First try at version 2.

LiveFrost/LFDisplayBridge.h

@@ -31,7 +31,7 @@
 + (instancetype) sharedInstance;
 
 @property (nonatomic, readonly, assign) CFMutableSetRef subscribedViews;
-- (void) addSubscribedViewsObject:(UIView<LFDisplayBridgeTriggering> *)object;
-- (void) removeSubscribedViewsObject:(UIView<LFDisplayBridgeTriggering> *)object;
+- (void) addSubscribedLayer:(CALayer<LFDisplayBridgeTriggering> *)object;
+- (void) removeSubscribedLayer:(CALayer<LFDisplayBridgeTriggering> *)object;
 
 @end

LiveFrost/LFDisplayBridge.m

@@ -22,24 +22,24 @@
 
 #import "LFDisplayBridge.h"
 
-void LF_refreshAllSubscribedViewsApplierFunction(const void *value, void *context);
+void LF_refreshAllSubscribedLayersApplierFunction(const void *value, void *context);
 
 @interface LFDisplayBridge ()
 
-@property (nonatomic, readwrite, assign) CFMutableSetRef subscribedViews;
+@property (nonatomic, readwrite, assign) CFMutableSetRef subscribedLayers;
 @property (nonatomic, readonly, strong) CADisplayLink *displayLink;
 
 @end
 
-void LF_refreshAllSubscribedViewsApplierFunction(const void *value, void *context) {
+void LF_refreshAllSubscribedLayersApplierFunction(const void *value, void *context) {
 	[(__bridge UIView<LFDisplayBridgeTriggering> *)value refresh];
 }
 
 #if !__has_feature(objc_arc)
-	#error This implementation file must be compiled with Objective-C ARC.
+#error This implementation file must be compiled with Objective-C ARC.
 
-	#error Compile this file with the -fobjc-arc flag under your target's Build Phases,
-	#error   or convert your project to Objective-C ARC.
+#error Compile this file with the -fobjc-arc flag under your target's Build Phases,
+#error	 or convert your project to Objective-C ARC.
 #endif
 
 @implementation LFDisplayBridge
@@ -55,32 +55,32 @@ + (instancetype) sharedInstance {
 
 - (id) init {
 	if (self = [super init]) {
-		_subscribedViews = CFSetCreateMutable(kCFAllocatorDefault, 0, NULL);
+		_subscribedLayers = CFSetCreateMutable(kCFAllocatorDefault, 0, NULL);
 		_displayLink = [CADisplayLink displayLinkWithTarget:self selector:@selector(handleDisplayLink:)];
 		[_displayLink addToRunLoop:[NSRunLoop mainRunLoop] forMode:NSRunLoopCommonModes];
 	}
 	return self;
 }
 
-- (void) addSubscribedViewsObject:(UIView<LFDisplayBridgeTriggering> *)object {
-	CFSetAddValue(_subscribedViews, (__bridge const void*)object);
+- (void) dealloc {
+	[_displayLink invalidate];
+	CFRelease(_subscribedLayers);
 }
 
-- (void) removeSubscribedViewsObject:(UIView<LFDisplayBridgeTriggering> *)object {
-	CFSetRemoveValue(_subscribedViews, (__bridge const void*)object);
+- (void) addSubscribedLayer:(CALayer<LFDisplayBridgeTriggering> *)object {
+	CFSetAddValue(_subscribedLayers, (__bridge const void*)object);
 }
 
-- (void) handleDisplayLink:(CADisplayLink *)displayLink {
-	[self refresh];
+- (void) removeSubscribedLayer:(CALayer<LFDisplayBridgeTriggering> *)object {
+	CFSetRemoveValue(_subscribedLayers, (__bridge const void*)object);
 }
 
-- (void) dealloc {
-	[_displayLink invalidate];
-	CFRelease(_subscribedViews);
+- (void) handleDisplayLink:(CADisplayLink *)displayLink {
+	[self refresh];
 }
 
 - (void) refresh {
-	CFSetApplyFunction(_subscribedViews, LF_refreshAllSubscribedViewsApplierFunction, NULL);
+	CFSetApplyFunction(_subscribedLayers, LF_refreshAllSubscribedLayersApplierFunction, NULL);
 }
 
 @end

LiveFrost/LFGlassLayer.h

@@ -0,0 +1,47 @@
+//
+// Copyright (c) 2013-2014 Evadne Wu and Nicholas Levin
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+//
+// Contains contributions from Nam Kennic
+//
+
+#import <Accelerate/Accelerate.h>
+#import <QuartzCore/QuartzCore.h>
+#import "LFDisplayBridge.h"
+
+@interface LFGlassLayer : CALayer <LFDisplayBridgeTriggering>
+
+@property (nonatomic, assign) CGFloat blurRadius;
+@property (nonatomic, assign) CGFloat scaleFactor;
+
+@property (nonatomic, assign) NSUInteger frameInterval;
+
+- (BOOL) blurOnceIfPossible;
+
+// optional properties for greater customization
+@property (nonatomic, weak) CALayer *customBlurTargetLayer;
+@property (nonatomic, assign) CGRect customBlurBounds;
+@property (nonatomic, assign) CGPoint customBlurPosition;
+@property (nonatomic, assign) CGPoint customBlurAnchorPoint;
+@property (nonatomic, assign) CGRect customBlurFrame;
+
+- (void) resetCustomPositioning;
+
+@end