MacViews: Implement basic NSEvent -> ui::Event conversion for Mac

ui/events/cocoa/events_mac_unittest.mm

 // Copyright 2014 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/events/cocoa/cocoa_event_utils.h"
+#include "ui/events/event_utils.h"
 
-#import <objc/objc-class.h>
+#import <Cocoa/Cocoa.h>
 
+#include "base/mac/scoped_cftyperef.h"
+#include "base/memory/scoped_ptr.h"
 #include "testing/gtest/include/gtest/gtest.h"
-#include "testing/platform_test.h"
 #include "ui/events/event_constants.h"
-#include "ui/events/event_utils.h"
 #import "ui/events/test/cocoa_test_event_utils.h"
+#include "ui/gfx/point.h"
 #import "ui/gfx/test/ui_cocoa_test_helper.h"
 
+namespace {
+
+NSWindow* g_test_window = nil;
+
+}  // namespace
+
+// Mac APIs for creating test events are frustrating. Quartz APIs have, e.g.,
+// CGEventCreateMouseEvent() which can't set a window or modifier flags.
+// Cocoa APIs have +[NSEvent mouseEventWithType:..] which can't set
+// buttonNumber or scroll deltas. To work around this, these tests use some
+// Objective C magic to donate member functions to NSEvent temporarily.
+@interface MiddleMouseButtonNumberDonor : NSObject
+@end
+
+@interface TestWindowDonor : NSObject
+@end
+
+@implementation MiddleMouseButtonNumberDonor
+- (NSUInteger)buttonNumber { return 2; }
+@end
+
+@implementation TestWindowDonor
+- (NSWindow*)window { return g_test_window; }
+@end
+
 namespace ui {
 
 namespace {
 
-class CocoaEventUtilsTest : public CocoaTest {
+class EventsMacTest : public CocoaTest {
+ public:
+  EventsMacTest() {}
+
+  gfx::Point Flip(gfx::Point window_location) {
+    window_location.set_y(
+        NSHeight([test_window() frame]) - window_location.y());
+    return window_location;
+  }
+
+  void SwizzleMiddleMouseButton() {
+    DCHECK(!swizzler_);
+    swizzler_.reset(new ScopedClassSwizzler(
+        [NSEvent class],
+        [MiddleMouseButtonNumberDonor class],
+        @selector(buttonNumber)));
+  }
+
+  void SwizzleTestWindow() {
+    DCHECK(!g_test_window);
+    DCHECK(!swizzler_);
+    g_test_window = test_window();
+    swizzler_.reset(new ScopedClassSwizzler(
+        [NSEvent class],
+        [TestWindowDonor class],
+        @selector(window)));
+  }
+
+  void ClearSwizzle() {
+    swizzler_.reset();
+    g_test_window = nil;
+  }
+
+  NSEvent* TestMouseEvent(NSEventType type,
+                          const gfx::Point &window_location,
+                          NSInteger modifier_flags) {
+    NSPoint point = NSPointFromCGPoint(Flip(window_location).ToCGPoint());
+    return [NSEvent mouseEventWithType:type
+                              location:point
+                         modifierFlags:modifier_flags
+                             timestamp:0
+                          windowNumber:[test_window() windowNumber]
+                               context:nil
+                           eventNumber:0
+                            clickCount:0
+                              pressure:1.0];
+  }
+
+  NSEvent* TestScrollEvent(const gfx::Point& window_location,
+                           int32_t delta_x,
+                           int32_t delta_y) {
+    SwizzleTestWindow();
+    base::ScopedCFTypeRef<CGEventRef> scroll(
+        CGEventCreateScrollWheelEvent(NULL,
+                                      kCGScrollEventUnitLine,
+                                      2,
+                                      delta_y,
+                                      delta_x));
+    // CGEvents are always in global display coordinates. These are like screen
+    // coordinates, but flipped. But first the point needs to be converted out
+    // of window coordinates (which also requires flipping).
+    NSPoint window_point =
+        NSPointFromCGPoint(Flip(window_location).ToCGPoint());
+    NSPoint screen_point = [test_window() convertBaseToScreen:window_point];
+    CGFloat primary_screen_height =
+        NSHeight([[[NSScreen screens] objectAtIndex:0] frame]);
+    screen_point.y = primary_screen_height - screen_point.y;
+    CGEventSetLocation(scroll, NSPointToCGPoint(screen_point));
+    return [NSEvent eventWithCGEvent:scroll];
+  }
+
+ private:
+  scoped_ptr<ScopedClassSwizzler> swizzler_;
+
+  DISALLOW_COPY_AND_ASSIGN(EventsMacTest);
 };
 
-TEST_F(CocoaEventUtilsTest, EventFlagsFromNative) {
+}  // namespace
+
+TEST_F(EventsMacTest, EventFlagsFromNative) {
   // Left click.
   NSEvent* left = cocoa_test_event_utils::MouseEventWithType(NSLeftMouseUp, 0);
   EXPECT_EQ(EF_LEFT_MOUSE_BUTTON, EventFlagsFromNative(left));
 
   // Right click.
   NSEvent* right = cocoa_test_event_utils::MouseEventWithType(NSRightMouseUp,
                                                               0);
   EXPECT_EQ(EF_RIGHT_MOUSE_BUTTON, EventFlagsFromNative(right));
 
   // Middle click.
@@ skipping 33 matching lines @@
   EXPECT_EQ(EF_LEFT_MOUSE_BUTTON | EF_SHIFT_DOWN | EF_CONTROL_DOWN,
             EventFlagsFromNative(shiftctrl));
 
   // Cmd + Alt + Right
   NSEvent* cmdalt = cocoa_test_event_utils::MouseEventWithType(
       NSLeftMouseUp, NSCommandKeyMask | NSAlternateKeyMask);
   EXPECT_EQ(EF_LEFT_MOUSE_BUTTON | EF_COMMAND_DOWN | EF_ALT_DOWN,
             EventFlagsFromNative(cmdalt));
 }
 
-}  // namespace
+// Tests mouse button presses and mouse wheel events.
+TEST_F(EventsMacTest, ButtonEvents) {
+  gfx::Point location(5, 10);
+  gfx::Vector2d offset;
+
+  NSEvent* event = TestMouseEvent(NSLeftMouseDown, location, 0);
+  EXPECT_EQ(ui::ET_MOUSE_PRESSED, ui::EventTypeFromNative(event));
+  EXPECT_EQ(ui::EF_LEFT_MOUSE_BUTTON, ui::EventFlagsFromNative(event));
+  EXPECT_EQ(location, ui::EventLocationFromNative(event));
+
+  SwizzleMiddleMouseButton();
+  event = TestMouseEvent(NSOtherMouseDown, location, NSShiftKeyMask);
+  EXPECT_EQ(ui::ET_MOUSE_PRESSED, ui::EventTypeFromNative(event));
+  EXPECT_EQ(ui::EF_MIDDLE_MOUSE_BUTTON | ui::EF_SHIFT_DOWN,
+            ui::EventFlagsFromNative(event));
+  EXPECT_EQ(location, ui::EventLocationFromNative(event));
+  ClearSwizzle();
+
+  event = TestMouseEvent(NSRightMouseUp, location, 0);
+  EXPECT_EQ(ui::ET_MOUSE_RELEASED, ui::EventTypeFromNative(event));
+  EXPECT_EQ(ui::EF_RIGHT_MOUSE_BUTTON, ui::EventFlagsFromNative(event));
+  EXPECT_EQ(location, ui::EventLocationFromNative(event));
+
+  // Scroll up.
+  event = TestScrollEvent(location, 0, 1);
+  EXPECT_EQ(ui::ET_MOUSEWHEEL, ui::EventTypeFromNative(event));
+  EXPECT_EQ(0, ui::EventFlagsFromNative(event));
+  EXPECT_EQ(location.ToString(), ui::EventLocationFromNative(event).ToString());
+  offset = ui::GetMouseWheelOffset(event);
+  EXPECT_GT(offset.y(), 0);
+  EXPECT_EQ(0, offset.x());
+  ClearSwizzle();
+
+  // Scroll down.
+  event = TestScrollEvent(location, 0, -1);
+  EXPECT_EQ(ui::ET_MOUSEWHEEL, ui::EventTypeFromNative(event));
+  EXPECT_EQ(0, ui::EventFlagsFromNative(event));
+  EXPECT_EQ(location, ui::EventLocationFromNative(event));
+  offset = ui::GetMouseWheelOffset(event);
+  EXPECT_LT(offset.y(), 0);
+  EXPECT_EQ(0, offset.x());
+  ClearSwizzle();
+
+  // Scroll left.
+  event = TestScrollEvent(location, 1, 0);
+  EXPECT_EQ(ui::ET_MOUSEWHEEL, ui::EventTypeFromNative(event));
+  EXPECT_EQ(0, ui::EventFlagsFromNative(event));
+  EXPECT_EQ(location, ui::EventLocationFromNative(event));
+  offset = ui::GetMouseWheelOffset(event);
+  EXPECT_EQ(0, offset.y());
+  EXPECT_GT(offset.x(), 0);
+  ClearSwizzle();
+
+  // Scroll right.
+  event = TestScrollEvent(location, -1, 0);
+  EXPECT_EQ(ui::ET_MOUSEWHEEL, ui::EventTypeFromNative(event));
+  EXPECT_EQ(0, ui::EventFlagsFromNative(event));
+  EXPECT_EQ(location, ui::EventLocationFromNative(event));
+  offset = ui::GetMouseWheelOffset(event);
+  EXPECT_EQ(0, offset.y());
+  EXPECT_LT(offset.x(), 0);
+  ClearSwizzle();
+}
 
 }  // namespace ui