mash: Fix ShelfItem mojo struct; add enums and traits.

ash/public/interfaces/shelf_struct_traits.cc

+// Copyright 2017 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 "ash/public/interfaces/shelf_struct_traits.h"
+
+#include "mojo/common/common_custom_types_struct_traits.h"
+#include "skia/public/interfaces/bitmap_skbitmap_struct_traits.h"
+#include "ui/gfx/image/image_skia.h"
+
+namespace mojo {
+
+// static
+ash::ShelfItemType StructTraits<ash::mojom::ShelfItemDataView,

[James Cook, 2017/03/16 16:48:50]

optional: Is it possible to do "using ash::mojom::ShelfItemDataView" to improve
line wrapping in this file?

also optional: That might give you enough space to change "i" to "item"

[msw, 2017/03/16 23:15:50]

I defined these inline for efficiency gains, at Yuzhu's suggestion.

+                                ash::ShelfItem>::type(const ash::ShelfItem& i) {
+  return i.type;
+}
+
+// static
+const SkBitmap& StructTraits<ash::mojom::ShelfItemDataView,
+                             ash::ShelfItem>::image(const ash::ShelfItem& i) {
+  // TODO(msw): Remove this when we have a gfx::Image[Skia] mojom.
+  static const SkBitmap kNullSkBitmap;
+  return i.image.isNull() ? kNullSkBitmap : *i.image.bitmap();
+}
+
+// static
+int64_t StructTraits<ash::mojom::ShelfItemDataView, ash::ShelfItem>::shelf_id(
+    const ash::ShelfItem& i) {
+  return i.id;
+}
+
+// static
+ash::ShelfItemStatus
+StructTraits<ash::mojom::ShelfItemDataView, ash::ShelfItem>::status(
+    const ash::ShelfItem& i) {
+  return i.status;
+}
+
+// static
+const std::string&
+StructTraits<ash::mojom::ShelfItemDataView, ash::ShelfItem>::app_id(
+    const ash::ShelfItem& i) {
+  return i.app_id;
+}
+
+// static
+const base::string16&
+StructTraits<ash::mojom::ShelfItemDataView, ash::ShelfItem>::title(
+    const ash::ShelfItem& i) {
+  return i.title;
+}
+
+// static
+bool StructTraits<ash::mojom::ShelfItemDataView, ash::ShelfItem>::shows_tooltip(
+    const ash::ShelfItem& i) {
+  return i.shows_tooltip;
+}
+
+// static
+bool StructTraits<ash::mojom::ShelfItemDataView,
+                  ash::ShelfItem>::pinned_by_policy(const ash::ShelfItem& i) {
+  return i.pinned_by_policy;
+}
+
+// static
+bool StructTraits<ash::mojom::ShelfItemDataView, ash::ShelfItem>::Read(
+    ash::mojom::ShelfItemDataView data,
+    ash::ShelfItem* out) {
+  SkBitmap image;
+  if (!data.ReadType(&out->type) || !data.ReadImage(&image) ||
+      !data.ReadStatus(&out->status) || !data.ReadAppId(&out->app_id) ||
+      !data.ReadTitle(&out->title)) {
+    return false;
+  }
+  out->id = data.shelf_id();
+  out->image = gfx::ImageSkia::CreateFrom1xBitmap(image);

[James Cook, 2017/03/16 16:48:50]

This needs a TODO or bug -- I think we support 2x bitmaps for high DPI icons. If
we do, and we convert to mojo for classic ash, we might break that.

[Tom Sepez, 2017/03/16 17:59:25]

Can this fail?

[msw, 2017/03/16 23:15:50]

Done.

[msw, 2017/03/16 23:15:50]

It seems the returned ImageSkia instance is always valid but may be isNull(). It
still seems okay to return true in that case; it's not technically a requirement
that a ShelfItem have a non-empty image icon.

+  out->shows_tooltip = data.shows_tooltip();
+  out->pinned_by_policy = data.pinned_by_policy();
+  return true;
+}
+
+}  // namespace mojo