// Copyright 2011 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "ui/base/cocoa/base_view.h"

#include "base/check_op.h"
#include "base/mac/mac_util.h"
#include "ui/base/cocoa/tracking_area.h"

NSString* kViewDidBecomeFirstResponder =
    @"Chromium.kViewDidBecomeFirstResponder";
NSString* kSelectionDirection = @"Chromium.kSelectionDirection";

@implementation BaseView {
  ui::ScopedCrTrackingArea _trackingArea;
  BOOL _dragging;
  NSEvent* __strong _pendingExitEvent;
  NSInteger _pressureEventStage;
}

- (instancetype)initWithFrame:(NSRect)frame tracking:(BOOL)tracking {
  if ((self = [super initWithFrame:frame])) {
    if (tracking) {
      [self enableTracking];
    }
  }
  return self;
}

- (void)dealloc {
  [self disableTracking];
}

- (void)enableTracking {
  if (_trackingArea.get()) {
    return;
  }

  NSTrackingAreaOptions trackingOptions = NSTrackingMouseEnteredAndExited |
                                          NSTrackingMouseMoved |
                                          NSTrackingActiveAlways |
                                          NSTrackingInVisibleRect;
  CrTrackingArea* trackingArea =
      [[CrTrackingArea alloc] initWithRect:NSZeroRect
                                   options:trackingOptions
                                     owner:self
                                  userInfo:nil];
  _trackingArea.reset(trackingArea);
  [self addTrackingArea:_trackingArea.get()];
}

- (void)disableTracking {
  if (_trackingArea.get()) {
    [self removeTrackingArea:_trackingArea.get()];
    _trackingArea.reset();
  }
}

- (void)handleLeftMouseUp:(NSEvent*)theEvent {
  DCHECK_EQ(theEvent.type, NSEventTypeLeftMouseUp);
  _dragging = NO;
  if (!_pendingExitEvent) {
    return;
  }

  NSEvent* exitEvent =
      [NSEvent enterExitEventWithType:NSEventTypeMouseExited
                             location:theEvent.locationInWindow
                        modifierFlags:theEvent.modifierFlags
                            timestamp:theEvent.timestamp
                         windowNumber:theEvent.windowNumber
                              context:nil
                          eventNumber:_pendingExitEvent.eventNumber
                       trackingNumber:_pendingExitEvent.trackingNumber
                             userData:_pendingExitEvent.userData];
  [self mouseEvent:exitEvent];
  _pendingExitEvent = nil;
}

- (void)mouseEvent:(NSEvent*)theEvent {
  // This method left intentionally blank.
}

- (EventHandled)keyEvent:(NSEvent*)theEvent {
  // The default implementation of this method does not handle any key events.
  // Derived classes should return kEventHandled if they handled an event,
  // otherwise it will be forwarded on to |super|.
  return kEventNotHandled;
}

- (void)forceTouchEvent:(NSEvent*)theEvent {
  // This method left intentionally blank.
}

- (void)tabletEvent:(NSEvent*)theEvent {
  // This method left intentionally blank.
}

- (void)mouseDown:(NSEvent*)theEvent {
  _dragging = YES;
  [self mouseEvent:theEvent];
}

- (void)rightMouseDown:(NSEvent*)theEvent {
  [self mouseEvent:theEvent];
}

- (void)otherMouseDown:(NSEvent*)theEvent {
  [self mouseEvent:theEvent];
}

- (void)mouseUp:(NSEvent*)theEvent {
  [self mouseEvent:theEvent];
  [self handleLeftMouseUp:theEvent];
}

- (void)rightMouseUp:(NSEvent*)theEvent {
  [self mouseEvent:theEvent];
}

- (void)otherMouseUp:(NSEvent*)theEvent {
  [self mouseEvent:theEvent];
}

- (void)mouseMoved:(NSEvent*)theEvent {
  [self mouseEvent:theEvent];
}

- (void)mouseDragged:(NSEvent*)theEvent {
  [self mouseEvent:theEvent];
}

- (void)rightMouseDragged:(NSEvent*)theEvent {
  [self mouseEvent:theEvent];
}

- (void)otherMouseDragged:(NSEvent*)theEvent {
  [self mouseEvent:theEvent];
}

- (void)mouseEntered:(NSEvent*)theEvent {
  if (_pendingExitEvent) {
    _pendingExitEvent = nil;
    return;
  }

  [self mouseEvent:theEvent];
}

- (void)mouseExited:(NSEvent*)theEvent {
  // The tracking area will send an exit event even during a drag, which isn't
  // how the event flow for drags should work. This stores the exit event, and
  // sends it when the drag completes instead.
  if (_dragging) {
    _pendingExitEvent = theEvent;
    return;
  }

  [self mouseEvent:theEvent];
}

- (void)keyDown:(NSEvent*)theEvent {
  if ([self keyEvent:theEvent] != kEventHandled)
    [super keyDown:theEvent];
}

- (void)keyUp:(NSEvent*)theEvent {
  if ([self keyEvent:theEvent] != kEventHandled)
    [super keyUp:theEvent];
}

- (void)pressureChangeWithEvent:(NSEvent*)theEvent {
  NSInteger newStage = theEvent.stage;
  if (_pressureEventStage == newStage)
    return;

  // Call the force touch event when the stage reaches 2, which is the value
  // for force touch.
  if (newStage == 2) {
    [self forceTouchEvent:theEvent];
  }
  _pressureEventStage = newStage;
}

- (void)flagsChanged:(NSEvent*)theEvent {
  if ([self keyEvent:theEvent] != kEventHandled)
    [super flagsChanged:theEvent];
}

- (gfx::Rect)flipNSRectToRect:(NSRect)rect {
  gfx::Rect new_rect(rect);
  new_rect.set_y(NSHeight(self.bounds) - new_rect.bottom());
  return new_rect;
}

- (NSRect)flipRectToNSRect:(gfx::Rect)rect {
  NSRect new_rect = rect.ToCGRect();
  new_rect.origin.y = NSHeight(self.bounds) - NSMaxY(new_rect);
  return new_rect;
}

- (void)tabletProximity:(NSEvent*)theEvent {
  [self tabletEvent:theEvent];
}

@end
