Kanti's Thinking , Study

<?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">
<Button
  android:id="@+id/btnOK"
  android:layout_width="fill_parent"
  android:layout_height="wrap_content"
  android:text="OK" />
</LinearLayout>

public class MainActivity extends Activity {

  private Button btnOK;

  @Override
  public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    btnOK = (Button)findViewById(R.id.btnOK);
    btnOK.setOnClickListener(new OnClickListener() {
      @Override
      public void onClick(View v) {
        Toast.makeText(MainActivity.this, "Hello!", Toast.LENGTH_LONG).show();
      }
    });
  }
}

public class MainActivity extends Activity {

  private Button btnOK;

  @Override
  public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    btnOK = (Button) findViewById(R.id.btnOK);
    btnOK.setOnClickListener(new BtnOKOnClick(this));
  }
}

class BtnOKOnClick implements OnClickListener {
  private Context mContext;

  public BtnOKOnClick(Context context) {
    mContext = context;
  }

  @Override
  public void onClick(View v) {
    Toast.makeText(mContext, "Hello!", Toast.LENGTH_LONG).show();
  }
}

public class MainActivity extends Activity implements OnClickListener {

  private Button btnOK;

  @Override
  public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    btnOK = (Button) findViewById(R.id.btnOK);
    btnOK.setOnClickListener(this);
  }

  @Override
  public void onClick(View v) {
    switch (R.id.btnOK) {
    case R.id.btnOK:
      Toast.makeText(this, "Hello!", Toast.LENGTH_LONG).show();
      break;
    }
  }
}

안드로이드에서는 새로운 클래스를 생성할때마다 1KB의 메모리를 소비합니다.

Customizing Android ListView Colors

<?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">
 <ListView
  android:id="@android:id/list"
  android:layout_width="wrap_content"
  android:layout_height="wrap_content"
  android:listSelector="@android:color/transparent"
  />
 <TextView
  android:id="@android:id/empty"
  android:layout_width="wrap_content"
  android:layout_height="wrap_content"
  android:text="@string/empty"
  />
</LinearLayout>

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
 android:layout_width="fill_parent" 
 android:layout_height="fill_parent"
 android:orientation="horizontal" 
 android:padding="10sp"
 android:background="@drawable/item_selector">
 <CheckBox
  android:id="@+id/checkbox"
  android:layout_width="wrap_content"
  android:layout_height="wrap_content"
  android:focusable="false"
  />
 <TextView 
  android:id="@+id/title" 
  android:layout_width="fill_parent"
  android:layout_height="wrap_content"
  android:ellipsize="end"
  android:singleLine="true" 
  android:textStyle="bold"
  android:padding="7dip"
  android:textSize="18sp"
  android:layout_toRightOf="@id/checkbox"
  android:textColor="@color/black"
  />
</RelativeLayout>

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item 
     android:state_pressed="true" 
     android:drawable="@color/green" />
    <item 
     android:state_selected="true" 
     android:drawable="@color/blue" />
 <item 
     android:drawable="@color/white" />
</selector>

<?xml version="1.0" encoding="utf-8"?>
<resources> 
 <color name="red">#ff00</color>
 <color name="green">#f0f0</color>
 <color name="blue">#f00f</color>
 <color name="white">#ffff</color>
 <color name="black">#f000</color>
</resources>

What I've done is create an activity that contains my custom view already in the xml file, and then programmatically create a new one and add it to the layout. What I find is the one that is made in the xml has the proper styling, and the one I create programmatically doesn't.

The difference between the two as far as I can tell is that the system uses theCustomLayout1(Context context, AttributeSet attrs) constructor. The problem is I can't figure out how to get the AttributeSet for the application to pass to this custom view when I create it programmatically.

Here's the Activity:

import android.app.Activity;
import android.os.Bundle;
import android.widget.LinearLayout;


public class ThemeOne extends Activity {


   @Override


   public void onCreate(Bundle savedInstanceState) {


       super.onCreate(savedInstanceState);


        setContentView(R.layout.main);


        LinearLayout layout = (LinearLayout) findViewById(R.id.mainlayout);


        layout.addView(new CustomLayout1(getApplicationContext()));


   }


}




 

Here's the main xml:

<?xml version="1.0" encoding="utf-8"?>


<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
 android:orientation="vertical" 


 android:id="@+id/mainlayout"


 android:layout_width="fill_parent"


 android:layout_height="fill_parent">


 <com.clearsync.test.theme1.CustomLayout1 android:id="@+id/maincustom"


  android:layout_width="fill_parent"


  android:layout_height="wrap_content" />


</LinearLayout>

The custom view class:

import com.clearsync.test.theme1.R;


import android.content.Context;


import android.util.AttributeSet;


import android.view.LayoutInflater;


import android.widget.LinearLayout;


public class CustomLayout1 extends LinearLayout {


 private Context context = null;


 public CustomLayout1(Context context) {


  super(context);


  this.context = context;


  create();


 }


 public CustomLayout1(Context context, AttributeSet attrs) {


  super(context, attrs);


  this.context = context;


  create();


 }


 private void create(){


  LayoutInflater layoutInflater = (LayoutInflater)context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);


  layoutInflater.inflate(R.layout.inflateme, this, true);


 }


}

and finally, the custom view 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">


 <TextView android:layout_width="wrap_content"


  android:layout_height="wrap_content" 


  android:text="Oh, Hewroh..."


  style="?textview_style1" />


</LinearLayout>

Gallery에 Item 들을 추가하게 되면 0번 인덱스나 마지막 인덱스로 아이템들을 스크롤 시키게되면 외쪽 또는 오른쪽으로 더이상 스크롤을 할 수 없게 된다.

여기서 구현 하고자 하는 내용은 0번 또는 마지막 인덱스로 스크롤 되더라도 큐와 같이 무한 스크롤 되도록 구현하는 방법.

핵심 포인트

Gallery Adapter에 실제 가지고 있는 Item의 개수의 3배를 가지고 있는 것처럼 보여 지게 하고

Gallery에 setOnItemSelectedListener를 추가하여 OnItemSelectedListener의 onItemSelected에서 가운데 범위를 넘어 서는 경우

Selected Item을 변경해 주면 무한 스크롤을 구현 할 수 있다.

Sample)

//-------------------------------------------------------------------------------------

//  GalleryAdapter Class

//-------------------------------------------------------------------------------------

package reno.gallerytest;

import android.content.*;
import android.view.*;
import android.widget.*;

public class GalleryAdapter extends BaseAdapter {
    private Context mContext;
    private String[] resString = {"1111", "2222", "3333", "4444", "5555"};
    public GalleryAdapter (Context c)
    {
        this.mContext = c;
    }
   
    @Override
    public int getCount() {
        // TODO Auto-generated method stub
        return resString.length*3;  // 총 Item 개수를 X 3으로 리턴한다. 이유는 Index의 맨 끝으로 이동시 좌,우에 Item이 연속되는 것 처럼 보기기 위함.
    }

    @Override
    public Object getItem(int arg0) {
        // TODO Auto-generated method stub
        return resString[arg0%resString.length];
    }

    @Override
    public long getItemId(int arg0) {
        // TODO Auto-generated method stub
        return arg0%resString.length;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        // TODO Auto-generated method stub
        TextView txtView;
        position = position % resString.length;
       
        if(convertView == null)
        {
            txtView = new TextView(mContext);
        }else
        {
            txtView = (TextView)convertView;
        }
       
        txtView.setText(resString[position]);
        txtView.setLayoutParams(new Gallery.LayoutParams(75, 75));
        return txtView;       
    }

}

//------------------------------------------------------------------------------------------------

// GalleryTest Class

//------------------------------------------------------------------------------------------------

package reno.gallerytest;

import android.app.Activity;
import android.graphics.*;
import android.os.Bundle;
import android.widget.*;
import android.util.*;
import android.view.*;

public class GalleryTest extends Activity {
    /** Called when the activity is first created. */
    private RGallery unitGallery;
   
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
       
        unitGallery = (RGallery)findViewById(R.id.galUit);       
        unitGallery.setAdapter(new GalleryAdapter(this));     
        unitGallery.setSpacing(0);       
        unitGallery.setSelection(6);
        unitGallery.setBackgroundColor(Color.GRAY);
        unitGallery.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener(){
            public void  onItemSelected  (AdapterView<?> parent, View view, int position, long id)
            {
                Log.d("GalleryTest", "onItemSelected index=" + String.valueOf(position));
                if(position < 5)
                    unitGallery.setSelection(position + 5);
                else if(position >= 10)
                    unitGallery.setSelection(position - 5);

                    // 이 부분이 무한 스크롤을 해주는 부분으로 가운데 영역을 벗어 나는 경우 setSelection으로 Position을 이동시켜 마치 무한 스크롤이 되게 보여 준다.

            }
           
            public void  onNothingSelected  (AdapterView<?> parent)
            {
               
            }
        });
    }
}

//----------------------------------------------------------------------------------------

//  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"
    >
<Gallery
android:id="@+id/galUit"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
>
</Gallery>
</LinearLayout>

Android Coverflow Widget

Here's an Android Coverflow like Widget that I created. It's based on the Android Gallery widget and is used in the same way, with a ViewAdapter. My main aim when coding this coverflow widget was to create an easily re-usable component using the standard Android 2D libraries.Yes, that's right I'm using the 2D libs, as they support perspective transformations and that is all that is needed for coverflow. I could have used Open GL, but I wanted to see what could be achieved without it. So here are the results.






The Video shows the Coverflow widget running on a HTC G1 (Dream). I can't remember the exact spec's of the phone but it's a fairly old one and is only running version 1.1 of Android. I'm moving the images using the track ball and then I also move them with screen touches. It is possible to drag, fling and touch on individual image to bring them to the centre. With a few tweaks I've managed to get the responsiveness and performance on this to be pretty good, it seems to be comparable to the standard gallery widget, and in my quick test the motion tracking was fluid and fast. I'm not sure how well it would run on newer versions of hardware and the Android OS, but I can only assume that things should be better. How much better I don't know, so if you try this on a different device or a newer OS I would love to hear how things worked.

참조사이트
http://www.inter-fuser.com/2010/01/android-coverflow-widget.html

소스
Here's the zip of the coverflow example: Coverflow.zip

이미지 효과로 이미지 크기의 절반을 반대 되는 이미지를 만들고,
그 반대된 이미지에 대해서는 반사 된 듯한 효과를 주는 소스 입니다.

package com.android.reflection2;

import android.app.Activity;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.LinearGradient;
import android.graphics.Matrix;
import android.graphics.Paint;
import android.graphics.PorterDuffXfermode;
import android.graphics.Bitmap.Config;
import android.graphics.PorterDuff.Mode;
import android.graphics.Shader.TileMode;
import android.os.Bundle;
import android.widget.ImageView;

public class Reflection extends Activity {
	/** Called when the activity is first created. */

	ImageView view1;

	@Override
	public void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.main);

		view1 = (ImageView) findViewById(R.id.ImageView01);

		Bitmap bitmapOriginal = BitmapFactory.decodeResource(getResources(),
				R.drawable.android);

		int nWidth = bitmapOriginal.getWidth();
		int nHeight = bitmapOriginal.getHeight();

		Matrix matrix = new Matrix();
		matrix.preScale(1, -1);

		Bitmap bitmapReflection = Bitmap.createBitmap(bitmapOriginal, 0,
				nHeight / 2, nWidth, nHeight / 2, matrix, false);

		Bitmap bitmapOrigianlAndReflection = Bitmap.createBitmap(nWidth,
				(nHeight + nHeight / 2), Config.ARGB_8888);

		Canvas canvas = new Canvas(bitmapOrigianlAndReflection);
		canvas.drawBitmap(bitmapOriginal, 0, 0, null);
		Paint deafaultPaint = new Paint();
		canvas.drawRect(0, nHeight, nWidth, nHeight + 5, deafaultPaint);
		canvas.drawBitmap(bitmapReflection, 0, nHeight + 5, null);

		Paint paint = new Paint();
		LinearGradient shader = new LinearGradient(0, bitmapOriginal
				.getHeight(), 0, bitmapOrigianlAndReflection.getHeight() + 5,
				0x70ffffff, 0x00ffffff, TileMode.CLAMP);
		paint.setShader(shader);
		paint.setXfermode(new PorterDuffXfermode(Mode.DST_IN));
		canvas.drawRect(0, nHeight, nWidth, bitmapOrigianlAndReflection
				.getHeight() + 5, paint);

		view1.setImageBitmap(bitmapOrigianlAndReflection);
	}
}

결과 화면은 이런 식으로 나옵니다.