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

 // Copyright (c) 2011 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.
 
 #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:
 
 NativeTabContentsViewAura::NativeTabContentsViewAura(
     internal::NativeTabContentsViewDelegate* delegate)
     : views::NativeWidgetAura(delegate->AsNativeWidgetDelegate()),
-      delegate_(delegate) {
+      delegate_(delegate),
+      current_drag_op_(WebKit::WebDragOperationNone) {
 }
 
 NativeTabContentsViewAura::~NativeTabContentsViewAura() {
 }
 
 TabContents* NativeTabContentsViewAura::GetTabContents() const {
   return delegate_->GetTabContents();
 }
 
-void NativeTabContentsViewAura::EndDragging() {
-  delegate_->OnNativeTabContentsViewDraggingEnded();
-  // TODO(beng):
-  NOTIMPLEMENTED();
-}
-
 ////////////////////////////////////////////////////////////////////////////////
 // NativeTabContentsViewAura, NativeTabContentsView implementation:
 
 void NativeTabContentsViewAura::InitNativeTabContentsView() {
   views::Widget::InitParams params(views::Widget::InitParams::TYPE_CONTROL);
   params.native_widget = this;
   // We don't draw anything so we don't need a texture.
   params.create_texture_for_layer = false;
   params.ownership = views::Widget::InitParams::WIDGET_OWNS_NATIVE_WIDGET;
   params.parent = NULL;
@@ skipping 12 matching lines @@
   // Nothing to do.
 }
 
 RenderWidgetHostView* NativeTabContentsViewAura::CreateRenderWidgetHostView(
     RenderWidgetHost* render_widget_host) {
   RenderWidgetHostViewAura* view =
       new RenderWidgetHostViewAura(render_widget_host);
   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;
 }
 
 gfx::NativeWindow NativeTabContentsViewAura::GetTopLevelNativeWindow() const {
   // TODO(beng):
   NOTIMPLEMENTED();
   return NULL;
 }
 
 void NativeTabContentsViewAura::SetPageTitle(const string16& title) {
   GetNativeView()->set_title(title);
 }
 
 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() {
   return this;
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 // NativeTabContentsViewAura, views::NativeWidgetAura overrides:
 
 void NativeTabContentsViewAura::OnBoundsChanged(const gfx::Rect& old_bounds,
@@ skipping 13 matching lines @@
         break;
       default:
         // TODO(oshima): mouse wheel
         break;
     }
   }
   // Pass all mouse event to renderer.
   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:
 
 // static
 NativeTabContentsView* NativeTabContentsView::CreateNativeTabContentsView(
     internal::NativeTabContentsViewDelegate* delegate) {
   return new NativeTabContentsViewAura(delegate);
 }