Broke out layout metric information from ViewsDelegate to LayoutProvider

chrome/browser/ui/views/harmony/chrome_layout_delegate.h

+// 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.
+
+#ifndef CHROME_BROWSER_UI_VIEWS_HARMONY_CHROME_LAYOUT_DELEGATE_H_
+#define CHROME_BROWSER_UI_VIEWS_HARMONY_CHROME_LAYOUT_DELEGATE_H_
+
+#include <memory>
+
+#include "base/macros.h"
+#include "ui/gfx/geometry/insets.h"
+#include "ui/views/layout/grid_layout.h"
+#include "ui/views/layout/layout_delegate.h"
+
+enum class ChromeInsetsMetric {

[Peter Kasting, 2017/04/06 08:13:36]

Seems like we don't even need this class or the chrome-side-specific
GetInsetsMetric() function, if we're not adding any new values on this side.

(Do you think we're imminently going to add new values?)

[kylix_rd, 2017/04/06 16:48:19]

As I worked on this patch, I saw several places in the code that would likely
require a chrome-side-specific Inset. I didn't change them at this point since
this is more about the underlying mechanism. I suppose it all depends on what is
a reasonable notion of "imminently". I would say its likely within the next
couple of weeks.

[kylix_rd, 2017/04/07 18:33:36]

I went ahead and removed the override for GetInsetsMetric(). My reasoning for
keeping in it was that it would serve as a proper boilerplate for any additions
required on the Chrome side. However, the GetDistanceMetric() override clearly
demonstrates this, so my concern is a bit flat. This is regardless of which enum
approach we settle on.

+  BUBBLE_DIALOG = views::InsetsMetric::BUBBLE_DIALOG,
+  DIALOG_BUTTON = views::InsetsMetric::DIALOG_BUTTON,
+  DIALOG_FRAME_VIEW = views::InsetsMetric::DIALOG_FRAME_VIEW,
+  PANEL = views::InsetsMetric::PANEL,
+  VECTOR_IMAGE_BUTTON = views::InsetsMetric::VECTOR_IMAGE_BUTTON,
+};
+
+enum class ChromeDistanceMetric {
+  BUTTON_HORIZONTAL_PADDING = views::DistanceMetric::BUTTON_HORIZONTAL_PADDING,
+  CLOSE_BUTTON_MARGIN = views::DistanceMetric::CLOSE_BUTTON_MARGIN,
+  DIALOG_BUTTON_MINIMUM_WIDTH =
+      views::DistanceMetric::DIALOG_BUTTON_MINIMUM_WIDTH,
+  RELATED_BUTTON_HORIZONTAL = views::DistanceMetric::RELATED_BUTTON_HORIZONTAL,
+  RELATED_CONTROL_HORIZONTAL =
+      views::DistanceMetric::RELATED_CONTROL_HORIZONTAL,
+  RELATED_CONTROL_VERTICAL = views::DistanceMetric::RELATED_CONTROL_VERTICAL,
+  // Margin between the edge of a dialog and the left, right, or bottom of a

[Peter Kasting, 2017/04/06 08:13:36]

Nit: Maybe blank line above this?

[kylix_rd, 2017/04/06 16:48:19]

Done.

+  // contained button.
+  DIALOG_BUTTON_MARGIN,
+  // Spacing between a dialog button and the content above it.
+  DIALOG_BUTTON_TOP,
+  // Horizontal or vertical margin between the edge of a panel and the
+  // contained content.
+  PANEL_CONTENT_MARGIN,
+  // The maximum width a button can have and still influence the sizes of
+  // other linked buttons.  This allows short buttons to have linked widths
+  // without long buttons making things overly wide.
+  BUTTON_MAX_LINKABLE_WIDTH,
+  // Default minimum width of a button.
+  BUTTON_MINIMUM_WIDTH,
+  // Smaller horizontal spacing between other controls that are logically
+  // related.
+  RELATED_CONTROL_HORIZONTAL_SMALL,
+  // Smaller vertical spacing between controls that are logically related.
+  RELATED_CONTROL_VERTICAL_SMALL,
+  // Horizontal spacing between an item such as an icon or checkbox and a
+  // label related to it.
+  RELATED_LABEL_HORIZONTAL,
+  // Horizontal indent of a subsection relative to related items above, e.g.
+  // checkboxes below explanatory text/headings.
+  SUBSECTION_HORIZONTAL_INDENT,
+  // Horizontal spacing between controls that are logically unrelated.
+  UNRELATED_CONTROL_HORIZONTAL,
+  // Larger horizontal spacing between unrelated controls.
+  UNRELATED_CONTROL_HORIZONTAL_LARGE,
+  // Vertical spacing between controls that are logically unrelated.
+  UNRELATED_CONTROL_VERTICAL,
+  // Larger vertical spacing between unrelated controls.
+  UNRELATED_CONTROL_VERTICAL_LARGE,
+};
+
+enum class DialogWidth {
+  SMALL,
+  MEDIUM,
+  LARGE,
+};
+
+class ChromeLayoutDelegate : public views::LayoutDelegate {
+ public:
+  ChromeLayoutDelegate();
+  ~ChromeLayoutDelegate() override;
+
+  static ChromeLayoutDelegate* Get();
+  static std::unique_ptr<views::LayoutDelegate> CreateLayoutDelegate();
+
+  virtual gfx::Insets GetInsetsMetric(ChromeInsetsMetric metric) const;
+  virtual int GetDistanceMetric(ChromeDistanceMetric metric) const;
+
+  const views::TypographyProvider& GetTypographyProvider() const override;
+
+  // Returns the alignment used for control labels in a GridLayout; for example,
+  // in this GridLayout:
+  //   ---------------------------
+  //   | Label 1      Checkbox 1 |
+  //   | Label 2      Checkbox 2 |
+  //   ---------------------------
+  // This value controls the alignment used for "Label 1" and "Label 2".
+  virtual views::GridLayout::Alignment GetControlLabelGridAlignment() const;
+
+  // Returns whether to use extra padding on dialogs. If this is false, content
+  // Views for dialogs should not insert extra padding at their own edges.
+  virtual bool UseExtraDialogPadding() const;
+
+  // Returns whether to show the icon next to the title text on a dialog.
+  virtual bool ShouldShowWindowIcon() const;
+
+  // DEPRECATED.  Returns whether Harmony mode is enabled.
+  //
+  // Instead of using this, create a generic solution that works for all UI
+  // types, e.g. by adding a new LayoutDistance value that means what you need.
+  //
+  // TODO(pkasting): Fix callers and remove this.
+  virtual bool IsHarmonyMode() const;
+
+  // Returns the preferred width in DIPs for a dialog of the specified |width|.
+  // May return 0 if the dialog has no preferred width.
+  virtual int GetDialogPreferredWidth(DialogWidth width) const;
+
+ private:
+  gfx::Insets GetInsetsMetric(views::InsetsMetric metric) const override;
+  int GetDistanceMetric(views::DistanceMetric metric) const override;
+
+  DISALLOW_COPY_AND_ASSIGN(ChromeLayoutDelegate);
+};
+
+#endif  // CHROME_BROWSER_UI_VIEWS_HARMONY_CHROME_LAYOUT_DELEGATE_H_