How to Scroll large image in ImageView Android Example

Cross Button in EditText Android for deleting clearing text in EditText Example source code:
Example allow delete text in EditText by cross button, or do Button click performance.

main.xml type your package name and class
Put into drawable folder cross and ok image.

       <cz.okhelp.wiktionary.CustomEditText
            android:id="@+id/editTextZadejSlovo"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_weight="2"
            android:ems="10"
            android:hint="TypeAndPressGreen"
            android:singleLine="true"
            android:lines="1"
            android:maxLines="1" 
            android:drawableLeft="@drawable/cross"
            android:drawableRight="@drawable/ok" />
<!--button is invisible 0 height 0 width for performance click on button in EditText-->
        <Button
            android:id="@+id/btnGO"
            android:layout_width="0sp"
            android:layout_height="0sp"
            android:layout_weight="0"
            android:text="GO" />

CustomEditText.java

package cz.okhelp.wiktionary; // your package name

import android.content.Context;
import android.graphics.Rect;
import android.graphics.drawable.Drawable;
import android.util.AttributeSet;
import android.view.KeyEvent;
import android.view.MotionEvent;
import android.widget.Button;
import android.widget.EditText;

public class CustomEditText extends EditText
{
  private Drawable dLeft,dRight;
  private Rect lBounds,rBounds;
  private static Button btnOk;

  public CustomEditText(Context context, AttributeSet attrs, int defStyle) {
    super(context, attrs, defStyle);
  }
  public CustomEditText(Context context, AttributeSet attrs) {
    super(context, attrs);
  }
  public CustomEditText(Context context) {
    super(context);
  }

  @Override
  public void setCompoundDrawables(Drawable left, Drawable top,
      Drawable right, Drawable bottom)
  {
   if(left !=null) {
    	dLeft = left;
    }
   if(right !=null){
      dRight = right;
    } 
    
    super.setCompoundDrawables(left, top, right, bottom);
  }

	@Override
	public boolean onKeyUp(int keyCode, KeyEvent event) {
		if (keyCode == KeyEvent.KEYCODE_ENTER) {
    	btnOk.requestFocus();
    	btnOk.performClick();

		}
		return super.onKeyUp(keyCode, event);
	}
  
  @Override
  public boolean onTouchEvent(MotionEvent event)
  {
  	final int x = (int)event.getX();
  	final int y = (int)event.getY();

  	if(event.getAction() == MotionEvent.ACTION_UP && dLeft!=null) {
  		lBounds = dLeft.getBounds();
  		
  		int n1 = this.getLeft();
  		int n2 = this.getLeft()+lBounds.width();
  		int n3 = this.getPaddingTop();
  		int n4 = this.getHeight()-this.getPaddingBottom();
  		// leva strana
  		if(    x>=(this.getLeft()) 
  				&& x<=(this.getLeft()+lBounds.width())
  				&& y>=this.getPaddingTop() 
  				&& y<=(this.getHeight()-this.getPaddingBottom()))
  		{
  			this.setText("");
  			event.setAction(MotionEvent.ACTION_CANCEL);//use this to prevent the keyboard from coming up
  		}
  	}
  	if(event.getAction() == MotionEvent.ACTION_UP && dRight!=null)
    {
      rBounds = dRight.getBounds();
      int n1 = this.getRight()-rBounds.width();
      int n2 = this.getRight()-this.getPaddingRight();
      int n3 = this.getPaddingTop();
      int n4 = this.getHeight()-this.getPaddingBottom();
      // prava strana
      if(x>=(this.getRight()-rBounds.width()) && x<=(this.getRight()-this.getPaddingRight())
      		&& y>=this.getPaddingTop() && y<=(this.getHeight()-this.getPaddingBottom()))
      {
      	btnOk.requestFocus();
      	btnOk.performClick();
      	event.setAction(MotionEvent.ACTION_CANCEL);//use this to prevent the keyboard from coming up
      }
    }
    
    return super.onTouchEvent(event);
  }

  @Override
  protected void finalize() throws Throwable
  {
    dRight = null;
    rBounds = null;
    super.finalize();
  }
	public void setBtnOk(Button btnOk) {
		this.btnOk = btnOk;
	}
	public Button getBtnOk() {
		return btnOk;
	}
}  

YourActivity.java

//onCreate
        Button  mBtnGO = (Button)findViewById(R.id.btnGO);
        CustomEditText mEditZadani = (CustomEditText)this.findViewById(R.id.editTextZadejSlovo);
        mEditZadani.setBtnOk(mBtnGO);
        mBtnGO.setOnClickListener(new View.OnClickListener() {
          @Override
          public void onClick(View v) {
             // do stuff for signInButtonClick
          }
        });

//android.okhelp.cz/wiktionary-aplikace-pro-android/

Terms Screen size, density, density independent pixel, resolution as a picture - pictogram.


Test your knowledge
Q: How to find out the phone screen size?
A: (By length of display diagonale in inch -  Not to measure a diagonal of device!!!)

Q: What resolution has 720 x 1280 display?
A: (921600 pixels)

Q: What does it mean "240 dpi" screen density?
A: (Display have density 240 x 240  dots - "Tri-color LED etc." - per every physical (real) square inch. If you have icon 240x240 pixels, this will just occupy an area of one square inch on the display.)

Q: Phone have screen density 240 dpi. Image for 160 dpi screen density have size 128x 128 pixels. What will be the size of the image for 240 dpi screen density?
A: (Calculate the virtual pixels size.   128 * (240/160)  =  192.  You have to resize image to new size 192 x 192 physical pixels and put into folder drawable-hdpi (high) ~240dpi  for phone with screen density 240 dpi. ) or use density independend pixels 128dp x 128dp.

 

 

PNG, GIF, BMP, JPG

// //www.apache.org/licenses/LICENSE-2.0

// 1.)  Bitmap from stream
            InputStream is = context.getResources().openRawResource(R.drawable.my_image);
            mBitmap = BitmapFactory.decodeStream(is);
           

// 2.) 
            Bitmap ball = BitmapFactory.decodeResource(getResources(), R.drawable.ball);
            int dstWidth =120;
            int dstHeight = 120;
            mBitmap = Bitmap.createScaledBitmap(ball, dstWidth, dstHeight, true);

// 3.)
Bitmap  mBitmap = Bitmap.createBitmap(320, 480, Bitmap.Config.ARGB_8888);


        Bitmap  mBitmap;
        Canvas  mCanvas;
        Paint   mBitmapPaint;
            
            mBitmap = Bitmap.createBitmap(320, 480, Bitmap.Config.ARGB_8888);
            mCanvas = new Canvas(mBitmap);
            mBitmapPaint = new Paint(Paint.DITHER_FLAG);

// 4.)
          Bitmap  mBitmap = Bitmap.createBitmap(w, h, Bitmap.Config.RGB_565);
          Canvas  mCanvas.setBitmap(mBitmap);
            mCanvas.drawColor(0xFFFFFFFF);

How get Android SDK location - PATH on PC from Eclipse tutorial.

1. Open dialog from menu Window -> AVD and SDK manager


2. In dialog select Available packages


3. On top of dialog will displayed similar path: SKD Location: C:\PROGRA~1\Android\android-sdk-windows\

Android development
Java float is 32 bit single precision type and used when fractional precision calculation is required.

Java float je 32 bitů veliké číslo sloužící především pro přesný výsledek za desetinnou tečkou například při dělení čísel. Pro větší přesnost použíijte 64 bitový typ Double.

		// declaration and assignment of value  type float
		float x = 18.41785f;
		//print formated  value
		System.out.printf("The value of x is %.3f%n", x); // 18.418
                
                // declaring more variables in single statement
                float f1 = 12.4F, f2 = 564.5F, f3 = 14.589F;

		// float range of value
		System.out.println(Float.MIN_VALUE); // 4E-45
		System.out.println(Float.MAX_VALUE); // 4028235E38

		// is NaN  Not-a-Number
		float f = (float) Math.sqrt(-15);
		boolean bNaN = Float.isNaN(f);
		System.out.print(bNaN); // true
		
                // check if a string is a valid number in Java example
                // convert string to float Java example
		String sF = "12.8";
		float fParse = Float.parseFloat(sF);

	       // convert strings to numbers
	      String sFl = "15.48";
	      float fFromString = (Float.valueOf(sFl)).floatValue();

// float to string in Java example code
Float fObj = new Float(68.5);
String str = fObj.toString();
// else 
Float fS = 11.6f;
String sFloat = fS.toString();

              // compare two float variables
	      Float fComp1 = 4.3f;
	      if(fComp1.equals(4.3f))
	  		System.out.print("true");

	    // compares the two specified float values in Java example
	    int i =	Float.compare(11.5f, 11.7f); // -1 first < second
	    // 0 first == second
	    // 1 first > second
	    System.out.print(i);