learn the building blocks of augmented reality for both marker- and location-based apps.

Case studies are included in this one-of-a-kind book, which pairs nicely with other Android development books. After reading Pro Android Augmented Reality, you'll be able to build augmented reality rich media apps or integrate all the best augmented reality into your favorite Android smartphone and/or tablet.

What you�ll learn

• How to use most Android cameras
• How to find the user's location with GPS data
• How to detect movement and orientation of the device
• How to program against the accelerometer and compass
• How to use the AndAR library in marker recognition
• How to create an artificial horizon for your app
• How to integrate the Google Maps API into AR apps
• How to build enterprise augmented reality apps using the case studies in this book

Who this book is for

This book is for Android developers familiar with Android programming, but new to the camera, accelerometer, magnetometer and building augmented reality applications in general.

Table of Contents

1. Applications of Augmented Reality
2. Basics of Augmented Reality on the Android Platform
3. Adding Overlays
4. Artificial Horizons
5. Other Features of Augmented Reality
6. A Simple App Using AR
7. A More Complex Project Using More AR Features
8. A Project Using All AR Features
9. An AR Game

Decompiling Android

Decompiling Android looks at the the reason why Android apps can be decompiled to recover their source code, what it means to Android developers and how you can protect your code from prying eyes. This is also a good way to see how good and bad Android apps are constructed and how to learn from them in building your own apps.

This is becoming an increasingly important topic as the Android marketplace grows and developers are unwittingly releasing the apps with lots of back doors allowing people to potentially obtain credit card information and database logins to back-end systems, as they don�t realize how easy it is to decompile their Android code.       

• In depth examination of the Java and Android class file structures
• Tools and techniques for decompiling Android apps
• Tools and techniques for protecting your Android apps

What you�ll learn

• How to download an Android app and decompile it into its original Java source and HTML5 and CSS code
• How to protect your Android apps so that others cannot decompile it
• To identify potential security threats that currently exist and how to avoid them  
• What tools are available to decompile and protect Android apps
• The structure of a Java Classfile and an Android classfile
• How the standard JVM and the Dalvik JVM differ
• How to create your own Android decompiler and obfuscator

Who this book is for

This book is for Android developers and their managers. It's also for hackers and hobbyist types who wish to see how Android apps are constructed as a means of learning how to build Android apps.

Table of Contents

1. Laying the Groundwork
2. Ghost in the Machine 
3. Inside the DEX File
4. Tools of the Trade
5. Decompiler Design
6. Decompiler Implementation
7. Case Studies

Retain fragment instance across Activity re-creation (such as from a configuration change)

Fragment.setRetainInstance (boolean retain) control whether a fragment instance is retained across Activity re-creation (such as from a configuration change). This can only be used with fragments not in the back stack. If set, the fragment lifecycle will be slightly different when an activity is recreated:

• onDestroy() will not be called (but onDetach() still will be, because the fragment is being detached from its current activity).
• onCreate(Bundle) will not be called since the fragment is not being re-created.
• onAttach(Activity) and onActivityCreated(Bundle) will still be called.

Example:

In the example, there are two Fragment, MyFragment and MyFragment2. Basically, both Fragments are same, except that MyFragment2 call setRetainInstance(true) in onCreate(). It can be noticed that onCreate() and onDestroy() of MyFragment2 will not be called when orientation change, and the field myState of MyFragment2 will not be cleared.

Main layout, contain two fragments.

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
   android:layout_width="fill_parent"
   android:layout_height="fill_parent"
   android:orientation="horizontal" >

   <fragment
       class="com.example.androidretaininstance.MyFragment"
       android:id="@+id/myfragment1"
       android:layout_width="0px"
       android:layout_weight="1"
       android:layout_height="match_parent" />
   <fragment
       class="com.example.androidretaininstance.MyFragment2"
       android:id="@+id/myfragment2"
       android:layout_width="0px"
       android:layout_weight="1"
       android:layout_height="match_parent" />

</LinearLayout>

/res/layout/fragmentlayout.xml, the layout of the fragment

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
   android:layout_width="fill_parent"
   android:layout_height="fill_parent"
   android:orientation="vertical" >
   <TextView
       android:id="@+id/myid"
       android:layout_width="match_parent"
       android:layout_height="wrap_content" />
   <ScrollView 
       android:layout_width="match_parent"
       android:layout_height="match_parent">
       <TextView
           android:id="@+id/mystatus"
           android:layout_width="match_parent"
           android:layout_height="wrap_content" />
   </ScrollView>

</LinearLayout>

MyFragment.java

package com.example.androidretaininstance;

import android.app.Fragment;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
import android.widget.Toast;

public class MyFragment extends Fragment {
 
 int myID;
 String myState = "";
 
 TextView textID;
 TextView textStatus;

 @Override
 public View onCreateView(LayoutInflater inflater, ViewGroup container,
   Bundle savedInstanceState) {
  View myFragmentView = inflater.inflate(R.layout.fragmentlayout, container, false);
  textID = (TextView)myFragmentView.findViewById(R.id.myid);
  textStatus = (TextView)myFragmentView.findViewById(R.id.mystatus);
  
  textID.setText("ID = " + String.valueOf(myID));
  
  updateStatus(myID + ":onCreateView()");
  return myFragmentView;
  
 }

 @Override
 public void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  myID = getId();
  updateStatus(myID + ":onCreate()");
 }

 @Override
 public void onDestroy() {
  super.onDestroy();
  updateStatus(myID + ":onDestroy()");
 }
 
 private void updateStatus(String st){
  
  if(textStatus == null){
   myState += st + " (delayed)\n";
  }else{
   myState += st +"\n";
   textStatus.setText(myState);
  }
  
  Toast.makeText(getActivity(), st, Toast.LENGTH_LONG).show();
 }
 
}

MyFragment2.java, extends MyFragment, override onCreate() to call setRetainInstance(true).

package com.example.androidretaininstance;

import android.os.Bundle;

public class MyFragment2 extends MyFragment {

 @Override
 public void onCreate(Bundle savedInstanceState) {
  // TODO Auto-generated method stub
  super.onCreate(savedInstanceState);
  setRetainInstance(true);
 }
 
}

Download the files.

Retrieve old activity state for configuration change by overriding onRetainNonConfigurationInstance() method

As mentioned in the post "Activity will be re-started when screen orientation changed", the old activity will be destroyed when orientation changed. And also mentioned in last exercise "EditText keep no change after orientation changed", the states of some views will be kept. But it's not always true; for example, refer to the exercise in "GridView", the GridView will always reload photos from SD Card when orientation changed.

To maintain the old states, we can overriding the method onRetainNonConfigurationInstance() to return the old activity. Via the returned activity object, we can retrieve the fields of the old activity.

Please notice that the method onRetainNonConfigurationInstance() is deprecated, If you are targeting HONEYCOMB or later, consider instead using a Fragment with Fragment.setRetainInstance(boolean).

Modify the java code in the exercise "GridView loading photos from SD Card", override the method onRetainNonConfigurationInstance() to return the activity object, this. In orCreate() method, check if old activity exist by calling getLastNonConfigurationInstance(). If the returned object not null, means old activity exist.

 @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        
        GridView gridview = (GridView) findViewById(R.id.gridview);
        
        //Check if old activity exist
        MainActivity oldActivity = (MainActivity)getLastNonConfigurationInstance();
        if(oldActivity == null){
         myImageAdapter = new ImageAdapter(this);
            gridview.setAdapter(myImageAdapter);
            
            String ExternalStorageDirectoryPath = Environment
              .getExternalStorageDirectory()
              .getAbsolutePath();
            
            String targetPath = ExternalStorageDirectoryPath + "/test/";
            
            Toast.makeText(getApplicationContext(), targetPath, Toast.LENGTH_LONG).show();
            File targetDirector = new File(targetPath);
            
            File[] files = targetDirector.listFiles();
            for (File file : files){
             myImageAdapter.add(file.getAbsolutePath());
            } 
            
            // Get memory class of this device, exceeding this amount will throw an
            // OutOfMemory exception.
            final int memClass 
             = ((ActivityManager)getSystemService(Context.ACTIVITY_SERVICE))
              .getMemoryClass();
            
            // Use 1/8th of the available memory for this memory cache.
            final int cacheSize = 1024 * 1024 * memClass / 8;
            
            mMemoryCache = new LruCache<String, Bitmap>(cacheSize) {
             
             @Override
             protected int sizeOf(String key, Bitmap bitmap) {
              // The cache size will be measured in bytes rather than number of items.
              return bitmap.getByteCount(); 
             }
            };
        }else{
         Toast.makeText(getApplicationContext(), "oldActivity exist", Toast.LENGTH_LONG).show();
         myImageAdapter = oldActivity.myImageAdapter;
         gridview.setAdapter(myImageAdapter);
         
        }
        
    }
 
 @Override
 public Object onRetainNonConfigurationInstance() {
  // TODO Auto-generated method stub
  return this;
 }

Download the files.

Make a Symbolic Link on Windows XP

I found out on Friday to make a symbolic link with Windows XP, you need to download a special utility.



Get Junction from Microsoft here.



To create a link use the following syntax:

junction <link> <path>

for example

junction c:\progs c:\Program Files

EditText keep no change after orientation changed

As mentioned in the post "Activity will be re-started when screen orientation changed", onCreate() method will be called when orientation changed, to re-layout the screen. But in case of some views, such as EditText, the Android life-cycle mechanism will restore the states.

Here is a example, there are two EditText in the layout. The first one is assigned with a ID, it will update the TextView once text changed. The second one have no ID assigned. You can notice that the text in the first EditText (with ID) will keep no change after orientation changed, and onTextChanged() method of the TextChangedListener will be called also, to update the TextView.

On the other hand, the second EditText (without ID assigned) will clear to empty when orientation changed.

Layout

<LinearLayout 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" 
    android:orientation="vertical">

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/hello_world"
        tools:context=".MainActivity" />
    <TextView
        android:id="@+id/lasttext"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        tools:context=".MainActivity" />
    <EditText
        android:id="@+id/intext"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        tools:context=".MainActivity" />
    <EditText
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        tools:context=".MainActivity" />

</LinearLayout>

package com.example.androidorientationchange;

import android.os.Bundle;
import android.app.Activity;
import android.text.Editable;
import android.text.TextWatcher;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;

public class MainActivity extends Activity {
 
 TextView lastText;
 EditText inText;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        
        lastText = (TextView)findViewById(R.id.lasttext);
        
     inText = (EditText)findViewById(R.id.intext);
     inText.addTextChangedListener(new TextWatcher(){

   @Override
   public void afterTextChanged(Editable s) {
    // TODO Auto-generated method stub
    
   }

   @Override
   public void beforeTextChanged(CharSequence s, int start, int count,
     int after) {
    // TODO Auto-generated method stub
    
   }

   @Override
   public void onTextChanged(CharSequence s, int start, int before,
     int count) {
    // TODO Auto-generated method stub
    
    
    lastText.setText(s);
    
    Toast.makeText(MainActivity.this, 
         "onTextChanged: " + s, Toast.LENGTH_SHORT).show();
   }});
     
     Toast.makeText(MainActivity.this, 
       "onCreate", Toast.LENGTH_LONG).show();
    }

}

Next:
- Retrieve old activity state for configuration change by overriding onRetainNonConfigurationInstance() method

Mac and Windows Native App Packaging for Java and JavaFX

With the release of Java 7 u6, native packaging support for Windows and Mac Java FX applications is available to everyone. This is totally awesome and I plan to dive in, but haven't yet. But don't wait for me, here are the details so you can get started.



For Mac OS X packaging, here are the details:

• Java Mac Packaging Guide


• AppBundler Project

And for Windows, check out Igor's original post:

Igor's Packaging Blog Post

Android Programming with App Inventor

Here is a great introduction of the re-released MIT App Inventor.

Related Link:
- MIT App Inventor

Implement slide top-down vertical animation

The exercise "Implement slide-in and slide-out animation" implement horizontal animation using build in animation xml android.R.anim.slide_in_left and android.R.anim.slide_out_right. Currently, there are no build-in vertical animation xml supported. To implement vertical animation, create it by ourself.



/res/anim/slidedown_in.xml

<?xml version="1.0" encoding="utf-8"?>
<translate xmlns:android="http://schemas.android.com/apk/res/android"
    android:interpolator="@android:anim/accelerate_interpolator"
    android:fromYDelta="-50%"
    android:toYDelta="0.0"
    android:duration="1000" />

/res/anim/slidedown_out.xml

<?xml version="1.0" encoding="utf-8"?>
<translate xmlns:android="http://schemas.android.com/apk/res/android"
    android:interpolator="@android:anim/accelerate_interpolator"
    android:fromYDelta="0.0"
    android:toYDelta="50%"
    android:duration="1000" />

Layout.

<?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="fill_parent"
   >
<ImageView
   android:id="@+id/image1"
   android:layout_width="wrap_content"
   android:layout_height="match_parent"
   android:src="@drawable/ic_launcher"
   android:visibility="invisible"
   />
<ImageView
   android:id="@+id/image2"
   android:layout_width="wrap_content"
   android:layout_height="match_parent"
   android:src="@drawable/ic_launcher"
   android:visibility="invisible"
   />
<ImageView
   android:id="@+id/image3"
   android:layout_width="wrap_content"
   android:layout_height="match_parent"
   android:src="@drawable/ic_launcher"
   android:visibility="invisible"
   />
</LinearLayout>

Main code.

package com.exercise.androidanimation;

import android.os.Bundle;
import android.app.Activity;
import android.view.View;
import android.view.animation.Animation;
import android.view.animation.Animation.AnimationListener;
import android.view.animation.AnimationUtils;
import android.widget.ImageView;

public class MainActivity extends Activity {
 
 ImageView image1, image2, image3;
 Animation animationSlideDownIn, animationSlideDownOut;
 ImageView curSlidingImage;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        
        image1 = (ImageView)findViewById(R.id.image1);
        image2 = (ImageView)findViewById(R.id.image2);
        image3 = (ImageView)findViewById(R.id.image3);
        
        animationSlideDownIn = AnimationUtils.loadAnimation(this, R.anim.slidedown_in);
        animationSlideDownOut = AnimationUtils.loadAnimation(this, R.anim.slidedown_out);
        
        animationSlideDownIn.setAnimationListener(animationSlideInListener);
        animationSlideDownOut.setAnimationListener(animationSlideOutListener);

        curSlidingImage = image1;
        image1.startAnimation(animationSlideDownIn);
        image1.setVisibility(View.VISIBLE);
    }

 @Override
 protected void onPause() {
  // TODO Auto-generated method stub
  super.onPause();
  image1.clearAnimation();
  image2.clearAnimation();
  image3.clearAnimation();
 }
 
 AnimationListener animationSlideInListener
 = new AnimationListener(){

  @Override
  public void onAnimationEnd(Animation arg0) {
   // TODO Auto-generated method stub
   if(curSlidingImage == image1){
    image1.startAnimation(animationSlideDownOut); 
   }else if(curSlidingImage == image2){
    image2.startAnimation(animationSlideDownOut); 
   }else if(curSlidingImage == image3){
    image3.startAnimation(animationSlideDownOut); 
   } 
  }

  @Override
  public void onAnimationRepeat(Animation animation) {
   // TODO Auto-generated method stub
   
  }

  @Override
  public void onAnimationStart(Animation animation) {
   // TODO Auto-generated method stub
   
  }
  
 };
 
 AnimationListener animationSlideOutListener
 = new AnimationListener(){

  @Override
  public void onAnimationEnd(Animation animation) {
   // TODO Auto-generated method stub
   if(curSlidingImage == image1){
    curSlidingImage = image2;
    image2.startAnimation(animationSlideDownIn);
    image1.setVisibility(View.INVISIBLE);
    image2.setVisibility(View.VISIBLE);
    image3.setVisibility(View.INVISIBLE); 
   }else if(curSlidingImage == image2){
    curSlidingImage = image3;
    image3.startAnimation(animationSlideDownIn);
    image1.setVisibility(View.INVISIBLE);
    image2.setVisibility(View.INVISIBLE);
    image3.setVisibility(View.VISIBLE); 
   }else if(curSlidingImage == image3){
    curSlidingImage = image1;
    image1.startAnimation(animationSlideDownIn);
    image1.setVisibility(View.VISIBLE);
    image2.setVisibility(View.INVISIBLE);
    image3.setVisibility(View.INVISIBLE); 
   }
  }

  @Override
  public void onAnimationRepeat(Animation animation) {
   // TODO Auto-generated method stub
   
  }

  @Override
  public void onAnimationStart(Animation animation) {
   // TODO Auto-generated method stub
   
  }
  
 };

}

Download the files.

Java 7 u6 Released

Java 7 u6 is in the wild. Full Mac OS X support is the big calling card in this release, along with Java FX 2.2.



Java 7 u6

iOS vs Android Home Screens and the Nexus 7

Well with all the buzz around the Google Nexus 7 I decided to get one. So one thing that I though was really interesting is how the home screens are laid out. I found this a bit odd coming from the iPhone world.













When you compare the two, they sorta look like this.

The Apple devices always home to the left most page. So when you press the home button twice you end up on the left.



How Android is Different

With the Android device, the home page is always in the center. You can navigate two pages to the left or right. But pressing the home button twice always takes you to the center page. Once I figured this out, it made sense.



However, the thing that really threw me off at first was the Android widgets. With iOS, the only thing that shows up on a page are icons or folders. No deviations from that. With Android, you can put Widgets on a page. Widgets are little mini apps that can take anywhere from a row of space to the entire page. The home page on the Nexus 7 is filled with a Google Play widget. It took me quite a bit of playing around to figure this out.



I think Google would be better off to make the widget maybe half a page or smaller. That way, the new apps are installed on the home page and users can see as they are added. Without that sort of behavior it is less than obvious where new app icons get added.



First Impressions

The size and weight of the Nexus 7 are pretty cool. It is a great device for reading books. Although, I do think Google would be better off with their own ePub reader. Finding and installing one took much more work than it should have.



Anyway, I'll add more as I spend more time with it.

Java Logger Example

If you are interested in creating a simple single instance logger for an application, here is a simple logging example I created a few weeks back. The page includes a brief description and the code is commented.



I hope to be posting a lot more examples in the weeks to come. Often when writing about stuff, one does not get enough practice actually doing. So I am making a concerted effort to spend a lot more time practicing.

Screenium Screen Recorder

This weekend I was trying to figure out how to make a copy of a streamed Flash movie. There is stream recording software out there. However, the easy to use stuff is not free, nor does it work that well. But sometimes, the simplest solution is the best.



So I ended up buying Screenium which is an inexpensive screen recording tool for the Mac. And it did an excellent job of making a copy of the video. Of course it is not perfect as I had to capture the audio and video. But for my purposes, making a copy of an interview for future reference, it worked great.



Also, Screenium is on sale this week for 50% off. So if you want a copy I think you need to buy it today at the latest.

Preview build of ADT 21 and of the SDK Tools, r21 released

Preview 1 is mostly a bugfix release. It contains a number of bug fixes in various areas that were new in ADT 20, such as the new template infrastructure. Whereas 20.0.1, 20.0.2 and the upcoming 20.0.3 contained a small number of absolutely critical fixes, ADT 21 contains a much larger number of general bug fixes and infrastructure improvements.

Details: http://tools.android.com/download/adt-21-preview

The Right way to Redirect a Page

Well it seems like every time I do something new with my website, there is always something to learn. I'm in the process of rewriting the CMS I use for the how to's and examples on http://blueskyworkshop.com/topics/. I know I needed to use an HTTP header to forward pages. But after some additional reading, I learned what I was doing was not enough.



To tell a search engine like Google a page has moved, you have to send it a 301 Moved Permanently header. Then, the next time Google's spider reads the site, it will move the statistics associated with the page from the old location to the new one. This is done in PHP as follows:

<?php
// Permanent redirection
header("HTTP/1.1 301 Moved Permanently");
header("Location: http://www.somacon.com/");
exit();
?>

Get the details from Somacon here. The post includes a number of examples for several different languages.



I should be able to confirm the older pages are no longer being referenced using Google Analytics. Anyway, I guess we will see in a few weeks.

Google IO 2012 Sessions on the Net

This is totally awesome! Google has made all the Google IO 2012 sessions available on the Net. So if you were like me who would have loved to go and get those goodies, but couldn't, at least you can listen to the sessions.

Wired Writer gets Hacked Hard

If you haven't heard about this story, it worth a look. A Wired writer was hacked on Friday. His MacBook, iPhone, Twitter account, and GMail all taken over. The interesting part is that most of the hacks used social engineering to get enough information about his accounts to take them over. No password cracker or anything like that.

Apple Dropping Safari for Windows

It looks like Apple is discontinuing support for Safari on Windows. With the release of Mountain Lion last week, Safari was updated to version 6. However, there is no Windows version 6 of Safari. When you go to the Apple website for Safari there's no download option if you're using Windows. However, if you Google for Safari 5.1.7 you will see that there is a link to a support site that has the download.



Here are a couple stories detailing the change.

SitePoint: Dropping Windows Safari is a Mistake

MacWorld: Safari 6 Not for Windows



I have to agree with the SitePoint Writer, getting rid of Safari on Windows seems like a bad idea. Although it is not that popular it is very useful as a development tool. Maybe Apple should consider open sourcing the Windows version? It is important for there to be another WebKit browser on Windows other than Chrome.

Valve Running a Business like a Market

At the end of last week, I saw this longish story on the Valve blog discussing how valve manages their company like a market. To sum up, Valve the company has no management structure. Employees are given a desk with wheels and are told to go find projects they are interested in and start pitching in. Projects and teams are self organizing. Employees are free to work on whatever they want. Sounds cool. However, I have my doubts. Could you apply the same principles to Tech Support? Janitorial services? I wonder.... What do you think?

Share with photo using ShareActionProvider

Last exercise demonstrate how to "send email with photo by starting activity with Intent of ACTION_SEND". In this exercise, we will do the same thing using ShareActionProvider.

ShareActionProvider was introduced since API Level 14. This is a provider for a share action. It is responsible for creating views that enable data sharing and also to show a sub menu with sharing activities if the hosting item is placed on the overflow menu.

Modify /res/menu/activity_main.xml to define the android:actionProviderClass attribute for the corresponding in your menu resource file.

<menu xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:id="@+id/menu_item_share"
        android:showAsAction="ifRoom"
        android:title="Share"
        android:actionProviderClass="android.widget.ShareActionProvider" />
</menu>

In order for ShareActionProvider to function, you must provide it a share intent. Find the corresponding MenuItem while inflating your menu resource in your Activity or Fragment. Next, call MenuItem.getActionProvider() to retreive an instance of ShareActionProvider. Use setShareIntent() to update the share intent associated with that action item. ~ refer to onCreateOptionsMenu(Menu menu) in the code.

When you need to update the content to be shared (ex. EditText changed, photo attached), call setShareIntent(shareIntent) again to update the intent. ~ refer setShareIntent(Intent shareIntent) in the code.

package com.example.androidsharephoto;

import android.net.Uri;
import android.os.Bundle;
import android.app.Activity;
import android.content.Intent;
import android.text.Editable;
import android.text.TextWatcher;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ShareActionProvider;
import android.widget.TextView;

public class MainActivity extends Activity {
 
 private ShareActionProvider myShareActionProvider;
 
 EditText edittextEmailAddress;
    EditText edittextEmailSubject;
    EditText edittextEmailText;
    TextView textImagePath;
    Button buttonSelectImage;
    
    final int RQS_LOADIMAGE = 0;
    
    Uri imageUri = null;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        
        edittextEmailAddress = (EditText)findViewById(R.id.email_address);
        edittextEmailSubject = (EditText)findViewById(R.id.email_subject);
        edittextEmailText = (EditText)findViewById(R.id.email_text);
        edittextEmailAddress.addTextChangedListener(commonTextWatcher);
        edittextEmailSubject.addTextChangedListener(commonTextWatcher);
        edittextEmailText.addTextChangedListener(commonTextWatcher);
        
        textImagePath = (TextView)findViewById(R.id.imagepath);
        
        buttonSelectImage = (Button)findViewById(R.id.selectimage);
        buttonSelectImage.setOnClickListener(buttonSelectImageOnClickListener);
    }
    
    TextWatcher commonTextWatcher
    = new TextWatcher(){

  @Override
  public void afterTextChanged(Editable s) {
   // TODO Auto-generated method stub
   setShareIntent(createShareIntent());
  }

  @Override
  public void beforeTextChanged(CharSequence s, int start, int count,
    int after) {
   // TODO Auto-generated method stub
   
  }

  @Override
  public void onTextChanged(CharSequence s, int start, int before,
    int count) {
   // TODO Auto-generated method stub
   
  }};
    
    OnClickListener buttonSelectImageOnClickListener
    = new OnClickListener(){

  @Override
  public void onClick(View arg0) {
   Intent intent = new Intent(Intent.ACTION_PICK,
     android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
   startActivityForResult(intent, RQS_LOADIMAGE);
  }};
  
 @Override
 protected void onActivityResult(int requestCode, int resultCode, Intent data) {
  // TODO Auto-generated method stub
  super.onActivityResult(requestCode, resultCode, data);
   
  if (resultCode == RESULT_OK){
   switch(requestCode){
   case RQS_LOADIMAGE:
    imageUri = data.getData();
    textImagePath.setText(imageUri.toString());
    setShareIntent(createShareIntent());
    break; 
   }  
  }
 }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.activity_main, menu);
        
        MenuItem item = menu.findItem(R.id.menu_item_share);
        myShareActionProvider = (ShareActionProvider)item.getActionProvider();
        myShareActionProvider.setShareHistoryFileName(
          ShareActionProvider.DEFAULT_SHARE_HISTORY_FILE_NAME);
        myShareActionProvider.setShareIntent(createShareIntent());
        return true;
    }
    
    

 private Intent createShareIntent() {
     String emailAddress = edittextEmailAddress.getText().toString();
  String emailSubject = edittextEmailSubject.getText().toString();
  String emailText = edittextEmailText.getText().toString();
  String emailAddressList[] = {emailAddress};
  
  Intent shareIntent = new Intent(Intent.ACTION_SEND); 
  
  shareIntent.putExtra(Intent.EXTRA_EMAIL, emailAddressList);  
  shareIntent.putExtra(Intent.EXTRA_SUBJECT, emailSubject); 
  shareIntent.putExtra(Intent.EXTRA_TEXT, emailText); 
  
  if(imageUri != null){
   shareIntent.putExtra(Intent.EXTRA_STREAM, imageUri);
   shareIntent.setType("image/png");
  }else{
   shareIntent.setType("plain/text");
  }
  
     return shareIntent; 
    }
 
 private void setShareIntent(Intent shareIntent) {
  if (myShareActionProvider != null) {
   myShareActionProvider.setShareIntent(shareIntent); 
  } 
 }

    
}

Layout file:

<?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"
   >
<TextView 
   android:layout_width="fill_parent"
   android:layout_height="wrap_content"
   android:text="@string/hello_world"
   />
<TextView 
   android:layout_width="fill_parent"
   android:layout_height="wrap_content"
   android:text="Enter email address:"
   />
<EditText 
   android:id="@+id/email_address"
   android:layout_width="fill_parent"
   android:layout_height="wrap_content"
   android:inputType="textEmailAddress"
   />
<TextView 
   android:layout_width="fill_parent"
   android:layout_height="wrap_content"
   android:text="Enter email Subject:"
   />
<EditText 
   android:id="@+id/email_subject"
   android:layout_width="fill_parent"
   android:layout_height="wrap_content"
   android:inputType="textEmailSubject"
   />
<TextView 
   android:layout_width="fill_parent"
   android:layout_height="wrap_content"
   android:text="Enter Text:"
   />
<EditText 
   android:id="@+id/email_text"
   android:layout_width="fill_parent"
   android:layout_height="wrap_content"
   />
<TextView
    android:id="@+id/imagepath"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    />
<Button
    android:id="@+id/selectimage"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:text="Select image"
    />
</LinearLayout>

Download the files.

Send email with Image by starting activity using Intent of ACTION_SEND

In the previous posts "Send email using Intent.ACTION_SEND" and "Select Image using Android build-in Gallery" demonstrate how to send text email and load image by starting activity using Intent. In this exercise, both function are work together to send email with photos attached.

To attach image in email intent, call putExtra() to attach the image uri, and call setType() to set type of "image/png".

package com.exercise.AndroidEMail;

import android.net.Uri;
import android.os.Bundle;
import android.app.Activity;
import android.content.Intent;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;

public class MainActivity extends Activity {
 
 EditText edittextEmailAddress;
    EditText edittextEmailSubject;
    EditText edittextEmailText;
    TextView textImagePath;
    Button buttonSelectImage;
    Button buttonSendEmail_intent;
    
    final int RQS_LOADIMAGE = 0;
    final int RQS_SENDEMAIL = 1;
    
    Uri imageUri = null;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        
        edittextEmailAddress = (EditText)findViewById(R.id.email_address);
        edittextEmailSubject = (EditText)findViewById(R.id.email_subject);
        edittextEmailText = (EditText)findViewById(R.id.email_text);
        textImagePath = (TextView)findViewById(R.id.imagepath);
        buttonSelectImage = (Button)findViewById(R.id.selectimage);
        buttonSendEmail_intent = (Button)findViewById(R.id.sendemail_intent);
        
        buttonSelectImage.setOnClickListener(buttonSelectImageOnClickListener);
        buttonSendEmail_intent.setOnClickListener(buttonSendEmail_intentOnClickListener);
    }

    OnClickListener buttonSelectImageOnClickListener
    = new OnClickListener(){

  @Override
  public void onClick(View arg0) {
   Intent intent = new Intent(Intent.ACTION_PICK,
     android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
   startActivityForResult(intent, RQS_LOADIMAGE);
  }};
  
 OnClickListener buttonSendEmail_intentOnClickListener
 = new OnClickListener(){
  
  @Override
  public void onClick(View arg0) {
   String emailAddress = edittextEmailAddress.getText().toString();
   String emailSubject = edittextEmailSubject.getText().toString();
   String emailText = edittextEmailText.getText().toString();
   String emailAddressList[] = {emailAddress};
   
   Intent intent = new Intent(Intent.ACTION_SEND); 
   
   intent.putExtra(Intent.EXTRA_EMAIL, emailAddressList);  
   intent.putExtra(Intent.EXTRA_SUBJECT, emailSubject); 
   intent.putExtra(Intent.EXTRA_TEXT, emailText); 
   
   if(imageUri != null){
    intent.putExtra(Intent.EXTRA_STREAM, imageUri);
    intent.setType("image/png");
   }else{
    intent.setType("plain/text");
   }
   
   startActivity(Intent.createChooser(intent, "Choice App to send email:"));
    
  }};

 @Override
 protected void onActivityResult(int requestCode, int resultCode, Intent data) {
  // TODO Auto-generated method stub
  super.onActivityResult(requestCode, resultCode, data);
  
  if (resultCode == RESULT_OK){
   switch(requestCode){
   case RQS_LOADIMAGE:
    imageUri = data.getData();
    textImagePath.setText(imageUri.toString());
    break;
   case RQS_SENDEMAIL:
    
    break;
   }
    
  }
 }

    
}

<?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"
   >
<TextView 
   android:layout_width="fill_parent"
   android:layout_height="wrap_content"
   android:text="@string/hello_world"
   />
<TextView 
   android:layout_width="fill_parent"
   android:layout_height="wrap_content"
   android:text="Enter email address:"
   />
<EditText 
   android:id="@+id/email_address"
   android:layout_width="fill_parent"
   android:layout_height="wrap_content"
   android:inputType="textEmailAddress"
   />
<TextView 
   android:layout_width="fill_parent"
   android:layout_height="wrap_content"
   android:text="Enter email Subject:"
   />
<EditText 
   android:id="@+id/email_subject"
   android:layout_width="fill_parent"
   android:layout_height="wrap_content"
   android:inputType="textEmailSubject"
   />
<TextView 
   android:layout_width="fill_parent"
   android:layout_height="wrap_content"
   android:text="Enter Text:"
   />
<EditText 
   android:id="@+id/email_text"
   android:layout_width="fill_parent"
   android:layout_height="wrap_content"
   />
<TextView
    android:id="@+id/imagepath"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    />
<Button
    android:id="@+id/selectimage"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:text="Select image"
    />
<Button 
   android:id="@+id/sendemail_intent"
   android:layout_width="fill_parent"
   android:layout_height="wrap_content"
   android:text=" Send email using Intent.ACTION_SEND "
   />
</LinearLayout>

Download the files.


Related:
- Share with photo using ShareActionProvider

Ruby iOS Development Tool

Smashing Magazine has this story on the RubyMotion development tool. This is an iOS development tool which allows you to develops apps using the Ruby language instead of Objective C. The tool is Mac OS X only and costs $199.



There are more and more of these Objective C alternative tools coming out. I will try to mention the reasonably price options. Some that I have seen are ridiculously expensive.

Million Short Search Engine

Ran across some links to millionshort.com yesterday. The idea is to eliminate some of the top ranking sites before you do a search. An interesting idea. Seems more like a Google feature request, than any sort of search breakthrough. I seemed only find old sites that didn't have any new content. Anyway, definitely worth a look.

All's quiet with the jailbreak out...

Where's semaphore? I've been quite busy completely reworking the plumbing of TU. I know I've been saying it for a long time but with how little spare time I have, (wife + family: 3 kids all in 2 sports + teaching + work) I've been nibbling at it slowly. Trust me. My wife would attest to this: I have been working on the rewrite :D




I've gotten the bare framework set for the TU rewrite but I want a more complete solution before I release. The new TU will support all the things that the old version supported with the addition of restoring custom and stock firmware without iTunes. I have run into the same snags that everyone else has run into that has tried this but I have a few ideas.




You guys are awesome. Thank you for being the coolest group of people I have ever associated with.




If you haven't jailbroken iOS 5.1.1 go get absinthe 2.0.x (link to the right) or redsn0w and jailbreak and make sure you save your 5.1.1 SHSH for when 6.0 drops.

Create custom background for Views

This exercise demonstrate how to create custom background, which can be applied on various views such as TextView, Button, ImageButton...etc.

Create /res/drawable/mybackground.xml to define our custom background.

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">

    <item android:state_pressed="true" >
        <shape>
            <gradient
                android:startColor="#FF0000"
                android:endColor="#FF00FF"
                android:angle="180" />
            <stroke
                android:width="3dp"
                android:color="@android:color/background_dark" />
            <corners
                android:radius="3dp" />
            <padding
                android:left="50dp"
                android:top="10dp"
                android:right="50dp"
                android:bottom="10dp" />
        </shape>
    </item>

    <item android:state_focused="true" >
        <shape>
            <gradient
                android:startColor="@android:color/background_light"
                android:endColor="@android:color/background_dark"
                android:angle="180" />
            <stroke
                android:width="3dp"
                android:color="@android:color/background_dark" />
            <corners
                android:radius="3dp" />
            <padding
                android:left="50dp"
                android:top="10dp"
                android:right="50dp"
                android:bottom="10dp" />
        </shape>
    </item>

    <item>        
        <shape>
            <gradient
                android:startColor="@android:color/background_light"
                android:endColor="@android:color/background_dark"
                android:angle="180" />
            <stroke
                android:width="3dp"
                android:color="@android:color/background_dark" />
            <corners
                android:radius="3dp" />
            <padding
                android:left="50dp"
                android:top="10dp"
                android:right="50dp"
                android:bottom="10dp" />
        </shape>
    </item>
</selector>

Use the custom background in layout file.

<LinearLayout 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" 
    android:orientation="vertical">

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Hello, it's a TextView"
        android:clickable="true"
        android:background="@drawable/mybackground"
        android:layout_margin="5dp" />
    
 <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Hello, it's a Button"
        android:background="@drawable/mybackground"
        android:layout_margin="5dp" />
        
    <ImageButton
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:src="@drawable/ic_launcher"
        android:background="@drawable/mybackground"
        android:layout_margin="5dp" />

</LinearLayout>

Download the files.

Related:
- Create custom Button using StateListDrawable

Create device artwork easily with Device Art Generator

With Dalvik Debug Monitor Server (DDMS) in Android SDK Tools (or the new screen capture feature on Android 4), it's easy to capture your current screen. How to...if you want create device artwork like the one in right?


With Device Art Generator, you can create device artwork with your own screen easily. The device art generator allows you to quickly wrap your app screenshots in real device artwork. This provides better visual context for your app screenshots on your web site or in other promotional materials.

Simple steps to generate device artwork using Device Art Generator:

• Drag a screenshot from your desktop onto a device shown in screen.
• Customize the generated image and drag the generated image to your desktop to save.

Official Android Blog launched

Google launched Official Android Blog(http://officialandroid.blogspot.com/) to post news and notes from the Android team.

Create custom Button using StateListDrawable

android.graphics.drawable.StateListDrawable lets you assign a number of graphic images to a single Drawable and swap out the visible item by a string ID value.

It can be defined in an XML file with the <selector> element. Each state Drawable is defined in a nested <item> element. For more information, see the guide to Drawable Resources.

it's a simple exercise create custom Button using StateListDrawable.

Prepare your custom button images of default, focused and pressed in /res/drawable/ folder.

Create /res/drawable/mybutton.xml to define each state Drawable.

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item 
        android:state_pressed="true"
        android:drawable="@drawable/button_pressed" />
    <item 
        android:state_focused="true"
        android:drawable="@drawable/button_focused" />
    <item
        android:drawable="@drawable/button" />
</selector>

Assign the custom button in layout using android:background="@drawable/mybutton".

<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" >

    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerHorizontal="true"
        android:layout_centerVertical="true"
        android:background="@drawable/mybutton" />

</RelativeLayout>

Download the files.


Related:
- Create custom background for Views

Changing the Mouse to a Link Pointer

While working on a collapsable vi cheat sheet over the weekend, I needed to figure out how to make the pointer look like a link when mousing over a header. Turns out it is pretty easy. Just create a style like this:



.Toggle { cursor: pointer; }



Add that to the header and it acts like a link even when it is not.

Google Play Developer Program Policy (�Content Policy�) Updated

The Google Play Developer Program Policy (�Content Policy�) updated. Improvements include the addition of clarifying language for existing policies, support for new Google Play features and content, as well as the introduction of a new section addressing ad behavior in apps.

Visit and familiarize yourself with the above policies. If you find any existing applications in your catalog to be in non-compliance, Google ask you to remedy and republish the application within 30 calendar days of this notification. After this time period, applications discovered to be in violation may be subject to removal from Google Play. Any newly published applications must adhere to the latest version of the Content Policy for Google Play.

Source: Google Play for Developers - Google Play Developer Program Policy (�Content Policy�) Update.

Contact Me 2012

If you need to contact me for any reason, just add a comment to this post. Please include contact information if you need me to get back to you. I will not post any personal information to this thread.

Introducing Google Fiber: The Next Chapter of the Internet

Google Fiber starts with Internet speeds 100 times faster than what most Americans have today. In this video, we see the evolution of the Internet represented in three different stages. It started with Dial-Up, grew with Broadband -- and with Google Fiber, the possibilities are endless. Pre-register now at http://www.google.com/fiber

About the Video:
The cars and model installation were built by hand, and filmed at Agua Dolce airport in Santa Clarita, CA. The installation now resides in the Fiber Space in Kansas City. For more info about the Fiber Space, please visit http://google.com/fiber/fiberspace

JQuery Accordion Style vi Cheat Sheet

Over the weekend I was able to complete an accordion style vi cheat sheet using JQuery on the Tools section of my web site. It is based on a really good cheat sheet that is linked at the bottom of my page. I just added some style changes, reordered it and made it expand or collapse sections.



If I can find the time, I'll try to make a offline version of the cheat sheet using HTML5.

Introduction to Android App Development for the Kindle Fire

Get Started Fast with Android App Development for Amazon�s Best-Selling Kindle Fire!

Practically overnight, the Amazon Kindle Fire has become the world�s top-selling Android-based tablet. Now, in this electronic-only mini-book, expert Android developers provide an introduction to the basics of Kindle Fire development.

Lauren Darcey and Shane Conder first introduce you to Android and walk you through installing its latest development tools. Next, you�ll learn the essential design principles you need to write Android Kindle Fire apps, discover how Android applications are structured and configured, and walk through incorporating user interfaces and other application resources into your projects.

It�s simply the fastest way to start developing apps for today�s hottest Android tablet!

Get Current Stories/News with DuckDuckGo

One thing that is not obvious with the DuckDuckGo search engine is how do I get a list of new links on a subject? It is pretty easy. Just add the following to text to the end of your query: sort:date



For example to search for the latest JQuery stories I could submit: jquery sort:date.

Apply LruCache on GridView

The example "Caching Bitmaps with LruCache" provide a example to Apply LruCache on Gallery. This exercise is GridView version using LruCache.

Reference: http://developer.android.com/training/displaying-bitmaps/cache-bitmap.html#memory-cache

To using android.util.LruCache in the code, targetSdkVersion of "13" is needed to be specified in AndroidManifest.xml.

The layout file, refer to the post "GridView loading photos from SD Card".

package com.example.androidgridview;

import java.io.File;
import java.lang.ref.WeakReference;
import java.util.ArrayList;

import android.os.AsyncTask;
import android.os.Bundle;
import android.os.Environment;
import android.app.Activity;
import android.app.ActivityManager;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.util.LruCache;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.GridView;
import android.widget.ImageView;
import android.widget.Toast;

public class MainActivity extends Activity {

    public class ImageAdapter extends BaseAdapter {
     
     private Context mContext;
     ArrayList<String> itemList = new ArrayList<String>();
     
     public ImageAdapter(Context c) {
      mContext = c; 
     }
     
     void add(String path){
      itemList.add(path); 
     }

  @Override
  public int getCount() {
   return itemList.size();
  }

  @Override
  public Object getItem(int arg0) {
   // TODO Auto-generated method stub
   return null;
  }

  @Override
  public long getItemId(int position) {
   // TODO Auto-generated method stub
   return 0;
  }

  @Override
  public View getView(int position, View convertView, ViewGroup parent) {
   ImageView imageView;
         if (convertView == null) {  // if it's not recycled, initialize some attributes
             imageView = new ImageView(mContext);
             imageView.setLayoutParams(new GridView.LayoutParams(220, 220));
             imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);
             imageView.setPadding(8, 8, 8, 8);
         } else {
             imageView = (ImageView) convertView;
         }

         //Bitmap bm = decodeSampledBitmapFromUri(itemList.get(position), 220, 220);
         
         // Use the path as the key to LruCache
         final String imageKey = itemList.get(position);
           final Bitmap bm = getBitmapFromMemCache(imageKey);
           
         if (bm == null){
          BitmapWorkerTask task = new BitmapWorkerTask(imageView);
          task.execute(imageKey);
         };

         imageView.setImageBitmap(bm);
         return imageView;
  }
  
  public Bitmap decodeSampledBitmapFromUri(String path, int reqWidth, int reqHeight) {
   
   Bitmap bm = null;
   // First decode with inJustDecodeBounds=true to check dimensions
   final BitmapFactory.Options options = new BitmapFactory.Options();
   options.inJustDecodeBounds = true;
   BitmapFactory.decodeFile(path, options);
       
   // Calculate inSampleSize
   options.inSampleSize = calculateInSampleSize(options, reqWidth, reqHeight);
       
   // Decode bitmap with inSampleSize set
   options.inJustDecodeBounds = false;
   bm = BitmapFactory.decodeFile(path, options); 
       
   return bm;   
  }
  
  public int calculateInSampleSize(
    
   BitmapFactory.Options options, int reqWidth, int reqHeight) {
   // Raw height and width of image
   final int height = options.outHeight;
   final int width = options.outWidth;
   int inSampleSize = 1;
   
   if (height > reqHeight || width > reqWidth) {
    if (width > height) {
     inSampleSize = Math.round((float)height / (float)reqHeight);    
    } else {
     inSampleSize = Math.round((float)width / (float)reqWidth);    
    }   
   }
   
   return inSampleSize;    
  }
  
  class BitmapWorkerTask extends AsyncTask<String, Void, Bitmap>{
   
   private final WeakReference<ImageView> imageViewReference;
   
   public BitmapWorkerTask(ImageView imageView) {
    // Use a WeakReference to ensure the ImageView can be garbage collected
    imageViewReference = new WeakReference<ImageView>(imageView); 
   }
   
   @Override
   protected Bitmap doInBackground(String... params) {
    final Bitmap bitmap = decodeSampledBitmapFromUri(params[0], 200, 200);
    addBitmapToMemoryCache(String.valueOf(params[0]), bitmap);
    return bitmap;
   }

   @Override
   protected void onPostExecute(Bitmap bitmap) {
    if (imageViewReference != null && bitmap != null) {
     final ImageView imageView = (ImageView)imageViewReference.get();
     if (imageView != null) {
      imageView.setImageBitmap(bitmap); 
     } 
    } 
   }
  }

 }
    
    ImageAdapter myImageAdapter;
    
    private LruCache<String, Bitmap> mMemoryCache;

 @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        
        GridView gridview = (GridView) findViewById(R.id.gridview);
        myImageAdapter = new ImageAdapter(this);
        gridview.setAdapter(myImageAdapter);
        
        String ExternalStorageDirectoryPath = Environment
          .getExternalStorageDirectory()
          .getAbsolutePath();
        
        String targetPath = ExternalStorageDirectoryPath + "/test/";
        
        Toast.makeText(getApplicationContext(), targetPath, Toast.LENGTH_LONG).show();
        File targetDirector = new File(targetPath);
        
        File[] files = targetDirector.listFiles();
        for (File file : files){
         myImageAdapter.add(file.getAbsolutePath());
        } 
        
        // Get memory class of this device, exceeding this amount will throw an
        // OutOfMemory exception.
        final int memClass 
         = ((ActivityManager)getSystemService(Context.ACTIVITY_SERVICE))
          .getMemoryClass();
        
        // Use 1/8th of the available memory for this memory cache.
        final int cacheSize = 1024 * 1024 * memClass / 8;
        
        mMemoryCache = new LruCache<String, Bitmap>(cacheSize) {
         
         @Override
         protected int sizeOf(String key, Bitmap bitmap) {
          // The cache size will be measured in bytes rather than number of items.
          return bitmap.getByteCount(); 
         }
        };
    }
 
 public void addBitmapToMemoryCache(String key, Bitmap bitmap) {
  if (getBitmapFromMemCache(key) == null) {
   mMemoryCache.put(key, bitmap); 
  } 
 }
 
 public Bitmap getBitmapFromMemCache(String key) {
  return (Bitmap) mMemoryCache.get(key); 
 }

}

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