// Copyright (c) 2011 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 "views/events/event.h"

#include <gdk/gdk.h>

#include "base/logging.h"
#include "ui/base/keycodes/keyboard_code_conversion_gtk.h"

namespace views {

namespace {

ui::EventType EventTypeFromNative(NativeEvent native_event) {
  // Add new event types as necessary.
  switch (native_event->type) {
    case GDK_KEY_PRESS:
      return ui::ET_KEY_PRESSED;
    case GDK_KEY_RELEASE:
      return ui::ET_KEY_RELEASED;
    case GDK_SCROLL:
      return ui::ET_MOUSEWHEEL;
    default:
      NOTREACHED();
      break;
  }
  return ui::ET_UNKNOWN;
}

GdkEventKey* GetGdkEventKeyFromNative(NativeEvent native_event) {
  DCHECK(native_event->type == GDK_KEY_PRESS ||
         native_event->type == GDK_KEY_RELEASE);
  return &native_event->key;
}

gfx::Point GetMouseEventLocation(NativeEvent native_event) {
  double x = 0, y = 0;
  if (gdk_event_get_coords(native_event, &x, &y))
    return gfx::Point(static_cast<int>(x), static_cast<int>(y));
  return gfx::Point();
}

int GetMouseWheelOffset(NativeEvent native_event) {
  DCHECK(native_event->type == GDK_SCROLL);
  int offset = (native_event->scroll.direction == GDK_SCROLL_UP ||
                native_event->scroll.direction == GDK_SCROLL_LEFT) ? 1 : -1;

  // Scale the offset magnitude by window size, to preserve legacy behavior.
  // TODO(msw): Investigate the use of offset magnitude throughout the codebase.
  int width = 0, height = 0;
  gdk_window_get_geometry(native_event->scroll.window, NULL, NULL, &width,
                          &height, NULL);
  if (native_event->scroll.direction == GDK_SCROLL_UP ||
      native_event->scroll.direction == GDK_SCROLL_DOWN)
    offset = offset * height / 5;
  else
    offset = offset * width / 5;

  return offset;
}

unsigned int GetGdkStateFromNative(NativeEvent native_event) {
  switch (native_event->type) {
    case GDK_KEY_PRESS:
    case GDK_KEY_RELEASE:
      return native_event->key.state;
    case GDK_BUTTON_PRESS:
    case GDK_2BUTTON_PRESS:
    case GDK_3BUTTON_PRESS:
    case GDK_BUTTON_RELEASE:
      return native_event->button.state;
    case GDK_SCROLL:
      return native_event->scroll.state;
    case GDK_MOTION_NOTIFY:
      return native_event->motion.state;
    case GDK_ENTER_NOTIFY:
    case GDK_LEAVE_NOTIFY:
      return native_event->crossing.state;
    default:
      NOTREACHED();
      break;
  }
  return 0;
}

}  // namespace

////////////////////////////////////////////////////////////////////////////////
// Event, public:

// static
int Event::GetFlagsFromGdkState(unsigned int state) {
  int flags = 0;
  if (state & GDK_LOCK_MASK)
    flags |= ui::EF_CAPS_LOCK_DOWN;
  if (state & GDK_CONTROL_MASK)
    flags |= ui::EF_CONTROL_DOWN;
  if (state & GDK_SHIFT_MASK)
    flags |= ui::EF_SHIFT_DOWN;
  if (state & GDK_MOD1_MASK)
    flags |= ui::EF_ALT_DOWN;
  if (state & GDK_BUTTON1_MASK)
    flags |= ui::EF_LEFT_BUTTON_DOWN;
  if (state & GDK_BUTTON2_MASK)
    flags |= ui::EF_MIDDLE_BUTTON_DOWN;
  if (state & GDK_BUTTON3_MASK)
    flags |= ui::EF_RIGHT_BUTTON_DOWN;
  return flags;
}

////////////////////////////////////////////////////////////////////////////////
// Event, private:

void Event::Init() {
  native_event_ = NULL;
  native_event_2_ = NULL;
}

void Event::InitWithNativeEvent(NativeEvent native_event) {
  native_event_ = native_event;
  // TODO(beng): remove once we rid views of Gtk/Gdk.
  native_event_2_ = NULL;
}

#if !defined(TOUCH_UI)
void Event::InitWithNativeEvent2(NativeEvent2 native_event_2,
                                 FromNativeEvent2) {
  // No one should ever call this on non-Touch Linux.
  // TODO(beng): remove once we rid views of Gtk/Gdk.
  NOTREACHED();
  native_event_2_ = NULL;
}
#endif

////////////////////////////////////////////////////////////////////////////////
// LocatedEvent, protected:

LocatedEvent::LocatedEvent(NativeEvent native_event)
    : Event(native_event, EventTypeFromNative(native_event),
            GetFlagsFromGdkState(GetGdkStateFromNative(native_event))),
      location_(GetMouseEventLocation(native_event)) {
}

#if !defined(TOUCH_UI)
LocatedEvent::LocatedEvent(NativeEvent2 native_event_2,
                           FromNativeEvent2 from_native)
    : Event(native_event_2, ui::ET_UNKNOWN, 0, from_native) {
  // No one should ever call this on Gtk-views.
  // TODO(msw): remove once we rid views of Gtk/Gdk.
  NOTREACHED();
}
#endif

////////////////////////////////////////////////////////////////////////////////
// KeyEvent, public:

KeyEvent::KeyEvent(NativeEvent native_event)
    : Event(native_event, EventTypeFromNative(native_event),
            GetFlagsFromGdkState(GetGdkStateFromNative(native_event))),
      key_code_(ui::WindowsKeyCodeForGdkKeyCode(
                GetGdkEventKeyFromNative(native_event)->keyval)) {
}

#if !defined(TOUCH_UI)
KeyEvent::KeyEvent(NativeEvent2 native_event_2, FromNativeEvent2 from_native)
    : Event(native_event_2, ui::ET_UNKNOWN, 0, from_native) {
  // No one should ever call this on Gtk-views.
  // TODO(beng): remove once we rid views of Gtk/Gdk.
  NOTREACHED();
}
#endif

////////////////////////////////////////////////////////////////////////////////
// MouseWheelEvent, public:

MouseWheelEvent::MouseWheelEvent(NativeEvent native_event)
    : LocatedEvent(native_event),
      offset_(GetMouseWheelOffset(native_event)) {
}

#if !defined(TOUCH_UI)
MouseWheelEvent::MouseWheelEvent(NativeEvent2 native_event_2,
                                 FromNativeEvent2 from_native)
    : LocatedEvent(native_event_2, from_native) {
  // No one should ever call this on Gtk-views.
  // TODO(msw): remove once we rid views of Gtk/Gdk.
  NOTREACHED();
}
#endif

}  // namespace views