First shot at implementing drag&drop for Aura

ui/aura_shell/shell.cc

Index: ui/aura_shell/shell.cc
diff --git a/ui/aura_shell/shell.cc b/ui/aura_shell/shell.cc
index 659bfc8bdf0e353b562504a1da9361e49eba00f3..f76927564e55e5b961d294b784efb5e45becedc9 100644
--- a/ui/aura_shell/shell.cc
+++ b/ui/aura_shell/shell.cc
@@ -8,6 +8,7 @@
 #include "base/command_line.h"
 #include "ui/aura/aura_switches.h"
 #include "ui/aura/desktop.h"
+#include "ui/aura/event.h"
 #include "ui/aura/screen_aura.h"
 #include "ui/aura/toplevel_window_container.h"
 #include "ui/aura/window.h"
@@ -20,8 +21,10 @@
 #include "ui/aura_shell/shell_factory.h"
 #include "ui/aura_shell/shell_window_ids.h"
 #include "ui/aura_shell/workspace/workspace_controller.h"
+#include "ui/base/dragdrop/os_exchange_data_provider_aura.h"
 #include "ui/gfx/compositor/layer.h"
 #include "ui/gfx/compositor/layer_animator.h"
+#include "views/controls/image_view.h"
 #include "views/widget/native_widget_aura.h"
 #include "views/widget/widget.h"
 
@@ -70,6 +73,19 @@ void CreateSpecialContainers(aura::Window::Windows* containers) {
   containers->push_back(menu_container);
 }
 
+
+Widget* CreateDragWidget() {
+  Widget* drag_widget = new Widget;
+  Widget::InitParams params;
+  params.type = Widget::InitParams::TYPE_TOOLTIP;

[Ben Goodger (Google), 2011/11/07 20:33:36]

I fear overloading types like this. It's not actually a tooltip.

[varunjain, 2011/11/08 21:59:35]

My intention was to put it in the same container as the tooltip. In terms of
z-order, it should be as on top as tooltips. Would you rather I create a new
type?

+  params.keep_on_top = true;
+  params.accept_events = false;
+  params.ownership = Widget::InitParams::WIDGET_OWNS_NATIVE_WIDGET;
+  drag_widget->Init(params);
+  drag_widget->SetOpacity(0xFF);
+  return drag_widget;
+}
+
 }  // namespace
 
 // static
@@ -79,7 +95,9 @@ Shell* Shell::instance_ = NULL;
 // Shell, public:
 
 Shell::Shell()
-    : ALLOW_THIS_IN_INITIALIZER_LIST(method_factory_(this)) {
+    : ALLOW_THIS_IN_INITIALIZER_LIST(method_factory_(this)),
+      drag_data_(NULL),
+      drag_widget_(NULL) {
   aura::Desktop::GetInstance()->SetDelegate(this);
 }
 
@@ -196,4 +214,65 @@ aura::Window* Shell::GetTopmostWindowToActivate(aura::Window* ignore) const {
   return container->GetTopmostWindowToActivate(ignore);
 }
 
+aura::DragDropController* Shell::GetDragDropController() const {
+#if defined(OS_WIN)
+  return NULL;

[Ben Goodger (Google), 2011/11/07 20:33:36]

why?

[varunjain, 2011/11/08 21:59:35]

Done.

+#else
+  return const_cast<aura_shell::Shell*>(this);
+#endif
+}
+
+void Shell::StartDragAndDrop(const ui::OSExchangeData& data,
+                             int operation,
+                             const gfx::Point& location) {
+#if !defined(OS_WIN)

[Ben Goodger (Google), 2011/11/07 20:33:36]

why?

[varunjain, 2011/11/08 21:59:35]

Done.

+  DCHECK(drag_data_ == NULL);
+  DCHECK(drag_widget_.get() == NULL);
+  drag_data_ = &data;
+  drag_widget_.reset(CreateDragWidget());
+  const ui::OSExchangeDataProviderAura& provider =
+      static_cast<const ui::OSExchangeDataProviderAura&>(data.provider());
+
+  views::ImageView* image_view = new views::ImageView();
+  image_view->SetImage(provider.drag_image());
+  drag_widget_->SetContentsView(image_view);
+  drag_widget_->SetBounds(gfx::Rect(location,
+      image_view->GetPreferredSize()));
+  drag_widget_->Show();
+#endif
+}
+
+void Shell::DragUpdate(const aura::MouseEvent& event) {
+#if !defined(OS_WIN)

[Ben Goodger (Google), 2011/11/07 20:33:36]

why?

[varunjain, 2011/11/08 21:59:35]

Done.

+  // TODO(varunjain): forward drag update to the window under cursor:
+  aura::Window* window = aura::Desktop::GetInstance()->
+      GetEventHandlerForPoint(event.location());
+  // window->DragUpdate(data, event);
+
+  DCHECK(drag_widget_.get());
+  if (drag_widget_->IsVisible()) {
+    gfx::Rect bounds = drag_widget_->GetClientAreaScreenBounds();
+    bounds.set_origin(event.location());
+    drag_widget_->SetBounds(bounds);
+  }
+  NOTIMPLEMENTED();
+#endif
+}
+
+void Shell::Drop(const aura::MouseEvent& event) {
+#if !defined(OS_WIN)

[Ben Goodger (Google), 2011/11/07 20:33:36]

etc

[varunjain, 2011/11/08 21:59:35]

Done.

+  // TODO(varunjain): forward drop event to the window under cursor
+  aura::Window* window = aura::Desktop::GetInstance()->
+      GetEventHandlerForPoint(event.location());
+  // if (window->CanDrop(data, event))
+  //   window->Drop(data, event);
+  // else
+  //   Do drag widget flying back animation
+  drag_widget_->Hide();
+  drag_widget_.reset();
+  drag_data_ = NULL;
+  NOTIMPLEMENTED();
+#endif
+}
+
 }  // namespace aura_shell