content/app_shim_remote_cocoa/web_contents_view_cocoa.mm

// Copyright 2018 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 "content/app_shim_remote_cocoa/web_contents_view_cocoa.h"

#import "base/mac/mac_util.h"
#import "content/app_shim_remote_cocoa/web_drag_source_mac.h"
#import "content/browser/web_contents/web_drag_dest_mac.h"
#include "content/common/web_contents_ns_view_bridge.mojom.h"
#import "third_party/mozilla/NSPasteboard+Utils.h"
#include "ui/base/clipboard/clipboard_constants.h"
#include "ui/base/clipboard/custom_data_helper.h"
#include "ui/base/cocoa/cocoa_base_utils.h"
#include "ui/base/dragdrop/cocoa_dnd_util.h"
#include "ui/base/dragdrop/drag_drop_types.h"

using remote_cocoa::mojom::DraggingInfo;
using remote_cocoa::mojom::SelectionDirection;
using remote_cocoa::mojom::Visibility;
using content::DropData;

// Ensure that the ui::DragDropTypes::DragOperation enum values stay in sync
// with NSDragOperation constants, since the code below uses
// NSDragOperationToDragOperation to filter invalid values.
#define STATIC_ASSERT_ENUM(a, b)                            \
  static_assert(static_cast<int>(a) == static_cast<int>(b), \
                "enum mismatch: " #a)
STATIC_ASSERT_ENUM(NSDragOperationNone, ui::DragDropTypes::DRAG_NONE);
STATIC_ASSERT_ENUM(NSDragOperationCopy, ui::DragDropTypes::DRAG_COPY);
STATIC_ASSERT_ENUM(NSDragOperationLink, ui::DragDropTypes::DRAG_LINK);
STATIC_ASSERT_ENUM(NSDragOperationMove, ui::DragDropTypes::DRAG_MOVE);

////////////////////////////////////////////////////////////////////////////////
// WebContentsViewCocoa

@implementation WebContentsViewCocoa {
  BOOL _inFullScreenTransition;
}

- (id)initWithViewsHostableView:(ui::ViewsHostableView*)v {
  self = [super initWithFrame:NSZeroRect];
  if (self != nil) {
    _viewsHostableView = v;
    [self registerDragTypes];

    [[NSNotificationCenter defaultCenter]
        addObserver:self
           selector:@selector(viewDidBecomeFirstResponder:)
               name:kViewDidBecomeFirstResponder
             object:nil];
  }
  return self;
}

- (void)dealloc {
  // This probably isn't strictly necessary, but can't hurt.
  [self unregisterDraggedTypes];

  [[NSNotificationCenter defaultCenter] removeObserver:self];

  [super dealloc];
}

- (void)populateDraggingInfo:(DraggingInfo*)info
          fromNSDraggingInfo:(id<NSDraggingInfo>)nsInfo {
  NSPoint windowPoint = [nsInfo draggingLocation];

  NSPoint viewPoint = [self convertPoint:windowPoint fromView:nil];
  NSRect viewFrame = [self frame];
  info->location_in_view =
      gfx::PointF(viewPoint.x, viewFrame.size.height - viewPoint.y);

  NSPoint screenPoint =
      ui::ConvertPointFromWindowToScreen([self window], windowPoint);
  NSScreen* screen = [[self window] screen];
  NSRect screenFrame = [screen frame];
  info->location_in_screen =
      gfx::PointF(screenPoint.x, screenFrame.size.height - screenPoint.y);

  NSPasteboard* pboard = [nsInfo draggingPasteboard];
  if ([pboard containsURLDataConvertingTextToURL:YES]) {
    GURL url;
    ui::PopulateURLAndTitleFromPasteboard(&url, NULL, pboard, YES);
    info->url.emplace(url);
  }
  info->operation_mask = ui::DragDropTypes::NSDragOperationToDragOperation(
      [nsInfo draggingSourceOperationMask]);
}

- (BOOL)allowsVibrancy {
  // Returning YES will allow rendering this view with vibrancy effect if it is
  // incorporated into a view hierarchy that uses vibrancy, it will have no
  // effect otherwise.
  // For details see Apple documentation on NSView and NSVisualEffectView.
  return YES;
}

// Registers for the view for the appropriate drag types.
- (void)registerDragTypes {
  NSArray* types =
      [NSArray arrayWithObjects:ui::kChromeDragDummyPboardType,
                                kWebURLsWithTitlesPboardType, NSURLPboardType,
                                NSStringPboardType, NSHTMLPboardType,
                                NSRTFPboardType, NSFilenamesPboardType,
                                ui::kWebCustomDataPboardType, nil];
  [self registerForDraggedTypes:types];
}

- (void)mouseEvent:(NSEvent*)theEvent {
  if (!_host)
    return;
  _host->OnMouseEvent([theEvent type] == NSMouseMoved,
                      [theEvent type] == NSMouseExited);
}

- (void)setMouseDownCanMoveWindow:(BOOL)canMove {
  _mouseDownCanMoveWindow = canMove;
}

- (BOOL)mouseDownCanMoveWindow {
  // This is needed to prevent mouseDowns from moving the window
  // around. The default implementation returns YES only for opaque
  // views. WebContentsViewCocoa does not draw itself in any way, but
  // its subviews do paint their entire frames. Returning NO here
  // saves us the effort of overriding this method in every possible
  // subview.
  return _mouseDownCanMoveWindow;
}

- (void)pasteboard:(NSPasteboard*)sender provideDataForType:(NSString*)type {
  [_dragSource lazyWriteToPasteboard:sender forType:type];
}

- (void)startDragWithDropData:(const DropData&)dropData
            dragOperationMask:(NSDragOperation)operationMask
                        image:(NSImage*)image
                       offset:(NSPoint)offset {
  if (!_host)
    return;
  _dragSource.reset([[WebDragSource alloc]
           initWithHost:_host
                   view:self
               dropData:&dropData
                  image:image
                 offset:offset
             pasteboard:[NSPasteboard pasteboardWithName:NSDragPboard]
      dragOperationMask:operationMask]);
  [_dragSource startDrag];
}

// NSDraggingSource methods

- (NSDragOperation)draggingSourceOperationMaskForLocal:(BOOL)isLocal {
  if (_dragSource)
    return [_dragSource draggingSourceOperationMaskForLocal:isLocal];
  // No web drag source - this is the case for dragging a file from the
  // downloads manager. Default to copy operation. Note: It is desirable to
  // allow the user to either move or copy, but this requires additional
  // plumbing to update the download item's path once its moved.
  return NSDragOperationCopy;
}

// Called when a drag initiated in our view ends.
- (void)draggedImage:(NSImage*)anImage
             endedAt:(NSPoint)screenPoint
           operation:(NSDragOperation)operation {
  [_dragSource
      endDragAt:screenPoint
      operation:ui::DragDropTypes::NSDragOperationToDragOperation(operation)];

  // Might as well throw out this object now.
  _dragSource.reset();
}

// Called when a drag initiated in our view moves.
- (void)draggedImage:(NSImage*)draggedImage movedTo:(NSPoint)screenPoint {
}

// Called when a file drag is dropped and the promised files need to be written.
- (NSArray*)namesOfPromisedFilesDroppedAtDestination:(NSURL*)dropDest {
  if (![dropDest isFileURL])
    return nil;

  NSString* fileName = [_dragSource dragPromisedFileTo:[dropDest path]];
  if (!fileName)
    return nil;

  return @[ fileName ];
}

// NSDraggingDestination methods

- (NSDragOperation)draggingEntered:(id<NSDraggingInfo>)sender {
  if (!_host)
    return NSDragOperationNone;

  // Fill out a DropData from pasteboard.
  DropData dropData;
  content::PopulateDropDataFromPasteboard(&dropData,
                                          [sender draggingPasteboard]);
  _host->SetDropData(dropData);

  auto draggingInfo = DraggingInfo::New();
  [self populateDraggingInfo:draggingInfo.get() fromNSDraggingInfo:sender];
  uint32_t result = 0;
  _host->DraggingEntered(std::move(draggingInfo), &result);
  return result;
}

- (void)draggingExited:(id<NSDraggingInfo>)sender {
  if (!_host)
    return;
  _host->DraggingExited();
}

- (NSDragOperation)draggingUpdated:(id<NSDraggingInfo>)sender {
  if (!_host)
    return NSDragOperationNone;
  auto draggingInfo = DraggingInfo::New();
  [self populateDraggingInfo:draggingInfo.get() fromNSDraggingInfo:sender];
  uint32_t result = 0;
  _host->DraggingUpdated(std::move(draggingInfo), &result);
  return result;
}

- (BOOL)performDragOperation:(id<NSDraggingInfo>)sender {
  if (!_host)
    return NO;
  auto draggingInfo = DraggingInfo::New();
  [self populateDraggingInfo:draggingInfo.get() fromNSDraggingInfo:sender];
  bool result = false;
  _host->PerformDragOperation(std::move(draggingInfo), &result);
  return result;
}

- (void)clearViewsHostableView {
  _viewsHostableView = nullptr;
}

- (void)setHost:(remote_cocoa::mojom::WebContentsNSViewHost*)host {
  if (!host)
    [_dragSource clearHostAndWebContentsView];
  _host = host;
}

- (void)viewDidBecomeFirstResponder:(NSNotification*)notification {
  if (!_host)
    return;

  NSView* view = [notification object];
  if (![[self subviews] containsObject:view])
    return;

  NSSelectionDirection ns_direction =
      static_cast<NSSelectionDirection>([[[notification userInfo]
          objectForKey:kSelectionDirection] unsignedIntegerValue]);

  SelectionDirection direction;
  switch (ns_direction) {
    case NSDirectSelection:
      direction = SelectionDirection::kDirect;
      break;
    case NSSelectingNext:
      direction = SelectionDirection::kForward;
      break;
    case NSSelectingPrevious:
      direction = SelectionDirection::kReverse;
      break;
    default:
      return;
  }
  _host->OnBecameFirstResponder(direction);
}

- (void)updateWebContentsVisibility {
  if (!_host || _inFullScreenTransition)
    return;
  Visibility visibility = Visibility::kVisible;
  if ([self isHiddenOrHasHiddenAncestor] || ![self window])
    visibility = Visibility::kHidden;
  else if ([[self window] occlusionState] & NSWindowOcclusionStateVisible)
    visibility = Visibility::kVisible;
  else
    visibility = Visibility::kOccluded;
  _host->OnWindowVisibilityChanged(visibility);
}

- (void)resizeSubviewsWithOldSize:(NSSize)oldBoundsSize {
  // Subviews do not participate in auto layout unless the the size this view
  // changes. This allows RenderWidgetHostViewMac::SetBounds(..) to select a
  // size of the subview that differs from its superview in preparation for an
  // upcoming WebContentsView resize.
  // See http://crbug.com/264207 and http://crbug.com/655112.
}

- (void)setFrameSize:(NSSize)newSize {
  [super setFrameSize:newSize];

  // Perform manual layout of subviews, e.g., when the window size changes.
  for (NSView* subview in [self subviews])
    [subview setFrame:[self bounds]];
}

- (void)viewWillMoveToWindow:(NSWindow*)newWindow {
  NSWindow* oldWindow = [self window];
  NSNotificationCenter* notificationCenter =
      [NSNotificationCenter defaultCenter];

  if (oldWindow) {
    NSArray* notificationsToRemove = @[
      NSWindowDidChangeOcclusionStateNotification,
      NSWindowWillEnterFullScreenNotification,
      NSWindowDidEnterFullScreenNotification,
      NSWindowWillExitFullScreenNotification,
      NSWindowDidExitFullScreenNotification
    ];
    for (NSString* notificationName in notificationsToRemove) {
      [notificationCenter removeObserver:self
                                    name:notificationName
                                  object:oldWindow];
    }
  }
  if (newWindow) {
    [notificationCenter addObserver:self
                           selector:@selector(windowChangedOcclusionState:)
                               name:NSWindowDidChangeOcclusionStateNotification
                             object:newWindow];
    // The fullscreen transition causes spurious occlusion notifications.
    // See https://crbug.com/1081229
    [notificationCenter addObserver:self
                           selector:@selector(fullscreenTransitionStarted:)
                               name:NSWindowWillEnterFullScreenNotification
                             object:newWindow];
    [notificationCenter addObserver:self
                           selector:@selector(fullscreenTransitionComplete:)
                               name:NSWindowDidEnterFullScreenNotification
                             object:newWindow];
    [notificationCenter addObserver:self
                           selector:@selector(fullscreenTransitionStarted:)
                               name:NSWindowWillExitFullScreenNotification
                             object:newWindow];
    [notificationCenter addObserver:self
                           selector:@selector(fullscreenTransitionComplete:)
                               name:NSWindowDidExitFullScreenNotification
                             object:newWindow];
  }
}

- (void)windowChangedOcclusionState:(NSNotification*)notification {
  [self updateWebContentsVisibility];
}

- (void)fullscreenTransitionStarted:(NSNotification*)notification {
  _inFullScreenTransition = YES;
}

- (void)fullscreenTransitionComplete:(NSNotification*)notification {
  _inFullScreenTransition = NO;
}

- (void)viewDidMoveToWindow {
  [self updateWebContentsVisibility];
}

- (void)viewDidHide {
  [self updateWebContentsVisibility];
}

- (void)viewDidUnhide {
  [self updateWebContentsVisibility];
}

// ViewsHostable protocol implementation.
- (ui::ViewsHostableView*)viewsHostableView {
  return _viewsHostableView;
}

@end