Make drag and drop work on webpage. Also slightly modify drag drop workflow.

chrome/browser/ui/views/tab_contents/native_tab_contents_view_aura.cc

Index: chrome/browser/ui/views/tab_contents/native_tab_contents_view_aura.cc
diff --git a/chrome/browser/ui/views/tab_contents/native_tab_contents_view_aura.cc b/chrome/browser/ui/views/tab_contents/native_tab_contents_view_aura.cc
index 5084ddbd5014464c6c8dfb82e1500e9c406ae98f..7fd5c80761d08aef223a16dfbd557709befa5b6d 100644
--- a/chrome/browser/ui/views/tab_contents/native_tab_contents_view_aura.cc
+++ b/chrome/browser/ui/views/tab_contents/native_tab_contents_view_aura.cc
@@ -4,14 +4,123 @@
 
 #include "chrome/browser/ui/views/tab_contents/native_tab_contents_view_aura.h"
 
+#include "base/event_types.h"
+#include "base/message_loop.h"
 #include "chrome/browser/ui/views/tab_contents/native_tab_contents_view_delegate.h"
+#include "content/browser/renderer_host/render_view_host.h"
 #include "content/browser/renderer_host/render_widget_host_view_aura.h"
 #include "content/browser/tab_contents/tab_contents.h"
 #include "content/browser/tab_contents/tab_contents_view.h"
+#include "ui/aura/client/aura_constants.h"
+#include "ui/aura/client/drag_drop_client.h"
+#include "ui/aura/desktop.h"
 #include "ui/aura/event.h"
 #include "ui/aura/window.h"
+#include "ui/base/dragdrop/drag_drop_types.h"
+#include "ui/base/dragdrop/os_exchange_data.h"
+#include "ui/base/dragdrop/os_exchange_data_provider_aura.h"
 #include "ui/views/widget/widget.h"
 #include "views/views_delegate.h"
+#include "webkit/glue/webdropdata.h"
+
+namespace {
+
+// Listens to all mouse drag events during a drag and drop and sends them to
+// the renderer.
+class WebDragSourceAura : public MessageLoopForUI::Observer {
+ public:
+  explicit WebDragSourceAura(NativeTabContentsViewAura* view)
+      : view_(view) {
+    MessageLoopForUI::current()->AddObserver(this);
+  }
+
+  virtual ~WebDragSourceAura() {
+    MessageLoopForUI::current()->RemoveObserver(this);
+  }
+
+  // MessageLoop::Observer implementation:
+  virtual base::EventStatus WillProcessEvent(
+      const base::NativeEvent& event) OVERRIDE {
+    return base::EVENT_CONTINUE;
+  }
+  virtual void DidProcessEvent(const base::NativeEvent& event) OVERRIDE {
+    ui::EventType type = ui::EventTypeFromNative(event);
+    RenderViewHost* rvh = NULL;
+    switch (type) {
+      case ui::ET_MOUSE_DRAGGED:
+        rvh = view_->GetTabContents()->render_view_host();
+        if (rvh) {
+          gfx::Point screen_loc = ui::EventLocationFromNative(event);
+          gfx::Point client_loc = screen_loc;
+          aura::Window* window = rvh->view()->GetNativeView();
+          aura::Window::ConvertPointToWindow(aura::Desktop::GetInstance(),
+              window, &client_loc);
+          rvh->DragSourceMovedTo(client_loc.x(), client_loc.y(),
+              screen_loc.x(), screen_loc.y());
+        }
+        break;
+      default:
+        break;
+    }
+  }
+
+ private:
+  NativeTabContentsViewAura* view_;
+
+  DISALLOW_COPY_AND_ASSIGN(WebDragSourceAura);
+};
+
+// Utility to fill a ui::OSExchangeDataProviderAura object from WebDropData.
+void PrepareDragData(const WebDropData& drop_data,
+                     ui::OSExchangeDataProviderAura* provider) {
+  if (!drop_data.plain_text.empty())
+    provider->SetString(drop_data.plain_text);
+  if (drop_data.url.is_valid())
+    provider->SetURL(drop_data.url, drop_data.url_title);
+  // TODO(varunjain): support other formats.
+}
+
+// Utility to fill a WebDropData object from ui::OSExchangeData.
+void PrepareWebDropData(WebDropData* drop_data,
+                        const ui::OSExchangeData& data) {
+  string16 plain_text, url_title;
+  GURL url;
+  data.GetString(&plain_text);
+  if (!plain_text.empty())
+    drop_data->plain_text = plain_text;
+  data.GetURLAndTitle(&url, &url_title);
+  if (url.is_valid()) {
+    drop_data->url = url;
+    drop_data->url_title = url_title;
+  }
+  // TODO(varunjain): support other formats.
+}
+
+// Utilities to convert between WebKit::WebDragOperationsMask and
+// ui::DragDropTypes.
+int ConvertFromWeb(WebKit::WebDragOperationsMask ops) {
+  int drag_op = ui::DragDropTypes::DRAG_NONE;
+  if (ops & WebKit::WebDragOperationCopy)
+    drag_op |= ui::DragDropTypes::DRAG_COPY;
+  if (ops & WebKit::WebDragOperationMove)
+    drag_op |= ui::DragDropTypes::DRAG_MOVE;
+  if (ops & WebKit::WebDragOperationLink)
+    drag_op |= ui::DragDropTypes::DRAG_LINK;
+  return drag_op;
+}
+
+WebKit::WebDragOperationsMask ConvertToWeb(int drag_op) {
+  int web_drag_op = WebKit::WebDragOperationNone;
+  if (drag_op & ui::DragDropTypes::DRAG_COPY)
+    web_drag_op |= WebKit::WebDragOperationCopy;
+  if (drag_op & ui::DragDropTypes::DRAG_MOVE)
+    web_drag_op |= WebKit::WebDragOperationMove;
+  if (drag_op & ui::DragDropTypes::DRAG_LINK)
+    web_drag_op |= WebKit::WebDragOperationLink;
+  return (WebKit::WebDragOperationsMask) web_drag_op;
+}
+
+}  // namespace
 
 ////////////////////////////////////////////////////////////////////////////////
 // NativeTabContentsViewAura, public:
@@ -19,7 +128,8 @@
 NativeTabContentsViewAura::NativeTabContentsViewAura(
     internal::NativeTabContentsViewDelegate* delegate)
     : views::NativeWidgetAura(delegate->AsNativeWidgetDelegate()),
-      delegate_(delegate) {
+      delegate_(delegate),
+      current_drag_op_(WebKit::WebDragOperationNone) {
 }
 
 NativeTabContentsViewAura::~NativeTabContentsViewAura() {
@@ -29,12 +139,6 @@ TabContents* NativeTabContentsViewAura::GetTabContents() const {
   return delegate_->GetTabContents();
 }
 
-void NativeTabContentsViewAura::EndDragging() {
-  delegate_->OnNativeTabContentsViewDraggingEnded();
-  // TODO(beng):
-  NOTIMPLEMENTED();
-}
-
 ////////////////////////////////////////////////////////////////////////////////
 // NativeTabContentsViewAura, NativeTabContentsView implementation:
 
@@ -67,6 +171,12 @@ RenderWidgetHostView* NativeTabContentsViewAura::CreateRenderWidgetHostView(
   view->InitAsChild();
   GetNativeView()->AddChild(view->GetNativeView());
   view->Show();
+
+  // We listen to drag drop events in the newly created view's window.
+  aura::Window* window = static_cast<aura::Window*>(view->GetNativeView());
+  DCHECK(window);
+  window->SetProperty(aura::kDragDropDelegateKey,
+      static_cast<aura::WindowDragDropDelegate*>(this));
   return view;
 }
 
@@ -84,25 +194,51 @@ void NativeTabContentsViewAura::StartDragging(const WebDropData& drop_data,
                                              WebKit::WebDragOperationsMask ops,
                                              const SkBitmap& image,
                                              const gfx::Point& image_offset) {
-  // TODO(beng):
-  NOTIMPLEMENTED();
+  aura::DragDropClient* client = static_cast<aura::DragDropClient*>(
+      aura::Desktop::GetInstance()->GetProperty(
+          aura::kDesktopDragDropClientKey));
+  if (!client)
+    return;
+
+  ui::OSExchangeDataProviderAura* provider = new ui::OSExchangeDataProviderAura;
+  PrepareDragData(drop_data, provider);
+  if (!image.isNull())
+    provider->set_drag_image(image);
+  ui::OSExchangeData data(provider);  // takes ownership of |provider|.
+
+  scoped_ptr<WebDragSourceAura> drag_source(new WebDragSourceAura(this));
+
+  // We need to enable recursive tasks on the message loop so we can get
+  // updates while in the system DoDragDrop loop.
+  bool old_state = MessageLoop::current()->NestableTasksAllowed();
+  MessageLoop::current()->SetNestableTasksAllowed(true);
+  int result_op = client->StartDragAndDrop(data, ConvertFromWeb(ops));
+  MessageLoop::current()->SetNestableTasksAllowed(old_state);
+
+  EndDrag(ConvertToWeb(result_op));
+  GetTabContents()->render_view_host()->DragSourceSystemDragEnded();
 }
 
 void NativeTabContentsViewAura::CancelDrag() {
-  // TODO(beng):
-  NOTIMPLEMENTED();
+  aura::DragDropClient* client = static_cast<aura::DragDropClient*>(
+      aura::Desktop::GetInstance()->GetProperty(
+          aura::kDesktopDragDropClientKey));
+  if (client)
+    client->DragCancel();
 }
 
 bool NativeTabContentsViewAura::IsDoingDrag() const {
-  // TODO(beng):
-  NOTIMPLEMENTED();
+  aura::DragDropClient* client = static_cast<aura::DragDropClient*>(
+      aura::Desktop::GetInstance()->GetProperty(
+          aura::kDesktopDragDropClientKey));
+  if (client)
+    return client->IsDragDropInProgress();
   return false;
 }
 
 void NativeTabContentsViewAura::SetDragCursor(
     WebKit::WebDragOperation operation) {
-  // TODO(beng):
-  NOTIMPLEMENTED();
+  current_drag_op_ = operation;
 }
 
 views::NativeWidget* NativeTabContentsViewAura::AsNativeWidget() {
@@ -136,6 +272,51 @@ bool NativeTabContentsViewAura::OnMouseEvent(aura::MouseEvent* event) {
   return views::NativeWidgetAura::OnMouseEvent(event);
 }
 
+void NativeTabContentsViewAura::OnDragEntered(
+    const aura::DropTargetEvent& event) {
+  WebDropData drop_data;
+  PrepareWebDropData(&drop_data, event.data());
+  WebKit::WebDragOperationsMask op = ConvertToWeb(event.source_operations());
+
+  gfx::Point screen_pt = aura::Desktop::GetInstance()->last_mouse_location();
+  GetTabContents()->render_view_host()->DragTargetDragEnter(
+      drop_data, event.location(), screen_pt, op);
+}
+
+int NativeTabContentsViewAura::OnDragUpdated(
+    const aura::DropTargetEvent& event) {
+  WebKit::WebDragOperationsMask op = ConvertToWeb(event.source_operations());
+  gfx::Point screen_pt = aura::Desktop::GetInstance()->last_mouse_location();
+  GetTabContents()->render_view_host()->DragTargetDragOver(
+      event.location(), screen_pt, op);
+  return ConvertFromWeb(current_drag_op_);
+}
+
+void NativeTabContentsViewAura::OnDragExited() {
+  GetTabContents()->render_view_host()->DragTargetDragLeave();
+}
+
+int NativeTabContentsViewAura::OnPerformDrop(
+    const aura::DropTargetEvent& event) {
+  GetTabContents()->render_view_host()->DragTargetDrop(
+      event.location(), aura::Desktop::GetInstance()->last_mouse_location());
+  return current_drag_op_;
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// NativeTabContentsViewAura, private:
+
+void NativeTabContentsViewAura::EndDrag(WebKit::WebDragOperationsMask ops) {
+  gfx::Point screen_loc = aura::Desktop::GetInstance()->last_mouse_location();
+  gfx::Point client_loc = screen_loc;
+  RenderViewHost* rvh = GetTabContents()->render_view_host();
+  aura::Window* window = rvh->view()->GetNativeView();
+  aura::Window::ConvertPointToWindow(aura::Desktop::GetInstance(),
+      window, &client_loc);
+  rvh->DragSourceEndedAt(client_loc.x(), client_loc.y(), screen_loc.x(),
+      screen_loc.y(), ops);
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 // NativeTabContentsView, public: