Use UIAlertController on iOS8 for Context Menu.

ui/base/ios/cru_context_menu_controller.mm

 // Copyright 2012 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 "ui/base/ios/cru_context_menu_controller.h"
 
 #include <algorithm>
 
 #include "base/ios/ios_util.h"
+#include "base/ios/weak_nsobject.h"
 #include "base/logging.h"
 #import "base/mac/scoped_nsobject.h"
-#include "base/strings/sys_string_conversions.h"
 #include "ui/base/device_form_factor.h"
 #import "ui/base/ios/cru_context_menu_holder.h"
 #include "ui/base/l10n/l10n_util.h"
-#include "ui/gfx/font_list.h"
 #import "ui/gfx/ios/NSString+CrStringDrawing.h"
-#include "ui/gfx/text_elider.h"
 #include "ui/strings/grit/ui_strings.h"
 
+namespace {
+
+// Returns the screen's height in pixels.

[lliabraa, 2015/04/23 20:06:40]

s/pixels/points/

[Eugene But (OOO till 7-30), 2015/04/23 20:59:52]

Done.

+CGFloat GetScreenHeight() {
+  DCHECK(!base::ios::IsRunningOnIOS8OrLater());
+  switch ([[UIApplication sharedApplication] statusBarOrientation]) {
+    case UIInterfaceOrientationLandscapeLeft:
+    case UIInterfaceOrientationLandscapeRight:
+      return CGRectGetWidth([[UIScreen mainScreen] applicationFrame]);
+    case UIInterfaceOrientationPortraitUpsideDown:
+    case UIInterfaceOrientationPortrait:
+    case UIInterfaceOrientationUnknown:
+      return CGRectGetHeight([[UIScreen mainScreen] applicationFrame]);
+  }
+}
+
+}  // namespace
+
+// Abstracts system implementation of popovers and action sheets.
+@protocol CRUContextMenuControllerImpl<NSObject>
+
+// Whether the context menu is visible.
+@property(nonatomic, readonly, getter=isVisible) BOOL visible;
+
+// Displays a context menu.
+- (void)showWithHolder:(CRUContextMenuHolder*)menuHolder
+               atPoint:(CGPoint)localPoint
+                inView:(UIView*)view;
+@end
+
+// Backs up CRUContextMenuController on iOS 7 by using UIActionSheet.
+@interface CRUActionSheetController
+    : NSObject<CRUContextMenuControllerImpl, UIActionSheetDelegate> {
+  // The action sheet used to display the UI.
+  base::scoped_nsobject<UIActionSheet> _sheet;
+  // Holds all the titles and actions for the menu.
+  base::scoped_nsobject<CRUContextMenuHolder> _menuHolder;
+}
+@end
+
+// Backs up CRUContextMenuController on iOS 8 and higher by using
+// UIAlertController.
+@interface CRUAlertController : NSObject<CRUContextMenuControllerImpl>
+@end
+
+// Displays a context menu. Implements Bridge pattern.
 @implementation CRUContextMenuController {
-  // Holds all the titles and actions for the menu.
-  base::scoped_nsobject<CRUContextMenuHolder> menuHolder_;
-  // The action sheet controller used to display the UI.
-  base::scoped_nsobject<UIActionSheet> sheet_;
-  // Whether the context menu is visible.
-  BOOL visible_;
-}
-
-
-// Clean up and reset for the next time.
-- (void)cleanup {
-  // iOS 8 fires multiple callbacks when a button is clicked; one round for the
-  // button that's clicked and a second round with |buttonIndex| equivalent to
-  // tapping outside the context menu. Here the sheet's delegate is reset so
-  // that only the first round of callbacks is processed.
-  // Note that iOS 8 needs the |sheet_| to stay alive so it's not reset until
-  // this CRUContextMenuController is dealloc'd.
-  [sheet_ setDelegate:nil];
-  menuHolder_.reset();
-  visible_ = NO;
-}
+  // Implementation specific for iOS version.
+  base::scoped_nsprotocol<id<CRUContextMenuControllerImpl>> _impl;
+}
+
+- (BOOL)isVisible {
+  return [_impl isVisible];
+}
+
+- (instancetype)init {
+  self = [super init];
+  if (self) {
+    if (base::ios::IsRunningOnIOS8OrLater()) {
+      _impl.reset([[CRUAlertController alloc] init]);
+    } else {
+      _impl.reset([[CRUActionSheetController alloc] init]);
+    }
+  }
+  return self;
+}
+
+- (void)showWithHolder:(CRUContextMenuHolder*)menuHolder
+               atPoint:(CGPoint)point
+                inView:(UIView*)view {
+  DCHECK(menuHolder.itemCount);
+  // Check that the view is still visible on screen, otherwise just return and
+  // don't show the context menu.
+  DCHECK([view window] || [view isKindOfClass:[UIWindow class]]);
+  if (![view window] && ![view isKindOfClass:[UIWindow class]])
+    return;
+  [_impl showWithHolder:menuHolder atPoint:point inView:view];
+}
+
+@end
+
+#pragma mark -
+#pragma mark iOS 7
+
+@implementation CRUActionSheetController
+@synthesize visible = _visible;
 
 - (void)dealloc {
-  if (visible_) {
-    // Context menu must be dismissed explicitly if it is still visible at this
-    // stage.
-    NSUInteger cancelButtonIndex = [menuHolder_ itemCount];
-    [sheet_ dismissWithClickedButtonIndex:cancelButtonIndex animated:NO];
-  }
-  sheet_.reset();
+  if (_visible) {
+    // Context menu must be dismissed explicitly if it is still visible.
+    NSUInteger cancelButtonIndex = [_menuHolder itemCount];
+    [_sheet dismissWithClickedButtonIndex:cancelButtonIndex animated:NO];
+  }
   [super dealloc];
 }
 
-- (BOOL)isVisible {
-  return visible_;
-}
+- (void)showWithHolder:(CRUContextMenuHolder*)menuHolder
+               atPoint:(CGPoint)point
+                inView:(UIView*)view {
+  // If the content of UIActionSheet does not fit the screen then scroll bars
+  // are added to the menu items area. If that's the case - elide the title to
+  // avoid having scrollbars for menu items.
+  CGSize spaceAvailableForTitle =
+      [self sizeForTitleThatFitsMenuWithHolder:menuHolder
+                                       atPoint:point
+                                        inView:view];
+  NSString* menuTitle = menuHolder.menuTitle;
+  if (menuTitle) {
+    // Show at least one line of text, even if that means the action sheet's
+    // items will need to scroll.
+    const CGFloat kMinimumVerticalSpace = 21;
+    spaceAvailableForTitle.height =
+        std::max(kMinimumVerticalSpace, spaceAvailableForTitle.height);
+    menuTitle = [menuTitle cr_stringByElidingToFitSize:spaceAvailableForTitle];
+  }
+
+  // Present UIActionSheet.
+  _sheet.reset(
+      [self newActionSheetWithHolder:menuHolder title:menuTitle delegate:self]);
+  [_sheet setCancelButtonIndex:menuHolder.itemCount];
+  [_sheet showFromRect:CGRectMake(point.x, point.y, 1.0, 1.0)
+                inView:view
+              animated:YES];
+
+  _menuHolder.reset([menuHolder retain]);
+  _visible = YES;
+}
+
+#pragma mark Implementation
+
+// Returns an approximation of the free space available for the title of an
+// actionSheet filled with |menu| shown in |view| at |point|.
+- (CGSize)sizeForTitleThatFitsMenuWithHolder:(CRUContextMenuHolder*)menuHolder
+                                     atPoint:(CGPoint)point
+                                      inView:(UIView*)view {
+  // Create a dummy UIActionSheet.
+  base::scoped_nsobject<UIActionSheet> dummySheet(
+      [self newActionSheetWithHolder:menuHolder title:nil delegate:nil]);
+  // Temporarily add the dummy UIActionSheet to |view|.
+  [dummySheet showFromRect:CGRectMake(point.x, point.y, 1.0, 1.0)
+                    inView:view
+                  animated:NO];
+  // On iPad the actionsheet is positioned under or over |point| (as opposed
+  // to next to it) when the user clicks within approximately 200 points of
+  // respectively the top or bottom edge. This reduces the amount of vertical
+  // space available for the title, hence the large padding on ipad.
+  const CGFloat kPaddingiPad = 200;
+  const CGFloat kPaddingiPhone = 20;
+  BOOL isIPad = ui::GetDeviceFormFactor() == ui::DEVICE_FORM_FACTOR_TABLET;
+  const CGFloat padding = isIPad ? kPaddingiPad : kPaddingiPhone;
+  // A title uses the full width of the actionsheet and all the vertical
+  // space on the screen.
+  CGSize result = CGSizeMake(
+      CGRectGetWidth([dummySheet frame]),
+      GetScreenHeight() - CGRectGetHeight([dummySheet frame]) - padding);
+  [dummySheet dismissWithClickedButtonIndex:0 animated:NO];
+  return result;
+}
+
+// Returns an UIActionSheet. Callers responsible for releasing returned object.
+- (UIActionSheet*)newActionSheetWithHolder:(CRUContextMenuHolder*)menuHolder
+                                     title:(NSString*)title
+                                  delegate:(id<UIActionSheetDelegate>)delegate {
+  UIActionSheet* sheet = [[UIActionSheet alloc] initWithTitle:title
+                                                     delegate:delegate
+                                            cancelButtonTitle:nil
+                                       destructiveButtonTitle:nil
+                                            otherButtonTitles:nil];
+
+  for (NSString* itemTitle in menuHolder.itemTitles) {
+    [sheet addButtonWithTitle:itemTitle];
+  }
+  [sheet addButtonWithTitle:l10n_util::GetNSString(IDS_APP_CANCEL)];
+  return sheet;
+}
+
+#pragma mark UIActionSheetDelegate
 
 // Called when the action sheet is dismissed in the modal context menu sheet.
 // There is no way to dismiss the sheet without going through this method. Note
 // that on iPad this method is called with the index of an nonexistent cancel
 // button when the user taps outside the sheet.
 - (void)actionSheet:(UIActionSheet*)actionSheet
     didDismissWithButtonIndex:(NSInteger)buttonIndex {
-  // On iOS 8, if the user taps an item in the context menu, then taps outside
-  // the context menu, the |buttonIndex| passed into this method may be
-  // different from the |buttonIndex| passed into
-  // |actionsheet:willDismissWithButtonIndex:|. See crbug.com/411894.
-  NSUInteger buttonIndexU = buttonIndex;
+  NSUInteger unsignedButtonIndex = buttonIndex;
   // Assumes "cancel" button is last in order.
-  if (buttonIndexU < [menuHolder_ itemCount])
-    [menuHolder_ performActionAtIndex:buttonIndexU];
-  [self cleanup];
+  if (unsignedButtonIndex < [_menuHolder itemCount])
+    [_menuHolder performActionAtIndex:unsignedButtonIndex];
+  _menuHolder.reset();
+  _visible = NO;
 }
 
 // Called when the user chooses a button in the modal context menu sheet. Note
 // that on iPad this method is called with the index of an nonexistent cancel
 // button when the user taps outside the sheet.
 - (void)actionSheet:(UIActionSheet*)actionSheet
     clickedButtonAtIndex:(NSInteger)buttonIndex {
   // Some use cases (e.g. opening a new tab on handset) should not wait for the
   // action sheet to animate away before executing the action.
-  if ([menuHolder_ shouldDismissImmediatelyOnClickedAtIndex:buttonIndex]) {
-    [sheet_ dismissWithClickedButtonIndex:buttonIndex animated:NO];
-  }
-}
+  if ([_menuHolder shouldDismissImmediatelyOnClickedAtIndex:buttonIndex]) {
+    [_sheet dismissWithClickedButtonIndex:buttonIndex animated:NO];
+  }
+}
+
+@end
 
 #pragma mark -
-#pragma mark WebContextMenuDelegate methods
-
-// Displays a menu using a sheet with the given title.
-- (void)showWithHolder:(CRUContextMenuHolder*)menuHolder
-               atPoint:(CGPoint)localPoint
+#pragma mark iOS8 and higher
+
+@implementation CRUAlertController
+@synthesize visible = _visible;
+
+- (CGSize)sizeForTitleThatFitsMenuWithHolder:(CRUContextMenuHolder*)menuHolder
+                                     atPoint:(CGPoint)point
+                                      inView:(UIView*)view {
+  // On presenting and dismissing a dummy UIAlertController flushes a screen.
+  // As a workaround return an estimation of the space available depending
+  // on the device's type.
+  const CGFloat kAvailableWidth = 320;
+  const CGFloat kAvailableHeightTablet = 200;
+  const CGFloat kAvailableHeightPhone = 100;
+  if (ui::GetDeviceFormFactor() == ui::DEVICE_FORM_FACTOR_TABLET) {
+    return CGSizeMake(kAvailableWidth, kAvailableHeightTablet);
+  }
+  return CGSizeMake(kAvailableWidth, kAvailableHeightPhone);
+}
+
+- (void)showWithHolder:(CRUContextMenuHolder*)menuHolder
+               atPoint:(CGPoint)point
                 inView:(UIView*)view {
-  DCHECK([menuHolder itemCount]);
-  menuHolder_.reset([menuHolder retain]);
-  // Check that the view is still visible on screen, otherwise just return and
-  // don't show the context menu.
-  DCHECK([view window] || [view isKindOfClass:[UIWindow class]]);
-  if (![view window] && ![view isKindOfClass:[UIWindow class]])
-    return;
-  CGSize spaceAvailableForTitle =
-      [CRUContextMenuController
-          availableSpaceForTitleInActionSheetWithMenu:menuHolder_
-                                              atPoint:localPoint
-                                               inView:view];
-  NSString* title = menuHolder.menuTitle;
-  if (title) {
-    // Show at least one line of text, even if that means the UIActionSheet's
-    // items will need to scroll.
-    const CGFloat kMinimumVerticalSpace = 21;
-    spaceAvailableForTitle.height =
-        std::max(kMinimumVerticalSpace, spaceAvailableForTitle.height);
-    title = [title cr_stringByElidingToFitSize:spaceAvailableForTitle];
-  }
-  // Create the sheet.
-  sheet_.reset(
-      [[UIActionSheet alloc] initWithTitle:title
-                                  delegate:self
-                         cancelButtonTitle:nil
-                    destructiveButtonTitle:nil
-                         otherButtonTitles:nil]);
-  // Add the labels, in order, to the sheet.
-  for (NSString* label in [menuHolder_ itemTitles]) {
-    [sheet_ addButtonWithTitle:label];
-  }
+  UIAlertController* alert = [UIAlertController
+      alertControllerWithTitle:menuHolder.menuTitle
+                       message:nil
+                preferredStyle:UIAlertControllerStyleActionSheet];
+  alert.popoverPresentationController.sourceView = view;
+  alert.popoverPresentationController.sourceRect =
+      CGRectMake(point.x, point.y, 1.0, 1.0);
+
+  // Add the actions.
+  base::WeakNSObject<CRUAlertController> weakSelf(self);
+  [menuHolder.itemTitles enumerateObjectsUsingBlock:^(NSString* itemTitle,
+                                                      NSUInteger itemIndex,
+                                                      BOOL*) {
+    void (^actionHandler)(UIAlertAction*) = ^(UIAlertAction* action) {
+      [menuHolder performActionAtIndex:itemIndex];
+      weakSelf.get()->_visible = NO;
+    };
+    [alert addAction:[UIAlertAction actionWithTitle:itemTitle
+                                              style:UIAlertActionStyleDefault
+                                            handler:actionHandler]];
+  }];
+
   // Cancel button goes last, to match other browsers.
-  [sheet_ addButtonWithTitle:l10n_util::GetNSString(IDS_APP_CANCEL)];
-  [sheet_ setCancelButtonIndex:[menuHolder_ itemCount]];
-  [sheet_ showFromRect:CGRectMake(localPoint.x, localPoint.y, 1.0, 1.0)
-                inView:view
-              animated:YES];
-
-  visible_ = YES;
-}
-
-// Returns an approximation of the free space available for the title of an
-// actionSheet filled with |menu| shown in |view| at |point|.
-+ (CGSize)
-    availableSpaceForTitleInActionSheetWithMenu:(CRUContextMenuHolder*)menu
-                                        atPoint:(CGPoint)point
-                                         inView:(UIView*)view {
-  BOOL isIpad = ui::GetDeviceFormFactor() == ui::DEVICE_FORM_FACTOR_TABLET;
-  if (base::ios::IsRunningOnIOS8OrLater()) {
-    // On iOS8 presenting and dismissing a dummy UIActionSheet does not work
-    // (http://crbug.com/392245 and rdar://17677745).
-    // As a workaround we return an estimation of the space available depending
-    // on the device's type.
-    const CGFloat kAvailableWidth = 320;
-    const CGFloat kAvailableHeightTablet = 200;
-    const CGFloat kAvailableHeightPhone = 100;
-    if (isIpad) {
-      return CGSizeMake(kAvailableWidth, kAvailableHeightTablet);
-    }
-    return CGSizeMake(kAvailableWidth, kAvailableHeightPhone);
-  } else {
-    // Creates a dummy UIActionSheet.
-    base::scoped_nsobject<UIActionSheet> dummyActionSheet(
-        [[UIActionSheet alloc] initWithTitle:nil
-                                    delegate:nil
-                           cancelButtonTitle:nil
-                      destructiveButtonTitle:nil
-                           otherButtonTitles:nil]);
-    for (NSString* label in [menu itemTitles]) {
-      [dummyActionSheet addButtonWithTitle:label];
-    }
-    [dummyActionSheet addButtonWithTitle:
-        l10n_util::GetNSString(IDS_APP_CANCEL)];
-    // Temporarily adds the dummy UIActionSheet to |view|.
-    [dummyActionSheet showFromRect:CGRectMake(point.x, point.y, 1.0, 1.0)
-                            inView:view
-                          animated:NO];
-    // On iPad the actionsheet is positioned under or over |point| (as opposed
-    // to next to it) when the user clicks within approximately 200 points of
-    // respectively the top or bottom edge. This reduces the amount of vertical
-    // space available for the title, hence the large padding on ipad.
-    const int kPaddingiPad = 200;
-    const int kPaddingiPhone = 20;
-    CGFloat padding = isIpad ? kPaddingiPad : kPaddingiPhone;
-    // A title uses the full width of the actionsheet and all the vertical
-    // space on the screen.
-    CGSize availableSpaceForTitle =
-        CGSizeMake([dummyActionSheet frame].size.width,
-            [CRUContextMenuController screenHeight] -
-            [dummyActionSheet frame].size.height -
-            padding);
-    [dummyActionSheet dismissWithClickedButtonIndex:0 animated:NO];
-    return availableSpaceForTitle;
-  }
-}
-
-// Returns the screen's height in pixels.
-+ (int)screenHeight {
-  DCHECK(!base::ios::IsRunningOnIOS8OrLater());
-  switch ([[UIApplication sharedApplication] statusBarOrientation]) {
-    case UIInterfaceOrientationLandscapeLeft:
-    case UIInterfaceOrientationLandscapeRight:
-      return [[UIScreen mainScreen] applicationFrame].size.width;
-    case UIInterfaceOrientationPortraitUpsideDown:
-    case UIInterfaceOrientationPortrait:
-    case UIInterfaceOrientationUnknown:
-      return [[UIScreen mainScreen] applicationFrame].size.height;
-  }
-}
-
-@end
-
-@implementation CRUContextMenuController (UsedForTesting)
-- (UIActionSheet*)sheet {
-  return sheet_.get();
-}
-@end
+  UIAlertAction* cancel_action =
+      [UIAlertAction actionWithTitle:l10n_util::GetNSString(IDS_APP_CANCEL)
+                               style:UIAlertActionStyleCancel
+                             handler:nil];
+  [alert addAction:cancel_action];
+
+  // Present sheet/popover using controller that is added to view hierarchy.
+  UIViewController* topController = view.window.rootViewController;
+  while (topController.presentedViewController)
+    topController = topController.presentedViewController;
+  [topController presentViewController:alert
+                              animated:YES
+                            completion:^{
+                              weakSelf.get()->_visible = YES;
+                            }];
+}
+
+@end