Revert "Switch to the (old) new way of doing file promising"

This reverts commit 4278cdb.

# Conflicts:
#	content/app_shim_remote_cocoa/web_drag_source_mac.mm

content/app_shim_remote_cocoa/web_contents_view_cocoa.h

@@ -26,16 +26,17 @@ class WebContentsNSViewHost;
 @class WebDragSource;
 
 CONTENT_EXPORT
-@interface WebContentsViewCocoa
-    : BaseView <ViewsHostable, NSDraggingSource, NSDraggingDestination> {
+@interface WebContentsViewCocoa : BaseView <ViewsHostable> {
  @private
-  // Instances of this class are owned by both `_host` and AppKit. The `_host`
-  // must call `-setHost:nil` in its destructor.
+  // Instances of this class are owned by both host_ and AppKit. It is
+  // possible for an instance to outlive its webContentsView_. The host_ must
+  // call -clearHostAndView in its destructor.
   raw_ptr<remote_cocoa::mojom::WebContentsNSViewHost> _host;
 
   // The interface exported to views::Views that embed this as a sub-view.
   raw_ptr<ui::ViewsHostableView> _viewsHostableView;
 
+  base::scoped_nsobject<WebDragSource> _dragSource;
   BOOL _mouseDownCanMoveWindow;
 
   // Utility to copy screenshots to a usable directory for PWAs. This utility
@@ -44,12 +45,6 @@ CONTENT_EXPORT
   // https://crbug.com/1148078
   std::unique_ptr<remote_cocoa::DroppedScreenShotCopierMac>
       _droppedScreenShotCopier;
-
-  // Drag variables.
-  base::scoped_nsobject<WebDragSource> _dragSource;
-  NSDragOperation _dragOperation;
-  NSPoint _dragOffset;
-  CGFloat _dragImageHeight;
 }
 
 // Set or un-set the mojo interface through which to communicate with the
@@ -62,6 +57,11 @@ CONTENT_EXPORT
 // in-PWA-process instances, to limit the workaround's effect to just PWAs.
 - (void)enableDroppedScreenShotCopier;
 
+// Returns the available drag operations. This is a required method for
+// NSDraggingSource. It is supposedly deprecated, but the non-deprecated API
+// -[NSWindow dragImage:...] still relies on it.
+- (NSDragOperation)draggingSourceOperationMaskForLocal:(BOOL)isLocal;
+
 // Private interface.
 // TODO(ccameron): Document these functions.
 - (instancetype)initWithViewsHostableView:(ui::ViewsHostableView*)v;

content/app_shim_remote_cocoa/web_contents_view_cocoa.mm

@@ -22,8 +22,6 @@
 #include "ui/base/cocoa/cocoa_base_utils.h"
 #include "ui/base/dragdrop/cocoa_dnd_util.h"
 #include "ui/base/dragdrop/drag_drop_types.h"
-#include "ui/gfx/image/image.h"
-#include "ui/resources/grit/ui_resources.h"
 
 #include "base/files/file_util.h"
 #include "base/files/scoped_temp_dir.h"
@@ -33,6 +31,14 @@
 using remote_cocoa::mojom::DraggingInfo;
 using remote_cocoa::mojom::SelectionDirection;
 
+namespace {
+// Time to delay clearing the pasteboard for after a drag ends. This is
+// required because Safari requests data from multiple processes, and clearing
+// the pasteboard after the first access results in unreliable drag operations
+// (http://crbug.com/1227001).
+const int64_t kPasteboardClearDelay = 0.5 * NSEC_PER_SEC;
+}
+
 namespace remote_cocoa {
 
 // DroppedScreenShotCopierMac is a utility to copy screenshots to a usable
@@ -224,68 +230,64 @@ - (void)startDragWithDropData:(const DropData&)dropData
   [pasteboard clearContents];
 
   _dragSource.reset([[WebDragSource alloc] initWithHost:_host
-                                               dropData:dropData]);
-  NSDraggingItem* draggingItem = [[[NSDraggingItem alloc]
-      initWithPasteboardWriter:_dragSource] autorelease];
-
-  if (!image) {
-    image = content::GetContentClient()
-                ->GetNativeImageNamed(IDR_DEFAULT_FAVICON)
-                .ToNSImage();
-  }
-
-  NSRect imageRect = NSMakeRect(mouseLocation.x, mouseLocation.y,
-                                image.size.width, image.size.height);
-  imageRect.origin.x -= offset.x;
-  // Deal with Cocoa's flipped coordinate system.
-  imageRect.origin.y -= image.size.height - offset.y;
-  [draggingItem setDraggingFrame:imageRect contents:image];
-
-  _dragOperation = operationMask;
-  _dragOffset = offset;
-  _dragImageHeight = image.size.height;
-
-  // Run the drag operation.
-  [self beginDraggingSessionWithItems:@[ draggingItem ]
-                                event:dragEvent
-                               source:self];
+                                                   view:self
+                                               dropData:&dropData
+                                                  image:image
+                                                 offset:offset
+                                             pasteboard:pasteboard
+                                      dragOperationMask:operationMask]);
+  [_dragSource startDrag];
 }
 
 // NSDraggingSource methods
 
-- (NSDragOperation)draggingSession:(NSDraggingSession*)session
-    sourceOperationMaskForDraggingContext:(NSDraggingContext)context {
-  return _dragOperation;
+- (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)draggingSession:(NSDraggingSession*)session
-           endedAtPoint:(NSPoint)screenPoint
-              operation:(NSDragOperation)operation {
-  // Reconstruct the screen point by removing the offset. It seems like the
-  // underlying drag machinery is measuring from the corner of the dragged
-  // image.
-  screenPoint.x += _dragOffset.x;
-  screenPoint.y += _dragImageHeight - _dragOffset.y;
-
-  NSPoint localPoint = NSZeroPoint;
-  if (self.window) {
-    NSPoint basePoint =
-        ui::ConvertPointFromScreenToWindow(self.window, screenPoint);
-    localPoint = [self convertPoint:basePoint fromView:nil];
-  }
+- (void)draggedImage:(NSImage*)anImage
+             endedAt:(NSPoint)screenPoint
+           operation:(NSDragOperation)operation {
+  [_dragSource
+      endDragAt:screenPoint
+      operation:ui::DragDropTypes::NSDragOperationToDragOperation(operation)];
+
+  WebDragSource* currentDragSource = _dragSource.get();
+
+  dispatch_after(
+      dispatch_time(DISPATCH_TIME_NOW, (int64_t)kPasteboardClearDelay),
+      dispatch_get_main_queue(), ^{
+        if (_dragSource.get() == currentDragSource) {
+          // Clear the drag pasteboard. Even though this is called in dealloc,
+          // we need an explicit call because NSPasteboard can retain the drag
+          // source.
+          [_dragSource clearPasteboard];
+          _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;
 
-  // Flip the two points as per Cocoa's coordinate system.
-  NSRect viewFrame = self.frame;
-  NSRect screenFrame = self.window.screen.frame;
-  _host->EndDrag(
-      operation,
-      gfx::PointF(localPoint.x, viewFrame.size.height - localPoint.y),
-      gfx::PointF(screenPoint.x, screenFrame.size.height - screenPoint.y));
+  NSString* fileName = [_dragSource dragPromisedFileTo:[dropDest path]];
+  if (!fileName)
+    return nil;
 
-  // The drag is complete. Disconnect the drag source.
-  [_dragSource webContentsIsGone];
-  _dragSource.reset();
+  return @[ fileName ];
 }
 
 // NSDraggingDestination methods
@@ -344,9 +346,8 @@ - (void)clearViewsHostableView {
 }
 
 - (void)setHost:(remote_cocoa::mojom::WebContentsNSViewHost*)host {
-  if (!host) {
-    [_dragSource webContentsIsGone];
-  }
+  if (!host)
+    [_dragSource clearHostAndWebContentsView];
   _host = host;
 }
 

content/app_shim_remote_cocoa/web_drag_source_mac.h

@@ -9,11 +9,12 @@
 
 #import <Cocoa/Cocoa.h>
 
+#include <memory>
+
 #include "base/files/file_path.h"
 #include "base/mac/scoped_cftyperef.h"
 #include "base/mac/scoped_nsobject.h"
 #include "content/common/content_export.h"
-#include "content/public/common/drop_data.h"
 #include "url/gurl.h"
 
 namespace content {
@@ -26,18 +27,37 @@ class WebContentsNSViewHost;
 }  // namespace mojom
 }  // namespace remote_cocoa
 
-// A class that handles managing the data for drags from the
-// WebContentsViewCocoa.
+// A class that handles tracking and event processing for a drag and drop
+// originating from the content area.
 CONTENT_EXPORT
-@interface WebDragSource : NSObject <NSPasteboardWriting> {
+@interface WebDragSource : NSObject {
  @private
-  // The host through which to communicate with the WebContents. Owns
-  // this object. This pointer gets reset when the WebContents goes away with
-  // `webContentsIsGone`.
+  // The host through which to communicate with the WebContentsImpl. Owns
+  // |self| and resets |host_| via clearHostAndWebContentsView.
   raw_ptr<remote_cocoa::mojom::WebContentsNSViewHost> _host;
 
-  // The drop data.
-  content::DropData _dropData;
+  // The view from which the drag was initiated. Weak reference.
+  // An instance of this class may outlive |contentsView_|. The destructor of
+  // |contentsView_| must set this ivar to |nullptr|.
+  NSView* _contentsView;
+
+  // Our drop data. Should only be initialized once.
+  std::unique_ptr<content::DropData> _dropData;
+
+  // The image to show as drag image. Can be nil.
+  base::scoped_nsobject<NSImage> _dragImage;
+
+  // The offset to draw |dragImage_| at.
+  NSPoint _imageOffset;
+
+  // Our pasteboard.
+  base::scoped_nsobject<NSPasteboard> _pasteboard;
+
+  // Change count associated with this pasteboard owner change.
+  int _changeCount;
+
+  // A mask of the allowed drag operations.
+  NSDragOperation _dragOperationMask;
 
   // The file name to be saved to for a drag-out download.
   base::FilePath _downloadFileName;
@@ -49,12 +69,40 @@ CONTENT_EXPORT
   base::ScopedCFTypeRef<CFStringRef> _fileUTI;
 }
 
-// Initialize a WebDragSource object for a drag.
+// Initialize a WebDragSource object for a drag (originating on the given
+// contentsView and with the given dropData and pboard). Fill the pasteboard
+// with data types appropriate for dropData.
 - (instancetype)initWithHost:(remote_cocoa::mojom::WebContentsNSViewHost*)host
-                    dropData:(const content::DropData&)dropData;
+                        view:(NSView*)contentsView
+                    dropData:(const content::DropData*)dropData
+                       image:(NSImage*)image
+                      offset:(NSPoint)offset
+                  pasteboard:(NSPasteboard*)pboard
+           dragOperationMask:(NSDragOperation)dragOperationMask;
+
+// Call when the web contents is gone.
+- (void)clearHostAndWebContentsView;
+
+// Returns a mask of the allowed drag operations.
+- (NSDragOperation)draggingSourceOperationMaskForLocal:(BOOL)isLocal;
+
+// Start the drag (on the originally provided contentsView); can do this right
+// after -initWithContentsView:....
+- (void)startDrag;
+
+// End the drag and clear the pasteboard; hook up to
+// -draggedImage:endedAt:operation:.
+- (void)endDragAt:(NSPoint)screenPoint
+        operation:(NSDragOperation)operation;
+
+// Remove this WebDragSource as the owner of the drag pasteboard.
+- (void)clearPasteboard;
 
-// Call when the WebContents is gone.
-- (void)webContentsIsGone;
+// Call to drag a promised file to the given path (should be called before
+// -endDragAt:...); hook up to -namesOfPromisedFilesDroppedAtDestination:.
+// Returns the file name (not including path) of the file deposited (or which
+// will be deposited).
+- (NSString*)dragPromisedFileTo:(NSString*)path;
 
 @end
 

content/browser/web_contents/web_contents_view_mac_unittest.mm

@@ -0,0 +1,40 @@
+// Copyright 2012 The Chromium Authors
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#import "content/browser/web_contents/web_contents_view_mac.h"
+
+#include "base/mac/scoped_nsobject.h"
+#import "content/app_shim_remote_cocoa/web_contents_view_cocoa.h"
+#include "content/public/browser/web_contents.h"
+#include "content/public/test/test_renderer_host.h"
+#include "testing/gtest/include/gtest/gtest.h"
+#include "testing/gtest_mac.h"
+#include "testing/platform_test.h"
+#include "ui/base/test/cocoa_helper.h"
+#import "ui/base/test/cocoa_helper.h"
+
+namespace content {
+
+namespace {
+
+class WebContentsNSViewTest : public ui::CocoaTest {};
+
+}  // namespace
+
+TEST_F(WebContentsNSViewTest, NonWebDragSourceTest) {
+  // The designated initializer is private but init should be fine in this case.
+  base::scoped_nsobject<WebContentsViewCocoa> view(
+      [[WebContentsViewCocoa alloc] init]);
+
+  // Tests that |draggingSourceOperationMaskForLocal:| returns the expected mask
+  // when dragging without a WebDragSource - i.e. when |startDragWithDropData:|
+  // hasn't yet been called. Dragging a file from the downloads manager, for
+  // example, requires this to work.
+  EXPECT_EQ(NSDragOperationCopy,
+      [view draggingSourceOperationMaskForLocal:YES]);
+  EXPECT_EQ(NSDragOperationCopy,
+      [view draggingSourceOperationMaskForLocal:NO]);
+}
+
+}  // namespace content