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Get the color of a specific pixel Java Android example


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             ImputStream      is = this.getResources().openRawResource(R.drawable.colors);
             Bitmap    mBitmap2 = BitmapFactory.decodeStream(is);
        
         int  w = mBitmap2.getWidth();
         int  h = mBitmap2.getHeight();
//  int x , y have to be smaller as w , h 
         int _color =  mBitmap2.getPixel(x, y);


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213

Round number float - double to int - long Java example | round-number-float-to-int-java-example



int nf = Math.round(5.789f);
System.out.print(nf); // 6

float f = 28.611f; 
int n3 = Math.round(f);
System.out.println(n3); // 29

double d = 1234.56;
long lon = Math.round(d);
System.out.println(lon); // 1235

int diff = 90 - 40;
// float fDeleni = diff / 10; // error code
float fDeleni = (float)diff / 10.f; // ok
int nRound = Math.round(fDeleni);


// Caution:
int n2 = (int) 8.999f;
System.out.println(n2); // 8


9

Button Android | button-android


Google Android button example source code for developers.

// get handle
Button myButton;
myButton = (Button)findViewById(R.id.idMyButton);
//set focus
myButton.requestFocus();
// set background image
myButton.setBackgroundResource(R.drawable.backImage);
// or
myButton.setBackgroundDrawable(getResources().getDrawable( R.drawable.someImage));

// set visibility
myButton.setVisibility(View.INVISIBLE); // VISIBLE

///////// SET LISTENER
       Button myButton =(Button)findViewById(R.id.button1);
        myButton.setOnClickListener(new Button.OnClickListener() {
            public void onClick(View v) {
                Toast.makeText(getApplicationContext(), "AHOJ",
                    Toast.LENGTH_LONG).show();
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// or set onClickListener
 myButton.setOnClickListener(myListener);
//end onCreate .....
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        public void onClick(View v) {

        }
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122

Eclipse Graphical Editor does not display a xml source code - error bug | eclipse-graphical-editor-does-not-display-code-error-bug


Try this solutions:
1.) Save xml file
2.) Close tab with xml file
3.) Reopen xml file

1.) Open from menu Window->Android SDK Manager
2.) Select available updates (Tools, SDK etc.)
3.) Install updates

1.) Open from menu Help->Check for Updates
2.) Install available plugins what You need
3.) Restart Eclipse


110

Create Button and TextView dynamically - Android sample | create-button-dynamically-android-sample



public class MainActivity extends Activity {

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        
        LinearLayout layout = (LinearLayout) findViewById(R.id.layout);
            TextView textView = new TextView(this);
            textView.setText("Text View ");
            LinearLayout.LayoutParams p = new LinearLayout.LayoutParams(
                    LinearLayout.LayoutParams.FILL_PARENT,
                    LinearLayout.LayoutParams.WRAP_CONTENT
            );
            layout.addView(textView, p);

            Button buttonView = new Button(this);
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8

Display screen size resolution density dimension Android | display-screen-dimension


Get display, screen resolution - dimension Android phone development example source code.

 Display display = getWindowManager().getDefaultDisplay();
int nWidth = display.getWidth();
int nHeight = display.getHeight();

          DisplayMetrics metrics = new DisplayMetrics();
            getWindowManager().getDefaultDisplay().getMetrics(metrics);
            //get density per inch for example: 120 , 160 , 240
            mXDpi = metrics.xdpi; // 160 The exact physical pixels per inch of the screen in the X dimension. 
            mYDpi = metrics.ydpi;

// density
int nDensity = metrics.densityDpi; // 160 screen density expressed as dots-per-inch

          float  mMetersToPixelsX = mXDpi / 0.0254f; // 1 inch == 0.0254 metre
          float  mMetersToPixelsY = mYDpi / 0.0254f;
          
// Resolution
// The total number of physical pixels on a screen.
int wPix = metrics.widthPixels; // 320 The absolute width of the display in pixels.
int hPix = metrics.heightPixels; // 480 The absolute height of the display in pixels.
int nWidthDisplay = (wPix < hPix)? wPix : hPix;

float nWidthScreenInInch = wPix / mXDpi; //320 / 160 == 2.0 in inch.
float nHeightScreenInInch = hPix / mYDpi; //480 / 160 == 3.0 in inch.

// for example:
// density 120 per inch
//width 320 pix / 120 dpi == width 2.66 inch
//height 480 pix / 120 dpi == height 4.0 inch 

// density 240 per inch
//width 320 pix / 240 dpi == width 1.33 inch
//height 480 pix / 240 dpi == height 2.0 inch 




Example:
HTC Desire HD
11 (4.3) Diagonal cm (in)
480×800 Resolution
85 (217) ppcm (PPI - Pixels per inch)

480 / 217 = 2.21 inch
800 / 217 = 3.69 inch
Math.sqrt( 2.21*2.21 + 3.69 * 3.69) = 4.3 inch - diagonal

//en.wikipedia.org/wiki/Pixels_per_inch
//en.wikipedia.org/wiki/Dots_per_inch

Typical screen widths:

320dp: a typical phone screen (240x320 ldpi, 320x480 mdpi, 480x800 hdpi, etc).
480dp: a tweener tablet like the Streak (480x800 mdpi).
600dp: a 7” tablet (600x1024 mdpi).
720dp: a 10” tablet (720x1280 mdpi, 800x1280 mdpi, etc).


Emulator skins in the Android SDK
//developer.android.com/guide/practices/screens_support.html









































Low density (120), ldpi

Medium density (160), mdpi

High density (240), hdpi

Extra high density (320), xhdpi

Small screen
QVGA (240x320) 480x640

Normal screen
WQVGA400 (240x400)

WQVGA432 (240x432)
HVGA (320x480) WVGA800 (480x800)

WVGA854 (480x854)

600x1024
640x960

Large screen
WVGA800** (480x800)

WVGA854** (480x854)
WVGA800* (480x800)

WVGA854* (480x854)

600x1024

Extra Large screen
1024x600 WXGA (1280x800)

1024x768
1280x768
1536x1152
1920x1152

1920x1200
2048x1536
2560x1536

2560x1600
* To emulate this configuration, specify a
custom density of 160 when creating an AVD that uses a WVGA800 or WVGA854 skin.

** To emulate this configuration, specify a custom density of 120 when creating an AVD that
uses a WVGA800 or WVGA854 skin.

† This skin is available with the Android 3.0 platform


Editace: 2013-12-09 13:06:02
Počet článků v kategorii: 397
Url:get-the-color-of-a-specific-pixel-java-android-example

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