[react-native] Open-source ReactART for native

Libraries/ART/Brushes/ARTLinearGradient.m

@@ -0,0 +1,49 @@
+/**
+ * Copyright (c) 2015-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 "ARTLinearGradient.h"
+
+#import "RCTConvert+ART.h"
+#import "RCTLog.h"
+
+@implementation ARTLinearGradient
+{
+  CGGradientRef _gradient;
+  CGPoint _startPoint;
+  CGPoint _endPoint;
+}
+
+- (instancetype)initWithArray:(NSArray *)array
+{
+  if ((self = [super initWithArray:array])) {
+    if (array.count < 5) {
+      RCTLogError(@"-[%@ %@] expects 5 elements, received %@",
+                  self.class, NSStringFromSelector(_cmd), array);
+      return nil;
+    }
+    _startPoint = [RCTConvert CGPoint:array offset:1];
+    _endPoint = [RCTConvert CGPoint:array offset:3];
+    _gradient = CGGradientRetain([RCTConvert CGGradient:array offset:5]);
+  }
+  return self;
+}
+
+- (void)dealloc
+{
+  CGGradientRelease(_gradient);
+}
+
+- (void)paint:(CGContextRef)context
+{
+  CGGradientDrawingOptions extendOptions =
+    kCGGradientDrawsBeforeStartLocation | kCGGradientDrawsAfterEndLocation;
+  CGContextDrawLinearGradient(context, _gradient, _startPoint, _endPoint, extendOptions);
+}
+
+@end