我正在使用具有缩放功能的自定义TextureView（适用于Android播放器）。问题是我不能做准确的缩放。当你第一次尝试放大时，似乎没有问题。在一些缩放视图跳转到另一个位置后。我将把自定义textureView代码放在这里：
public class PanZoomTextureView extends TextureView {
protected Context mContext;
protected float mPosX;
protected float mPosY;
protected float mFocusX; // these two focus variables are not needed
protected float mFocusY;
protected float mLastTouchX;
protected float mLastTouchY;
protected static final int INVALID_POINTER_ID = -1;
// The ‘active pointer’ is the one currently moving our object.
protected int mActivePointerId = INVALID_POINTER_ID;
protected ScaleGestureDetector mScaleDetector;
protected float mScaleFactor = 1.f;
// The next three are set by calling supportsPan, supportsZoom, ...
protected boolean mSupportsPan = true;
protected boolean mSupportsZoom = true;
private MediaController controller;
/**
*/
public PanZoomTextureView(Context context) {
this(context, null, 0);
}
public PanZoomTextureView(Context context, AttributeSet attrs) {
this(context, attrs, 0);
}
public PanZoomTextureView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
mContext = context;
setupScaleDetector(context);
}
private void invalidateDraw() {
Matrix ma = new Matrix();
float x = 0, y = 0;
x = mPosX;
y = mPosY;
if (mSupportsZoom || mSupportsPan) {
if (mSupportsPan && mSupportsZoom) {
if (mScaleDetector.isInProgress()) {
ma.setScale(mScaleFactor, mScaleFactor, mFocusX, mFocusY);
mPosX = (getWidth() - getWidth() * mScaleFactor) * (mFocusX / getWidth()) / 2;
mPosY = (getHeight() - getHeight() * mScaleFactor) * (mFocusY / getHeight()) / 2;
Log.d("Multitouch", "'in progress' mposx, mposy, focusX, focusY: " + mPosX + " " + mPosY + " " + mFocusX + " " + mFocusY);
} else {
// Pinch zoom is not in progress. Just do translation
// of canvas at whatever the current scale is.
ma.setTranslate(x, y);
ma.postScale(mScaleFactor, mScaleFactor);
Log.d("Multitouch", "x, y , focusX, focusY , scalefactor : " + x + " " + y + " " + mFocusX + " " + mFocusY + " " + mScaleFactor);
}
}
}
setTransform(ma);
}
public void setMediaController(MediaController c) {
this.controller = c;
}
/**
* Handle touch and multitouch events so panning and zooming can be supported.
*/
@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);
Log.d("OnTouchDown:", "lastX, lastY: " + mLastTouchX + " , " + mLastTouchY);
if (ev.getPointerCount() == 1) {
if (controller.isShowing()) {
controller.hide();
} else {
controller.show(10000);
}
}
break;
}
case MotionEvent.ACTION_MOVE: {
//register active pointer index
final int pointerIndex = ev.findPointerIndex(mActivePointerId);
// x and y values from active pointer
final float x = ev.getX(pointerIndex);
final float y = ev.getY(pointerIndex);
final float dx = (x - mLastTouchX);
final float dy = (y - mLastTouchY);
// Only move if the view supports panning and
// ScaleGestureDetector isn't processing a gesture.
if (!mScaleDetector.isInProgress()) {
Log.d("OnTouch1:", "dX, dY: " + dx + " , " + dy);
if (mPosX > 5) {
mPosX = 3;
}
if (mPosY > 5) {
mPosY = 3;
}
if (mPosX < ((-1) * (getWidth() - getWidth() / mScaleFactor) - 5)) {
mPosX = ((-1) * (getWidth() - getWidth() / mScaleFactor) - 2);
}
if (mPosY < ((-1) * (getHeight() - getHeight() / mScaleFactor) - 5)) {
mPosY = ((-1) * (getHeight() - getHeight() / mScaleFactor) - 2);
}
if ((mPosX + dx) > 5 && (mPosY + dy) > 5) {
mPosX = 3;
mPosY = 3;
Log.d("OnTouch1:", "mPosx, mPosy: " + mPosX + " , " + mPosY);
} else if ((mPosY + dy) > 5 && (mPosX + dx) < 5 && (mPosX + dx) > ((-1) * (getWidth() - getWidth() / mScaleFactor) - 5)) {
mPosY = 3;
mPosX += dx;
Log.d("OnTouch2:", "mPosx, mPosy: " + mPosX + " , " + mPosY);
} else {
mPosX += dx;
mPosY += dy;
Log.d("OnTouch8:", "mPosx, mPosy: " + mPosX + " , " + mPosY);
}
invalidateDraw();
}
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;
}
/**
* This method sets up the scale detector object used by the view. It is called by the constructor.
*
* @return void
*/
protected void setupScaleDetector(Context context) {
// Create our ScaleGestureDetector
mScaleDetector = new ScaleGestureDetector(context, new ScaleListener());
}
/**
* ScaleListener
*/
protected class ScaleListener extends ScaleGestureDetector.SimpleOnScaleGestureListener {
@Override
public boolean onScale(ScaleGestureDetector detector) {
mScaleFactor *= detector.getScaleFactor();
Log.e("Multitouch", "-------scaling factor:" + mScaleFactor);
// Don't let the object get too small or too large.
mScaleFactor = Math.max(1.f, Math.min(mScaleFactor, 4));
mFocusX = detector.getFocusX();
mFocusY = detector.getFocusY();
invalidateDraw();
return true;
}
}
}
此外，如果有人想在这里测试真实项目，请链接：https://github.com/Shuhrat-java/PanZoomPlayer