Android - 如何在缩放后进行缩放？

时间：2014-04-23 03:39:48

标签： android position point

  

enter image description here

这张图片是我的问题。你能帮帮我吗？

    import java.io.IOException;
    import java.net.InetSocketAddress;
    import java.net.Socket;
    import java.net.SocketAddress;

    import android.content.Context;
    import android.graphics.Bitmap;
    import android.graphics.Matrix;
    import android.graphics.PointF;
    import android.graphics.drawable.Drawable;
    import android.util.AttributeSet;
    import android.util.FloatMath;
    import android.util.Log;
    import android.view.MotionEvent;
    import android.widget.ImageView;
    import android.widget.Toast;
    import android.widget.ImageView.ScaleType;

    public class ImageViewTouch extends ImageView{
private static final String TAG = "ImageViewTouch";
private static final boolean D = false;

private Matrix matrix;
private Matrix savedMatrix;
private Matrix savedMatrix2;

private Drawable d;

private static final int NONE = 0;
private static final int DRAG = 1;
private static final int ZOOM = 2;
private int mode = NONE;

private PointF start = new PointF();
private PointF mid = new PointF();
private float oldDist = 1f;

private static final int WIDTH = 0;
private static final int HEIGHT = 1;

private boolean isInit = true;

private boolean isMoving;
private boolean isScaling;
private boolean isRestoring;

public ImageViewTouch(Context context, AttributeSet attrs, int defStyle) 
{
    super(context, attrs, defStyle);
    setScaleType(ScaleType.MATRIX);
    matrix = new Matrix();
    savedMatrix = new Matrix();
    savedMatrix2 = new Matrix();
}

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

public ImageViewTouch(Context context) {
    this(context, null);

}

@Override
protected void onLayout(boolean changed, int left, int top, int right, int bottom) 
{
    if (D) Log.i(TAG, "onLayout");
    d = this.getDrawable();
    super.onLayout(changed, left, top, right, bottom);
    if (isInit == false)
    {
        init();
        isInit = true;
    }
}

@Override
public void setImageBitmap(Bitmap bm) 
{
    if (D) Log.i(TAG, "setImageBitmap");
    super.setImageBitmap(bm);
    if(isInit == true)
    {
        init();
    }
}

@Override
public void setImageResource(int resId) {
    if (D) Log.i(TAG, "setImageResource");
    super.setImageResource(resId);
    d = getDrawable();
    isInit = false;
    init();
}

protected void init() 
{
    d = this.getDrawable();
    initImgPos();
    setImageMatrix(matrix);
    isInit = false;
}

public void initImgPos()
{
    float[] value = new float[9];
    this.matrix.getValues(value);

    int width = this.getWidth();
    int height = this.getHeight();

    if (d == null)  return;
    int imageWidth = d.getIntrinsicWidth();
    int imageHeight = d.getIntrinsicHeight();
    int scaleWidth = (int) (imageWidth * value[0]);
    int scaleHeight = (int) (imageHeight * value[4]);

    if (imageWidth > width || imageHeight > height)
    {

        float xratio = (float)width / (float)imageWidth;
        float yratio = (float)height / (float)imageHeight;

        // Math.min fits the image to the shorter axis. (with letterboxes around)
        // Math.max fits the image th the longer axis. (with the other axis cropped)
        value[0] = value[4] = Math.max(xratio, yratio);
    }

    scaleWidth = (int) (imageWidth * value[0]);
    scaleHeight = (int) (imageHeight * value[4]);

    // align the image to the top left corner
    value[2] = 0;
    value[5] = 0;

    // center the image. it will be aligned to the top left corner otherwise.
    value[2] = (float) width / 2 - (float)scaleWidth / 2;
    value[5] = (float) height / 2 - (float)scaleHeight / 2;

    matrix.setValues(value);
    setImageMatrix(matrix);
}

@Override
public boolean onTouchEvent(MotionEvent event) 
{
    if(D) dumpEvent(event);

    switch (event.getAction() & MotionEvent.ACTION_MASK) 
    {
    case MotionEvent.ACTION_DOWN:
        savedMatrix.set(matrix);
        start.set(event.getX(), event.getY());
        mode = DRAG;

        break;

    case MotionEvent.ACTION_POINTER_DOWN:
        oldDist = spacing(event);
        if (oldDist > 10f) 
        {
            savedMatrix.set(matrix);
            midPoint(mid, event);
            mode = ZOOM;
        }
        break;

    case MotionEvent.ACTION_UP:

    case MotionEvent.ACTION_POINTER_UP:
        mode = NONE;
        restore(matrix);
        break;

    case MotionEvent.ACTION_MOVE:
        if (mode == DRAG) 
        {
            matrix.set(savedMatrix);
            matrix.postTranslate(event.getX() - start.x, event.getY() - start.y);
        }
        else if (mode == ZOOM) 
        {
            float newDist = spacing(event);
            if (newDist > 10f) 
            {
                matrix.set(savedMatrix);
                float scale = newDist / oldDist;
                matrix.postScale(scale, scale, mid.x, mid.y);
            }
        }
        break;
    }

    // Matrix value modification
    // comment out below 2 lines to remove all restrictions on image transformation.
    matrixTuning(matrix);
    setImageMatrix(savedMatrix2);

    return true;
}

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);
}

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);
}

private void matrixTuning(Matrix matrix)
{
    float[] value = new float[9];
    matrix.getValues(value);
    float[] savedValue = new float[9];
    savedMatrix2.getValues(savedValue);

    int width = getWidth();
    int height = getHeight();


    Drawable d = getDrawable();
    if (d == null)  return;
    int imageWidth = d.getIntrinsicWidth();
    int imageHeight = d.getIntrinsicHeight();
    int scaleWidth = (int) (imageWidth * value[0]);
    int scaleHeight = (int) (imageHeight * value[4]);

    // don't let the image go outside
    if (value[2] < width - scaleWidth)   value[2] = width - scaleWidth;
    if (value[5] < height - scaleHeight)   value[5] = height - scaleHeight;
    if (value[2] > 0)   value[2] = 0;
    if (value[5] > 0)   value[5] = 0;

    // maximum zoom ratio: 2x
    if (value[0] > 2 || value[4] > 2)
    {
        value[0] = savedValue[0];
        value[4] = savedValue[4];
        value[2] = savedValue[2];
        value[5] = savedValue[5];
    }

    // don't let the image become smaller than the screen
    if (imageWidth > width || imageHeight > height)
    {
        if (scaleWidth < width && scaleHeight < height)
        {
            int target = WIDTH;
            if (imageWidth < imageHeight) target = HEIGHT;

            if (target == WIDTH) value[0] = value[4] = (float)width / imageWidth;
            if (target == HEIGHT) value[0] = value[4] = (float)height / imageHeight;

            scaleWidth = (int) (imageWidth * value[0]); 
            scaleHeight = (int) (imageHeight * value[4]);

            if (scaleWidth > width) value[0] = value[4] = (float)width / imageWidth;
            if (scaleHeight > height) value[0] = value[4] = (float)height / imageHeight;
        }
    }

    // don't allow scale down under its size
    else
    {
        if (value[0] < 1)   value[0] = 1;
        if (value[4] < 1)   value[4] = 1;
    }

    // center the image
    scaleWidth = (int) (imageWidth * value[0]);
    scaleHeight = (int) (imageHeight * value[4]);
    if (scaleWidth < width)
    {
        value[2] = (float) width / 2 - (float)scaleWidth / 2;
    }
    if (scaleHeight < height)
    {
        value[5] = (float) height / 2 - (float)scaleHeight / 2;
    }

    matrix.setValues(value);
    savedMatrix2.set(matrix);
}

private void restore(Matrix m) 
{
    setImageMatrix(matrix);
}

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(TAG, sb.toString());
}
}

请给我这个问题的解决方案。它可以很好地操作此代码以进行缩放。但是，我不知道捏缩放后的点。我想知道绝对点的形象。

0 个答案:

没有答案
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