检测用户是否在UITextView中键入了表情符号字符 [英] Detect if a user has typed an emoji character in UITextView
问题描述
我有一个UITextView，我需要检测用户是否输入了表情符号字符.
我认为仅检查最新字符的unicode值就足够了，但是对于新的emoji表情符号2，有些字符会散布在整个unicode索引中(即Apple新设计的版权和注册徽标).
也许与用NSLocale或LocalizedString值检查字符的语言有关吗?
有人知道一个好的解决方案吗?
谢谢！
这些年来，随着苹果添加了带有新方法的新表情符号(例如，通过将角色预诅咒而生成的肤色表情符号)，这些检测表情符号的解决方案不断地被打破.附加字符)，等等
我终于崩溃了，只写了下面的方法，该方法适用于所有当前的表情符号，并且应该适用于所有未来的表情符号.
该解决方案创建一个带有字符和黑色背景的UILabel. CG然后为标签拍摄快照，然后我扫描快照中的所有像素以查找任何非纯黑色像素.我添加黑色背景的原因是为了避免由于子像素渲染
该解决方案在我的设备上运行非常快，我每秒可以检查数百个字符，但是应该注意，这是一个CoreGraphics解决方案，不应像常规文本方法那样大量使用.图形处理的数据量很大，因此一次检查数千个字符可能会导致明显的延迟.
-(BOOL)isEmoji:(NSString *)character {
UILabel *characterRender = [[UILabel alloc] initWithFrame:CGRectMake(0, 0, 1, 1)];
characterRender.text = character;
characterRender.backgroundColor = [UIColor blackColor];//needed to remove subpixel rendering colors
[characterRender sizeToFit];
CGRect rect = [characterRender bounds];
UIGraphicsBeginImageContextWithOptions(rect.size,YES,0.0f);
CGContextRef contextSnap = UIGraphicsGetCurrentContext();
[characterRender.layer renderInContext:contextSnap];
UIImage *capturedImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
CGImageRef imageRef = [capturedImage CGImage];
NSUInteger width = CGImageGetWidth(imageRef);
NSUInteger height = CGImageGetHeight(imageRef);
CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
unsigned char *rawData = (unsigned char*) calloc(height * width * 4, sizeof(unsigned char));
NSUInteger bytesPerPixel = 4;
NSUInteger bytesPerRow = bytesPerPixel * width;
NSUInteger bitsPerComponent = 8;
CGContextRef context = CGBitmapContextCreate(rawData, width, height,
bitsPerComponent, bytesPerRow, colorSpace,
kCGImageAlphaPremultipliedLast | kCGBitmapByteOrder32Big);
CGColorSpaceRelease(colorSpace);
CGContextDrawImage(context, CGRectMake(0, 0, width, height), imageRef);
CGContextRelease(context);
BOOL colorPixelFound = NO;
int x = 0;
int y = 0;
while (y < height && !colorPixelFound) {
while (x < width && !colorPixelFound) {
NSUInteger byteIndex = (bytesPerRow * y) + x * bytesPerPixel;
CGFloat red = (CGFloat)rawData[byteIndex];
CGFloat green = (CGFloat)rawData[byteIndex+1];
CGFloat blue = (CGFloat)rawData[byteIndex+2];
CGFloat h, s, b, a;
UIColor *c = [UIColor colorWithRed:red green:green blue:blue alpha:1.0f];
[c getHue:&h saturation:&s brightness:&b alpha:&a];
b /= 255.0f;
if (b > 0) {
colorPixelFound = YES;
}
x++;
}
x=0;
y++;
}
return colorPixelFound;
}
I have a UITextView and I need to detect if a user enters an emoji character.
I would think that just checking the unicode value of the newest character would suffice but with the new emoji 2s, some characters are scattered all throughout the unicode index (i.e. Apple's newly designed copyright and register logos).
Perhaps something to do with checking the language of the character with NSLocale or LocalizedString values?
Does anyone know a good solution?
Thanks!
Over the years these emoji-detecting solutions keep breaking as Apple adds new emojis w/ new methods (like skin-toned emojis built by pre-cursing a character with an additional character), etc.
I finally broke down and just wrote the following method which works for all current emojis and should work for all future emojis.
The solution creates a UILabel with the character and a black background. CG then takes a snapshot of the label and I scan all pixels in the snapshot for any non solid-black pixels. The reason I add the black background is to avoid issues of false-coloring due to Subpixel Rendering
The solution runs VERY fast on my device, I can check hundreds of characters a second, but it should be noted that this is a CoreGraphics solution and should not be used heavily like you could with a regular text method. Graphics processing is data heavy so checking thousands of characters at once could result in noticeable lag.
-(BOOL)isEmoji:(NSString *)character {
UILabel *characterRender = [[UILabel alloc] initWithFrame:CGRectMake(0, 0, 1, 1)];
characterRender.text = character;
characterRender.backgroundColor = [UIColor blackColor];//needed to remove subpixel rendering colors
[characterRender sizeToFit];
CGRect rect = [characterRender bounds];
UIGraphicsBeginImageContextWithOptions(rect.size,YES,0.0f);
CGContextRef contextSnap = UIGraphicsGetCurrentContext();
[characterRender.layer renderInContext:contextSnap];
UIImage *capturedImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
CGImageRef imageRef = [capturedImage CGImage];
NSUInteger width = CGImageGetWidth(imageRef);
NSUInteger height = CGImageGetHeight(imageRef);
CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
unsigned char *rawData = (unsigned char*) calloc(height * width * 4, sizeof(unsigned char));
NSUInteger bytesPerPixel = 4;
NSUInteger bytesPerRow = bytesPerPixel * width;
NSUInteger bitsPerComponent = 8;
CGContextRef context = CGBitmapContextCreate(rawData, width, height,
bitsPerComponent, bytesPerRow, colorSpace,
kCGImageAlphaPremultipliedLast | kCGBitmapByteOrder32Big);
CGColorSpaceRelease(colorSpace);
CGContextDrawImage(context, CGRectMake(0, 0, width, height), imageRef);
CGContextRelease(context);
BOOL colorPixelFound = NO;
int x = 0;
int y = 0;
while (y < height && !colorPixelFound) {
while (x < width && !colorPixelFound) {
NSUInteger byteIndex = (bytesPerRow * y) + x * bytesPerPixel;
CGFloat red = (CGFloat)rawData[byteIndex];
CGFloat green = (CGFloat)rawData[byteIndex+1];
CGFloat blue = (CGFloat)rawData[byteIndex+2];
CGFloat h, s, b, a;
UIColor *c = [UIColor colorWithRed:red green:green blue:blue alpha:1.0f];
[c getHue:&h saturation:&s brightness:&b alpha:&a];
b /= 255.0f;
if (b > 0) {
colorPixelFound = YES;
}
x++;
}
x=0;
y++;
}
return colorPixelFound;
}
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