Support app window draggable areas in mash.

chrome/browser/ui/views/apps/chrome_native_app_window_views_aura_ash.cc

Index: chrome/browser/ui/views/apps/chrome_native_app_window_views_aura_ash.cc
diff --git a/chrome/browser/ui/views/apps/chrome_native_app_window_views_aura_ash.cc b/chrome/browser/ui/views/apps/chrome_native_app_window_views_aura_ash.cc
index 718bbe92d49cb191aff3b2ca46c6d7ab47be8597..0367bc0c101a40d8eb9649e2efb1895328dc62e8 100644
--- a/chrome/browser/ui/views/apps/chrome_native_app_window_views_aura_ash.cc
+++ b/chrome/browser/ui/views/apps/chrome_native_app_window_views_aura_ash.cc
@@ -28,6 +28,14 @@
 #include "ui/views/controls/menu/menu_runner.h"
 #include "ui/views/widget/widget.h"
 
+#if defined(MOJO_SHELL_CLIENT)
+#include "components/mus/public/cpp/property_type_converters.h"
+#include "components/mus/public/cpp/window.h"
+#include "components/mus/public/interfaces/window_manager.mojom.h"
+#include "ui/aura/mus/mus_util.h"
+#include "ui/gfx/skia_util.h"
+#endif
+
 using extensions::AppWindow;
 
 namespace {
@@ -140,6 +148,11 @@ void ChromeNativeAppWindowViewsAuraAsh::OnBeforeWidgetInit(
         ash::Shell::GetContainer(ash::Shell::GetPrimaryRootWindow(),
                                  ash::kShellWindowId_ImeWindowParentContainer);
   }
+#if defined(MOJO_SHELL_CLIENT)
+  init_params->mus_properties
+      [mus::mojom::WindowManager::kRemoveStandardFrame_Property] =
+      mojo::ConvertTo<std::vector<uint8_t>>(init_params->remove_standard_frame);

[dcheng, 2016/06/16 09:04:36]

How does a bool turn into a vector of bytes?
(Am I interpreting this correctly?)

More generically... why do we need to do this? Why is it defined in mus'
property_type_converters.h and not somewhere else? It seems like a recipe for
violating ODR.

[msw, 2016/06/16 16:54:21]

Yes, see the impl here:
https://cs.chromium.org/chromium/src/components/mus/public/cpp/lib/property_t...
We keep a map of named std::vector<uint8_t> properties on the mus::Window,
shared across the services that use mus::Window:
https://cs.chromium.org/chromium/src/components/mus/public/cpp/window.h?rcl=0...
This is a similar pattern to aura::Window's map of templated WindowProperty
structs:
https://cs.chromium.org/chromium/src/ui/aura/window.h?rcl=1466075871&l=304
This CL demonstrates one use case: informing the WM not to paint a frame, but to
still support draggable areas.
It seems natural that the converters for properties set on mus windows would be
part of the mus public cpp client library.

[sky, 2016/06/16 20:03:07]

property_type_converters contains common types used by most clients of mus. It
won't contain all converters, but certainly the common ones.

[dcheng, 2016/06/16 20:13:54]

Right, but there's nothing mus-specific about the templates parameters in this
particular case. If someone ever defines the TypeConverter template in another
translation unit with the same template arguments, but defines the body
differently, then we have an ODR violation.

More generally... why type converter? We do want to remove these, now that we
have struct traits. Maybe these should just be mus utilities
(BoolToWindowProperty), etc?

+#endif
 }
 
 void ChromeNativeAppWindowViewsAuraAsh::OnBeforePanelWidgetInit(
@@ -312,3 +325,29 @@ void ChromeNativeAppWindowViewsAuraAsh::SetFullscreen(int fullscreen_types) {
     ash::Shell::GetInstance()->UpdateShelfVisibility();
   }
 }
+
+void ChromeNativeAppWindowViewsAuraAsh::UpdateDraggableRegions(
+    const std::vector<extensions::DraggableRegion>& regions) {
+  ChromeNativeAppWindowViewsAura::UpdateDraggableRegions(regions);
+
+#if defined(MOJO_SHELL_CLIENT)
+  SkRegion* draggable_region = GetDraggableRegion();
+  // Set the NativeAppWindow's draggable region on the mus window.
+  if (draggable_region && !draggable_region->isEmpty() && widget() &&
+      GetMusWindow(widget()->GetNativeWindow())) {
+    // Supply client area insets that encompass all draggable regions.
+    gfx::Insets insets(draggable_region->getBounds().bottom(), 0, 0, 0);
+
+    // Invert the draggable regions to determine the additional client areas.
+    SkRegion inverted_region;
+    inverted_region.setRect(draggable_region->getBounds());
+    inverted_region.op(*draggable_region, SkRegion::kDifference_Op);
+    std::vector<gfx::Rect> additional_client_regions;
+    for (SkRegion::Iterator i(inverted_region); !i.done(); i.next())
+      additional_client_regions.push_back(gfx::SkIRectToRect(i.rect()));
+
+    GetMusWindow(widget()->GetNativeWindow())
+        ->SetClientArea(insets, std::move(additional_client_regions));
+  }
+#endif
+}