iOS 折纸（折纸/手风琴）效果动画，带手动控制
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iOS Paper fold (origami / accordion) effect animation, with manual control
提问by Ashley Cameron
I'm looking for tips on how to implement the popular 'paper folding / origami' effect in my iOS project.
我正在寻找有关如何在我的 iOS 项目中实现流行的“折纸/折纸”效果的技巧。
I'm aware of projects such as: https://github.com/xyfeng/XYOrigamibut they only offer the 'animated' effect, with no manual control over the opening animation.
我知道一些项目，例如：https: //github.com/xyfeng/XYOrigami，但它们只提供“动画”效果，无法手动控制开场动画。
I've struggled to dissect that project and come up with what I'm after.
我一直在努力剖析那个项目并想出我想要的东西。
To be more exact, I'm looking on how to implement the effect shown here: http://vimeo.com/41495357where the folding animation is not simply animated open, but the user controls the opening folds.
更准确地说，我正在研究如何实现此处显示的效果：http: //vimeo.com/41495357其中折叠动画不是简单的动画打开，而是用户控制打开折叠。
Any help would be much appreciated, thanks in advance!
任何帮助将不胜感激，提前致谢！
EDIT:
编辑：
Okay, here's some example code to better illustrate what I'm struggling with:
好的，这里有一些示例代码可以更好地说明我正在努力解决的问题：
This method triggers the origami effect animation:
该方法触发折纸效果动画：
- (void)showOrigamiTransitionWith:(UIView *)view
NumberOfFolds:(NSInteger)folds
Duration:(CGFloat)duration
Direction:(XYOrigamiDirection)direction
completion:(void (^)(BOOL finished))completion
{
if (XY_Origami_Current_State != XYOrigamiTransitionStateIdle) {
return;
}
XY_Origami_Current_State = XYOrigamiTransitionStateUpdate;
//add view as parent subview
if (![view superview]) {
[[self superview] insertSubview:view belowSubview:self];
}
//set frame
CGRect selfFrame = self.frame;
CGPoint anchorPoint;
if (direction == XYOrigamiDirectionFromRight) {
selfFrame.origin.x = self.frame.origin.x - view.bounds.size.width;
view.frame = CGRectMake(self.frame.origin.x+self.frame.size.width-view.frame.size.width, self.frame.origin.y, view.frame.size.width, view.frame.size.height);
anchorPoint = CGPointMake(1, 0.5);
}
else {
selfFrame.origin.x = self.frame.origin.x + view.bounds.size.width;
view.frame = CGRectMake(self.frame.origin.x, self.frame.origin.y, view.frame.size.width, view.frame.size.height);
anchorPoint = CGPointMake(0, 0.5);
}
UIGraphicsBeginImageContext(view.frame.size);
[view.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *viewSnapShot = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
//set 3D depth
CATransform3D transform = CATransform3DIdentity;
transform.m34 = -1.0/800.0;
CALayer *origamiLayer = [CALayer layer];
origamiLayer.frame = view.bounds;
origamiLayer.backgroundColor = [UIColor colorWithWhite:0.2 alpha:1].CGColor;
origamiLayer.sublayerTransform = transform;
[view.layer addSublayer:origamiLayer];
//setup rotation angle
double startAngle;
CGFloat frameWidth = view.bounds.size.width;
CGFloat frameHeight = view.bounds.size.height;
CGFloat foldWidth = frameWidth/(folds*2);
CALayer *prevLayer = origamiLayer;
for (int b=0; b < folds*2; b++) {
CGRect imageFrame;
if (direction == XYOrigamiDirectionFromRight) {
if(b == 0)
startAngle = -M_PI_2;
else {
if (b%2)
startAngle = M_PI;
else
startAngle = -M_PI;
}
imageFrame = CGRectMake(frameWidth-(b+1)*foldWidth, 0, foldWidth, frameHeight);
}
else {
if(b == 0)
startAngle = M_PI_2;
else {
if (b%2)
startAngle = -M_PI;
else
startAngle = M_PI;
}
imageFrame = CGRectMake(b*foldWidth, 0, foldWidth, frameHeight);
}
CATransformLayer *transLayer = [self transformLayerFromImage:viewSnapShot Frame:imageFrame Duration:duration AnchorPiont:anchorPoint StartAngle:startAngle EndAngle:0];
[prevLayer addSublayer:transLayer];
prevLayer = transLayer;
}
[CATransaction begin];
[CATransaction setCompletionBlock:^{
self.frame = selfFrame;
[origamiLayer removeFromSuperlayer];
XY_Origami_Current_State = XYOrigamiTransitionStateShow;
if (completion)
completion(YES);
}];
[CATransaction setValue:[NSNumber numberWithFloat:duration] forKey:kCATransactionAnimationDuration];
CAAnimation *openAnimation = [CAKeyframeAnimation animationWithKeyPath:@"position.x" function:openFunction fromValue:self.frame.origin.x+self.frame.size.width/2 toValue:selfFrame.origin.x+self.frame.size.width/2];
openAnimation.fillMode = kCAFillModeForwards;
[openAnimation setRemovedOnCompletion:NO];
[self.layer addAnimation:openAnimation forKey:@"position"];
[CATransaction commit];
}
The method grabs a CATransform Layer from this method:
该方法从该方法中获取一个 CATransform 层：
- (CATransformLayer *)transformLayerFromImage:(UIImage *)image Frame:(CGRect)frame Duration:(CGFloat)duration AnchorPiont:(CGPoint)anchorPoint StartAngle:(double)start EndAngle:(double)end;
{
CATransformLayer *jointLayer = [CATransformLayer layer];
jointLayer.anchorPoint = anchorPoint;
CGFloat layerWidth;
if (anchorPoint.x == 0) //from left to right
{
layerWidth = image.size.width - frame.origin.x;
jointLayer.frame = CGRectMake(0, 0, layerWidth, frame.size.height);
if (frame.origin.x) {
jointLayer.position = CGPointMake(frame.size.width, frame.size.height/2);
}
else {
jointLayer.position = CGPointMake(0, frame.size.height/2);
}
}
else
{ //from right to left
layerWidth = frame.origin.x + frame.size.width;
jointLayer.frame = CGRectMake(0, 0, layerWidth, frame.size.height);
jointLayer.position = CGPointMake(layerWidth, frame.size.height/2);
}
//map image onto transform layer
CALayer *imageLayer = [CALayer layer];
imageLayer.frame = CGRectMake(0, 0, frame.size.width, frame.size.height);
imageLayer.anchorPoint = anchorPoint;
imageLayer.position = CGPointMake(layerWidth*anchorPoint.x, frame.size.height/2);
[jointLayer addSublayer:imageLayer];
CGImageRef imageCrop = CGImageCreateWithImageInRect(image.CGImage, frame);
imageLayer.contents = (__bridge id)imageCrop;
imageLayer.backgroundColor = [UIColor clearColor].CGColor;
//add shadow
NSInteger index = frame.origin.x/frame.size.width;
double shadowAniOpacity;
CAGradientLayer *shadowLayer = [CAGradientLayer layer];
shadowLayer.frame = imageLayer.bounds;
shadowLayer.backgroundColor = [UIColor darkGrayColor].CGColor;
shadowLayer.opacity = 0.0;
shadowLayer.colors = [NSArray arrayWithObjects:(id)[UIColor blackColor].CGColor, (id)[UIColor clearColor].CGColor, nil];
if (index%2) {
shadowLayer.startPoint = CGPointMake(0, 0.5);
shadowLayer.endPoint = CGPointMake(1, 0.5);
shadowAniOpacity = (anchorPoint.x)?0.24:0.32;
}
else {
shadowLayer.startPoint = CGPointMake(1, 0.5);
shadowLayer.endPoint = CGPointMake(0, 0.5);
shadowAniOpacity = (anchorPoint.x)?0.32:0.24;
}
[imageLayer addSublayer:shadowLayer];
//animate open/close animation
CABasicAnimation* animation = [CABasicAnimation animationWithKeyPath:@"transform.rotation.y"];
[animation setDuration:duration];
[animation setFromValue:[NSNumber numberWithDouble:start]];
[animation setToValue:[NSNumber numberWithDouble:end]];
[animation setRemovedOnCompletion:NO];
[jointLayer addAnimation:animation forKey:@"jointAnimation"];
//animate shadow opacity
animation = [CABasicAnimation animationWithKeyPath:@"opacity"];
[animation setDuration:duration];
[animation setFromValue:[NSNumber numberWithDouble:(start)?shadowAniOpacity:0]];
[animation setToValue:[NSNumber numberWithDouble:(start)?0:shadowAniOpacity]];
[animation setRemovedOnCompletion:NO];
[shadowLayer addAnimation:animation forKey:nil];
return jointLayer;
}
Basically, I need to remove the automatic animation, and control the progress of the effect using some manually set value (e.g.: uislider value, or content offset).
基本上，我需要移除自动动画，并使用一些手动设置的值（例如：uislider 值或内容偏移量）来控制效果的进度。
Once again, any help provided is much appreciated!
再次感谢您提供的任何帮助！
采纳答案by YooneO
I write another library for folding transition : https://github.com/geraldhuard/YFoldView
我为折叠过渡编写了另一个库：https: //github.com/geraldhuard/YFoldView
Hope it works for you.
希望对你有效。
回答by honcheng
Try this. You have drag control over the paper fold, left and right side.
尝试这个。您可以拖动控制纸张折叠的左侧和右侧。
回答by prince
This is the best solution I've seen:
这是我见过的最好的解决方案：
http://api.mutado.com/mobile/paperstack/
http://api.mutado.com/mobile/paperstack/
EDIT: What about this: the paper folding/unfolding effect in twitter for iPad
编辑：这个怎么样：iPad 版 twitter 中的纸张折叠/展开效果
