From 0c91cfc6a25ebe4dce9fa649ca10da02099537a7 Mon Sep 17 00:00:00 2001
From: Rossen Hristov <rossen.hristov@telerik.com>
Date: Thu, 26 Nov 2015 16:59:22 +0200
Subject: [PATCH] Fixed Issue #1160: The image supplied to
 Label.backgroundImage is rendered upside down

---
 ui/styling/background.d.ts   |  2 +-
 ui/styling/background.ios.ts | 23 ++++++++++++++++++++++-
 ui/styling/stylers.ios.ts    | 11 ++++-------
 3 files changed, 27 insertions(+), 9 deletions(-)

diff --git a/ui/styling/background.d.ts b/ui/styling/background.d.ts
index ce1ab4ba9..ffd16781f 100644
--- a/ui/styling/background.d.ts
+++ b/ui/styling/background.d.ts
@@ -44,6 +44,6 @@ declare module "ui/styling/background" {
     }
 
     export module ios {
-        export function createBackgroundUIColor(view: viewModule.View): any /* UIColor */;
+        export function createBackgroundUIColor(view: viewModule.View, flip?: boolean): any /* UIColor */;
     }
 }
diff --git a/ui/styling/background.ios.ts b/ui/styling/background.ios.ts
index ab0cfe7a0..17f019b76 100644
--- a/ui/styling/background.ios.ts
+++ b/ui/styling/background.ios.ts
@@ -5,7 +5,7 @@ import common = require("./background-common");
 global.moduleMerge(common, exports);
 
 export module ios {
-    export function createBackgroundUIColor(view: viewModule.View): UIColor {
+    export function createBackgroundUIColor(view: viewModule.View, flip?: boolean): UIColor {
         if(!view._nativeView){
             return undefined;
         }
@@ -64,9 +64,30 @@ export module ios {
 
             img.drawAsPatternInRect(patternRect);
         }
+
         var bkgImage = UIGraphicsGetImageFromCurrentImageContext();
         UIGraphicsEndImageContext();
 
+        if (flip) {
+            var flippedImage = _flipImage(bkgImage);
+            return UIColor.alloc().initWithPatternImage(flippedImage);
+        }
+
         return UIColor.alloc().initWithPatternImage(bkgImage);
     }
+
+    // Flipping the default coordinate system
+    // https://developer.apple.com/library/ios/documentation/2DDrawing/Conceptual/DrawingPrintingiOS/GraphicsDrawingOverview/GraphicsDrawingOverview.html
+    function _flipImage(originalImage: UIImage): UIImage {
+        UIGraphicsBeginImageContextWithOptions(originalImage.size, false, 0.0);
+        var context = UIGraphicsGetCurrentContext();
+        CGContextSaveGState(context);
+        CGContextTranslateCTM(context, 0.0, originalImage.size.width);
+        CGContextScaleCTM(context, 1.0, -1.0);
+        originalImage.drawInRect(CGRectMake(0, 0, originalImage.size.width, originalImage.size.height))
+        CGContextRestoreGState(context);
+        var flippedImage = UIGraphicsGetImageFromCurrentImageContext();
+        UIGraphicsEndImageContext();
+        return flippedImage;
+    }
 }
diff --git a/ui/styling/stylers.ios.ts b/ui/styling/stylers.ios.ts
index 88c899d16..e30105666 100644
--- a/ui/styling/stylers.ios.ts
+++ b/ui/styling/stylers.ios.ts
@@ -323,7 +323,8 @@ export class LabelStyler implements definition.stylers.Styler {
     private static setBackgroundInternalProperty(view: view.View, newValue: any) {
         var uiLabel: UILabel = <UILabel>view._nativeView;
         if (uiLabel && uiLabel.layer) {
-            var uiColor = <UIColor>background.ios.createBackgroundUIColor(view);
+            var flipImage = true;
+            var uiColor = <UIColor>background.ios.createBackgroundUIColor(view, flipImage);
             var cgColor = uiColor ? uiColor.CGColor : null;
             uiLabel.layer.backgroundColor = cgColor;
         }
@@ -340,12 +341,8 @@ export class LabelStyler implements definition.stylers.Styler {
 
     private static getNativeBackgroundInternalValue(view: view.View): any {
         var uiLabel: UILabel = <UILabel>view._nativeView;
-        if (uiLabel && uiLabel.layer) {
-            var cgColor = uiLabel.layer.backgroundColor;
-            if (cgColor) {
-                return UIColor.colorWithCGColor(cgColor);
-                
-            }
+        if (uiLabel && uiLabel.layer && uiLabel.layer.backgroundColor) {
+            return UIColor.colorWithCGColor(uiLabel.layer.backgroundColor);
         }
 
         return undefined;