Prise Zoomen auf Textansicht android

Question

Hallo Freund Ich habe Pinch Zoom Textview getan und es funktioniert gut, aber das Problem ist, wenn ich die Textansicht Position verkleinerte verändert und ich möchte die Position von Textansicht wird während des Zoom in und verkleinern, das ist meine

Code

public class MainActivity extends Activity { 

    TextView scaleGesture; 
    ScaleGestureDetector scaleGestureDetector; 

    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_main); 
     scaleGesture = (TextView)findViewById(R.id.article); 
     scaleGesture.setText("this is some text"); 
     scaleGestureDetector = new ScaleGestureDetector(this, new simpleOnScaleGestureListener()); 
    } 

    @Override 
    public boolean onCreateOptionsMenu(Menu menu) { 
     // Inflate the menu; this adds items to the action bar if it is present. 
     getMenuInflater().inflate(R.menu.activity_main, menu); 
     return true; 
    } 


    @Override 
    public boolean onTouchEvent(MotionEvent event) { 
     // TODO Auto-generated method stub 
     scaleGestureDetector.onTouchEvent(event); 
     return true; 
    } 

    public class simpleOnScaleGestureListener extends 
      SimpleOnScaleGestureListener { 

     @Override 
     public boolean onScale(ScaleGestureDetector detector) { 
      // TODO Auto-generated method stub 
      float size = scaleGesture.getTextSize(); 
      Log.d("TextSizeStart", String.valueOf(size)); 

      float factor = detector.getScaleFactor(); 
      Log.d("Factor", String.valueOf(factor)); 


      float product = size*factor; 
      Log.d("TextSize", String.valueOf(product)); 
      scaleGesture.setTextSize(TypedValue.COMPLEX_UNIT_PX, product); 

      size = scaleGesture.getTextSize(); 
      Log.d("TextSizeEnd", String.valueOf(size)); 
      return true; 
     } 
    } 
} 

Answer 1

ich habe diese Art und Weise getan:

activity_main.xml:

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

    <TextView 
     android:id="@+id/mytv" 
     android:layout_width="fill_parent" 
     android:layout_height="wrap_content" 
     android:layout_alignParentLeft="true" 
     android:layout_alignParentTop="true" 
     android:text="This is my sample text for pinch zoom demo, you can zoom in and out using pinch zoom, thanks" /> 

</RelativeLayout> 

MainActivity.java:

import android.app.Activity; 
import android.os.Bundle; 
import android.view.MotionEvent; 
import android.view.View; 
import android.view.View.OnTouchListener; 
import android.widget.TextView; 

public class MyTextViewPinchZoomClass extends Activity implements OnTouchListener { 

    final static float STEP = 200; 
    TextView mytv; 
    float mRatio = 1.0f; 
    int mBaseDist; 
    float mBaseRatio; 
    float fontsize = 13; 

    public void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_main); 

     mytv = (TextView) findViewById(R.id.mytv); 
     mytv.setTextSize(mRatio + 13); 
    } 

    public boolean onTouchEvent(MotionEvent event) { 
     if (event.getPointerCount() == 2) { 
      int action = event.getAction(); 
      int pureaction = action & MotionEvent.ACTION_MASK; 
      if (pureaction == MotionEvent.ACTION_POINTER_DOWN) { 
       mBaseDist = getDistance(event); 
       mBaseRatio = mRatio; 
      } else { 
       float delta = (getDistance(event) - mBaseDist)/STEP; 
       float multi = (float) Math.pow(2, delta); 
       mRatio = Math.min(1024.0f, Math.max(0.1f, mBaseRatio * multi)); 
       mytv.setTextSize(mRatio + 13); 
      } 
     } 
     return true; 
    } 

    int getDistance(MotionEvent event) { 
     int dx = (int) (event.getX(0) - event.getX(1)); 
     int dy = (int) (event.getY(0) - event.getY(1)); 
     return (int) (Math.sqrt(dx * dx + dy * dy)); 
    } 

    public boolean onTouch(View v, MotionEvent event) { 
     return false; 
    } 
} 

Geschehen

Answer 2

public class MainActivity extends Activity { 

TextView scaleGesture; 
ScaleGestureDetector scaleGestureDetector; 

@Override 
protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_main); 
    scaleGesture = (TextView)findViewById(R.id.article); 
    scaleGesture.setText("this is some text"); 
    scaleGestureDetector = new ScaleGestureDetector(this, new simpleOnScaleGestureListener()); 
} 

@Override 
public boolean onCreateOptionsMenu(Menu menu) { 
    // Inflate the menu; this adds items to the action bar if it is present. 
    getMenuInflater().inflate(R.menu.activity_main, menu); 
    return true; 
} 


@Override 
public boolean onTouchEvent(MotionEvent event) { 
    // TODO Auto-generated method stub 
    scaleGestureDetector.onTouchEvent(event); 
    return true; 
} 

public class simpleOnScaleGestureListener extends 
     SimpleOnScaleGestureListener { 

    @Override 
    public boolean onScale(ScaleGestureDetector detector) { 
     // TODO Auto-generated method stub 
     float size = scaleGesture.getTextSize(); 
     Log.d("TextSizeStart", String.valueOf(size)); 

     float factor = detector.getScaleFactor(); 
     Log.d("Factor", String.valueOf(factor)); 


     float product = size*factor; 
     Log.d("TextSize", String.valueOf(product)); 
     scaleGesture.setTextSize(TypedValue.COMPLEX_UNIT_PX, product); 

     size = scaleGesture.getTextSize(); 
     Log.d("TextSizeEnd", String.valueOf(size)); 
     return true; 
    } 
} 
} 

Ansicht

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" 
xmlns:tools="http://schemas.android.com/tools" 
android:layout_width="match_parent" 
android:layout_height="match_parent" 
tools:context=".MainActivity" > 
<TextView 
    android:id="@+id/article" 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" /> 

Answer 3

Code unten verwenden Bitte

öffentliche Klasse TouchExampleView erweitert Ansicht { private static final int INVALID_POINTER_ID = -1;

private Drawable mIcon; 
private float mPosX; 
private float mPosY; 

private float mLastTouchX; 
private float mLastTouchY; 
private int mActivePointerId = INVALID_POINTER_ID; 

private ScaleGestureDetector mScaleDetector; 
private float mScaleFactor = 1.f; 

public TouchExampleView(Context context) { 
    this(context, null, 0); 
} 

public TouchExampleView(Context context, AttributeSet attrs) { 
    this(context, attrs, 0); 
} 

public TouchExampleView(Context context, AttributeSet attrs, int defStyle) { 
    super(context, attrs, defStyle); 
    mIcon = context.getResources().getDrawable(R.drawable.toggle); 
    mIcon.setBounds(0, 0, mIcon.getIntrinsicWidth(), 
      mIcon.getIntrinsicHeight()); 

    mScaleDetector = new ScaleGestureDetector(context, new ScaleListener()); 
} 

@Override 
public boolean onTouchEvent(MotionEvent ev) { 
    // Let the ScaleGestureDetector inspect all events. 
    mScaleDetector.onTouchEvent(ev); 

    final int action = ev.getAction(); 
    switch (action & MotionEvent.ACTION_MASK) { 
    case MotionEvent.ACTION_DOWN: { 
     final float x = ev.getX(); 
     final float y = ev.getY(); 

     mLastTouchX = x; 
     mLastTouchY = y; 
     mActivePointerId = ev.getPointerId(0); 
     break; 
    } 

    case MotionEvent.ACTION_MOVE: { 
     final int pointerIndex = ev.findPointerIndex(mActivePointerId); 
     final float x = ev.getX(pointerIndex); 
     final float y = ev.getY(pointerIndex); 

     // Only move if the ScaleGestureDetector isn't processing a gesture. 
     if (!mScaleDetector.isInProgress()) { 
      final float dx = x - mLastTouchX; 
      final float dy = y - mLastTouchY; 

      mPosX += dx; 
      mPosY += dy; 

      invalidate(); 
     } 

     mLastTouchX = x; 
     mLastTouchY = y; 

     break; 
    } 

    case MotionEvent.ACTION_UP: { 
     mActivePointerId = INVALID_POINTER_ID; 
     break; 
    } 

    case MotionEvent.ACTION_CANCEL: { 
     mActivePointerId = INVALID_POINTER_ID; 
     break; 
    } 

    case MotionEvent.ACTION_POINTER_UP: { 
     final int pointerIndex = (ev.getAction() & MotionEvent.ACTION_POINTER_INDEX_MASK) >> MotionEvent.ACTION_POINTER_INDEX_SHIFT; 
     final int pointerId = ev.getPointerId(pointerIndex); 
     if (pointerId == mActivePointerId) { 
      // This was our active pointer going up. Choose a new 
      // active pointer and adjust accordingly. 
      final int newPointerIndex = pointerIndex == 0 ? 1 : 0; 
      mLastTouchX = ev.getX(newPointerIndex); 
      mLastTouchY = ev.getY(newPointerIndex); 
      mActivePointerId = ev.getPointerId(newPointerIndex); 
     } 
     break; 
    } 
    } 

    return true; 
} 

@Override 
public void onDraw(Canvas canvas) { 
    super.onDraw(canvas); 

    canvas.save(); 
    canvas.translate(mPosX, mPosY); 
    canvas.scale(mScaleFactor, mScaleFactor); 
    Paint paint = new Paint(); 
    paint.setStyle(Style.FILL); 
    paint.setColor(Color.BLACK); 
    paint.setTextSize(20); 
    canvas.drawText("Hello how are you", mPosX, mPosY, paint); 
    mIcon.draw(canvas); 
    canvas.restore(); 
} 

private class ScaleListener extends 
     ScaleGestureDetector.SimpleOnScaleGestureListener { 
    @Override 
    public boolean onScale(ScaleGestureDetector detector) { 
     mScaleFactor *= detector.getScaleFactor(); 

     // Don't let the object get too small or too large. 
     mScaleFactor = Math.max(0.1f, Math.min(mScaleFactor, 5.0f)); 

     invalidate(); 
     return true; 
    } 
} 

}