Fix basic ash shelf layout in mash shell

Support bottom-alignment for the mash shelf and status area.
Don't set widget bounds in ash's layout manager for mash.
(The mash layout manager sets window bounds instead)

Make ShelfDelegateMus::OnShelfCreated set preferred sizes.
(needed by the mash shelf layout manager for placement)

Add AshWindowType enum and set it as a window property.
(needed by the mash shelf layout manager to discern windows)

BUG=557406
TEST=mash_shell supports shelf and status area bottom-alignment.
R=sky@chromium.org

Review URL: https://codereview.chromium.org/1709843003

Cr-Commit-Position: refs/heads/master@{#377727}

3 files changed, 40 insertions, 7 deletions

diff --git a/mash/wm/public/interfaces/BUILD.gn b/mash/wm/public/interfaces/BUILD.gn
index 65b21b4..5bc2601 100644
--- a/mash/wm/public/interfaces/BUILD.gn
+++ b/mash/wm/public/interfaces/BUILD.gn
@@ -6,6 +6,7 @@ import("//mojo/public/tools/bindings/mojom.gni")
 
 mojom("interfaces") {
   sources = [
+    "ash_window_type.mojom",
     "container.mojom",
     "user_window_controller.mojom",
   ]
diff --git a/mash/wm/public/interfaces/ash_window_type.mojom b/mash/wm/public/interfaces/ash_window_type.mojom
new file mode 100644
index 0000000..b4359b3
--- /dev/null
+++ b/mash/wm/public/interfaces/ash_window_type.mojom
@@ -0,0 +1,13 @@
+// Copyright 2016 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.
+
+module mash.wm.mojom;
+
+enum AshWindowType {
+  SHELF = 0,
+  STATUS_AREA,
+  COUNT
+};
+
+const string kAshWindowType_Property = "ash:window-type";
diff --git a/mash/wm/shelf_layout.cc b/mash/wm/shelf_layout.cc
index c2fe1ba..7aa3f9d 100644
--- a/mash/wm/shelf_layout.cc
+++ b/mash/wm/shelf_layout.cc
@@ -8,14 +8,28 @@
 #include "components/mus/public/cpp/window.h"
 #include "components/mus/public/cpp/window_property.h"
 #include "mash/wm/property_util.h"
+#include "mash/wm/public/interfaces/ash_window_type.mojom.h"
 #include "ui/gfx/geometry/rect.h"
 
 namespace mash {
 namespace wm {
 
+namespace {
+
+mojom::AshWindowType GetAshWindowType(const mus::Window* window) {
+  if (!window->HasSharedProperty(mojom::kAshWindowType_Property))
+    return mojom::AshWindowType::COUNT;
+
+  return static_cast<mojom::AshWindowType>(
+      window->GetSharedProperty<int32_t>(mojom::kAshWindowType_Property));
+}
+
+}  // namespace
+
 ShelfLayout::ShelfLayout(mus::Window* owner) : LayoutManager(owner) {
   AddLayoutProperty(mus::mojom::WindowManager::kPreferredSize_Property);
 }
+
 ShelfLayout::~ShelfLayout() {}
 
 // We explicitly don't make assertions about the number of children in this
@@ -23,13 +37,18 @@ ShelfLayout::~ShelfLayout() {}
 // shelf restarts.
 
 void ShelfLayout::LayoutWindow(mus::Window* window) {
-  gfx::Size preferred_size = GetWindowPreferredSize(window);
-
-  gfx::Rect container_bounds = owner()->bounds();
-  container_bounds.set_origin(
-      gfx::Point(0, container_bounds.height() - preferred_size.height()));
-  container_bounds.set_height(preferred_size.height());
-  window->SetBounds(container_bounds);
+  // TODO(msw): Support additional shelf alignments and RTL UI.
+  const gfx::Size size = GetWindowPreferredSize(window);
+  const int y = owner()->bounds().height() - size.height();
+  const mojom::AshWindowType ash_window_type = GetAshWindowType(window);
+  if (ash_window_type == mojom::AshWindowType::SHELF) {
+    window->SetBounds(gfx::Rect(0, y, size.width(), size.height()));
+  } else if (ash_window_type == mojom::AshWindowType::STATUS_AREA) {
+    window->SetBounds(gfx::Rect(owner()->bounds().width() - size.width(), y,
+                                size.width(), size.height()));
+  } else {
+    NOTREACHED() << "Unknown window in USER_SHELF container.";
+  }
 }
 
 }  // namespace wm