Broke out layout metric information from ViewsDelegate to LayoutProvider

ui/views/layout/layout_provider.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 "ui/views/layout/layout_provider.h"
+
+#include "base/logging.h"
+#include "base/memory/ptr_util.h"
+#include "ui/base/material_design/material_design_controller.h"
+#include "ui/views/layout/layout_constants.h"
+#include "ui/views/views_delegate.h"
+
+namespace views {
+
+namespace {
+static LayoutProvider* g_layout_delegate = nullptr;

[sky, 2017/04/12 22:43:57]

We generally don't use static in cases like this.

[kylix_rd, 2017/04/13 16:45:42]

Done.

+}
+
+LayoutProvider::LayoutProvider() {
+  g_layout_delegate = this;

[sky, 2017/04/12 22:43:57]

DCHECK(g_layout_delegate == nullptr)?

[kylix_rd, 2017/04/13 16:45:42]

This cannot be done because there are cases where a default base layout provider
is created and then later a more specific one may be created. This will ensure
that the "last one created, wins". See the unit tests where
set_layout_provider() is called.

+}
+
+LayoutProvider::~LayoutProvider() {
+  if (this == g_layout_delegate)
+    g_layout_delegate = nullptr;
+}
+
+// static
+LayoutProvider* LayoutProvider::Get() {
+  return g_layout_delegate;
+}
+
+gfx::Insets LayoutProvider::GetInsetsMetric(int metric) const {
+  DCHECK_LT(metric, VIEWS_INSETS_MAX);
+  switch (metric) {
+    case InsetsMetric::INSETS_DIALOG_BUTTON:
+      return gfx::Insets(0, kButtonHEdgeMarginNew, kButtonVEdgeMarginNew,
+                         kButtonHEdgeMarginNew);
+    case InsetsMetric::INSETS_DIALOG_TITLE:
+      return gfx::Insets(kPanelVertMargin, kButtonHEdgeMarginNew, 0,
+                         kButtonHEdgeMarginNew);
+    case InsetsMetric::INSETS_BUBBLE_CONTENTS:
+      return gfx::Insets(kPanelVertMargin, kPanelHorizMargin);
+    case InsetsMetric::INSETS_PANEL:
+      return gfx::Insets(kPanelVertMargin, kButtonHEdgeMarginNew);
+    case InsetsMetric::INSETS_VECTOR_IMAGE_BUTTON:
+      return gfx::Insets(kVectorButtonExtraTouchSize);
+  }
+  NOTREACHED();
+  return gfx::Insets();
+}
+
+int LayoutProvider::GetDistanceMetric(int metric) const {
+  DCHECK_GE(metric, VIEWS_INSETS_MAX);
+  switch (metric) {
+    case DistanceMetric::DISTANCE_CLOSE_BUTTON_MARGIN:
+      return kCloseButtonMargin;
+    case DistanceMetric::DISTANCE_RELATED_BUTTON_HORIZONTAL:
+      return kRelatedButtonHSpacing;
+    case DistanceMetric::DISTANCE_RELATED_CONTROL_HORIZONTAL:
+      return kRelatedControlHorizontalSpacing;
+    case DistanceMetric::DISTANCE_RELATED_CONTROL_VERTICAL:
+      return kRelatedControlVerticalSpacing;
+    case DistanceMetric::DISTANCE_DIALOG_BUTTON_MINIMUM_WIDTH:
+      return kDialogMinimumButtonWidth;
+    case DistanceMetric::DISTANCE_BUTTON_HORIZONTAL_PADDING:
+      return kButtonHorizontalPadding;
+  }
+  NOTREACHED();
+  return 0;
+}
+
+const TypographyProvider& LayoutProvider::GetTypographyProvider() const {
+  return typography_provider_;
+}
+
+}  // namespace views