Làm cách nào để phóng to chế độ xem văn bản trong Android?

Question

Bất kỳ ai cũng có thể hướng dẫn tôi thực hiện phóng to trong hoạt động & trên nhiều chế độ xem trong Android không? Tôi cần phải thực hiện phóng to trong các hoạt động của & khi chạm vào hình ảnh, chế độ xem văn bản. Bố cục bố mẹ của tôi nên là gì? Đây là mã để phóng to hình ảnh khi chạm vào hình ảnh. Làm cách nào để phóng to chế độ xem văn bản? Làm ơn giúp tôi.

// These matrices will be used to scale points of the image 
Matrix matrix = new Matrix(); 
Matrix savedMatrix = new Matrix(); 

// The 3 states (events) which the user is trying to perform 
static final int NONE = 0; 
static final int DRAG = 1; 
static final int ZOOM = 2; 
int mode = NONE; 

// these PointF objects are used to record the point(s) the user is touching 
PointF start = new PointF(); 
PointF mid = new PointF(); 
float oldDist = 1f; 

private void zoom(View v, MotionEvent event) 
{ 
    ImageView view = (ImageView) v; 
    view.setScaleType(ImageView.ScaleType.MATRIX); 
    float scale; 

    // dumpEvent(event); 
    // Handle touch events here... 

    switch (event.getAction() & MotionEvent.ACTION_MASK) 
    { 
    case MotionEvent.ACTION_DOWN: 
     // first finger down only 
     savedMatrix.set(matrix); 
     start.set(event.getX(), event.getY()); 

     mode = DRAG; 
     break; 

    case MotionEvent.ACTION_UP: // first finger lifted 

    case MotionEvent.ACTION_POINTER_UP: // second finger lifted 

     mode = NONE; 

     break; 

    case MotionEvent.ACTION_POINTER_DOWN: // first and second finger down 

     oldDist = spacing(event); 

     if (oldDist > 5f) 
     { 
      savedMatrix.set(matrix); 
      midPoint(mid, event); 
      mode = ZOOM; 

     } 
     break; 

    case MotionEvent.ACTION_MOVE: 

     if (mode == DRAG) 
     { 
      matrix.set(savedMatrix); 
      matrix.postTranslate(event.getX() - start.x, event.getY() - start.y); // create the transformation in the matrix of points 
     } 
     else if (mode == ZOOM) 
     { 
      // pinch zooming 
      float newDist = spacing(event); 

      if (newDist > 5f) 
      { 
       matrix.set(savedMatrix); 
       scale = newDist/oldDist; // setting the scaling of the 
       // matrix...if scale > 1 means 
       // zoom in...if scale < 1 means 
       // zoom out 
       matrix.postScale(scale, scale, mid.x, mid.y); 
      } 
     } 
     break; 
    } 

    view.setImageMatrix(matrix); // display the transformation on screen 

} 

/* 
* -------------------------------------------------------------------------- 
* Method: spacing Parameters: MotionEvent Returns: float Description: 
* 
* checks the spacing between the two fingers on touch 
* ---------------------------------------------------- 
*/ 

private float spacing(MotionEvent event) 
{ 
    float x = event.getX(0) - event.getX(1); 
    float y = event.getY(0) - event.getY(1); 
    return FloatMath.sqrt(x * x + y * y); 
} 

/* 
* -------------------------------------------------------------------------- 
* Method: midPoint Parameters: PointF object, MotionEvent Returns: void 
* Description: calculates the midpoint between the two fingers 
* ------------------------------------------------------------ 
*/ 

private void midPoint(PointF point, MotionEvent event) 
{ 
    float x = event.getX(0) + event.getX(1); 
    float y = event.getY(0) + event.getY(1); 
    point.set(x/2, y/2); 
} 

Answer 1

Để phóng to chế độ xem văn bản, bạn có thể sử dụng cùng mã mà bạn phải z oom một hình ảnh. Nhưng bạn nên thay đổi chế độ xem văn bản thành một lần xem hình ảnh và sau đó thực hiện các thao tác thu phóng. Dưới đây là liên kết để chuyển đổi TextView để ImageView Converting a TextView->Bitmap->ImageView, and nothing's showing up

Answer 2

Trên đây là ok nhưng bạn nó như sau ::

Trong onCreate(), bạn phải instialize TextView của bạn và thiết lập sự kiện ontouch vào nó như sau

TextView tv = (TextView)findViewById(R.id.name); 
tv.setText("text"); 
tv.setOnTouchListener(this); 

đây là mã hoàn chỉnh bao gồm mã của bạn :::

public class MyTextView extends Activity implements OnTouchListener{ 
    private static final String TAG = "Touch"; 
     @SuppressWarnings("unused") 
     private static final float MIN_ZOOM = 1f,MAX_ZOOM = 1f; 

     // These matrices will be used to scale points of the image 
     Matrix matrix = new Matrix(); 
     Matrix savedMatrix = new Matrix(); 

     // The 3 states (events) which the user is trying to perform 
     static final int NONE = 0; 
     static final int DRAG = 1; 
     static final int ZOOM = 2; 
     int mode = NONE; 

     // these PointF objects are used to record the point(s) the user is touching 
     PointF start = new PointF(); 
     PointF mid = new PointF(); 
     float oldDist = 1f; 
@Override 
protected void onCreate(Bundle savedInstanceState) { 
    // TODO Auto-generated method stub 
    super.onCreate(savedInstanceState); 
    TextView iv = new TextView(this); 
    iv.setText("text"); 
    iv.setOnTouchListener(this); 
    setContentView(iv); 
} 
@Override 
public boolean onTouch(View v, MotionEvent event) { 
    // TODO Auto-generated method stub 
    ImageView view = (ImageView) v; 
    view.setScaleType(ImageView.ScaleType.MATRIX); 
    float scale; 

    dumpEvent(event); 
    // Handle touch events here... 

    switch (event.getAction() & 255) 
    { 
     case MotionEvent.ACTION_DOWN: // first finger down only 
              savedMatrix.set(matrix); 
              start.set(event.getX(), event.getY()); 
              Log.d(TAG, "mode=DRAG"); // write to LogCat 
              mode = DRAG; 
              break; 

     case MotionEvent.ACTION_UP: // first finger lifted 

     case 6: // second finger lifted 

              mode = NONE; 
              Log.d(TAG, "mode=NONE"); 
              break; 

     case 5: // first and second finger down 

              oldDist = spacing(event); 
              Log.d(TAG, "oldDist=" + oldDist); 
              if (oldDist > 5f) { 
               savedMatrix.set(matrix); 
               midPoint(mid, event); 
               mode = ZOOM; 
               Log.d(TAG, "mode=ZOOM"); 
              } 
              break; 

     case MotionEvent.ACTION_MOVE: 

              if (mode == DRAG) 
              { 
               matrix.set(savedMatrix); 
               matrix.postTranslate(event.getX() - start.x, event.getY() - start.y); // create the transformation in the matrix of points 
              } 
              else if (mode == ZOOM) 
              { 
               // pinch zooming 
               float newDist = spacing(event); 
               Log.d(TAG, "newDist=" + newDist); 
               if (newDist > 5f) 
               { 
                matrix.set(savedMatrix); 
                scale = newDist/oldDist; // setting the scaling of the 
                       // matrix...if scale > 1 means 
                       // zoom in...if scale < 1 means 
                       // zoom out 
                matrix.postScale(scale, scale, mid.x, mid.y); 
               } 
              } 
              break; 
    } 

    view.setImageMatrix(matrix); // display the transformation on screen 

    return true; // indicate event was handled 
} 
private float spacing(MotionEvent event) 
{ 
    float x = event.getX(0) - event.getX(1); 
    float y = event.getY(0) - event.getY(1); 
    return FloatMath.sqrt(x * x + y * y); 
} 

/* 
* -------------------------------------------------------------------------- 
* Method: midPoint Parameters: PointF object, MotionEvent Returns: void 
* Description: calculates the midpoint between the two fingers 
* ------------------------------------------------------------ 
*/ 

private void midPoint(PointF point, MotionEvent event) 
{ 
    float x = event.getX(0) + event.getX(1); 
    float y = event.getY(0) + event.getY(1); 
    point.set(x/2, y/2); 
} 

/** Show an event in the LogCat view, for debugging */ 
private void dumpEvent(MotionEvent event) 
{ 
    String names[] = { "DOWN", "UP", "MOVE", "CANCEL", "OUTSIDE","POINTER_DOWN", "POINTER_UP", "7?", "8?", "9?" }; 
    StringBuilder sb = new StringBuilder(); 
    int action = event.getAction(); 
    int actionCode = action & MotionEvent.ACTION_MASK; 
    sb.append("event ACTION_").append(names[actionCode]); 

    if (actionCode == MotionEvent.ACTION_POINTER_DOWN || actionCode == MotionEvent.ACTION_POINTER_UP) 
    { 
     sb.append("(pid ").append(action >> MotionEvent.ACTION_POINTER_ID_SHIFT); 
     sb.append(")"); 
    } 

    sb.append("["); 
    for (int i = 0; i < event.getPointerCount(); i++) 
    { 
     sb.append("#").append(i); 
     sb.append("(pid ").append(event.getPointerId(i)); 
     sb.append(")=").append((int) event.getX(i)); 
     sb.append(",").append((int) event.getY(i)); 
     if (i + 1 < event.getPointerCount()) 
      sb.append(";"); 
    } 

    sb.append("]"); 
    Log.d("Touch Events ---------", sb.toString()); 
} 
} 

Answer 3

first you should convert Textview to imageview.Next you should apply sample image view drag functionality. 
    ----------------------------- 



      TextView tv = new TextView(this); 
      FrameLayout.LayoutParams layoutParams = new FrameLayout.LayoutParams(
        FrameLayout.LayoutParams.FILL_PARENT, 
        FrameLayout.LayoutParams.FILL_PARENT); 

      tv.setLayoutParams(layoutParams); 
      tv.setText("Text"); 
      tv.setTextColor(Color.BLACK); 
      tv.setBackgroundColor(Color.TRANSPARENT); 

      Bitmap testB; 

      testB = Bitmap.createBitmap(80, 100, Bitmap.Config.ARGB_8888); 
      Canvas c = new Canvas(testB); 
      tv.layout(30, 40, 200, 100); 
      tv.draw(c); 

      ImageView iv = (ImageView) findViewById(R.id.imageView); 
      iv.setLayoutParams(layoutParams); 
      iv.setBackgroundColor(Color.GRAY);`enter code here` 
      iv.setImageBitmap(testB); 
      iv.setMaxHeight(80); 
      iv.setMaxWidth(200); 

      iv.setOnTouchListener(this); 

Answer 4

Tôi tìm thấy một giải pháp rất đơn giản để thực hiện zoom in/out trên xem văn bản. Có thể nó giúp ai đó

package com.app; 

import android.os.Bundle; 
import android.util.TypedValue; 
import android.view.MotionEvent; 
import android.widget.TextView; 
import android.support.v7.app.AppCompatActivity; 
import android.view.View; 


public class MyActivity extends AppCompatActivity implements View.OnTouchListener{ 

    public static final int TEXT_MAX_SIZE = 140; 
    public static final int TEXT_MIN_SIZE = 40; 
    private static final int STEP = 4; 

    private int mBaseDistZoomIn; 
    private int mBaseDistZoomOut; 

    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.my_activity); 

     . 
     . 
     . 
     TextView viewById = (TextView) findViewById(R.id.some_text_view); 
     viewById.setOnTouchListener(this); 
    } 

    @Override 
    public boolean onTouch(View v, MotionEvent event) { 
     if (event.getPointerCount() == 2) { 
      TextView viewById = (TextView) findViewById(R.id.some_text_view); 
      int action = event.getAction(); 
      int pure = action & MotionEvent.ACTION_MASK; 

      if (pure == MotionEvent.ACTION_POINTER_DOWN 
        && viewById.getTextSize() <= TEXT_MAX_SIZE 
        && viewById.getTextSize() >= TEXT_MIN_SIZE) { 

       mBaseDistZoomIn = getDistanceFromEvent(event); 
       mBaseDistZoomOut = getDistanceFromEvent(event); 

      } else { 
       int currentDistance = getDistanceFromEvent(event); 
       if (currentDistance > mBaseDistZoomIn) { 
        float finalSize = viewById.getTextSize() + STEP; 
        if (finalSize > TEXT_MAX_SIZE) { 
         finalSize = TEXT_MAX_SIZE; 
        } 
        viewById.setTextSize(TypedValue.COMPLEX_UNIT_PX, finalSize); 
       } else { 
        if (currentDistance < mBaseDistZoomOut) { 
         float finalSize = viewById.getTextSize() - STEP; 
         if (finalSize < TEXT_MIN_SIZE) { 
          finalSize = TEXT_MIN_SIZE; 
         } 
         viewById.setTextSize(TypedValue.COMPLEX_UNIT_PX, finalSize); 
        } 
       } 
      } 
      return true; 
     } 
     return false; 
    } 


    // good function to get the distance between the multiple touch 
    int getDistanceFromEvent(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)); 
    } 
}