Upstream Chrome on iOS source code [7/11].

ios/chrome/browser/ui/reader_mode/reader_mode_controller.mm

+// Copyright 2015 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.
+
+#import "ios/chrome/browser/ui/reader_mode/reader_mode_controller.h"
+
+#include <memory>
+#include <utility>
+
+#include "base/ios/weak_nsobject.h"
+#include "base/mac/bind_objc_block.h"
+#include "base/mac/scoped_nsobject.h"
+#include "base/memory/ptr_util.h"
+#include "base/strings/sys_string_conversions.h"
+#include "components/infobars/core/infobar.h"
+#include "components/infobars/core/infobar_manager.h"
+#include "ios/chrome/browser/browser_state/chrome_browser_state.h"
+#include "ios/chrome/browser/dom_distiller/distiller_viewer.h"
+#include "ios/chrome/browser/dom_distiller/dom_distiller_service_factory.h"
+#include "ios/chrome/browser/infobars/infobar_manager_impl.h"
+#import "ios/chrome/browser/ui/reader_mode/reader_mode_checker.h"
+#import "ios/chrome/browser/ui/reader_mode/reader_mode_infobar_delegate.h"
+#import "ios/chrome/browser/ui/reader_mode/reader_mode_view.h"
+#include "ios/web/public/browser_state.h"
+#include "ios/web/public/web_state/web_state.h"
+
+@protocol ReaderModeCheckerObserverBridgeProtocol
+- (void)pageIsDistillable;
+@end
+
+@protocol InfoBarManagerObserverBridgeProtocol
+- (void)infoBarRemoved:(infobars::InfoBar*)infobar;
+@end
+
+namespace {
+// Used to find the ReaderModeView in the view hierarchy.
+const NSInteger kReaderModeViewTag = 42;
+const CGFloat kReaderModeAnimationDuration = .5;
+
+class ReaderModeCheckerObserverBridge : ReaderModeCheckerObserver {
+ public:
+  ReaderModeCheckerObserverBridge(
+      ReaderModeChecker* readerModeChecker,
+      id<ReaderModeCheckerObserverBridgeProtocol> observer)
+      : ReaderModeCheckerObserver(readerModeChecker), observer_(observer) {
+    DCHECK(observer);
+  };
+
+  void PageIsDistillable() override { [observer_ pageIsDistillable]; };
+
+ private:
+  id<ReaderModeCheckerObserverBridgeProtocol> observer_;
+};
+
+class InfoBarManagerObserverBridge : infobars::InfoBarManager::Observer {
+ public:
+  InfoBarManagerObserverBridge(
+      infobars::InfoBarManager* infoBarManager,
+      id<InfoBarManagerObserverBridgeProtocol> observer)
+      : infobars::InfoBarManager::Observer(),
+        manager_(infoBarManager),
+        observer_(observer) {
+    DCHECK(infoBarManager);
+    DCHECK(observer);
+    manager_->AddObserver(this);
+  };
+
+  ~InfoBarManagerObserverBridge() override {
+    if (manager_)
+      manager_->RemoveObserver(this);
+  }
+
+  void OnInfoBarRemoved(infobars::InfoBar* infobar, bool animate) override {
+    [observer_ infoBarRemoved:infobar];
+  }
+
+  void OnManagerShuttingDown(infobars::InfoBarManager* manager) override {
+    manager_->RemoveObserver(this);
+    manager_ = nullptr;
+  }
+
+ private:
+  infobars::InfoBarManager* manager_;
+  id<InfoBarManagerObserverBridgeProtocol> observer_;
+};
+}  // namespace
+
+@interface ReaderModeController ()<ReaderModeViewDelegate,
+                                   ReaderModeCheckerObserverBridgeProtocol,
+                                   InfoBarManagerObserverBridgeProtocol> {
+  std::unique_ptr<ReaderModeChecker> _checker;
+  std::unique_ptr<ReaderModeCheckerObserverBridge> _checkerBridge;
+  std::unique_ptr<InfoBarManagerObserverBridge> _infoBarBridge;
+  std::unique_ptr<dom_distiller::DistillerViewer> _viewer;
+  // The currently displayed infobar.
+  infobars::InfoBar* infobar_;
+  web::WebState* _webState;
+}
+@property(readonly, nonatomic) id<ReaderModeControllerDelegate> delegate;
+
+// Triggers a distillation and returns a DistillerViewer to keep as a handle to
+// the running distillation.
+- (std::unique_ptr<dom_distiller::DistillerViewer>)startDistillation
+    WARN_UNUSED_RESULT;
+- (void)distillationFinished:(const std::string&)html forURL:(const GURL&)url;
+
+// Returns a ReaderModeView that presents a waiting UI while the distillation
+// is taking place. Releasing this view will stop the distillation in progress.
+- (ReaderModeView*)readerModeViewWithFrame:(CGRect)frame;
+
+- (void)showInfoBar:(const std::string&)html forURL:(const GURL&)url;
+- (void)removeInfoBar;
+
+@end
+
+@implementation ReaderModeController
+@synthesize delegate = _delegate;
+
+- (instancetype)initWithWebState:(web::WebState*)webState
+                        delegate:(id<ReaderModeControllerDelegate>)delegate {
+  DCHECK(webState);
+  self = [super init];
+  if (self) {
+    _webState = webState;
+    _checker = base::MakeUnique<ReaderModeChecker>(_webState);
+    _delegate = delegate;
+    _checkerBridge =
+        base::MakeUnique<ReaderModeCheckerObserverBridge>(_checker.get(), self);
+    infobars::InfoBarManager* infobar_manager =
+        InfoBarManagerImpl::FromWebState(_webState);
+    _infoBarBridge =
+        base::MakeUnique<InfoBarManagerObserverBridge>(infobar_manager, self);
+  }
+  return self;
+}
+
+- (instancetype)init {
+  NOTREACHED();
+  return nil;
+}
+
+- (void)dealloc {
+  if (_webState)
+    [self detachFromWebState];
+  [super dealloc];
+}
+
+- (void)detachFromWebState {
+  [self removeInfoBar];
+  _webState = nullptr;
+}
+
+// Property accessor.
+- (ReaderModeChecker*)checker {
+  return _checker.get();
+}
+
+#pragma mark - Private methods.
+#pragma mark distillation
+
+- (std::unique_ptr<dom_distiller::DistillerViewer>)startDistillation {
+  DCHECK(_webState);
+  base::WeakNSObject<ReaderModeController> weakSelf(self);
+  GURL pageURL = _webState->GetLastCommittedURL();
+  ios::ChromeBrowserState* browserState =
+      ios::ChromeBrowserState::FromBrowserState(_webState->GetBrowserState());
+  return base::MakeUnique<dom_distiller::DistillerViewer>(
+      dom_distiller::DomDistillerServiceFactory::GetForBrowserState(
+          browserState),
+      browserState->GetPrefs(), pageURL,
+      base::BindBlock(^(
+          const GURL& pageURL, const std::string& html,
+          const std::vector<dom_distiller::DistillerViewer::ImageInfo>& images,
+          const std::string& title) {
+        [weakSelf distillationFinished:html forURL:pageURL];
+      }));
+}
+
+- (void)distillationFinished:(const std::string&)html forURL:(const GURL&)url {
+  UIView* superview = [self.delegate superviewForReaderModePanel];
+  DCHECK(_viewer || [superview viewWithTag:kReaderModeViewTag]);
+  if ([superview viewWithTag:kReaderModeViewTag]) {
+    [self.delegate loadReaderModeHTML:base::SysUTF8ToNSString(html) forURL:url];
+  } else if (_viewer) {
+    [self showInfoBar:html forURL:url];
+  }
+}
+
+#pragma mark view creation
+
+- (ReaderModeView*)readerModeViewWithFrame:(CGRect)frame {
+  DCHECK(_checker->CanSwitchToReaderMode());
+  ReaderModeView* view =
+      [[[ReaderModeView alloc] initWithFrame:frame delegate:self] autorelease];
+  [view assignDistillerViewer:[self startDistillation]];
+  return view;
+}
+
+#pragma mark infobar.
+
+- (void)showInfoBar:(const std::string&)html forURL:(const GURL&)url {
+  DCHECK(_webState);
+  base::WeakNSProtocol<id<ReaderModeControllerDelegate>> weakDelegate(
+      self.delegate);
+
+  // Non reference version of the variables needed.
+  const std::string html_non_ref(html);
+  const GURL url_non_ref(url);
+  auto infoBarDelegate =
+      base::MakeUnique<ReaderModeInfoBarDelegate>(base::BindBlock(^{
+        [weakDelegate loadReaderModeHTML:base::SysUTF8ToNSString(html_non_ref)
+                                  forURL:url_non_ref];
+      }));
+
+  infobars::InfoBarManager* infobar_manager =
+      InfoBarManagerImpl::FromWebState(_webState);
+
+  std::unique_ptr<infobars::InfoBar> infobar =
+      infobar_manager->CreateConfirmInfoBar(std::move(infoBarDelegate));
+  if (infobar_)
+    infobar_ = infobar_manager->ReplaceInfoBar(infobar_, std::move(infobar));
+  else
+    infobar_ = infobar_manager->AddInfoBar(std::move(infobar));
+}
+
+- (void)removeInfoBar {
+  DCHECK(_webState);
+  if (infobar_) {
+    infobars::InfoBarManager* infobar_manager =
+        InfoBarManagerImpl::FromWebState(_webState);
+    infobar_manager->RemoveInfoBar(infobar_);
+    infobar_ = nullptr;
+  }
+}
+
+#pragma mark - public methods.
+
+- (void)switchToReaderMode {
+  UIView* superview = [self.delegate superviewForReaderModePanel];
+  if ([superview viewWithTag:kReaderModeViewTag])
+    return;  // There is already a reader mode waiting view visible.
+
+  [self removeInfoBar];
+
+  // Get the view.
+  ReaderModeView* readerView = [self readerModeViewWithFrame:superview.bounds];
+  readerView.tag = kReaderModeViewTag;
+  [superview addSubview:readerView];
+
+  // Animate the view in. First the view is animated in (via transparency) and
+  // the the animation on the view itself is started.
+  readerView.alpha = 0.0;
+
+  [UIView animateWithDuration:kReaderModeAnimationDuration
+      delay:0.0
+      options:UIViewAnimationOptionCurveEaseIn
+      animations:^{
+        readerView.alpha = 1.0;
+      }
+      completion:^(BOOL finished) {
+        if (finished)
+          [readerView start];  // Starts the waiting animation on the view.
+      }];
+}
+
+#pragma mark - ReaderModeViewDelegate.
+
+- (void)exitReaderMode {
+  UIView* superview = [self.delegate superviewForReaderModePanel];
+  if (![superview viewWithTag:kReaderModeViewTag]) {
+    DCHECK(_viewer);
+    return;
+  }
+
+  ReaderModeView* readerView =
+      static_cast<ReaderModeView*>([superview viewWithTag:kReaderModeViewTag]);
+  if (!readerView)
+    return;
+
+  // First stop the view waiting animation (if any) and then remove the view.
+  [readerView stopWaitingWithCompletion:^{
+    [UIView animateWithDuration:kReaderModeAnimationDuration
+        delay:0.0
+        options:UIViewAnimationOptionCurveEaseIn
+        animations:^{
+          readerView.alpha = 0.0;
+        }
+        completion:^(BOOL finished) {
+          [readerView removeFromSuperview];
+        }];
+  }];
+}
+
+#pragma mark - ReaderModeCheckerObserverBridgeProtocol
+
+- (void)pageIsDistillable {
+  _viewer = [self startDistillation];
+}
+
+#pragma mark - InfoBarManagerObserverBridgeProtocol.
+
+- (void)infoBarRemoved:(infobars::InfoBar*)infobar {
+  if (infobar == infobar_) {
+    _viewer.reset();
+    infobar_ = nullptr;
+  }
+}
+
+@end