MacViews: Implement Tab Dragging

ui/base/test/ui_controls_mac.mm

 // Copyright 2013 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/base/test/ui_controls.h"
 
 #import <Cocoa/Cocoa.h>
 #include <vector>
 
 #include "base/bind.h"
 #include "base/callback.h"
+#import "base/mac/foundation_util.h"
+#import "base/mac/scoped_objc_class_swizzler.h"
 #include "base/message_loop/message_loop.h"
 #include "ui/base/cocoa/cocoa_base_utils.h"
 #include "ui/events/keycodes/keyboard_code_conversion_mac.h"
 #import "ui/events/test/cocoa_test_event_utils.h"
+#include "ui/gfx/geometry/point.h"
+#import "ui/gfx/mac/coordinate_conversion.h"
 
 // Implementation details: We use [NSApplication sendEvent:] instead
 // of [NSApplication postEvent:atStart:] so that the event gets sent
 // immediately.  This lets us run the post-event task right
 // immediately as well.  Unfortunately I cannot subclass NSEvent (it's
 // probably a class cluster) to allow other easy answers.  For
 // example, if I could subclass NSEvent, I could run the Task in it's
 // dealloc routine (which necessarily happens after the event is
 // dispatched).  Unlike Linux, Mac does not have message loop
 // observer/notification.  Unlike windows, I cannot post non-events
@@ skipping 19 matching lines @@
 
 using cocoa_test_event_utils::SynthesizeKeyEvent;
 using cocoa_test_event_utils::TimeIntervalSinceSystemStartup;
 
 namespace {
 
 // Stores the current mouse location on the screen. So that we can use it
 // when firing keyboard and mouse click events.
 NSPoint g_mouse_location = { 0, 0 };
 
+// Stores the current pressed mouse buttons. Indexed by
+// ui_controls::MouseButton.
+bool g_mouse_button_down[3] = {false, false, false};
+
 bool g_ui_controls_enabled = false;
 
 // Creates the proper sequence of autoreleased key events for a key down + up.
 void SynthesizeKeyEventsSequence(NSWindow* window,
                                  ui::KeyboardCode keycode,
                                  bool control,
                                  bool shift,
                                  bool alt,
                                  bool command,
                                  std::vector<NSEvent*>* events) {
@@ skipping 101 matching lines @@
       return window;
   }
 
   // Note that -[NSApplication orderedWindows] won't include NSPanels. If a test
   // uses those, it will need to handle that itself.
   return nil;
 }
 
 }  // namespace
 
+// Donates testing implementations of NSEvent methods.
+@interface FakeNSEventTestingDonor : NSObject
+@end
+
+@implementation FakeNSEventTestingDonor
++ (NSPoint)mouseLocation {
+  return g_mouse_location;
+}
+
++ (NSUInteger)pressedMouseButtons {
+  NSUInteger result = 0;
+  const int buttons[3] = {
+      ui_controls::LEFT, ui_controls::RIGHT, ui_controls::MIDDLE};
+  for (size_t i = 0; i < arraysize(buttons); ++i) {
+    if (g_mouse_button_down[buttons[i]])
+      result |= (1 << i);
+  }
+  return result;
+}
+@end
+
+// Donates testing implementations of NSWindow methods.
+@interface FakeNSWindowTestingDonor : NSObject
+@end
+
+@implementation FakeNSWindowTestingDonor
+- (NSPoint)mouseLocationOutsideOfEventStream {
+  NSWindow* window = base::mac::ObjCCastStrict<NSWindow>(self);
+  return ui::ConvertPointFromWindowToScreen(window, g_mouse_location);
+}
+@end
+
+namespace {
+
+// Swizzles several Cocoa functions that are used to directly get mouse state,
+// so that they will return the current simulated mouse position and pressed
+// mouse buttons.
+class NSEventSwizzler {
+ public:
+  static void Install() {
+    static NSEventSwizzler* swizzler = nullptr;
+    if (!swizzler) {
+      swizzler = new NSEventSwizzler();
+    }
+  }
+
+ protected:
+  NSEventSwizzler()
+      : mouse_location_swizzler_(new base::mac::ScopedObjCClassSwizzler(
+            [NSEvent class],
+            [FakeNSEventTestingDonor class],
+            @selector(mouseLocation))),
+        pressed_mouse_buttons_swizzler_(new base::mac::ScopedObjCClassSwizzler(
+            [NSEvent class],
+            [FakeNSEventTestingDonor class],
+            @selector(pressedMouseButtons))),
+        mouse_location_outside_of_event_stream_swizzler_(
+            new base::mac::ScopedObjCClassSwizzler(
+                [NSWindow class],
+                [FakeNSWindowTestingDonor class],
+                @selector(mouseLocationOutsideOfEventStream))) {}
+
+ private:
+  std::unique_ptr<base::mac::ScopedObjCClassSwizzler> mouse_location_swizzler_;
+  std::unique_ptr<base::mac::ScopedObjCClassSwizzler>
+      pressed_mouse_buttons_swizzler_;
+  std::unique_ptr<base::mac::ScopedObjCClassSwizzler>
+      mouse_location_outside_of_event_stream_swizzler_;
+
+  DISALLOW_COPY_AND_ASSIGN(NSEventSwizzler);
+};
+
+}  // namespace
+
 namespace ui_controls {
 
 void EnableUIControls() {
   g_ui_controls_enabled = true;
 }
 
 bool IsUIControlsEnabled() {
   return g_ui_controls_enabled;
 }
 
@@ skipping 46 matching lines @@
   CHECK(g_ui_controls_enabled);
   return SendMouseMoveNotifyWhenDone(x, y, base::Closure());
 }
 
 // Input position is in screen coordinates.  However, NSMouseMoved
 // events require them window-relative, so we adjust.  We *DO* flip
 // the coordinate space, so input events can be the same for all
 // platforms.  E.g. (0,0) is upper-left.
 bool SendMouseMoveNotifyWhenDone(long x, long y, const base::Closure& task) {
   CHECK(g_ui_controls_enabled);
-  CGFloat screenHeight =
-    [[[NSScreen screens] firstObject] frame].size.height;
-  g_mouse_location = NSMakePoint(x, screenHeight - y);  // flip!
+  g_mouse_location = gfx::ScreenPointToNSPoint(gfx::Point(x, y));  // flip!
+  NSEventSwizzler::Install();
 
   NSWindow* window = WindowAtCurrentMouseLocation();
 
   NSPoint pointInWindow = g_mouse_location;
   if (window)
     pointInWindow = ui::ConvertPointFromScreenToWindow(window, pointInWindow);
   NSTimeInterval timestamp = TimeIntervalSinceSystemStartup();
 
+  NSEventType event_type = NSMouseMoved;
+  if (g_mouse_button_down[LEFT]) {
+    event_type = NSLeftMouseDragged;
+  } else if (g_mouse_button_down[RIGHT]) {
+    event_type = NSRightMouseDragged;
+  } else if (g_mouse_button_down[MIDDLE]) {
+    event_type = NSOtherMouseDragged;
+  }
+
   NSEvent* event =
-      [NSEvent mouseEventWithType:NSMouseMoved
+      [NSEvent mouseEventWithType:event_type
                          location:pointInWindow
                     modifierFlags:0
                         timestamp:timestamp
                      windowNumber:[window windowNumber]
                           context:nil
                       eventNumber:0
-                       clickCount:0
-                         pressure:0.0];
+                       clickCount:event_type == NSMouseMoved ? 0 : 1
+                         pressure:event_type == NSMouseMoved ? 0.0 : 1.0];
   [[NSApplication sharedApplication] postEvent:event atStart:NO];
 
   if (!task.is_null()) {
     base::MessageLoop::current()->PostTask(
         FROM_HERE, base::Bind(&EventQueueWatcher, task));
   }
 
   return true;
 }
 
 bool SendMouseEvents(MouseButton type, int state) {
   CHECK(g_ui_controls_enabled);
   return SendMouseEventsNotifyWhenDone(type, state, base::Closure());
 }
 
 bool SendMouseEventsNotifyWhenDone(MouseButton type, int state,
                                    const base::Closure& task) {
   CHECK(g_ui_controls_enabled);
   // On windows it appears state can be (UP|DOWN).  It is unclear if
   // that'll happen here but prepare for it just in case.
   if (state == (UP|DOWN)) {
     return (SendMouseEventsNotifyWhenDone(type, DOWN, base::Closure()) &&
             SendMouseEventsNotifyWhenDone(type, UP, task));
   }
-  NSEventType etype = NSLeftMouseDown;
+  NSEventType event_type = NSLeftMouseDown;
   if (type == LEFT) {
     if (state == UP) {
-      etype = NSLeftMouseUp;
+      event_type = NSLeftMouseUp;
     } else {
-      etype = NSLeftMouseDown;
+      event_type = NSLeftMouseDown;
     }
   } else if (type == MIDDLE) {
     if (state == UP) {
-      etype = NSOtherMouseUp;
+      event_type = NSOtherMouseUp;
     } else {
-      etype = NSOtherMouseDown;
+      event_type = NSOtherMouseDown;
     }
   } else if (type == RIGHT) {
     if (state == UP) {
-      etype = NSRightMouseUp;
+      event_type = NSRightMouseUp;
     } else {
-      etype = NSRightMouseDown;
+      event_type = NSRightMouseDown;
     }
   } else {
+    NOTREACHED();
     return false;
   }
+  g_mouse_button_down[type] = state == DOWN;
+
   NSWindow* window = WindowAtCurrentMouseLocation();
   NSPoint pointInWindow = g_mouse_location;
   if (window)
     pointInWindow = ui::ConvertPointFromScreenToWindow(window, pointInWindow);
 
+  NSEventSwizzler::Install();
+
   NSEvent* event =
-      [NSEvent mouseEventWithType:etype
+      [NSEvent mouseEventWithType:event_type
                          location:pointInWindow
                     modifierFlags:0
                         timestamp:TimeIntervalSinceSystemStartup()
                      windowNumber:[window windowNumber]
                           context:nil
                       eventNumber:0
                        clickCount:1
                          pressure:(state == DOWN ? 1.0 : 0.0 )];

[tapted, 2016/06/06 07:12:36]

yeah, let's fix this too. I think even `git cl format` would complain about that
extra space.

[themblsha, 2016/06/06 17:20:27]

Done.

   [[NSApplication sharedApplication] postEvent:event atStart:NO];
 
   if (!task.is_null()) {
     base::MessageLoop::current()->PostTask(
         FROM_HERE, base::Bind(&EventQueueWatcher, task));
   }
 
   return true;
 }
 
 bool SendMouseClick(MouseButton type) {
   CHECK(g_ui_controls_enabled);
   return SendMouseEventsNotifyWhenDone(type, UP|DOWN, base::Closure());
 }
 
 void RunClosureAfterAllPendingUIEvents(const base::Closure& closure) {
   base::MessageLoop::current()->PostTask(
       FROM_HERE, base::Bind(&EventQueueWatcher, closure));
 }
 
 bool IsFullKeyboardAccessEnabled() {
   return [NSApp isFullKeyboardAccessEnabled];
 }
 
 }  // namespace ui_controls