Broke out layout metric information from ViewsDelegate to LayoutProvider

chrome/browser/ui/views/harmony/chrome_views_layout_delegate.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 "chrome/browser/ui/views/harmony/chrome_views_layout_delegate.h"
+
+#include "base/logging.h"
+#include "base/memory/ptr_util.h"
+#include "chrome/browser/ui/views/harmony/layout_delegate.h"
+// #include "chrome/browser/ui/views/harmony/harmony_views_layout_delegate.h"
+#include "ui/base/material_design/material_design_controller.h"
+#include "ui/views/layout/layout_constants.h"
+
+namespace {
+
+ChromeViewsLayoutDelegate* layout_delegate_ = nullptr;
+}
+
+ChromeViewsLayoutDelegate::ChromeViewsLayoutDelegate() {
+  DCHECK(!layout_delegate_);
+  layout_delegate_ = this;
+}
+
+ChromeViewsLayoutDelegate::~ChromeViewsLayoutDelegate() {
+  DCHECK_EQ(this, layout_delegate_);
+  layout_delegate_ = nullptr;
+}
+
+// static
+ChromeViewsLayoutDelegate* ChromeViewsLayoutDelegate::Get() {
+  return layout_delegate_;

[Peter Kasting, 2017/03/24 22:51:13]

It still seems like this could just be

  return static_cast<ChromeViewsLayoutDelegate*>(ViewsLayoutDelegate::Get());

The distinction is that if someone tried to call this method after having
created a ViewsLayoutDelegate (instead of a ChromeViewsLayoutDelegate), your
implementation would return null, while mine would trigger UB.  It doesn't seem
like that's worth tracking |layout_delegate_|, since code trying to call this
should have guaranteed it created the right kind of delegate already?

[kylix_rd, 2017/03/27 18:18:27]

I was also trying to avoid an unsafe downcast.

[Peter Kasting, 2017/03/27 20:06:48]

Right, that's what I was saying I didn't think was worth the extra tracking
complexity, since we shouldn't get into that scenario, and if we do we don't
handle it today anyway.

[kylix_rd, 2017/03/29 18:56:04]

Once I've verified that any calls to ChromeViewsLayoutDelegate::Get() will never
return null, then I'll feel more comfortable with removing this global and
coalescing it with the one from ViewsLayoutGlobal::Get().

[Peter Kasting, 2017/04/04 02:08:50]

Was this something you were going to do before landing this patch?  If not,
should it have a TODO somewhere?

+}
+
+// static
+std::unique_ptr<views::ViewsLayoutDelegate>
+ChromeViewsLayoutDelegate::CreateLayoutDelegate() {
+  return ui::MaterialDesignController::IsSecondaryUiMaterial()
+             ? base::MakeUnique<ChromeViewsLayoutDelegate>()
+             : base::MakeUnique<ChromeViewsLayoutDelegate>();
+}
+
+gfx::Insets ChromeViewsLayoutDelegate::GetInsetsMetric(
+    ChromeInsetsMetric metric) const {
+  const LayoutDelegate* layout_delegate = LayoutDelegate::Get();
+  switch (metric) {
+    case ChromeInsetsMetric::DIALOG_BUTTON: {
+      const int top = layout_delegate->GetMetric(
+          LayoutDelegate::Metric::DIALOG_BUTTON_TOP_SPACING);
+      const int margin = layout_delegate->GetMetric(
+          LayoutDelegate::Metric::DIALOG_BUTTON_MARGIN);
+      return gfx::Insets(top, margin, margin, margin);
+    }
+    case ChromeInsetsMetric::DIALOG_FRAME_VIEW: {
+      const int top = layout_delegate->GetMetric(
+          LayoutDelegate::Metric::PANEL_CONTENT_MARGIN);
+      const int side = layout_delegate->GetMetric(
+          LayoutDelegate::Metric::DIALOG_BUTTON_MARGIN);
+      // Titles are inset at the top and sides, but not at the bottom.
+      return gfx::Insets(top, side, 0, side);
+    }
+    case ChromeInsetsMetric::BUBBLE_DIALOG:
+      return gfx::Insets(layout_delegate->GetMetric(
+          LayoutDelegate::Metric::PANEL_CONTENT_MARGIN));
+    case ChromeInsetsMetric::PANEL_LAYOUT:
+      return gfx::Insets(
+          GetDistanceMetric(ChromeDistanceMetric::PANEL_CONTENT_MARGIN),
+          GetDistanceMetric(ChromeDistanceMetric::DIALOG_BUTTON_MARGIN));
+  }
+  NOTREACHED();
+  return gfx::Insets();
+}
+
+int ChromeViewsLayoutDelegate::GetDistanceMetric(
+    ChromeDistanceMetric metric) const {
+  switch (metric) {
+    case ChromeDistanceMetric::CLOSE_BUTTON_MARGIN:
+      return LayoutDelegate::Get()->GetMetric(
+          LayoutDelegate::Metric::DIALOG_CLOSE_BUTTON_MARGIN);
+    case ChromeDistanceMetric::RELATED_BUTTON_HORIZONTAL:
+      return LayoutDelegate::Get()->GetMetric(
+          LayoutDelegate::Metric::RELATED_BUTTON_HORIZONTAL_SPACING);
+    case ChromeDistanceMetric::RELATED_CONTROL_HORIZONTAL:
+      return LayoutDelegate::Get()->GetMetric(
+          LayoutDelegate::Metric::RELATED_CONTROL_HORIZONTAL_SPACING);
+    case ChromeDistanceMetric::RELATED_CONTROL_VERTICAL:
+      return LayoutDelegate::Get()->GetMetric(
+          LayoutDelegate::Metric::RELATED_CONTROL_VERTICAL_SPACING);
+    case ChromeDistanceMetric::DIALOG_BUTTON_MARGIN:
+      return LayoutDelegate::Get()->GetMetric(
+          LayoutDelegate::Metric::DIALOG_BUTTON_MARGIN);
+    case ChromeDistanceMetric::DIALOG_BUTTON_MINIMUM_WIDTH:
+      return LayoutDelegate::Get()->GetMetric(
+          LayoutDelegate::Metric::DIALOG_BUTTON_MINIMUM_WIDTH);
+    case ChromeDistanceMetric::BUTTON_HORIZONTAL_PADDING:
+      return LayoutDelegate::Get()->GetMetric(
+          LayoutDelegate::Metric::BUTTON_HORIZONTAL_PADDING);
+    case ChromeDistanceMetric::BUTTON_MAX_LINKABLE_WIDTH:
+      return LayoutDelegate::Get()->GetMetric(
+          LayoutDelegate::Metric::BUTTON_MAX_LINKABLE_WIDTH);
+    case ChromeDistanceMetric::BUTTON_MINIMUM_WIDTH:
+      return LayoutDelegate::Get()->GetMetric(
+          LayoutDelegate::Metric::BUTTON_MINIMUM_WIDTH);
+    case ChromeDistanceMetric::SUBSECTION_HORIZONTAL_INDENT:
+      return LayoutDelegate::Get()->GetMetric(
+          LayoutDelegate::Metric::SUBSECTION_HORIZONTAL_INDENT);
+    case ChromeDistanceMetric::PANEL_CONTENT_MARGIN:
+      return LayoutDelegate::Get()->GetMetric(
+          LayoutDelegate::Metric::PANEL_CONTENT_MARGIN);
+    case ChromeDistanceMetric::UNRELATED_CONTROL_HORIZONTAL:
+      return LayoutDelegate::Get()->GetMetric(
+          LayoutDelegate::Metric::UNRELATED_CONTROL_HORIZONTAL_SPACING);
+    case ChromeDistanceMetric::UNRELATED_CONTROL_HORIZONTAL_LARGE:
+      return LayoutDelegate::Get()->GetMetric(
+          LayoutDelegate::Metric::UNRELATED_CONTROL_HORIZONTAL_SPACING_LARGE);
+    case ChromeDistanceMetric::UNRELATED_CONTROL_VERTICAL:
+      return LayoutDelegate::Get()->GetMetric(
+          LayoutDelegate::Metric::UNRELATED_CONTROL_VERTICAL_SPACING);
+    case ChromeDistanceMetric::UNRELATED_CONTROL_VERTICAL_LARGE:
+      return LayoutDelegate::Get()->GetMetric(
+          LayoutDelegate::Metric::UNRELATED_CONTROL_VERTICAL_SPACING_LARGE);
+  }
+  NOTREACHED();
+  return 0;
+}
+
+const views::TypographyProvider&
+ChromeViewsLayoutDelegate::GetTypographyProvider() const {
+  return LayoutDelegate::Get()->GetTypographyProvider();
+}
+
+views::GridLayout::Alignment
+ChromeViewsLayoutDelegate::GetControlLabelGridAlignment() const {
+  return LayoutDelegate::Get()->GetControlLabelGridAlignment();
+}
+
+bool ChromeViewsLayoutDelegate::UseExtraDialogPadding() const {
+  return LayoutDelegate::Get()->UseExtraDialogPadding();
+}
+
+bool ChromeViewsLayoutDelegate::ShouldShowWindowIcon() const {
+  return LayoutDelegate::Get()->ShouldShowWindowIcon();
+}
+
+bool ChromeViewsLayoutDelegate::IsHarmonyMode() const {
+  return false;
+}
+
+int ChromeViewsLayoutDelegate::GetDialogPreferredWidth(
+    DialogWidth width) const {
+  return LayoutDelegate::Get()->GetDialogPreferredWidth(
+      static_cast<LayoutDelegate::DialogWidth>(width));
+}
+
+int ChromeViewsLayoutDelegate::GetDefaultDistanceMetric(
+    views::DistanceMetric metric) const {
+  return views::ViewsLayoutDelegate::GetDistanceMetric(metric);
+}
+
+gfx::Insets ChromeViewsLayoutDelegate::GetInsetsMetric(
+    views::InsetsMetric metric) const {
+  return GetInsetsMetric(static_cast<ChromeInsetsMetric>(metric));
+}
+
+int ChromeViewsLayoutDelegate::GetDistanceMetric(
+    views::DistanceMetric metric) const {
+  return GetDistanceMetric(static_cast<ChromeDistanceMetric>(metric));
+}