手势结束时
手势结束时，我们需要对位置进行修正。如果是裁剪区域边线，则要判断左右、上下边线之间的距离是否过短，边线是否超出 UIImageView 的范围等。如果左右边线距离过短则设置最小裁剪宽度，如果上线边线距离过短则设置最小裁剪高度，如果左边线超出了 UIImageView 左边线则需要紧贴 UIImageView 的左边线，并更新裁剪区域宽度，以此类推。然后更新 CAShapeLayer 上的空心蒙层即可。
如果是 UIImageView 则跟上一节一样要保证图片不会与裁剪区域出现空白。
// 滑动结束后进行位置修正
if (panGesture.state == UIGestureRecognizerStateEnded) {
switch (self.activeGestureView) {
case CROPVIEWLEFT: {
if (self.cropAreaWidth < 50) {
self.cropAreaX -= 50 - self.cropAreaWidth;
self.cropAreaWidth = 50;
}
if (self.cropAreaX < MAX(self.bigImageView.frame.origin.x, 15)) {
CGFloat temp = self.cropAreaX + self.cropAreaWidth;
self.cropAreaX = MAX(self.bigImageView.frame.origin.x, 15);
self.cropAreaWidth = temp - self.cropAreaX;
}
[self setUpCropLayer];
break;
}
case CROPVIEWRIGHT: {
if (self.cropAreaWidth < 50) {
self.cropAreaWidth = 50;
}
if (self.cropAreaX + self.cropAreaWidth > MIN(self.bigImageView.frame.origin.x + self.bigImageView.frame.size.width, self.cropView.frame.origin.x + self.cropView.frame.size.width - 15)) {
self.cropAreaWidth = MIN(self.bigImageView.frame.origin.x + self.bigImageView.frame.size.width, self.cropView.frame.origin.x + self.cropView.frame.size.width - 15) - self.cropAreaX;
}
[self setUpCropLayer];
break;
}
case CROPVIEWTOP: {
if (self.cropAreaHeight < 50) {
self.cropAreaY -= 50 - self.cropAreaHeight;
self.cropAreaHeight = 50;
}
if (self.cropAreaY < MAX(self.bigImageView.frame.origin.y, 15)) {
CGFloat temp = self.cropAreaY + self.cropAreaHeight;
self.cropAreaY = MAX(self.bigImageView.frame.origin.y, 15);
self.cropAreaHeight = temp - self.cropAreaY;
}
[self setUpCropLayer];
break;
}
case CROPVIEWBOTTOM: {
if (self.cropAreaHeight < 50) {
self.cropAreaHeight = 50;
}
if (self.cropAreaY + self.cropAreaHeight > MIN(self.bigImageView.frame.origin.y + self.bigImageView.frame.size.height, self.cropView.frame.origin.y + self.cropView.frame.size.height - 15)) {
self.cropAreaHeight = MIN(self.bigImageView.frame.origin.y + self.bigImageView.frame.size.height, self.cropView.frame.origin.y + self.cropView.frame.size.height - 15) - self.cropAreaY;
}
[self setUpCropLayer];
break;
}
case BIGIMAGEVIEW: {
CGRect currentFrame = view.frame;
if (currentFrame.origin.x >= self.cropAreaX) {
currentFrame.origin.x = self.cropAreaX;
}
if (currentFrame.origin.y >= self.cropAreaY) {
currentFrame.origin.y = self.cropAreaY;
}
if (currentFrame.size.width + currentFrame.origin.x < self.cropAreaX + self.cropAreaWidth) {
CGFloat movedLeftX = fabs(currentFrame.size.width + currentFrame.origin.x - (self.cropAreaX + self.cropAreaWidth));
currentFrame.origin.x += movedLeftX;
}
if (currentFrame.size.height + currentFrame.origin.y < self.cropAreaY + self.cropAreaHeight) {
CGFloat moveUpY = fabs(currentFrame.size.height + currentFrame.origin.y - (self.cropAreaY + self.cropAreaHeight));
currentFrame.origin.y += moveUpY;
}
[UIView animateWithDuration:0.3 animations:^{
[view setFrame:currentFrame];
}];
break;
}
default:
break;
}
}
