// Copyright 2020 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#import "ios/web/web_state/ui/crw_context_menu_controller.h"
#import "base/values.h"
#import "ios/web/common/crw_viewport_adjustment.h"
#import "ios/web/common/crw_viewport_adjustment_container.h"
#import "ios/web/common/features.h"
#import "ios/web/js_features/context_menu/context_menu_params_utils.h"
#import "ios/web/public/ui/context_menu_params.h"
#import "ios/web/public/web_state.h"
#import "ios/web/public/web_state_delegate.h"
#import "ios/web/web_state/ui/crw_context_menu_element_fetcher.h"
#import "ui/gfx/geometry/rect_f.h"
#import "ui/gfx/image/image.h"
namespace {
const CGFloat kJavaScriptTimeout = 1;
// Wrapper around CFRunLoop() to help crash server put all crashes happening
// while the loop is executed in the same bucket. Marked as `noinline` to
// prevent clang from optimising the function out in official builds.
void __attribute__((noinline)) ContextMenuNestedCFRunLoop() {
CFRunLoopRun();
}
} // namespace
@interface CRWContextMenuController () <UIContextMenuInteractionDelegate>
// The context menu responsible for the interaction.
@property(nonatomic, strong) UIContextMenuInteraction* contextMenu;
// View used to do the highlight/dismiss animation.
@property(nonatomic, strong) UIImageView* screenshotView;
@property(nonatomic, strong) WKWebView* webView;
@property(nonatomic, assign) web::WebState* webState;
@property(nonatomic, strong) CRWContextMenuElementFetcher* elementFetcher;
@end
@implementation CRWContextMenuController
@synthesize screenshotView = _screenshotView;
- (instancetype)initWithWebView:(WKWebView*)webView
webState:(web::WebState*)webState
containerView:(UIView*)containerView {
self = [super init];
if (self) {
_contextMenu = [[UIContextMenuInteraction alloc] initWithDelegate:self];
_webView = webView;
// Do not add the interaction to the WKWebView itself as this may interfer
// with the JS touch event. see crbug/351696381.
[containerView addInteraction:_contextMenu];
_webState = webState;
_elementFetcher =
[[CRWContextMenuElementFetcher alloc] initWithWebView:webView
webState:webState];
}
return self;
}
#pragma mark - Property
- (UIImageView*)screenshotView {
if (!_screenshotView) {
// If the views have a CGRectZero size, it is not taken into account.
CGRect rectSizedOne = CGRectMake(0, 0, 1, 1);
_screenshotView = [[UIImageView alloc] initWithFrame:rectSizedOne];
_screenshotView.backgroundColor = UIColor.clearColor;
}
return _screenshotView;
}
- (void)setScreenshotView:(UIImageView*)screenshotView {
if (_screenshotView.superview) {
[_screenshotView removeFromSuperview];
}
_screenshotView = screenshotView;
}
#pragma mark - UIContextMenuInteractionDelegate
- (UIContextMenuConfiguration*)contextMenuInteraction:
(UIContextMenuInteraction*)interaction
configurationForMenuAtLocation:(CGPoint)location {
CGPoint locationInWebView =
[self.webView.scrollView convertPoint:location fromView:interaction.view];
locationInWebView.x /= self.webView.scrollView.zoomScale;
locationInWebView.y /= self.webView.scrollView.zoomScale;
std::optional<web::ContextMenuParams> optionalParams =
[self fetchContextMenuParamsAtLocation:locationInWebView];
if (!optionalParams.has_value()) {
return nil;
}
web::ContextMenuParams params = optionalParams.value();
self.screenshotView.center = location;
// Adding the screenshotView here so they can be used in the
// delegate's methods. Will be removed if no menu is presented.
[interaction.view addSubview:self.screenshotView];
params.location = [self.webView convertPoint:location
fromView:interaction.view];
__block UIContextMenuConfiguration* configuration = nil;
if (self.webState && self.webState->GetDelegate()) {
self.webState->GetDelegate()->ContextMenuConfiguration(
self.webState, params, ^(UIContextMenuConfiguration* conf) {
configuration = conf;
});
}
if (configuration) {
// User long pressed on a link or an image. Cancelling all touches will
// intentionally suppress system context menu UI. See crbug.com/1250352.
[self cancelAllTouches];
} else {
[self.screenshotView removeFromSuperview];
}
return configuration;
}
- (UITargetedPreview*)contextMenuInteraction:
(UIContextMenuInteraction*)interaction
previewForHighlightingMenuWithConfiguration:
(UIContextMenuConfiguration*)configuration {
UIPreviewParameters* previewParameters = [[UIPreviewParameters alloc] init];
previewParameters.backgroundColor = UIColor.clearColor;
// If the preview view is not attached to the view hierarchy, fallback to nil
// to prevent app crashing. See crbug.com/1351669.
UITargetedPreview* targetPreview =
self.screenshotView.window
? [[UITargetedPreview alloc] initWithView:self.screenshotView
parameters:previewParameters]
: nil;
return targetPreview;
}
- (UITargetedPreview*)contextMenuInteraction:
(UIContextMenuInteraction*)interaction
previewForDismissingMenuWithConfiguration:
(UIContextMenuConfiguration*)configuration {
UIPreviewParameters* previewParameters = [[UIPreviewParameters alloc] init];
previewParameters.backgroundColor = UIColor.clearColor;
// If the dismiss view is not attached to the view hierarchy, fallback to nil
// to prevent app crashing. See crbug.com/1231888.
UITargetedPreview* targetPreview =
self.screenshotView.window
? [[UITargetedPreview alloc] initWithView:self.screenshotView
parameters:previewParameters]
: nil;
self.screenshotView = nil;
return targetPreview;
}
- (void)contextMenuInteraction:(UIContextMenuInteraction*)interaction
willPerformPreviewActionForMenuWithConfiguration:
(UIContextMenuConfiguration*)configuration
animator:
(id<UIContextMenuInteractionCommitAnimating>)animator {
if (self.webState && self.webState->GetDelegate()) {
self.webState->GetDelegate()->ContextMenuWillCommitWithAnimator(
self.webState, animator);
}
}
- (void)contextMenuInteraction:(UIContextMenuInteraction*)interaction
willEndForConfiguration:(UIContextMenuConfiguration*)configuration
animator:(id<UIContextMenuInteractionAnimating>)animator {
__weak UIView* weakScreenshotView = self.screenshotView;
[animator addCompletion:^{
// Check if `self.screenshotView` has already been replaced and removed.
if (self.screenshotView && self.screenshotView == weakScreenshotView) {
[self.screenshotView removeFromSuperview];
}
}];
}
#pragma mark - Private
// Prevents the web view gesture recognizer to get the touch events.
- (void)cancelAllTouches {
// All user gestures are handled by a subview of web view scroll view
// (WKContentView).
for (UIView* subview in self.webView.scrollView.subviews) {
for (UIGestureRecognizer* recognizer in subview.gestureRecognizers) {
if (recognizer.enabled) {
recognizer.enabled = NO;
recognizer.enabled = YES;
}
}
}
}
// Fetches the context menu params for the element at `locationInWebView`. The
// returned params can be empty.
- (std::optional<web::ContextMenuParams>)fetchContextMenuParamsAtLocation:
(CGPoint)locationInWebView {
// While traditionally using dispatch_async would be used here, we have to
// instead use CFRunLoop because dispatch_async blocks the thread. As this
// function is called by iOS when it detects the user's force touch, it is on
// the main thread and we cannot block that. CFRunLoop instead just loops on
// the main thread until the completion block is fired.
__block BOOL isRunLoopNested = NO;
__block BOOL javascriptEvaluationComplete = NO;
__block BOOL isRunLoopComplete = NO;
__block std::optional<web::ContextMenuParams> resultParams;
__weak __typeof(self) weakSelf = self;
[self.elementFetcher
fetchDOMElementAtPoint:locationInWebView
completionHandler:^(const web::ContextMenuParams& params) {
javascriptEvaluationComplete = YES;
resultParams = params;
if (isRunLoopNested) {
CFRunLoopStop(CFRunLoopGetCurrent());
}
}];
// Make sure to timeout in case the JavaScript doesn't return in a timely
// manner. While this is executing, the scrolling on the page is frozen.
// Interacting with the page will force this method to return even before any
// of this code is called.
dispatch_after(dispatch_time(DISPATCH_TIME_NOW,
(int64_t)(kJavaScriptTimeout * NSEC_PER_SEC)),
dispatch_get_main_queue(), ^{
if (!isRunLoopComplete) {
// JavaScript didn't complete. Cancel the JavaScript and
// return.
CFRunLoopStop(CFRunLoopGetCurrent());
__typeof(self) strongSelf = weakSelf;
[strongSelf.elementFetcher cancelFetches];
}
});
// CFRunLoopRun isn't necessary if javascript evaluation is completed by the
// time we reach this line.
if (!javascriptEvaluationComplete) {
isRunLoopNested = YES;
ContextMenuNestedCFRunLoop();
isRunLoopNested = NO;
}
isRunLoopComplete = YES;
return resultParams;
}
@end
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