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..f9a21ed3dbbce6d3e9987123c595e9cf3f208ec0 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 +4,74 @@
 
 #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 = static_cast<aura::Window*>(

[Ben Goodger (Google), 2011/11/28 17:07:44]

Cast unnecessary.

[varunjain, 2011/11/28 17:32:29]

Done.

+              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);
+};
+
+}  // namespace
 
 ////////////////////////////////////////////////////////////////////////////////
 // NativeTabContentsViewAura, public:
@@ -19,7 +79,8 @@
 NativeTabContentsViewAura::NativeTabContentsViewAura(
     internal::NativeTabContentsViewDelegate* delegate)
     : views::NativeWidgetAura(delegate->AsNativeWidgetDelegate()),
-      delegate_(delegate) {
+      delegate_(delegate),
+      current_drag_op_(WebKit::WebDragOperationNone) {
 }
 
 NativeTabContentsViewAura::~NativeTabContentsViewAura() {
@@ -29,12 +90,6 @@ TabContents* NativeTabContentsViewAura::GetTabContents() const {
   return delegate_->GetTabContents();
 }
 
-void NativeTabContentsViewAura::EndDragging() {
-  delegate_->OnNativeTabContentsViewDraggingEnded();
-  // TODO(beng):
-  NOTIMPLEMENTED();
-}
-
 ////////////////////////////////////////////////////////////////////////////////
 // NativeTabContentsViewAura, NativeTabContentsView implementation:
 
@@ -67,6 +122,12 @@ 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 +145,51 @@ 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 +223,99 @@ 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_;
+}
+

[Ben Goodger (Google), 2011/11/28 17:07:44]

Can we add a section marker here:

/////...etc
// NativeTabContentsViewAura, private:

[varunjain, 2011/11/28 17:32:29]

Done.

+void NativeTabContentsViewAura::PrepareDragData(

[Ben Goodger (Google), 2011/11/28 17:07:44]

Any of these functions that don't work with local state on the class can just be
defined in an anonymous namespace at the top of this file. It makes rebuilds
faster if these functions change signature.

[varunjain, 2011/11/28 17:32:29]

Done.

+    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.
+}
+
+void NativeTabContentsViewAura::PrepareWebDropData(
+    WebDropData* drop_data,
+    const ui::OSExchangeData& data) {

[Ben Goodger (Google), 2011/11/28 17:07:44]

ditto

[varunjain, 2011/11/28 17:32:29]

Done.

+  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.
+}
+
+int NativeTabContentsViewAura::ConvertFromWeb(

[Ben Goodger (Google), 2011/11/28 17:07:44]

ditto

[varunjain, 2011/11/28 17:32:29]

Done.

+    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 NativeTabContentsViewAura::ConvertToWeb(
+    int drag_op) {

[Ben Goodger (Google), 2011/11/28 17:07:44]

ditto

[varunjain, 2011/11/28 17:32:29]

Done.

+  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;
+}
+
+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 = static_cast<aura::Window*>(

[Ben Goodger (Google), 2011/11/28 17:07:44]

This cast isn't necessary. NativeView typedefs to aura::Window*

[varunjain, 2011/11/28 17:32:29]

Done.

+      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: