Change ui cursor identifiers to an enum class.

ui/base/cursor/cursor.h

 // Copyright (c) 2012 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 UI_BASE_CURSOR_CURSOR_H_
 #define UI_BASE_CURSOR_CURSOR_H_
 
 #include "build/build_config.h"
 #include "ui/base/ui_base_export.h"
 
 #if defined(OS_WIN)
 typedef struct HINSTANCE__* HINSTANCE;
 typedef struct HICON__* HICON;
 typedef HICON HCURSOR;
 #endif
 
 namespace ui {
 
 #if defined(OS_WIN)
 typedef ::HCURSOR PlatformCursor;
 #elif defined(USE_X11)
 typedef unsigned long PlatformCursor;
 #else
 typedef void* PlatformCursor;
 #endif
 
-// TODO(jamescook): Once we're on C++0x we could change these constants
-// to an enum and forward declare it in native_widget_types.h.
+enum class CursorType {
+  // Equivalent to a NULL HCURSOR on Windows.
+  CURSOR_NULL = 0,

[sky, 2017/04/24 20:12:43]

Sorry to mention this here, but the new style is kFoo, e.g. kNull here. The
style guide allows both, but says, "new code should prefer constant-style naming
if possible.".

[Elliot Glaysher, 2017/04/25 17:16:45]

Done.

 
-// Equivalent to a NULL HCURSOR on Windows.
-const int kCursorNull = 0;
+  // These cursors mirror WebKit cursors from WebCursorInfo, but are replicated
+  // here so we don't introduce a WebKit dependency.
+  POINTER = 1,
+  CROSS = 2,
+  HAND = 3,
+  IBEAM = 4,
+  WAIT = 5,
+  HELP = 6,
+  EAST_RESIZE = 7,
+  NORTH_RESIZE = 8,
+  NORTH_EAST_RESIZE = 9,
+  NORTH_WEST_RESIZE = 10,
+  SOUTH_RESIZE = 11,
+  SOUTH_EAST_RESIZE = 12,
+  SOUTH_WEST_RESIZE = 13,
+  WEST_RESIZE = 14,
+  NORTH_SOUTH_RESIZE = 15,
+  EAST_WEST_RESIZE = 16,
+  NORTH_EAST_SOUTH_WEST_RESIZE = 17,
+  NORTH_WEST_SOUTH_EAST_RESIZE = 18,
+  COLUMN_RESIZE = 19,
+  ROW_RESIZE = 20,
+  MIDDLE_PANNING = 21,
+  EAST_PANNING = 22,
+  NORTH_PANNING = 23,
+  NORTH_EAST_PANNING = 24,
+  NORTH_WEST_PANNING = 25,
+  SOUTH_PANNING = 26,
+  SOUTH_EAST_PANNING = 27,
+  SOUTH_WEST_PANNING = 28,
+  WEST_PANNING = 29,
+  MOVE = 30,
+  VERTICAL_TEXT = 31,
+  CELL = 32,
+  CONTEXT_MENU = 33,
+  ALIAS = 34,
+  PROGRESS = 35,
+  NO_DROP = 36,
+  COPY = 37,
+  NONE = 38,
+  NOT_ALLOWED = 39,
+  ZOOM_IN = 40,
+  ZOOM_OUT = 41,
+  GRAB = 42,
+  GRABBING = 43,
+  CUSTOM = 44,
 
-// These cursors mirror WebKit cursors from WebCursorInfo, but are replicated
-// here so we don't introduce a WebKit dependency.
-const int kCursorPointer = 1;
-const int kCursorCross = 2;
-const int kCursorHand = 3;
-const int kCursorIBeam = 4;
-const int kCursorWait = 5;
-const int kCursorHelp = 6;
-const int kCursorEastResize = 7;
-const int kCursorNorthResize = 8;
-const int kCursorNorthEastResize = 9;
-const int kCursorNorthWestResize = 10;
-const int kCursorSouthResize = 11;
-const int kCursorSouthEastResize = 12;
-const int kCursorSouthWestResize = 13;
-const int kCursorWestResize = 14;
-const int kCursorNorthSouthResize = 15;
-const int kCursorEastWestResize = 16;
-const int kCursorNorthEastSouthWestResize = 17;
-const int kCursorNorthWestSouthEastResize = 18;
-const int kCursorColumnResize = 19;
-const int kCursorRowResize = 20;
-const int kCursorMiddlePanning = 21;
-const int kCursorEastPanning = 22;
-const int kCursorNorthPanning = 23;
-const int kCursorNorthEastPanning = 24;
-const int kCursorNorthWestPanning = 25;
-const int kCursorSouthPanning = 26;
-const int kCursorSouthEastPanning = 27;
-const int kCursorSouthWestPanning = 28;
-const int kCursorWestPanning = 29;
-const int kCursorMove = 30;
-const int kCursorVerticalText = 31;
-const int kCursorCell = 32;
-const int kCursorContextMenu = 33;
-const int kCursorAlias = 34;
-const int kCursorProgress = 35;
-const int kCursorNoDrop = 36;
-const int kCursorCopy = 37;
-const int kCursorNone = 38;
-const int kCursorNotAllowed = 39;
-const int kCursorZoomIn = 40;
-const int kCursorZoomOut = 41;
-const int kCursorGrab = 42;
-const int kCursorGrabbing = 43;
-const int kCursorCustom = 44;
-const int kCursorDndNone = 45;
-const int kCursorDndMove = 46;
-const int kCursorDndCopy = 47;
-const int kCursorDndLink = 48;
+  // These additional drag and drop cursors are not listed in WebCursorInfo.
+  DND_NONE = 45,
+  DND_MOVE = 46,
+  DND_COPY = 47,
+  DND_LINK = 48,
+};
 
 enum CursorSetType {
   CURSOR_SET_NORMAL,
   CURSOR_SET_LARGE
 };
 
 // Ref-counted cursor that supports both default and custom cursors.
 class UI_BASE_EXPORT Cursor {
  public:
   Cursor();
 
   // Implicit constructor.
-  Cursor(int type);
+  Cursor(CursorType type);

[sky, 2017/04/24 20:12:43]

explicit (I'm not sure why it wasn't explicit before).

[Elliot Glaysher, 2017/04/25 17:16:45]

This can't be explicit.

gfx::NativeCursor is the typedef used in cross platform code to pass cursors
around. It is only a ui::Cursor on USE_AURA. Everywhere else it is a pointer
type, and the integer (now enum) is coerced to the underlying pointer type
instead of implicit construction.

 
   // Allow copy.
   Cursor(const Cursor& cursor);
 
   ~Cursor();
 
   void SetPlatformCursor(const PlatformCursor& platform);
 
   void RefCustomCursor();
   void UnrefCustomCursor();
 
-  int native_type() const { return native_type_; }
+  CursorType native_type() const { return native_type_; }
   PlatformCursor platform() const { return platform_cursor_; }
   float device_scale_factor() const {
     return device_scale_factor_;
   }
   void set_device_scale_factor(float device_scale_factor) {
     device_scale_factor_ = device_scale_factor;
   }
 
-  bool operator==(int type) const { return native_type_ == type; }
+  bool operator==(CursorType type) const { return native_type_ == type; }
   bool operator==(const Cursor& cursor) const {
     return native_type_ == cursor.native_type_ &&
            platform_cursor_ == cursor.platform_cursor_ &&
            device_scale_factor_ == cursor.device_scale_factor_;
   }
-  bool operator!=(int type) const { return native_type_ != type; }
+  bool operator!=(CursorType type) const { return native_type_ != type; }
   bool operator!=(const Cursor& cursor) const {
     return native_type_ != cursor.native_type_ ||
            platform_cursor_ != cursor.platform_cursor_ ||
            device_scale_factor_ != cursor.device_scale_factor_;
   }
 
   void operator=(const Cursor& cursor) {
     Assign(cursor);
   }
 
  private:
   void Assign(const Cursor& cursor);
 
   // See definitions above.
-  int native_type_;
+  CursorType native_type_;
 
   PlatformCursor platform_cursor_;
 
   // The device scale factor for the cursor.
   float device_scale_factor_;
 };
 
 }  // namespace ui
 
 #endif  // UI_BASE_CURSOR_CURSOR_H_