views: Account for device scale factor when drawing drag images for v…

…iews.

BUG=128820
TEST=manual


Review URL: https://chromiumcodereview.appspot.com/10574014

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@143052 0039d316-1c4b-4281-b951-d872f2087c98

chrome/browser/ui/views/bookmarks/bookmark_bar_view.cc

@@ -61,6 +61,7 @@
 #include "ui/views/controls/button/menu_button.h"
 #include "ui/views/controls/label.h"
 #include "ui/views/controls/menu/menu_item_view.h"
+#include "ui/views/drag_utils.h"
 #include "ui/views/metrics.h"
 #include "ui/views/view_constants.h"
 #include "ui/views/widget/tooltip_manager.h"
@@ -940,9 +941,10 @@ void BookmarkBarView::WriteDragDataForView(View* sender,
   for (int i = 0; i < GetBookmarkButtonCount(); ++i) {
     if (sender == GetBookmarkButton(i)) {
       views::TextButton* button = GetBookmarkButton(i);
-      gfx::Canvas canvas(button->size(), false);
-      button->PaintButton(&canvas, views::TextButton::PB_FOR_DRAG);
-      drag_utils::SetDragImageOnDataObject(canvas, button->size(), press_pt,
+      scoped_ptr<gfx::Canvas> canvas(
+          views::GetCanvasForDragImage(button->GetWidget(), button->size()));
+      button->PaintButton(canvas.get(), views::TextButton::PB_FOR_DRAG);
+      drag_utils::SetDragImageOnDataObject(*canvas, button->size(), press_pt,
                                            data);
       WriteBookmarkDragData(model_->bookmark_bar_node()->GetChild(i), data);
       return;

chrome/browser/ui/views/location_bar/location_bar_view.cc

@@ -1191,7 +1191,8 @@ void LocationBarView::WriteDragDataForView(views::View* sender,
       tab_contents->web_contents()->GetURL(),
       tab_contents->web_contents()->GetTitle(),
       tab_contents->favicon_tab_helper()->GetFavicon(),
-      data);
+      data,
+      sender->GetWidget());
 }
 
 int LocationBarView::GetDragOperationsForView(views::View* sender,

chrome/browser/ui/views/omnibox/omnibox_view_win.cc

@@ -2524,7 +2524,8 @@ void OmniboxViewWin::StartDragIfNecessary(const CPoint& point) {
     SkBitmap favicon;
     if (is_all_selected)
       model_->GetDataForURLExport(&url, &title, &favicon);
-    button_drag_utils::SetURLAndDragImage(url, title, favicon, &data);
+    button_drag_utils::SetURLAndDragImage(url, title, favicon, &data,
+                                          native_view_host_->GetWidget());
     supported_modes |= DROPEFFECT_LINK;
     content::RecordAction(UserMetricsAction("Omnibox_DragURL"));
   } else {

ui/views/button_drag_utils.cc

@@ -13,6 +13,7 @@
 #include "ui/gfx/canvas.h"
 #include "ui/gfx/image/image.h"
 #include "ui/views/controls/button/text_button.h"
+#include "ui/views/drag_utils.h"
 
 namespace button_drag_utils {
 
@@ -22,7 +23,8 @@ static const int kLinkDragImageMaxWidth = 200;
 void SetURLAndDragImage(const GURL& url,
                         const string16& title,
                         const gfx::ImageSkia& icon,
-                        ui::OSExchangeData* data) {
+                        ui::OSExchangeData* data,
+                        views::Widget* widget) {
   DCHECK(url.is_valid() && data);
 
   data->SetURL(url, title);
@@ -41,9 +43,10 @@ void SetURLAndDragImage(const GURL& url,
   button.SetBounds(0, 0, prefsize.width(), prefsize.height());
 
   // Render the image.
-  gfx::Canvas canvas(prefsize, false);
-  button.PaintButton(&canvas, views::TextButton::PB_FOR_DRAG);
-  drag_utils::SetDragImageOnDataObject(canvas, prefsize,
+  scoped_ptr<gfx::Canvas> canvas(
+      views::GetCanvasForDragImage(widget, prefsize));
+  button.PaintButton(canvas.get(), views::TextButton::PB_FOR_DRAG);
+  drag_utils::SetDragImageOnDataObject(*canvas, prefsize,
       gfx::Point(prefsize.width() / 2, prefsize.height() / 2), data);
 }
 

ui/views/button_drag_utils.h

@@ -19,14 +19,19 @@ namespace ui {
 class OSExchangeData;
 }
 
+namespace views {
+class Widget;
+}
+
 namespace button_drag_utils {
 
 // Sets url and title on data as well as setting a suitable image for dragging.
 // The image looks like that of the bookmark buttons.
 VIEWS_EXPORT void SetURLAndDragImage(const GURL& url,
                                      const string16& title,
                                      const gfx::ImageSkia& icon,
-                                     ui::OSExchangeData* data);
+                                     ui::OSExchangeData* data,
+                                     views::Widget* widget);
 
 }  // namespace drag_utils
 

ui/views/controls/menu/menu_controller.cc

@@ -20,6 +20,7 @@
 #include "ui/views/controls/menu/menu_controller_delegate.h"
 #include "ui/views/controls/menu/menu_scroll_view_container.h"
 #include "ui/views/controls/menu/submenu_view.h"
+#include "ui/views/drag_utils.h"
 #include "ui/views/view_constants.h"
 #include "ui/views/views_delegate.h"
 #include "ui/views/widget/root_view.h"
@@ -849,12 +850,13 @@ void MenuController::StartDrag(SubmenuView* source,
   View::ConvertPointToView(NULL, item, &press_loc);
   gfx::Point widget_loc(press_loc);
   View::ConvertPointToWidget(item, &widget_loc);
-  gfx::Canvas canvas(gfx::Size(item->width(), item->height()), false);
-  item->PaintButton(&canvas, MenuItemView::PB_FOR_DRAG);
+  scoped_ptr<gfx::Canvas> canvas(views::GetCanvasForDragImage(
+      source->GetWidget(), gfx::Size(item->width(), item->height())));
+  item->PaintButton(canvas.get(), MenuItemView::PB_FOR_DRAG);
 
   OSExchangeData data;
   item->GetDelegate()->WriteDragData(item, &data);
-  drag_utils::SetDragImageOnDataObject(canvas, item->size(), press_loc,
+  drag_utils::SetDragImageOnDataObject(*canvas, item->size(), press_loc,
                                        &data);
   StopScrolling();
   int drag_ops = item->GetDelegate()->GetDragOperations(item);

ui/views/drag_utils.cc

@@ -4,10 +4,16 @@
 
 #include "ui/views/drag_utils.h"
 
+#include "ui/gfx/canvas.h"
+#include "ui/gfx/size.h"
+
 #if defined(USE_AURA)
 #include "ui/aura/client/drag_drop_client.h"
 #include "ui/aura/root_window.h"
 #include "ui/aura/window.h"
+#include "ui/gfx/display.h"
+#include "ui/gfx/screen.h"
+#include "ui/views/widget/widget.h"
 #elif defined(OS_WIN)
 #include "ui/base/dragdrop/drag_drop_types.h"
 #include "ui/base/dragdrop/drag_source.h"
@@ -16,6 +22,21 @@
 #error
 #endif
 
+float GetDeviceScaleFactorForNativeView(views::Widget* widget) {
+  float device_scale_factor = 1;
+#if defined(USE_AURA)
+  // The following code should work on other platforms as well. But we do not
+  // yet care about device scale factor on other platforms. So to keep drag and
+  // drop behavior on other platforms un-touched, we wrap this in the #if guard.
+  if (widget && widget->GetNativeView()) {
+    gfx::Display display = gfx::Screen::GetDisplayNearestWindow(
+        widget->GetNativeView());
+    device_scale_factor = display.device_scale_factor();
+  }
+#endif
+  return device_scale_factor;
+}
+
 namespace views {
 
 void RunShellDrag(gfx::NativeView view,
@@ -40,4 +61,13 @@ void RunShellDrag(gfx::NativeView view,
 #endif
 }
 
+gfx::Canvas* GetCanvasForDragImage(views::Widget* widget,
+                                   const gfx::Size& canvas_size) {
+  float device_scale_factor = GetDeviceScaleFactorForNativeView(widget);
+  gfx::Size scaled_canvas_size = canvas_size.Scale(device_scale_factor);
+  gfx::Canvas* canvas = new gfx::Canvas(scaled_canvas_size, false);
+  canvas->Scale(device_scale_factor, device_scale_factor);
+  return canvas;
+}
+
 }  // namespace views

ui/views/drag_utils.h

@@ -10,21 +10,29 @@
 #include "ui/views/views_export.h"
 
 namespace gfx {
+class Canvas;
 class Point;
+class Size;
 }
 
 namespace ui {
 class OSExchangeData;
 }
 
 namespace views {
+class Widget;
 
 // Starts a drag operation. This blocks until the drag operation completes.
 VIEWS_EXPORT void RunShellDrag(gfx::NativeView view,
                             const ui::OSExchangeData& data,
                             const gfx::Point& location,
                             int operation);
 
+// Returns a canvas that can be used to draw the drag image. Caller owns the
+// returned object. |widget| is Widget hosting the view being dragged.
+VIEWS_EXPORT gfx::Canvas* GetCanvasForDragImage(Widget* widget,
+                                                const gfx::Size& canvas_size);
+
 }  // namespace views
 
 #endif  // UI_VIEWS_DRAG_UTILS_H_