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Compressing a bitmap to JPG format Android example


Codec, compress(), CompressFormat, quality, decodeByteArray(), Android example source code with image.

public class MainActivity extends Activity {
	
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(new SampleView(this));
	}

	private static Bitmap codec(Bitmap src, Bitmap.CompressFormat format,
			int quality) {
		ByteArrayOutputStream os = new ByteArrayOutputStream();
		src.compress(format, quality, os);

		byte[] array = os.toByteArray();
		return BitmapFactory.decodeByteArray(array, 0, array.length);
	}

	private static class SampleView extends View {

		// CONSTRUCTOR
		public SampleView(Context context) {
			super(context);
			setFocusable(true);

		}
		@Override
		protected void onDraw(Canvas canvas) {
			Paint paint = new Paint();
			
			canvas.drawColor(Color.GRAY);
            
                        //  you need to insert some image flower_blue into res/drawable folder
			Bitmap b = BitmapFactory.decodeResource(getResources(), R.drawable.flower_blue);
                        // Best of quality is 80 and more, 3 is very low quality of image 
			Bitmap bJPGcompress = codec(b, Bitmap.CompressFormat.JPEG, 3);
                   // get dimension of bitmap getHeight()  getWidth()
		   int h = b.getHeight();
           
           canvas.drawBitmap(b, 10,10, paint);
           canvas.drawBitmap(bJPGcompress, 10,10 + h + 10, paint);
           
		}

	}
}



jpg compression android

397LW NO topic_id



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223

Delete Canvas - Fill Canvas Android example | delete-canvas-fill-canvas-android-example


Fill the entire canvas with the specified color.

@Override
    public void onDraw(Canvas canvas) {
    canvas.drawColor(Color.GREEN);
}
20

How set gray text to EditText Android example | how-set-gray-text-to-edittext-android-example


Example source code for Android development. How set gray text to EditText when EditText is blank.
Hint text to display when the text is empty.
In layout/main.xml insert to EditText row Attribute Name android:hint="Some text"


<EditText
        android:id="@+id/myEdit" 
	android:layout_height="wrap_content" android:layout_width="fill_parent"
        android:hint="Some text"
	android:singleLine="true"
</EditText>	



Programatically you can use method setHint:


// setHint(CharSequence hint) example
(EditText)findViewById(R.id.myEdit).setHint("My text");
// or int resId as method setHint(int resId) 
EditText myEdit = findViewById(R.id.myEdit);
myEdit.setHint(R.string.app_name);



68

Write new file or append text Java Android example | write-file-java-android-example


BufferedWriter, FileWriter, write, close MODE_APPEND Java and Android example

Write to file Android example

try {
		String MYFILE = "my_file";
		String strText = "My text";

                // MODE_APPEND, MODE_WORLD_READABLE, MODE_WORLD_WRITEABLE
		// create new file or rewrite existing
                FileOutputStream fos = openFileOutput(MYFILE, getApplicationContext().MODE_PRIVATE);
                // append to file
                FileOutputStream fos = openFileOutput(MYFILE, getApplicationContext().MODE_APPEND);

		fos.write(strText.getBytes());
		fos.close();					
	} catch (IOException e) {
		e.toString();
    }	




Write to file Java example

try {
// new file    
BufferedWriter out = new BufferedWriter(
    		new FileWriter("outfilename"));
    // append text 
   BufferedWriter out = new BufferedWriter(new FileWriter("outfilename", true));
    out.write("some text");
    out.close();
 } catch (IOException e) {
   e.toString();
}			
155

Hue saturation, color, colored filtering Bitmap Image Android example | hue-color-colored-filter-bitmap-image-android-example


colored filtering bitmap android

/* Copyright (C) 2011 The Android Open Source Project
//www.apache.org/licenses/LICENSE-2.0
*/
public class MainActivity extends Activity {
private ImageView imageView;
private Button button1;
Drawable bitmapOrg;
private final int[] mColors =
{Color.BLUE, Color.GREEN, Color.RED, Color.LTGRAY, Color.MAGENTA, Color.CYAN,
		Color.YELLOW, Color.WHITE};
	
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.main);
		imageView = (ImageView)findViewById(R.id.imageView1);
		button1 = (Button)findViewById(R.id.button1);

		
		bitmapOrg = this.getResources().getDrawable(R.drawable.flower_blue);
        
        button1.setOnClickListener(new OnClickListener() {
            public void onClick(View view) {
                int mColor = (int) Math.floor(Math.random() * mColors.length);
                bitmapOrg.setColorFilter(mColors[mColor], PorterDuff.Mode.MULTIPLY);
                imageView.setImageDrawable(bitmapOrg);
                imageView.invalidate();
            }
        });	
 	}

}

373

FrameLayout fragment not visible Android | framelayout-fragment-not-visible-android


ListFragment show only one item issue

Try to change layout_width to 0dp

   <fragment android:name="cz.okhelp.android.fragchangfromlist.ArticleFragment"
              android:id="@+id/article_fragment"
              android:layout_weight="2"
              android:layout_width="0dp"
              android:layout_height="match_parent" />
<!--todo LAYOUT_WIDTH have to be 0dp !!!!!!!!!!!!!!!!!!!!! -->

    <FrameLayout android:id="@+id/article_fragment"
        android:layout_width="0dp"
        android:layout_height="match_parent"
        android:layout_weight="2" />


Editace: 2013-12-09 13:09:56
Počet článků v kategorii: 397
Url:compressing-a-bitmap-to-jpg-format-android-example
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