From 6201b36f0aee92e2208dc270e09ae6abd1c300cd Mon Sep 17 00:00:00 2001
From: Panayot Cankov <Panayot.Cankov@telerik.com>
Date: Fri, 13 May 2016 16:47:59 +0300
Subject: [PATCH] Add UIImage extensions for thread safe async loading and
 decoding

---
 .../TNSWidgets.xcodeproj/project.pbxproj      |  2 +
 ios/TNSWidgets/TNSWidgets/UIImage+TNSBlocks.h |  3 +
 ios/TNSWidgets/TNSWidgets/UIImage+TNSBlocks.m | 60 +++++++++++--------
 3 files changed, 41 insertions(+), 24 deletions(-)

diff --git a/ios/TNSWidgets/TNSWidgets.xcodeproj/project.pbxproj b/ios/TNSWidgets/TNSWidgets.xcodeproj/project.pbxproj
index 80fb9c3cc..d2043b482 100644
--- a/ios/TNSWidgets/TNSWidgets.xcodeproj/project.pbxproj
+++ b/ios/TNSWidgets/TNSWidgets.xcodeproj/project.pbxproj
@@ -382,6 +382,7 @@
 				F98F5CC51CD0EFEA00978308 /* Release */,
 			);
 			defaultConfigurationIsVisible = 0;
+			defaultConfigurationName = Release;
 		};
 		F98F5CC61CD0EFEA00978308 /* Build configuration list for PBXNativeTarget "TNSWidgetsTests" */ = {
 			isa = XCConfigurationList;
@@ -390,6 +391,7 @@
 				F98F5CC81CD0EFEA00978308 /* Release */,
 			);
 			defaultConfigurationIsVisible = 0;
+			defaultConfigurationName = Release;
 		};
 /* End XCConfigurationList section */
 	};
diff --git a/ios/TNSWidgets/TNSWidgets/UIImage+TNSBlocks.h b/ios/TNSWidgets/TNSWidgets/UIImage+TNSBlocks.h
index cdcbd3361..9e67228be 100644
--- a/ios/TNSWidgets/TNSWidgets/UIImage+TNSBlocks.h
+++ b/ios/TNSWidgets/TNSWidgets/UIImage+TNSBlocks.h
@@ -20,4 +20,7 @@
  */
 + (UIImage*) tns_safeImageNamed: (NSString*) name;
 
++ (void) tns_decodeImageWithData: (NSData*) data completion: (void (^) (UIImage*))callback;
++ (void) tns_decodeImageWidthContentsOfFile: (NSString*) file completion: (void (^) (UIImage*))callback;
+
 @end
diff --git a/ios/TNSWidgets/TNSWidgets/UIImage+TNSBlocks.m b/ios/TNSWidgets/TNSWidgets/UIImage+TNSBlocks.m
index 1fa7162f2..155c9a9f1 100644
--- a/ios/TNSWidgets/TNSWidgets/UIImage+TNSBlocks.m
+++ b/ios/TNSWidgets/TNSWidgets/UIImage+TNSBlocks.m
@@ -6,24 +6,13 @@
 //  Copyright © 2016 Telerik A D. All rights reserved.
 //
 #import <UIKit/UIKit.h>
+#import <CoreGraphics/CoreGraphics.h>
 #import "UIImage+TNSBlocks.h"
 
 @implementation UIImage (TNSBlocks)
 
-static NSLock* image_lock_handle;
 static dispatch_queue_t image_queue;
-
-void image_lock() {
-    if (image_lock_handle) {
-        [image_lock_handle lock];
-    }
-}
-
-void image_unlock() {
-    if (image_lock_handle) {
-        [image_lock_handle unlock];
-    }
-}
+static NSLock* image_lock_handle;
 
 + (void) initialize {
     image_queue = dispatch_queue_create("org.nativescript.TNSWidgets.image", NULL);
@@ -35,20 +24,21 @@ void image_unlock() {
     }
 }
 
-- (void) tns_decompressImage {
-    UIGraphicsBeginImageContext(CGSizeMake(1, 1));
-    [self drawAtPoint:CGPointZero];
-    UIGraphicsEndImageContext();
+- (void) tns_forceDecode {
+    CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
+    CGContextRef context = CGBitmapContextCreate(NULL, 1, 1, 8, 0, colorSpace, kCGImageAlphaPremultipliedFirst);
+    CGContextDrawImage(context, CGRectMake(0, 0, 1, 1), [self CGImage]);
+    CGContextRelease(context);
+    CGColorSpaceRelease(colorSpace);
 }
 
 + (void) tns_safeDecodeImageNamed: (NSString*) name completion: (void (^) (UIImage*))callback {
     dispatch_async(image_queue, ^(void){
-        image_lock();
+        [image_lock_handle lock];
         UIImage* image = [UIImage imageNamed: name];
-        if (image) {
-            [image tns_decompressImage];
-        }
-        image_unlock();
+        [image_lock_handle unlock];
+        [image tns_forceDecode];
+
         dispatch_async(dispatch_get_main_queue(), ^(void) {
             callback(image);
         });
@@ -56,10 +46,32 @@ void image_unlock() {
 }
 
 + (UIImage*) tns_safeImageNamed: (NSString*) name {
-    image_lock();
+    [image_lock_handle lock];
     UIImage* image = [UIImage imageNamed: name];
-    image_unlock();
+    [image_lock_handle unlock];
     return image;
 }
 
++ (void) tns_decodeImageWithData: (NSData*) data completion: (void (^) (UIImage*))callback {
+    dispatch_async(image_queue, ^(void) {
+        UIImage* image = [UIImage imageWithData: data];
+        [image tns_forceDecode];
+
+        dispatch_async(dispatch_get_main_queue(), ^(void) {
+            callback(image);
+        });
+    });
+}
+
++ (void) tns_decodeImageWidthContentsOfFile: (NSString*) file completion: (void (^) (UIImage*))callback {
+    dispatch_async(image_queue, ^(void) {
+        UIImage* image = [UIImage imageWithContentsOfFile: file];
+        [image tns_forceDecode];
+
+        dispatch_async(dispatch_get_main_queue(), ^(void) {
+            callback(image);
+        });
+    });
+}
+
 @end