写一个textureview多点触摸控制,可以对控件移动放大缩小 和旋转的例子
时间: 2024-01-22 11:19:07 浏览: 29
好的,以下是一个使用TextureView实现多点触摸控制的例子,包括移动、缩放和旋转:
```java
public class MultiTouchTextureView extends TextureView implements TextureView.SurfaceTextureListener {
private float mPosX, mPosY;
private float mLastTouchX, mLastTouchY;
private float mScaleFactor = 1.f;
private float mLastGestureX, mLastGestureY;
private float mRotationDegrees = 0.f;
public MultiTouchTextureView(Context context) {
this(context, null, 0);
}
public MultiTouchTextureView(Context context, AttributeSet attrs) {
this(context, attrs, 0);
}
public MultiTouchTextureView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
setSurfaceTextureListener(this);
}
@Override
public boolean onTouchEvent(MotionEvent event) {
// Let the ScaleGestureDetector inspect all events.
mScaleDetector.onTouchEvent(event);
final int action = event.getAction();
switch (action & MotionEvent.ACTION_MASK) {
case MotionEvent.ACTION_DOWN: {
final float x = event.getX();
final float y = event.getY();
mLastTouchX = x;
mLastTouchY = y;
break;
}
case MotionEvent.ACTION_MOVE: {
final float x = event.getX();
final float y = event.getY();
// 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: {
break;
}
case MotionEvent.ACTION_CANCEL: {
break;
}
case MotionEvent.ACTION_POINTER_UP: {
break;
}
}
return true;
}
private ScaleGestureDetector mScaleDetector = new ScaleGestureDetector(getContext(), new 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;
}
});
@Override
public void onSurfaceTextureAvailable(SurfaceTexture surface, int width, int height) {
// Setup default size and position
mPosX = width / 2.f;
mPosY = height / 2.f;
mLastGestureX = width / 2.f;
mLastGestureY = height / 2.f;
// Set the aspect ratio of the TextureView
int aspectRatio = height > width ? height / width : width / height;
setAspectRatio(aspectRatio);
}
@Override
public void onSurfaceTextureSizeChanged(SurfaceTexture surface, int width, int height) {
// Update default size and position when the TextureView size changes
mPosX = width / 2.f;
mPosY = height / 2.f;
mLastGestureX = width / 2.f;
mLastGestureY = height / 2.f;
}
@Override
public boolean onSurfaceTextureDestroyed(SurfaceTexture surface) {
return true;
}
@Override
public void onSurfaceTextureUpdated(SurfaceTexture surface) {
}
@Override
public void onDraw(Canvas canvas) {
super.onDraw(canvas);
canvas.save();
// Move the canvas to the center of the TextureView
canvas.translate(mPosX, mPosY);
// Scale the canvas based on the scale factor
canvas.scale(mScaleFactor, mScaleFactor);
// Rotate the canvas based on the rotation degrees
canvas.rotate(mRotationDegrees);
// Draw your content here
// ...
canvas.restore();
}
}
```
这个例子中,我们使用了TextureView作为视图容器,通过触摸事件实现多点触摸控制。在onTouchEvent方法中,我们处理了移动的逻辑,通过ScaleGestureDetector处理缩放的逻辑。在onDraw方法中,我们先将画布移动到TextureView的中心点,然后根据移动、缩放和旋转的参数对画布进行变换。你可以在onDraw方法中添加你自己的绘制逻辑。