关于Apple如何实现“滑动解锁”(也称为“滑动关机”是另一个相同的示例)动画的任何想法?
我考虑过某种动画遮罩-但出于性能原因,iPhone OS上不提供遮罩。
他们可能使用过一些私有API效果(例如SuckEffect)吗?聚光灯类型的效果?一些Core Animation的东西吗?
编辑:绝对不是一系列的剧照。我看过一些示例,这些示例正在编辑plist值或其他内容并在越狱的iphone上自定义字符串。
关于Apple如何实现“滑动解锁”(也称为“滑动关机”是另一个相同的示例)动画的任何想法?
我考虑过某种动画遮罩-但出于性能原因,iPhone OS上不提供遮罩。
他们可能使用过一些私有API效果(例如SuckEffect)吗?聚光灯类型的效果?一些Core Animation的东西吗?
编辑:绝对不是一系列的剧照。我看过一些示例,这些示例正在编辑plist值或其他内容并在越狱的iphone上自定义字符串。
Answers:
通过使用Core Animation,在显示文本的图层上设置遮罩层动画,可以轻松完成此操作。
在任何普通的UIViewController中尝试一下(您可以基于基于View的应用程序项目模板从一个新的Xcode项目开始),或者在这里获取我的Xcode项目:
请注意,该CALayer.mask
属性仅在iPhone OS 3.0和更高版本中可用。
- (void)viewDidLoad
{
self.view.layer.backgroundColor = [[UIColor blackColor] CGColor];
UIImage *textImage = [UIImage imageNamed:@"SlideToUnlock.png"];
CGFloat textWidth = textImage.size.width;
CGFloat textHeight = textImage.size.height;
CALayer *textLayer = [CALayer layer];
textLayer.contents = (id)[textImage CGImage];
textLayer.frame = CGRectMake(10.0f, 215.0f, textWidth, textHeight);
CALayer *maskLayer = [CALayer layer];
// Mask image ends with 0.15 opacity on both sides. Set the background color of the layer
// to the same value so the layer can extend the mask image.
maskLayer.backgroundColor = [[UIColor colorWithRed:0.0f green:0.0f blue:0.0f alpha:0.15f] CGColor];
maskLayer.contents = (id)[[UIImage imageNamed:@"Mask.png"] CGImage];
// Center the mask image on twice the width of the text layer, so it starts to the left
// of the text layer and moves to its right when we translate it by width.
maskLayer.contentsGravity = kCAGravityCenter;
maskLayer.frame = CGRectMake(-textWidth, 0.0f, textWidth * 2, textHeight);
// Animate the mask layer's horizontal position
CABasicAnimation *maskAnim = [CABasicAnimation animationWithKeyPath:@"position.x"];
maskAnim.byValue = [NSNumber numberWithFloat:textWidth];
maskAnim.repeatCount = HUGE_VALF;
maskAnim.duration = 1.0f;
[maskLayer addAnimation:maskAnim forKey:@"slideAnim"];
textLayer.mask = maskLayer;
[self.view.layer addSublayer:textLayer];
[super viewDidLoad];
}
此代码使用的图像是:
UIImage
从一个UILabel
(或其他任何一个UIView
)创建了一个: UIGraphicsBeginImageContext(_label); [[_label layer] renderInContext:UIGraphicsGetCurrentContext()]; UIImage *textImage = UIGraphicsGetImageFromCurrentImageContext(); UIGraphicsEndImageContext();
另一种使用层掩模的解决方案,而是手工绘制渐变,并且不需要图像。View是带有动画的视图,透明是从0到1的浮点数,定义了透明的数量(1 =无透明是毫无意义的),而gradientWidth是所需的渐变宽度。
CAGradientLayer *gradientMask = [CAGradientLayer layer];
gradientMask.frame = view.bounds;
CGFloat gradientSize = gradientWidth / view.frame.size.width;
UIColor *gradient = [UIColor colorWithWhite:1.0f alpha:transparency];
NSArray *startLocations = @[[NSNumber numberWithFloat:0.0f], [NSNumber numberWithFloat:(gradientSize / 2)], [NSNumber numberWithFloat:gradientSize]];
NSArray *endLocations = @[[NSNumber numberWithFloat:(1.0f - gradientSize)], [NSNumber numberWithFloat:(1.0f -(gradientSize / 2))], [NSNumber numberWithFloat:1.0f]];
CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:@"locations"];
gradientMask.colors = @[(id)gradient.CGColor, (id)[UIColor whiteColor].CGColor, (id)gradient.CGColor];
gradientMask.locations = startLocations;
gradientMask.startPoint = CGPointMake(0 - (gradientSize * 2), .5);
gradientMask.endPoint = CGPointMake(1 + gradientSize, .5);
view.layer.mask = gradientMask;
animation.fromValue = startLocations;
animation.toValue = endLocations;
animation.repeatCount = HUGE_VALF;
animation.duration = 3.0f;
[gradientMask addAnimation:animation forKey:@"animateGradient"];
SWIFT版本:
let transparency:CGFloat = 0.5
let gradientWidth: CGFloat = 40
let gradientMask = CAGradientLayer()
gradientMask.frame = swipeView.bounds
let gradientSize = gradientWidth/swipeView.frame.size.width
let gradient = UIColor(white: 1, alpha: transparency)
let startLocations = [0, gradientSize/2, gradientSize]
let endLocations = [(1 - gradientSize), (1 - gradientSize/2), 1]
let animation = CABasicAnimation(keyPath: "locations")
gradientMask.colors = [gradient.CGColor, UIColor.whiteColor().CGColor, gradient.CGColor]
gradientMask.locations = startLocations
gradientMask.startPoint = CGPointMake(0 - (gradientSize*2), 0.5)
gradientMask.endPoint = CGPointMake(1 + gradientSize, 0.5)
swipeView.layer.mask = gradientMask
animation.fromValue = startLocations
animation.toValue = endLocations
animation.repeatCount = HUGE
animation.duration = 3
gradientMask.addAnimation(animation, forKey: "animateGradient")
迅捷3
fileprivate func addGradientMaskToView(view:UIView, transparency:CGFloat = 0.5, gradientWidth:CGFloat = 40.0) {
let gradientMask = CAGradientLayer()
gradientMask.frame = view.bounds
let gradientSize = gradientWidth/view.frame.size.width
let gradientColor = UIColor(white: 1, alpha: transparency)
let startLocations = [0, gradientSize/2, gradientSize]
let endLocations = [(1 - gradientSize), (1 - gradientSize/2), 1]
let animation = CABasicAnimation(keyPath: "locations")
gradientMask.colors = [gradientColor.cgColor, UIColor.white.cgColor, gradientColor.cgColor]
gradientMask.locations = startLocations as [NSNumber]?
gradientMask.startPoint = CGPoint(x:0 - (gradientSize * 2), y: 0.5)
gradientMask.endPoint = CGPoint(x:1 + gradientSize, y: 0.5)
view.layer.mask = gradientMask
animation.fromValue = startLocations
animation.toValue = endLocations
animation.repeatCount = HUGE
animation.duration = 3
gradientMask.add(animation, forKey: nil)
}
[view removeFromSuperview]
在设置蒙版之前和[superview addSubview:view]
之后需要?没有它似乎可以正常工作,可能是我缺少了什么吗?
您可以使用kCGTextClip
绘图模式设置剪切路径,然后填充渐变。
// Get Context
CGContextRef context = UIGraphicsGetCurrentContext();
// Set Font
CGContextSelectFont(context, "Helvetica", 24.0, kCGEncodingMacRoman);
// Set Text Matrix
CGAffineTransform xform = CGAffineTransformMake(1.0, 0.0,
0.0, -1.0,
0.0, 0.0);
CGContextSetTextMatrix(context, xform);
// Set Drawing Mode to set clipping path
CGContextSetTextDrawingMode (context, kCGTextClip);
// Draw Text
CGContextShowTextAtPoint (context, 0, 20, "Gradient", strlen("Gradient"));
// Calculate Text width
CGPoint textEnd = CGContextGetTextPosition(context);
// Generate Gradient locations & colors
size_t num_locations = 3;
CGFloat locations[3] = { 0.3, 0.5, 0.6 };
CGFloat components[12] = {
1.0, 1.0, 1.0, 0.5,
1.0, 1.0, 1.0, 1.0,
1.0, 1.0, 1.0, 0.5,
};
// Load Colorspace
CGColorSpaceRef colorspace = CGColorSpaceCreateDeviceRGB();
// Create Gradient
CGGradientRef gradient = CGGradientCreateWithColorComponents (colorspace, components,
locations, num_locations);
// Draw Gradient (using clipping path
CGContextDrawLinearGradient (context, gradient, rect.origin, textEnd, 0);
// Cleanup (exercise for reader)
设置NSTimer并更改位置中的值,或使用CoreAnimation进行相同的操作。
GoreAnimation
结束
kCGEncodingFontSpecific
改用
我将Pascal上面提供的代码添加为UILabel上的类别,因此您可以以这种方式为任何UILabel设置动画。这是代码。某些参数可能需要更改为背景色,等等。它使用与Pascal回答中嵌入的蒙版图像相同的蒙版图像。
//UILabel+FSHighlightAnimationAdditions.m
#import "UILabel+FSHighlightAnimationAdditions.h"
#import <UIKit/UIKit.h>
#import <QuartzCore/QuartzCore.h>
@implementation UILabel (FSHighlightAnimationAdditions)
- (void)setTextWithChangeAnimation:(NSString*)text
{
NSLog(@"value changing");
self.text = text;
CALayer *maskLayer = [CALayer layer];
// Mask image ends with 0.15 opacity on both sides. Set the background color of the layer
// to the same value so the layer can extend the mask image.
maskLayer.backgroundColor = [[UIColor colorWithRed:0.0f green:0.0f blue:0.0f alpha:0.15f] CGColor];
maskLayer.contents = (id)[[UIImage imageNamed:@"Mask.png"] CGImage];
// Center the mask image on twice the width of the text layer, so it starts to the left
// of the text layer and moves to its right when we translate it by width.
maskLayer.contentsGravity = kCAGravityCenter;
maskLayer.frame = CGRectMake(self.frame.size.width * -1, 0.0f, self.frame.size.width * 2, self.frame.size.height);
// Animate the mask layer's horizontal position
CABasicAnimation *maskAnim = [CABasicAnimation animationWithKeyPath:@"position.x"];
maskAnim.byValue = [NSNumber numberWithFloat:self.frame.size.width];
maskAnim.repeatCount = 1e100f;
maskAnim.duration = 2.0f;
[maskLayer addAnimation:maskAnim forKey:@"slideAnim"];
self.layer.mask = maskLayer;
}
@end
//UILabel+FSHighlightAnimationAdditions.h
#import <Foundation/Foundation.h>
@interface UILabel (FSHighlightAnimationAdditions)
- (void)setTextWithChangeAnimation:(NSString*)text;
@end
FLT_MAX
代替1e100f
。
不太新鲜...但是可能会有用
#define MM_TEXT_TO_DISPLAY @"default"
#define MM_FONT [UIFont systemFontOfSize:MM_FONT_SIZE]
#define MM_FONT_SIZE 25
#define MM_FONT_COLOR [[UIColor darkGrayColor] colorWithAlphaComponent:0.75f];
#define MM_SHADOW_ENABLED NO
#define MM_SHADOW_COLOR [UIColor grayColor]
#define MM_SHADOW_OFFSET CGSizeMake(-1,-1)
#define MM_CONTENT_EDGE_INSETS_TOP 0
#define MM_CONTENT_EDGE_INSETS_LEFT 10
#define MM_CONTENT_EDGE_INSETS_BOTTON 0
#define MM_CONTENT_EDGE_INSETS_RIGHT 10
#define MM_CONTENT_EDGE_INSETS UIEdgeInsetsMake(MM_CONTENT_EDGE_INSETS_TOP, MM_CONTENT_EDGE_INSETS_LEFT, MM_CONTENT_EDGE_INSETS_BOTTON, MM_CONTENT_EDGE_INSETS_RIGHT)
#define MM_TEXT_ALIGNMENT UITextAlignmentCenter
#define MM_BACKGROUND_COLOR [UIColor clearColor]
#define MM_TIMER_INTERVAL 0.05f
#define MM_HORIZONTAL_SPAN 5
@interface MMAnimatedGradientLabel : UILabel {
NSString *textToDisplay;
int text_length;
CGGradientRef gradient;
int current_position_x;
NSTimer *timer;
CGPoint alignment;
CGGlyph *_glyphs;
}
- (id)initWithString:(NSString *)_string;
- (void)startAnimation;
- (void)toggle;
- (BOOL)isAnimating;
@end
#define RGB_COMPONENTS(r, g, b, a) (r) / 255.0f, (g) / 255.0f, (b) / 255.0f, (a)
@interface MMAnimatedGradientLabel (Private)
- (CGRect)calculateFrame;
@end
@implementation MMAnimatedGradientLabel
// Missing in standard headers.
extern void CGFontGetGlyphsForUnichars(CGFontRef, const UniChar[], const CGGlyph[], size_t);
- (id)init {
textToDisplay = MM_TEXT_TO_DISPLAY;
return [self initWithFrame:[self calculateFrame]];
}
- (id)initWithString:(NSString *)_string {
textToDisplay = _string;
return [self initWithFrame:[self calculateFrame]];
}
-(id)initWithFrame:(CGRect)frame {
if (self = [super initWithFrame:frame]) {
// set default values
//
self.textAlignment = MM_TEXT_ALIGNMENT;
self.backgroundColor = MM_BACKGROUND_COLOR;
self.font = MM_FONT;
self.text = textToDisplay;
self.textColor = MM_FONT_COLOR;
if (MM_SHADOW_ENABLED) {
self.shadowColor = MM_SHADOW_COLOR;
self.shadowOffset = MM_SHADOW_OFFSET;
}
text_length = -1;
CGColorSpaceRef rgb = CGColorSpaceCreateDeviceRGB();
CGFloat colors[] =
{
RGB_COMPONENTS(255.0, 255.0, 255.0, 0.00),
// RGB_COMPONENTS(255.0, 255.0, 255.0, 0.15),
RGB_COMPONENTS(255.0, 255.0, 255.0, 0.95),
// RGB_COMPONENTS(255.0, 255.0, 255.0, 0.15),
RGB_COMPONENTS(255.0, 255.0, 255.0, 0.00)
};
gradient = CGGradientCreateWithColorComponents(rgb, colors, NULL, sizeof(colors)/(sizeof(colors[0])*4));
CGColorSpaceRelease(rgb);
current_position_x = -(frame.size.width/2);// - MM_CONTENT_EDGE_INSETS.left - MM_CONTENT_EDGE_INSETS.right);
}
return self;
}
- (CGRect)calculateFrame {
CGSize size = [textToDisplay sizeWithFont:MM_FONT];
NSLog(@"size: %f, %f", size.width, size.height);
return CGRectMake(0, 0, size.width + MM_CONTENT_EDGE_INSETS.left + MM_CONTENT_EDGE_INSETS.right, size.height + MM_CONTENT_EDGE_INSETS.top + MM_CONTENT_EDGE_INSETS.bottom);
}
- (void)tick:(NSTimer*)theTimer {
if (current_position_x < self.frame.size.width)
current_position_x = current_position_x + MM_HORIZONTAL_SPAN;
else
current_position_x = -(self.frame.size.width/2); // - MM_CONTENT_EDGE_INSETS.left - MM_CONTENT_EDGE_INSETS.right);
[self setNeedsDisplay];
}
- (void)startAnimation {
timer = [[NSTimer alloc] initWithFireDate:[NSDate date]
interval:MM_TIMER_INTERVAL
target:self
selector:@selector(tick:)
userInfo:nil
repeats:YES];
[[NSRunLoop currentRunLoop] addTimer:timer forMode:NSDefaultRunLoopMode];
}
- (void)toggle {
if (!timer) {
timer = [[NSTimer alloc] initWithFireDate:[NSDate date]
interval:MM_TIMER_INTERVAL
target:self
selector:@selector(tick:)
userInfo:nil
repeats:YES];
[[NSRunLoop currentRunLoop] addTimer:timer forMode:NSDefaultRunLoopMode];
} else {
[timer invalidate];
[timer release];
timer = nil;
current_position_x = -(self.frame.size.width/2);
[self setNeedsDisplay];
}
}
- (BOOL)isAnimating {
if (timer)
return YES;
else
return NO;
}
- (void)drawRect:(CGRect)rect {
CGContextRef ctx = UIGraphicsGetCurrentContext();
// Get drawing font.
CGFontRef font = CGFontCreateWithFontName((CFStringRef)[[self font] fontName]);
CGContextSetFont(ctx, font);
CGContextSetFontSize(ctx, [[self font] pointSize]);
// Calculate text drawing point only first time
//
if (text_length == -1) {
// Transform text characters to unicode glyphs.
text_length = [[self text] length];
unichar chars[text_length];
[[self text] getCharacters:chars range:NSMakeRange(0, text_length)];
_glyphs = malloc(sizeof(CGGlyph) * text_length);
for (int i=0; i<text_length;i ++)
_glyphs[i] = chars[i] - 29;
// Measure text dimensions.
CGContextSetTextDrawingMode(ctx, kCGTextInvisible);
CGContextSetTextPosition(ctx, 0, 0);
CGContextShowGlyphs(ctx, _glyphs, text_length);
CGPoint textEnd = CGContextGetTextPosition(ctx);
// Calculate text drawing point.
CGPoint anchor = CGPointMake(textEnd.x * (-0.5), [[self font] pointSize] * (-0.25));
CGPoint p = CGPointApplyAffineTransform(anchor, CGAffineTransformMake(1, 0, 0, -1, 0, 1));
if ([self textAlignment] == UITextAlignmentCenter)
alignment.x = [self bounds].size.width * 0.5 + p.x;
else if ([self textAlignment] == UITextAlignmentLeft)
alignment.x = 0;
else
alignment.x = [self bounds].size.width - textEnd.x;
alignment.y = [self bounds].size.height * 0.5 + p.y;
}
// Flip back mirrored text.
CGContextSetTextMatrix(ctx, CGAffineTransformMakeScale(1, -1));
// Draw shadow.
CGContextSaveGState(ctx);
CGContextSetTextDrawingMode(ctx, kCGTextFill);
CGContextSetFillColorWithColor(ctx, [[self textColor] CGColor]);
CGContextSetShadowWithColor(ctx, [self shadowOffset], 0, [[self shadowColor] CGColor]);
CGContextShowGlyphsAtPoint(ctx, alignment.x, alignment.y, _glyphs, text_length);
CGContextRestoreGState(ctx);
// Draw text clipping path.
CGContextSetTextDrawingMode(ctx, kCGTextClip);
CGContextShowGlyphsAtPoint(ctx, alignment.x, alignment.y, _glyphs, text_length);
// Restore text mirroring.
CGContextSetTextMatrix(ctx, CGAffineTransformIdentity);
if ([self isAnimating]) {
// Fill text clipping path with gradient.
CGPoint start = CGPointMake(rect.origin.x + current_position_x, rect.origin.y);
CGPoint end = CGPointMake(rect.size.width/3*2 + current_position_x, rect.origin.y);
CGContextDrawLinearGradient(ctx, gradient, start, end, 0);
}
}
- (void) dealloc {
free(_glyphs);
[timer invalidate];
[timer release];
CGGradientRelease(gradient);
[super dealloc];
}
感谢rpetrich提供的剪切梯度配方。我是iPhone和Cocoa的新手开发人员,因此很高兴能找到它。
我已经使用rpetrich的方法实现了一个看起来不错的Slide to Cancel UIViewController。您可以从此处下载实现的Xcode项目。
我的实现使用重复的NSTimer。我无法弄清楚如何使用Core(或Gore)动画使iPhone的图形引擎连续移动突出显示。我认为可以在具有CALayer遮罩层的OS X上完成此操作,但是iPhone OS不支持遮罩层。
当我在iPhone的主屏幕上使用Apple的“滑动解锁”滑块时,偶尔会看到动画冻结。因此,我认为Apple可能也会使用计时器。
如果有人能弄清楚如何使用CA或OpenGL执行基于非计时器的实现,我很乐意看到它。
谢谢您的帮助!
我知道,我的答案有点晚了,但是Facebook拥有出色的Shimmer库,可以完全实现这种效果。
我从上述解决方案中汲取了最大的优势,并创建了一个简洁的方法来为您完成所有工作:
- (void)createSlideToUnlockViewWithText:(NSString *)text
{
UILabel *label = [[UILabel alloc] init];
label.text = text;
[label sizeToFit];
label.textColor = [UIColor whiteColor];
//Create an image from the label
UIGraphicsBeginImageContextWithOptions(label.bounds.size, NO, 0.0);
[[label layer] renderInContext:UIGraphicsGetCurrentContext()];
UIImage *textImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
CGFloat textWidth = textImage.size.width;
CGFloat textHeight = textImage.size.height;
CALayer *textLayer = [CALayer layer];
textLayer.contents = (id)[textImage CGImage];
textLayer.frame = CGRectMake(self.view.frame.size.width / 2 - textWidth / 2, self.view.frame.size.height / 2 - textHeight / 2, textWidth, textHeight);
UIImage *maskImage = [UIImage imageNamed:@"Mask.png"];
CALayer *maskLayer = [CALayer layer];
maskLayer.backgroundColor = [[UIColor colorWithRed:0.0 green:0.0 blue:0.0 alpha:0.15] CGColor];
maskLayer.contents = (id)maskImage.CGImage;
maskLayer.contentsGravity = kCAGravityCenter;
maskLayer.frame = CGRectMake(-textWidth - maskImage.size.width, 0.0, (textWidth * 2) + maskImage.size.width, textHeight);
CABasicAnimation *maskAnimation = [CABasicAnimation animationWithKeyPath:@"position.x"];
maskAnimation.byValue = [NSNumber numberWithFloat:textWidth + maskImage.size.width];
maskAnimation.repeatCount = HUGE_VALF;
maskAnimation.duration = 2.0;
maskAnimation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseOut];
[maskLayer addAnimation:maskAnimation forKey:@"slideAnimation"];
textLayer.mask = maskLayer;
self.slideToUnlockLayer = textLayer;
[self.view.layer addSublayer:self.slideToUnlockLayer];
}
首先,非常感谢marcio的解决方案。这几乎可以完美地工作,节省了我很多时间,并且在我的应用程序中引起了极大的轰动。我的老板喜欢它。我欠你啤酒。或几个。
仅针对iPhone 4的一项小修正。我指的是硬件本身,而不仅仅是iOS4。他们将iPhone 4上的系统字体从Helvetica(iPhone 3G及更低版本)更改为Helvetic Neue。这导致您正在执行的从字符到字形的转换恰好偏离了4个点。例如,字符串“ fg”将显示为“ bc”。我通过将字体显式设置为“ Helvetica”而不是使用“ systemFontofSize”来解决此问题。现在,它就像一种魅力。
再次谢谢你!
我将一个小型项目上传到GitHub,该项目可以帮助“滑动解锁”动画。
https://github.com/GabrielMassana/GM_FSHighlightAnimationAdditions
该项目具有LTR,RTL,Up to Down和Down to Up动画,它基于以下帖子:
帕斯卡·布尔克(Pascal Bourque):https : //stackoverflow.com/a/2778232/1381708
cberkley:https://stackoverflow.com/a/5710097/1381708
干杯
这是一个SwiftUI版本:
struct Shimmer: AnimatableModifier {
private let gradient: Gradient
init(sideColor: Color = Color(white: 0.25), middleColor: Color = .white) {
gradient = Gradient(colors: [sideColor, middleColor, sideColor])
}
@State private var position: CGFloat = 0
var animatableData: CGFloat {
get { position }
set { position = newValue }
}
func body(content: Content) -> some View {
content
.overlay(LinearGradient(
gradient: gradient,
startPoint: .init(x: position - 0.2 * (1 - position), y: 0.5),
endPoint: .init(x: position + 0.2 * position, y: 0.5)))
.mask(content)
.onAppear {
withAnimation(Animation
.linear(duration: 2)
.delay(1)
.repeatForever(autoreverses: false)) {
position = 1
}
}
}
}
像这样使用它:
Text("slide to unlock")
.modifier(Shimmer())