MacViews: Implemented Drag & Drop

ui/views/cocoa/bridged_content_view.mm

 // Copyright 2014 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/views/cocoa/bridged_content_view.h"
 
 #include "base/logging.h"
 #import "base/mac/mac_util.h"
 #import "base/mac/scoped_nsobject.h"
 #include "base/strings/sys_string_conversions.h"
 #include "skia/ext/skia_utils_mac.h"
 #include "ui/base/cocoa/cocoa_base_utils.h"
+#include "ui/base/dragdrop/drag_drop_types.h"
+#include "ui/base/dragdrop/os_exchange_data_provider_mac.h"
 #include "ui/base/ime/input_method.h"
 #include "ui/base/ime/text_input_client.h"
 #include "ui/compositor/canvas_painter.h"
 #import "ui/events/cocoa/cocoa_event_utils.h"
 #include "ui/events/keycodes/dom/dom_code.h"
 #import "ui/events/keycodes/keyboard_code_conversion_mac.h"
 #include "ui/gfx/canvas_paint_mac.h"
 #include "ui/gfx/geometry/rect.h"
 #import "ui/gfx/mac/coordinate_conversion.h"
 #include "ui/gfx/path.h"
 #import "ui/gfx/path_mac.h"
 #include "ui/gfx/scoped_ns_graphics_context_save_gstate_mac.h"
 #include "ui/strings/grit/ui_strings.h"
+#import "ui/views/cocoa/bridged_native_widget.h"
+#import "ui/views/cocoa/drag_drop_client_mac.h"
 #include "ui/views/controls/menu/menu_config.h"
 #include "ui/views/controls/menu/menu_controller.h"
 #include "ui/views/view.h"
+#include "ui/views/widget/native_widget_mac.h"
 #include "ui/views/widget/widget.h"
 
 using views::MenuController;
 
 namespace {
 
 NSString* const kFullKeyboardAccessChangedNotification =
     @"com.apple.KeyboardUIModeDidChange";
 
 // Returns true if all four corners of |rect| are contained inside |path|.
@@ skipping 179 matching lines @@
 // `plutil -convert xml1 -o StandardKeyBinding.xml StandardKeyBinding.dict` to
 // get something readable.
 - (void)handleAction:(int)commandId
              keyCode:(ui::KeyboardCode)keyCode
              domCode:(ui::DomCode)domCode
           eventFlags:(int)eventFlags;
 
 // Notification handler invoked when the Full Keyboard Access mode is changed.
 - (void)onFullKeyboardAccessModeChanged:(NSNotification*)notification;
 
+// Returns the native Widget's drag drop client. Possibly null.
+- (views::DragDropClientMac*)dragDropClient;
+
 // Menu action handlers.
 - (void)undo:(id)sender;
 - (void)redo:(id)sender;
 - (void)cut:(id)sender;
 - (void)copy:(id)sender;
 - (void)paste:(id)sender;
 - (void)selectAll:(id)sender;
 
 @end
 
@@ skipping 27 matching lines @@
     // Get notified whenever Full Keyboard Access mode is changed.
     [[NSDistributedNotificationCenter defaultCenter]
         addObserver:self
            selector:@selector(onFullKeyboardAccessModeChanged:)
                name:kFullKeyboardAccessChangedNotification
              object:nil];
 
     // Initialize the focus manager with the correct keyboard accessibility
     // setting.
     [self updateFullKeyboardAccess];
+    [self registerForDraggedTypes:ui::OSExchangeDataProviderMac::
+                                      SupportedPasteboardTypes()];
   }
   return self;
 }
 
 - (void)clearView {
   textInputClient_ = nullptr;
   hostedView_ = nullptr;
   [[NSDistributedNotificationCenter defaultCenter] removeObserver:self];
   [cursorTrackingArea_.get() clearOwner];
   [self removeTrackingArea:cursorTrackingArea_.get()];
@@ skipping 104 matching lines @@
   ui::KeyEvent event(ui::ET_KEY_PRESSED, keyCode, domCode, eventFlags);
   hostedView_->GetWidget()->GetInputMethod()->DispatchKeyEvent(&event);
 }
 
 - (void)onFullKeyboardAccessModeChanged:(NSNotification*)notification {
   DCHECK([[notification name]
       isEqualToString:kFullKeyboardAccessChangedNotification]);
   [self updateFullKeyboardAccess];
 }
 
+- (views::DragDropClientMac*)dragDropClient {
+  views::BridgedNativeWidget* bridge =
+      views::NativeWidgetMac::GetBridgeForNativeWindow([self window]);
+  return bridge ? bridge->drag_drop_client() : nullptr;
+}
+
 - (void)undo:(id)sender {
   // This DCHECK is more strict than a similar check in handleAction:. It can be
   // done here because the actors sending these actions should be calling
   // validateUserInterfaceItem: before enabling UI that allows these messages to
   // be sent. Checking it here would be too late to provide correct UI feedback
   // (e.g. there will be no "beep").
   DCHECK(textInputClient_->IsEditCommandEnabled(IDS_APP_UNDO));
   [self handleAction:IDS_APP_UNDO
              keyCode:ui::VKEY_Z
              domCode:ui::DomCode::US_Z
@@ skipping 169 matching lines @@
       ui::CanvasPainter(&canvas, 1.f).context());
 }
 
 // To maximize consistency with the Cocoa browser (mac_views_browser=0), accept
 // mouse clicks immediately so that clicking on Chrome from an inactive window
 // will allow the event to be processed, rather than merely activate the window.
 - (BOOL)acceptsFirstMouse:(NSEvent*)theEvent {
   return YES;
 }
 
+// NSDraggingDestination protocol overrides.
+
+- (NSDragOperation)draggingEntered:(id<NSDraggingInfo>)sender {
+  return [self draggingUpdated:sender];
+}
+
+- (NSDragOperation)draggingUpdated:(id<NSDraggingInfo>)sender {
+  views::DragDropClientMac* client = [self dragDropClient];
+  return client ? client->DragUpdate(sender) : ui::DragDropTypes::DRAG_NONE;
+}
+
+- (BOOL)performDragOperation:(id<NSDraggingInfo>)sender {
+  views::DragDropClientMac* client = [self dragDropClient];
+  return client && client->Drop(sender) != NSDragOperationNone;
+}
+
 - (NSTextInputContext*)inputContext {
   // If the textInputClient_ does not exist, return nil since this view does not
   // conform to NSTextInputClient protocol.
   if (!textInputClient_)
     return nil;
 
   // If a menu is active, and -[NSView interpretKeyEvents:] asks for the
   // input context, return nil. This ensures the action message is sent to
   // the view, rather than any NSTextInputClient a subview has installed.
   MenuController* menuController = MenuController::GetActiveInstance();
@@ skipping 572 matching lines @@
   if (action == @selector(copy:))
     return textInputClient_->IsEditCommandEnabled(IDS_APP_COPY);
   if (action == @selector(paste:))
     return textInputClient_->IsEditCommandEnabled(IDS_APP_PASTE);
   if (action == @selector(selectAll:))
     return textInputClient_->IsEditCommandEnabled(IDS_APP_SELECT_ALL);
 
   return NO;
 }
 
+// NSDraggingSource protocol implementation.
+
+- (NSDragOperation)draggingSession:(NSDraggingSession*)session
+    sourceOperationMaskForDraggingContext:(NSDraggingContext)context {
+  return NSDragOperationEvery;
+}
+
+- (void)draggingSession:(NSDraggingSession*)session
+           endedAtPoint:(NSPoint)screenPoint
+              operation:(NSDragOperation)operation {
+  views::DragDropClientMac* client = [self dragDropClient];
+  if (client)
+    client->EndDrag();
+}
+
 // NSAccessibility informal protocol implementation.
 
 - (id)accessibilityAttributeValue:(NSString*)attribute {
   if ([attribute isEqualToString:NSAccessibilityChildrenAttribute]) {
     return @[ hostedView_->GetNativeViewAccessible() ];
   }
 
   return [super accessibilityAttributeValue:attribute];
 }
 
 - (id)accessibilityHitTest:(NSPoint)point {
   return [hostedView_->GetNativeViewAccessible() accessibilityHitTest:point];
 }
 
 @end