Fix bug #104.

Implement show qrcode by core image generator instead of embed a web view.

ShadowsocksX-NG/SWBQRCodeWindowController.m

@@ -7,6 +7,7 @@
 //
 
 #import "SWBQRCodeWindowController.h"
+@import CoreImage;
 
 @interface SWBQRCodeWindowController ()
 
@@ -18,18 +19,56 @@
     [super windowDidLoad];
     
     // Implement this method to handle any initialization after your window controller's window has been loaded from its nib file.
-    [self.webView.mainFrame loadRequest:[NSURLRequest requestWithURL:[[NSBundle mainBundle] URLForResource:@"qrcode" withExtension:@"htm"]]];
-    self.webView.frameLoadDelegate = self;
+    [self setQRCode:self.qrCode];
 }
 
--(void)webView:(WebView *)sender didFinishLoadForFrame:(WebFrame *)frame {
-    if (self.qrCode) {
-        [self.webView stringByEvaluatingJavaScriptFromString:[NSString stringWithFormat:@"genCode('%@')", _qrCode]];
-    }
+- (void)setQRCode:(NSString*) qrCode {
+    CGImageRef cgImgRef = [self createQRImageForString:qrCode size:CGSizeMake(250, 250)];
+    
+    NSImage *image = [[NSImage alloc]initWithCGImage:cgImgRef size:CGSizeMake(250, 250)];
+    self.imageView.image = image;
 }
 
--(void)dealloc {
-    self.webView.frameLoadDelegate = nil;
+- (CGImageRef)createQRImageForString:(NSString *)string size:(CGSize)size {
+    // Setup the QR filter with our string
+    CIFilter *filter = [CIFilter filterWithName:@"CIQRCodeGenerator"];
+    [filter setDefaults];
+    
+    NSData *data = [string dataUsingEncoding:NSUTF8StringEncoding];
+    [filter setValue:data forKey:@"inputMessage"];
+    CIImage *image = [filter valueForKey:@"outputImage"];
+    
+    // Calculate the size of the generated image and the scale for the desired image size
+    CGRect extent = CGRectIntegral(image.extent);
+    CGFloat scale = MIN(size.width / CGRectGetWidth(extent), size.height / CGRectGetHeight(extent));
+    
+    // Since CoreImage nicely interpolates, we need to create a bitmap image that we'll draw into
+    // a bitmap context at the desired size;
+    size_t width = CGRectGetWidth(extent) * scale;
+    size_t height = CGRectGetHeight(extent) * scale;
+    CGColorSpaceRef cs = CGColorSpaceCreateDeviceGray();
+    CGContextRef bitmapRef = CGBitmapContextCreate(nil, width, height, 8, 0, cs, (CGBitmapInfo)kCGImageAlphaNone);
+    
+#if TARGET_OS_IPHONE
+    CIContext *context = [CIContext contextWithOptions:nil];
+#else
+    CIContext *context = [CIContext contextWithCGContext:bitmapRef options:nil];
+#endif
+    
+    CGImageRef bitmapImage = [context createCGImage:image fromRect:extent];
+    
+    CGContextSetInterpolationQuality(bitmapRef, kCGInterpolationNone);
+    CGContextScaleCTM(bitmapRef, scale, scale);
+    CGContextDrawImage(bitmapRef, extent, bitmapImage);
+    
+    // Create an image with the contents of our bitmap
+    CGImageRef scaledImage = CGBitmapContextCreateImage(bitmapRef);
+    
+    // Cleanup
+    CGContextRelease(bitmapRef);
+    CGImageRelease(bitmapImage);
+    
+    return scaledImage;
 }
 
 @end