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How to Scroll large image in ImageView Android Example


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main.xml

    <LinearLayout xmlns:android="//schemas.android.com/apk/res/android"
		android:orientation="vertical"
			android:gravity="top"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent" >

        <ScrollView
            android:id="@+id/scrollView1"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content" >

            <HorizontalScrollView
                android:id="@+id/horizontalScrollView1"
                android:layout_width="match_parent"
                android:layout_height="wrap_content" >

 
            <LinearLayout
			    android:gravity="top"
                android:layout_width="fill_parent"
                android:layout_height="wrap_content" >

                <ImageView
                    android:id="@+id/imageViewObrazekGeometrie"
                    android:layout_width="360dp"
                    android:layout_height="777dp"
                    android:src="@drawable/geometrie_vzorecky" />

            </LinearLayout>
            </HorizontalScrollView>
        </ScrollView>

    </LinearLayout>


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Další témata ....(Topics)


365

layout-sw600dp values-sw600dp Android example of use | layout-sw600dp-values-sw600dp-android-example-of-use


Why the app selects data from basic layout folder if smallest width is higher then the number in folder name?
Example 1
layout-sw600dp values-sw600dp (smallest width sw for data usage from this folder is 600dp density independent pixel!!!!!)
Device screen resolution is 1200 x 900 px (pixel) Wow, app to be select data from sw600dp folder! Realy?
DPI of device screen - dot per inch (pixel per inch) is 480 pixel it is wery important number!


  1. App selects smallest dimension of screen. In our case 900 px
    Medium screen have 160 dpi (The density-independent pixel is equivalent to one physical pixel on a 160 dpi screen, which is the baseline density assumed by the system for a "medium" density screen.).


  2. App calculate ratio 480 / 160 = 3 (The conversion of dp units to screen pixels: px = dp * (dpi / 160))


  3. App calculate smallest dimesnion of screen in dp 900 / 3 = 300 dip or dp (density independed pixel).


  4. App selects data from basic values and layout folder because sw600dp is greater than 300dp.





In our case smallest dimension of screen must be at least 1800 real - physical pixels (1800 px / 3 ratio(dpi/160) = 600 dp (dip density independend pixels) to be used data from folders values-sw600dp and layout-sw600dp.


Example 2 see Example 1 abouve
Device: Nexus 7 (2012) selected from Android Studio tool layout editor
Resolution: 800x1280 px
DPI: tvdpi (approximately 213dpi)
Ratio: 1.33 (213 / 160)
Smallest width in px: 800
Convert px to dp: 601.5 (800 / 1.33)
Result:Smallest width is 601.5dp The App to be used data from folders values-sw600dp and layout-sw600dp.
3

Download file from URL | download-file-from-url


Download image file from URL to ImageView Java Android source example code.



Context context = thisClass.this;
Drawable image = ImageOperations(context,
"//www.okhelp.cz/images/android/ad_4.png"
,"image.jpg");
ImageView imgView;
imgView = (ImageView)findViewById(R.id.idImageView);
imgView.setImageDrawable(image);

	private Drawable ImageOperations(Context ctx, String url, String saveFilename) {
		try {
			InputStream is = (InputStream) this.fetch(url);
			Drawable d = Drawable.createFromStream(is, "src");
			return d;
		} catch (MalformedURLException e) {
			e.printStackTrace();
			return null;
		} catch (IOException e) {
			e.printStackTrace();
			return null;
		}
	}

	public Object fetch(String address) throws MalformedURLException,IOException {
		URL url = new URL(address);
		Object content = url.getContent();
		return content;
	}
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();
            }
        });	

// or set onClickListener
 myButton.setOnClickListener(myListener);
//end onCreate .....
   private OnClickListener myListener = new OnClickListener() {
        public void onClick(View v) {

        }
   }



7

Show keyboard in WebView Android example | webview-keyboard


Show keyboard if WebView input have focus Android apps development example source code.

WebView webview;

//in onCreate

	webview = (WebView) findViewById(R.id.idWebviewPda);
	webview.getSettings().setJavaScriptEnabled(true);
	webview.loadUrl("//android.okhelp.cz");
	
	webview.requestFocus(View.FOCUS_DOWN);
    webview.setOnTouchListener(new View.OnTouchListener() {
        @Override
        public boolean onTouch(View v, MotionEvent event) {
            switch (event.getAction()) {
                case MotionEvent.ACTION_DOWN:
                case MotionEvent.ACTION_UP:
                    if (!v.hasFocus()) {
                        v.requestFocus();
                    }
                    break;
            }
            return false;
        }
    });

253

Play Sound Android Example | play-sound-android-example



import android.content.Context;
import android.media.AudioManager;
import android.media.SoundPool;

public class SoundManager
{
  private SoundPool soundPool;
  private int[] sm;
  Context context;

  public SoundManager(Context context) {
    this.context = context;
    soundPool = new SoundPool(4, AudioManager.STREAM_MUSIC, 0);
    sm = new int[2];
    // fill your sounds
    sm[0] = soundPool.load(context, R.raw.my_sound1, 1);
    sm[1] = soundPool.load(context, R.raw.my_sound2, 1);
  }

  public final void playSound(int sound) {
      AudioManager mgr = (AudioManager)context.getSystemService(
          Context.AUDIO_SERVICE);  
      float streamVolumeCurrent =
          mgr.getStreamVolume(AudioManager.STREAM_MUSIC);
      float streamVolumeMax = mgr.getStreamMaxVolume(AudioManager.STREAM_MUSIC);
      float volume = streamVolumeCurrent / streamVolumeMax;
      soundPool.play(sm[sound], volume, volume, 1, 0, 1f);
  }

  public final void cleanUpIfEnd() {
    sm = null;
    context = null;
    soundPool.release();
    soundPool = null;
  }
}


Editace: 2013-12-09 13:01:31
Počet článků v kategorii: 397
Url:how-to-scroll-large-image-in-imageview-android-example

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