Scale listener : ListActivity « UI « Android

1. Android
2. UI
3. ListActivity

Scale listener

   

package app.test;
import android.app.Activity;
import android.graphics.Matrix;
import android.os.Bundle;
import android.util.Log;
import android.view.MotionEvent;
import android.view.ScaleGestureDetector;
import android.widget.ImageView;

public class Test extends Activity {
  private ImageView image;
  private ScaleGestureDetector mScaleDetector;
    private float mScaleFactor = 1f;
  private Matrix mMatrix = new Matrix();
  @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        image = (ImageView)findViewById(R.id.image);
        mScaleDetector = new ScaleGestureDetector(this, new ScaleListener());
    }

  @Override
  public boolean onTouchEvent(MotionEvent ev) {
        mScaleDetector.onTouchEvent(ev);
        return true;
  }

    private class ScaleListener extends ScaleGestureDetector.SimpleOnScaleGestureListener {
    @Override
        public boolean onScale(ScaleGestureDetector detector) {
      mScaleFactor *= detector.getScaleFactor();
      mScaleFactor = Math.max(0.1f, Math.min(mScaleFactor, 5.0f));
            mMatrix.setScale(mScaleFactor, mScaleFactor);
            image.setImageMatrix(mMatrix);
            image.invalidate();
            return true;
        }
    }
}

//main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/layout"  android:orientation="vertical"
    android:layout_width="fill_parent"  android:layout_height="fill_parent" >

  <TextView  android:text="Use the pinch gesture to change the image size"
    android:layout_width="fill_parent"  android:layout_height="wrap_content" />

  <ImageView android:id="@+id/image"  android:src="@drawable/icon"
    android:layout_width="match_parent"  android:layout_height="match_parent"
    android:scaleType="matrix" />

</LinearLayout>

   
    
    
  

Related examples in the same category