使用矩阵调整大小后获取imageView的宽度和高度

时间:2013-11-26 11:27:10

标签: android

我想使用我从互联网上获得的代码获取缩放的imageView的宽度和高度:

public class MultiTouch extends Activity implements OnTouchListener {

// these matrices will be used to move and zoom image
private Matrix matrix = new Matrix();
private Matrix savedMatrix = new Matrix();
// we can be in one of these 3 states
private static final int NONE = 0;
private static final int DRAG = 1;
private static final int ZOOM = 2;
private int mode = NONE;
// remember some things for zooming
private PointF start = new PointF();
private PointF mid = new PointF();
private float oldDist = 1f;
private float d = 0f;
private float newRot = 0f;
private float[] lastEvent = null;

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);
    ImageView view = (ImageView) findViewById(R.id.imageView);
    view.setOnTouchListener(this);
}

public boolean onTouch(View v, MotionEvent event) {
    // handle touch events here
    ImageView view = (ImageView) v;

    switch (event.getAction() & MotionEvent.ACTION_MASK) {
        case MotionEvent.ACTION_DOWN:
            savedMatrix.set(matrix);
            start.set(event.getX(), event.getY());
            mode = DRAG;
            lastEvent = null;
            break;
        case MotionEvent.ACTION_POINTER_DOWN:
            oldDist = spacing(event);
            if (oldDist > 10f) {
                savedMatrix.set(matrix);
                midPoint(mid, event);
                mode = ZOOM;
            }
            lastEvent = new float[4];
            lastEvent[0] = event.getX(0);
            lastEvent[1] = event.getX(1);
            lastEvent[2] = event.getY(0);
            lastEvent[3] = event.getY(1);
            d = rotation(event);
            break;
        case MotionEvent.ACTION_UP:
        case MotionEvent.ACTION_POINTER_UP:
            mode = NONE;
            lastEvent = null;
            break;
        case MotionEvent.ACTION_MOVE:
            if (mode == DRAG) {
                matrix.set(savedMatrix);
                float dx = event.getX() - start.x;
                float dy = event.getY() - start.y;
                matrix.postTranslate(dx, dy);
            } 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);
                }
                if (lastEvent != null && event.getPointerCount() == 3) {
                    newRot = rotation(event);
                    float r = newRot - d;
                    float[] values = new float[9];
                    matrix.getValues(values);
                    float tx = values[2];
                    float ty = values[5];
                    float sx = values[0];
                    float xc = (view.getWidth() / 2) * sx;
                    float yc = (view.getHeight() / 2) * sx;
                    matrix.postRotate(r, tx + xc, ty + yc);
                }
            }
            break;
    }

    view.setImageMatrix(matrix);
    return true;
}

/**
 * Determine the space between the first two fingers
 */
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);
}

/**
 * Calculate the mid point of the first 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);
}

/**
 * Calculate the degree to be rotated by.
 *
 * @param event
 * @return Degrees
 */
private float rotation(MotionEvent event) {
    double delta_x = (event.getX(0) - event.getX(1));
    double delta_y = (event.getY(0) - event.getY(1));
    double radians = Math.atan2(delta_y, delta_x);
    return (float) Math.toDegrees(radians);
}

}

我的问题是,如果我的原始图像视图小于缩放图像,则图像显示但具有我的图像视图的原始大小。这是图像缩放的部分:

                 if (newDist > 10f) {
                    matrix.set(savedMatrix);
                    float scale = (newDist / oldDist);
                    matrix.postScale(scale, scale, mid.x, mid.y);
                }

我还要调整我的imageview容器的大小。

这是实际发生的事情。左图像是原始图像,右图像是实际结果。我希望imageview容器与缩放图像的大小相同。

enter image description here

2 个答案:

答案 0 :(得分:0)

WrapContent

HeightWidth使用ImageView

答案 1 :(得分:0)

您可以通过调用

从矩阵中获取scaleFactor
float[] matrixValues = new float[9];
yourMatrix.getValues(matrixValues);
float scaleX = matrixValues[Matrix.MSCALE_X];
float scaleY = matrixValues[Matrix.MSCALE_Y];

然后将主宽度和高度乘以适当的值

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