Upstream Chrome on iOS source code [6/11].

ios/chrome/browser/ui/qr_scanner/qr_scanner_view.h

+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef IOS_CHROME_BROWSER_UI_QR_SCANNER_QR_SCANNER_VIEW_H_
+#define IOS_CHROME_BROWSER_UI_QR_SCANNER_QR_SCANNER_VIEW_H_
+
+#import <AVFoundation/AVFoundation.h>
+#import <UIKit/UIKit.h>
+
+@protocol QRScannerViewDelegate
+
+// Called when the close button is pressed.
+- (void)dismissQRScannerView:(id)sender;
+// Called when the torch button is pressed.
+- (void)toggleTorch:(id)sender;
+
+@end
+
+// The view rendering the QR Scanner UI. The view contains the camera preview,
+// a semi-transparent overlay with a transparent viewport, border around the
+// viewport, the close and flash controls, and a label instructing the user to
+// correctly position the scanned code.
+@interface QRScannerView : UIView
+
+// The delegate which receives button events.
+@property(nonatomic, assign) id<QRScannerViewDelegate> delegate;
+
+- (instancetype)initWithFrame:(CGRect)frame
+                     delegate:(id<QRScannerViewDelegate>)delegate
+    NS_DESIGNATED_INITIALIZER;
+
+- (instancetype)initWithFrame:(CGRect)frame NS_UNAVAILABLE;
+
+- (instancetype)initWithCoder:(NSCoder*)coder NS_UNAVAILABLE;
+
+// Returns the displayed preview layer.
+- (AVCaptureVideoPreviewLayer*)getPreviewLayer;
+
+// Sets the state of the torch button to enabled or disabled according to the
+// value of |torchIsAvailable|.
+- (void)enableTorchButton:(BOOL)torchIsAvailable;
+
+// Sets the torch button icon to on or off based on the value of |torchIsOn|.
+- (void)setTorchButtonTo:(BOOL)torchIsOn;
+
+// Resets the frame of the preview layer to a CGRect with origin (0, 0) and
+// size equal to |size|.
+- (void)resetPreviewFrame:(CGSize)size;
+
+// Rotates the preview layer by |angle|. Used for a transform which prevents the
+// preview layer from rotating with the rest of the interface.
+- (void)rotatePreviewByAngle:(CGFloat)angle;
+
+// Rounds the parameters of the preview layer's transform.
+- (void)finishPreviewRotation;
+
+// Returns the rectangle in camera coordinates in which codes should be
+// recognized.
+- (CGRect)viewportRectOfInterest;
+
+// Display a flash animation when a result is scanned.
+- (void)animateScanningResultWithCompletion:(void (^)(void))completion;
+
+@end
+
+#endif  // IOS_CHROME_BROWSER_UI_QR_SCANNER_QR_SCANNER_VIEW_H_