Rename CK classes to AS classes

AsyncDisplayKit/TextKit/ASTextKitShadower.mm

@@ -0,0 +1,148 @@
+/*
+ *  Copyright (c) 2014-present, Facebook, Inc.
+ *  All rights reserved.
+ *
+ *  This source code is licensed under the BSD-style license found in the
+ *  LICENSE file in the root directory of this source tree. An additional grant
+ *  of patent rights can be found in the PATENTS file in the same directory.
+ *
+ */
+
+#import "ASTextKitShadower.h"
+
+static inline CGSize _insetSize(CGSize size, UIEdgeInsets insets)
+{
+  return UIEdgeInsetsInsetRect({.size = size}, insets).size;
+}
+
+static inline UIEdgeInsets _invertInsets(UIEdgeInsets insets)
+{
+  return {
+    .top = -insets.top,
+    .left = -insets.left,
+    .bottom = -insets.bottom,
+    .right = -insets.right
+  };
+}
+
+@implementation ASTextKitShadower {
+  UIEdgeInsets _calculatedShadowPadding;
+}
+
+- (instancetype)initWithShadowOffset:(CGSize)shadowOffset
+                         shadowColor:(UIColor *)shadowColor
+                       shadowOpacity:(CGFloat)shadowOpacity
+                        shadowRadius:(CGFloat)shadowRadius
+{
+  if (self = [super init]) {
+    _shadowOffset = shadowOffset;
+    _shadowColor = shadowColor;
+    _shadowOpacity = shadowOpacity;
+    _shadowRadius = shadowRadius;
+    _calculatedShadowPadding = UIEdgeInsetsMake(-INFINITY, -INFINITY, INFINITY, INFINITY);
+  }
+  return self;
+}
+
+/*
+ * This method is duplicated here because it gets called frequently, and we were
+ * wasting valuable time constructing a state object to ask it.
+ */
+- (BOOL)_shouldDrawShadow
+{
+  return _shadowOpacity != 0.0 && _shadowColor != nil && (_shadowRadius != 0 || !CGSizeEqualToSize(_shadowOffset, CGSizeZero));
+}
+
+- (void)setShadowInContext:(CGContextRef)context
+{
+  if ([self _shouldDrawShadow]) {
+    CGColorRef textShadowColor = CGColorRetain(_shadowColor.CGColor);
+    CGSize textShadowOffset = _shadowOffset;
+    CGFloat textShadowOpacity = _shadowOpacity;
+    CGFloat textShadowRadius = _shadowRadius;
+
+    if (textShadowOpacity != 1.0) {
+      CGFloat inherentAlpha = CGColorGetAlpha(textShadowColor);
+
+      CGColorRef oldTextShadowColor = textShadowColor;
+      textShadowColor = CGColorCreateCopyWithAlpha(textShadowColor, inherentAlpha * textShadowOpacity);
+      CGColorRelease(oldTextShadowColor);
+    }
+
+    CGContextSetShadowWithColor(context, textShadowOffset, textShadowRadius, textShadowColor);
+
+    CGColorRelease(textShadowColor);
+  }
+}
+
+
+- (UIEdgeInsets)shadowPadding
+{
+  if (_calculatedShadowPadding.top == -INFINITY) {
+    if (![self _shouldDrawShadow]) {
+      return UIEdgeInsetsZero;
+    }
+
+    UIEdgeInsets shadowPadding = UIEdgeInsetsZero;
+
+    // min values are expected to be negative for most typical shadowOffset and
+    // blurRadius settings:
+    shadowPadding.top = fminf(0.0f, _shadowOffset.height - _shadowRadius);
+    shadowPadding.left = fminf(0.0f, _shadowOffset.width - _shadowRadius);
+
+    shadowPadding.bottom = fminf(0.0f, -_shadowOffset.height - _shadowRadius);
+    shadowPadding.right = fminf(0.0f, -_shadowOffset.width - _shadowRadius);
+
+    _calculatedShadowPadding = shadowPadding;
+  }
+
+  return _calculatedShadowPadding;
+}
+
+- (CGSize)insetSizeWithConstrainedSize:(CGSize)constrainedSize
+{
+  return _insetSize(constrainedSize, _invertInsets([self shadowPadding]));
+}
+
+- (CGRect)insetRectWithConstrainedRect:(CGRect)constrainedRect
+{
+  return UIEdgeInsetsInsetRect(constrainedRect, _invertInsets([self shadowPadding]));
+}
+
+- (CGSize)outsetSizeWithInsetSize:(CGSize)insetSize
+{
+  return _insetSize(insetSize, [self shadowPadding]);
+}
+
+- (CGRect)outsetRectWithInsetRect:(CGRect)insetRect
+{
+  return UIEdgeInsetsInsetRect(insetRect, [self shadowPadding]);
+}
+
+- (CGRect)offsetRectWithInternalRect:(CGRect)internalRect
+{
+  return (CGRect){
+    .origin = [self offsetPointWithInternalPoint:internalRect.origin],
+    .size = internalRect.size
+  };
+}
+
+- (CGPoint)offsetPointWithInternalPoint:(CGPoint)internalPoint
+{
+  UIEdgeInsets shadowPadding = [self shadowPadding];
+  return (CGPoint){
+    internalPoint.x + shadowPadding.left,
+    internalPoint.y + shadowPadding.top
+  };
+}
+
+- (CGPoint)offsetPointWithExternalPoint:(CGPoint)externalPoint
+{
+  UIEdgeInsets shadowPadding = [self shadowPadding];
+  return (CGPoint){
+    externalPoint.x - shadowPadding.left,
+    externalPoint.y - shadowPadding.top
+  };
+}
+
+@end