[Mac] Add gfx::ScreenPoint[To|From]NSPoint.

Similarly to ScreenRect[To|From]NSRect, we want to avoid a proliferation of the
following patterns for doing this conversion:

gfx::Point point(ns_point.x,
                 NSMaxY([[[NSScreen screens] objectAtIndex:0] frame]) - ns_point.y);

Or alternatively, creating an NSRect, converting with gfx::ScreenRectFromNSRect(),
and taking the origin.

BUG=None

Review URL: https://codereview.chromium.org/1287573002

Cr-Commit-Position: refs/heads/master@{#342914}

3 files changed, 58 insertions, 12 deletions

diff --git a/ui/gfx/mac/coordinate_conversion.h b/ui/gfx/mac/coordinate_conversion.h
index 3deec9a..3b75485 100644
--- a/ui/gfx/mac/coordinate_conversion.h
+++ b/ui/gfx/mac/coordinate_conversion.h
@@ -11,15 +11,24 @@
 
 namespace gfx {
 
+class Point;
 class Rect;
 
 // Convert a gfx::Rect specified with the origin at the top left of the primary
 // display into AppKit secreen coordinates (origin at the bottom left).
-GFX_EXPORT NSRect ScreenRectToNSRect(const gfx::Rect& rect);
+GFX_EXPORT NSRect ScreenRectToNSRect(const Rect& rect);
 
 // Convert an AppKit NSRect with origin in the bottom left of the primary
 // display into a gfx::Rect with origin at the top left of the primary display.
-GFX_EXPORT gfx::Rect ScreenRectFromNSRect(const NSRect& point);
+GFX_EXPORT Rect ScreenRectFromNSRect(const NSRect& point);
+
+// Convert a gfx::Point specified with the origin at the top left of the primary
+// display into AppKit screen coordinates (origin at the bottom left).
+GFX_EXPORT NSPoint ScreenPointToNSPoint(const Point& point);
+
+// Convert an AppKit NSPoint with origin in the bottom left of the primary
+// display into a gfx::Point with origin at the top left of the primary display.
+GFX_EXPORT Point ScreenPointFromNSPoint(const NSPoint& point);
 
 }  // namespace gfx
 
diff --git a/ui/gfx/mac/coordinate_conversion.mm b/ui/gfx/mac/coordinate_conversion.mm
index b2c41a4..54b16e9 100644
--- a/ui/gfx/mac/coordinate_conversion.mm
+++ b/ui/gfx/mac/coordinate_conversion.mm
@@ -6,6 +6,7 @@
 
 #import <Cocoa/Cocoa.h>
 
+#include "ui/gfx/geometry/point.h"
 #include "ui/gfx/geometry/rect.h"
 
 namespace gfx {
@@ -20,18 +21,25 @@ CGFloat PrimaryDisplayHeight() {
 
 }  // namespace
 
-NSRect ScreenRectToNSRect(const gfx::Rect& rect) {
+NSRect ScreenRectToNSRect(const Rect& rect) {
   return NSMakeRect(rect.x(),
                     PrimaryDisplayHeight() - rect.y() - rect.height(),
                     rect.width(),
                     rect.height());
 }
 
-gfx::Rect ScreenRectFromNSRect(const NSRect& rect) {
-  return gfx::Rect(rect.origin.x,
-                   PrimaryDisplayHeight() - rect.origin.y - rect.size.height,
-                   rect.size.width,
-                   rect.size.height);
+Rect ScreenRectFromNSRect(const NSRect& rect) {
+  return Rect(rect.origin.x,
+              PrimaryDisplayHeight() - rect.origin.y - rect.size.height,
+              rect.size.width, rect.size.height);
+}
+
+NSPoint ScreenPointToNSPoint(const Point& point) {
+  return NSMakePoint(point.x(), PrimaryDisplayHeight() - point.y());
+}
+
+Point ScreenPointFromNSPoint(const NSPoint& point) {
+  return Point(point.x, PrimaryDisplayHeight() - point.y);
 }
 
 }  // namespace gfx
diff --git a/ui/gfx/mac/coordinate_conversion_unittest.mm b/ui/gfx/mac/coordinate_conversion_unittest.mm
index ae49317..ac882fa 100644
--- a/ui/gfx/mac/coordinate_conversion_unittest.mm
+++ b/ui/gfx/mac/coordinate_conversion_unittest.mm
@@ -81,28 +81,57 @@ void MacCoordinateConversionTest::TearDown() {
 //  ..             ..
 //   0            199
 TEST_F(MacCoordinateConversionTest, ScreenRectToFromNSRect) {
+  // Window on the primary screen.
   Rect gfx_rect = Rect(10, 20, 30, 40);
   NSRect ns_rect = ScreenRectToNSRect(gfx_rect);
   EXPECT_NSEQ(NSMakeRect(10, 140, 30, 40), ns_rect);
-  EXPECT_EQ(gfx_rect.ToString(), ScreenRectFromNSRect(ns_rect).ToString());
+  EXPECT_EQ(gfx_rect, ScreenRectFromNSRect(ns_rect));
 
   // Window in a screen to the left of the primary screen.
   gfx_rect = Rect(-40, 20, 30, 40);
   ns_rect = ScreenRectToNSRect(gfx_rect);
   EXPECT_NSEQ(NSMakeRect(-40, 140, 30, 40), ns_rect);
-  EXPECT_EQ(gfx_rect.ToString(), ScreenRectFromNSRect(ns_rect).ToString());
+  EXPECT_EQ(gfx_rect, ScreenRectFromNSRect(ns_rect));
 
   // Window in a screen below the primary screen.
   gfx_rect = Rect(10, 220, 30, 40);
   ns_rect = ScreenRectToNSRect(gfx_rect);
   EXPECT_NSEQ(NSMakeRect(10, -60, 30, 40), ns_rect);
-  EXPECT_EQ(gfx_rect.ToString(), ScreenRectFromNSRect(ns_rect).ToString());
+  EXPECT_EQ(gfx_rect, ScreenRectFromNSRect(ns_rect));
 
   // Window in a screen below and to the left primary screen.
   gfx_rect = Rect(-40, 220, 30, 40);
   ns_rect = ScreenRectToNSRect(gfx_rect);
   EXPECT_NSEQ(NSMakeRect(-40, -60, 30, 40), ns_rect);
-  EXPECT_EQ(gfx_rect.ToString(), ScreenRectFromNSRect(ns_rect).ToString());
+  EXPECT_EQ(gfx_rect, ScreenRectFromNSRect(ns_rect));
+}
+
+// Test point conversions using the same setup as ScreenRectToFromNSRect, but
+// using only the origin.
+TEST_F(MacCoordinateConversionTest, ScreenPointToFromNSPoint) {
+  // Point on the primary screen.
+  Point gfx_point = Point(10, 20);
+  NSPoint ns_point = ScreenPointToNSPoint(gfx_point);
+  EXPECT_NSEQ(NSMakePoint(10, 180), ns_point);
+  EXPECT_EQ(gfx_point, ScreenPointFromNSPoint(ns_point));
+
+  // Point in a screen to the left of the primary screen.
+  gfx_point = Point(-40, 20);
+  ns_point = ScreenPointToNSPoint(gfx_point);
+  EXPECT_NSEQ(NSMakePoint(-40, 180), ns_point);
+  EXPECT_EQ(gfx_point, ScreenPointFromNSPoint(ns_point));
+
+  // Point in a screen below the primary screen.
+  gfx_point = Point(10, 220);
+  ns_point = ScreenPointToNSPoint(gfx_point);
+  EXPECT_NSEQ(NSMakePoint(10, -20), ns_point);
+  EXPECT_EQ(gfx_point, ScreenPointFromNSPoint(ns_point));
+
+  // Point in a screen below and to the left primary screen.
+  gfx_point = Point(-40, 220);
+  ns_point = ScreenPointToNSPoint(gfx_point);
+  EXPECT_NSEQ(NSMakePoint(-40, -20), ns_point);
+  EXPECT_EQ(gfx_point, ScreenPointFromNSPoint(ns_point));
 }
 
 }  // namespace gfx