问题描述
我试图同时使用scalegesture监听器和gesturelistener在视图中。一切完美,如果比例为1,但如果比例设置为其他值,图像抽搐到一个新的位置,然后缩放流畅。
I am trying to use both scalegesture listener and gesturelistener in the view. Everything works perfectly if the scale is 1 but if the scale is set to some other value, the image jerks to a new position and then scales smoothly.
我的code的部分看起来像如下:
Part of my code looks like as follows:
public class SimpleView extends View {
Bitmap image;
ScaleGestureDetector scaleGesture;
GestureDetector gestures;
float touchX, touchY;
float horizontalOffset;
float verticalOffset;
float scale;
public SimpleView(Context context) {
super(context);
image = BitmapFactory.decodeResource(getResources(), R.drawable.some_image);
scaleGesture = new ScaleGestureDetector(getContext(),
new ScaleListener());
gestures = new GestureDetector(getContext(), new GestureListener(),
null, true);
scale = 0.6f; //if this is set to 1.0f everything works perfectly,
// else the imagetransports to a new position
// and scales perfectly thereafter
}
@Override
protected void onDraw(Canvas canvas) {
canvas.save();
canvas.translate(horizontalOffset, verticalOffset);
canvas.scale(scale, scale, touchX, touchY);
canvas.drawBitmap(image, getMatrix(), new Paint);
canvas.restore();
}
public class ScaleListener implements OnScaleGestureListener {
@Override
public boolean onScale(ScaleGestureDetector detector) {
float oldScale = scale;
scale *= detector.getScaleFactor();
scale = Math.max(0.5f, Math.min(scale, 5.0f));
if (scale != oldScale) {
touchX = detector.getFocusX();
touchY = detector.getFocusY();
invalidate(0, 0, screenWidth, screenHeight);
}
return true;
}
}
public class GestureListener implements OnGestureListener {
@Override
public boolean onScroll(MotionEvent e1, MotionEvent e2,
float distanceX, float distanceY) {
//Helps in drag
if (!scaleGesture.isInProgress()) {
horizontalOffset -= distanceX;
verticalOffset -= distanceY;
invalidate();
return true;
}
return false;
}
}
@Override
public boolean onTouchEvent(MotionEvent event) {
boolean result = scaleGesture.onTouchEvent(event);
boolean isScaling = result = scaleGesture.isInProgress();
if (!isScaling) {
if (!(event.getPointerCount() > 1)) {
result = gestures.onTouchEvent(event);
} else
result = false;
}
return result;
}
}
在情况下,我刻度值设置为1.0F,这个工程的顺利进行。当我更改规模为(比方说)0.6f的价值,其输送到一个新的位置,然后完美的作品。
In case I set the value of scale to 1.0f, this works smoothly. When I change the value of scale to (say) 0.6f, it transports to a new position and then works perfectly.
推荐答案
请看到@ToreRudberg的 - 你可能希望你的改革code纠正傻冒观察行为
Please see the answer by @ToreRudberg here - You might want to reform your code to correct the behavior your'e observing.
这篇关于canvas.scale(规模化,规模化,PX,PY)抽搐到新的位置的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持!