/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */

/* Mutter interface for talking to GTK+ UI module */

/*
 * Copyright (C) 2002 Havoc Pennington
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 2 of the
 * License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, see <http://www.gnu.org/licenses/>.
 */

#include <config.h>
#include <meta/prefs.h>
#include "ui.h"
#include "frames.h"
#include <meta/util.h>
#include "core.h"
#include "theme-private.h"

#include <string.h>
#include <stdlib.h>
#include <cairo-xlib.h>

struct _MetaUI
{
  Display *xdisplay;
  Screen *xscreen;
  MetaFrames *frames;

  /* For double-click tracking */
  gint button_click_number;
  Window button_click_window;
  int button_click_x;
  int button_click_y;
  guint32 button_click_time;
};

void
meta_ui_init (void)
{
  gdk_set_allowed_backends ("x11");

  if (!gtk_init_check (NULL, NULL))
    meta_fatal ("Unable to open X display %s\n", XDisplayName (NULL));

  /* We need to be able to fully trust that the window and monitor sizes
     that Gdk reports corresponds to the X ones, so we disable the automatic
     scale handling */
  gdk_x11_display_set_window_scale (gdk_display_get_default (), 1);
}

Display*
meta_ui_get_display (void)
{
  return GDK_DISPLAY_XDISPLAY (gdk_display_get_default ());
}

gint
meta_ui_get_screen_number (void)
{
  return gdk_screen_get_number (gdk_screen_get_default ());
}

/* For XInput2 */
#include "display-private.h"

static gboolean
is_input_event (XEvent *event)
{
  MetaDisplay *display = meta_get_display ();

  return (event->type == GenericEvent &&
          event->xcookie.extension == display->xinput_opcode);
}

static gboolean
is_interesting_input_event (XEvent *event)
{
  XIEvent *input_event;

  if (!is_input_event (event))
    return FALSE;

  input_event = (XIEvent *) event->xcookie.data;
  switch (input_event->evtype)
    {
    case XI_ButtonPress:
    case XI_ButtonRelease:
    case XI_Motion:
    case XI_Enter:
    case XI_Leave:
    case XI_TouchBegin:
    case XI_TouchUpdate:
    case XI_TouchEnd:
      return TRUE;
    default:
      return FALSE;
    }
}

/* We do some of our event handling in frames.c, which expects
 * GDK events delivered by GTK+.  However, since the transition to
 * client side windows, we can't let GDK see button events, since the
 * client-side tracking of implicit and explicit grabs it does will
 * get confused by our direct use of X grabs in the core code.
 *
 * So we do a very minimal GDK => GTK event conversion here and send on the
 * events we care about, and then filter them out so they don't go
 * through the normal GDK event handling.
 *
 * To reduce the amount of code, the only events fields filled out
 * below are the ones that frames.c uses. If frames.c is modified to
 * use more fields, more fields need to be filled out below.
 */

static void
maybe_redirect_mouse_event (XEvent *xevent)
{
  GdkDisplay *gdisplay;
  GdkDeviceManager *gmanager;
  GdkDevice *gdevice;
  MetaUI *ui;
  GdkEvent *gevent;
  GdkWindow *gdk_window;
  Window window;
  XIEvent *xev;
  XIDeviceEvent *xev_d = NULL;
  XIEnterEvent *xev_e = NULL;

  xev = (XIEvent *) xevent->xcookie.data;

  switch (xev->evtype)
    {
    case XI_ButtonPress:
    case XI_ButtonRelease:
    case XI_Motion:
      xev_d = (XIDeviceEvent *) xev;
      window = xev_d->event;
      break;
    case XI_Enter:
    case XI_Leave:
      xev_e = (XIEnterEvent *) xev;
      window = xev_e->event;
      break;
    default:
      /* Not interested in this event. */
      return;
    }

  gdisplay = gdk_x11_lookup_xdisplay (xev->display);
  ui = g_object_get_data (G_OBJECT (gdisplay), "meta-ui");
  if (!ui)
    return;

  gdk_window = gdk_x11_window_lookup_for_display (gdisplay, window);
  if (gdk_window == NULL)
    return;

  gmanager = gdk_display_get_device_manager (gdisplay);
  gdevice = gdk_x11_device_manager_lookup (gmanager, META_VIRTUAL_CORE_POINTER_ID);

  switch (xev->evtype)
    {
    case XI_ButtonPress:
    case XI_ButtonRelease:
      if (xev_d->evtype == XI_ButtonPress)
        {
          GtkSettings *settings = gtk_settings_get_default ();
          int double_click_time;
          int double_click_distance;
          int button;

          g_object_get (settings,
                        "gtk-double-click-time", &double_click_time,
                        "gtk-double-click-distance", &double_click_distance,
                        NULL);

          button = xev_d->detail;

          if (button == ui->button_click_number &&
              xev_d->event == ui->button_click_window &&
              xev_d->time < ui->button_click_time + double_click_time &&
              ABS (xev_d->event_x - ui->button_click_x) <= double_click_distance &&
              ABS (xev_d->event_y - ui->button_click_y) <= double_click_distance)
            {
              gevent = gdk_event_new (GDK_2BUTTON_PRESS);

              ui->button_click_number = 0;
            }
          else
            {
              gevent = gdk_event_new (GDK_BUTTON_PRESS);
              ui->button_click_number = button;
              ui->button_click_window = xev_d->event;
              ui->button_click_time = xev_d->time;
              ui->button_click_x = xev_d->event_x;
              ui->button_click_y = xev_d->event_y;
            }

          gevent->button.button = button;
        }
      else
        {
          gevent = gdk_event_new (GDK_BUTTON_RELEASE);
          gevent->button.button = xev_d->detail;
        }

      gevent->button.window = g_object_ref (gdk_window);
      gevent->button.time = xev_d->time;
      gevent->button.x = xev_d->event_x;
      gevent->button.y = xev_d->event_y;
      gevent->button.x_root = xev_d->root_x;
      gevent->button.y_root = xev_d->root_y;
      break;
    case XI_Motion:
      gevent = gdk_event_new (GDK_MOTION_NOTIFY);
      gevent->motion.window = g_object_ref (gdk_window);
      gevent->motion.time = xev_d->time;
      gevent->motion.x = xev_d->event_x;
      gevent->motion.y = xev_d->event_y;
      gevent->motion.x_root = xev_d->root_x;
      gevent->motion.y_root = xev_d->root_y;

      if (XIMaskIsSet (xev_d->buttons.mask, 1))
        gevent->motion.state |= GDK_BUTTON1_MASK;
      break;
    case XI_Enter:
    case XI_Leave:
      gevent = gdk_event_new (xev_e->evtype == XI_Enter ? GDK_ENTER_NOTIFY : GDK_LEAVE_NOTIFY);
      gevent->crossing.window = g_object_ref (gdk_window);
      gevent->crossing.time = xev_e->time;
      gevent->crossing.x = xev_e->event_x;
      gevent->crossing.y = xev_e->event_y;
      break;
    default:
      g_assert_not_reached ();
      break;
    }

  /* If we've gotten here, we've created the gdk_event and should send it on */
  gdk_event_set_device (gevent, gdevice);
  gtk_main_do_event (gevent);
  gdk_event_free (gevent);
}

static GdkFilterReturn
ui_filter_func (GdkXEvent *xevent,
                GdkEvent *event,
                gpointer data)
{
  if (is_interesting_input_event (xevent))
    {
      maybe_redirect_mouse_event (xevent);
      return GDK_FILTER_REMOVE;
    }
  else
    return GDK_FILTER_CONTINUE;
}

MetaUI*
meta_ui_new (Display *xdisplay,
             Screen  *screen)
{
  GdkDisplay *gdisplay;
  MetaUI *ui;

  ui = g_new0 (MetaUI, 1);
  ui->xdisplay = xdisplay;
  ui->xscreen = screen;

  gdisplay = gdk_x11_lookup_xdisplay (xdisplay);
  g_assert (gdisplay == gdk_display_get_default ());

  ui->frames = meta_frames_new (XScreenNumberOfScreen (screen));
  /* GTK+ needs the frame-sync protocol to work in order to properly
   * handle style changes. This means that the dummy widget we create
   * to get the style for title bars actually needs to be mapped
   * and fully tracked as a MetaWindow. Horrible, but mostly harmless -
   * the window is a 1x1 overide redirect window positioned offscreen.
   */
  gtk_widget_show (GTK_WIDGET (ui->frames));

  gdk_window_add_filter (NULL, ui_filter_func, NULL);

  g_object_set_data (G_OBJECT (gdisplay), "meta-ui", ui);

  return ui;
}

void
meta_ui_free (MetaUI *ui)
{
  GdkDisplay *gdisplay;

  gtk_widget_destroy (GTK_WIDGET (ui->frames));

  gdisplay = gdk_x11_lookup_xdisplay (ui->xdisplay);
  g_object_set_data (G_OBJECT (gdisplay), "meta-ui", NULL);

  gdk_window_remove_filter (NULL, ui_filter_func, NULL);

  g_free (ui);
}

static void
set_background_none (Display *xdisplay,
                     Window   xwindow)
{
  XSetWindowAttributes attrs;

  attrs.background_pixmap = None;
  XChangeWindowAttributes (xdisplay, xwindow,
                           CWBackPixmap, &attrs);
}

MetaUIFrame *
meta_ui_create_frame (MetaUI *ui,
                      Display *xdisplay,
                      Visual *xvisual,
                      gint x,
                      gint y,
                      gint width,
                      gint height,
                      gint screen_no,
                      gulong *create_serial)
{
  GdkDisplay *display = gdk_x11_lookup_xdisplay (xdisplay);
  GdkScreen *screen = gdk_display_get_screen (display, screen_no);
  GdkWindowAttr attrs;
  gint attributes_mask;
  GdkWindow *window;
  GdkVisual *visual;

  /* Default depth/visual handles clients with weird visuals; they can
   * always be children of the root depth/visual obviously, but
   * e.g. DRI games can't be children of a parent that has the same
   * visual as the client.
   */
  if (!xvisual)
    visual = gdk_screen_get_system_visual (screen);
  else
    {
      visual = gdk_x11_screen_lookup_visual (screen,
                                             XVisualIDFromVisual (xvisual));
    }

  attrs.title = NULL;

  /* frame.c is going to replace the event mask immediately, but
   * we still have to set it here to let GDK know what it is.
   */
  attrs.event_mask =
    GDK_EXPOSURE_MASK | GDK_BUTTON_PRESS_MASK | GDK_BUTTON_RELEASE_MASK |
    GDK_POINTER_MOTION_MASK | GDK_POINTER_MOTION_HINT_MASK |
    GDK_ENTER_NOTIFY_MASK | GDK_LEAVE_NOTIFY_MASK | GDK_FOCUS_CHANGE_MASK;
  attrs.x = x;
  attrs.y = y;
  attrs.wclass = GDK_INPUT_OUTPUT;
  attrs.visual = visual;
  attrs.window_type = GDK_WINDOW_CHILD;
  attrs.cursor = NULL;
  attrs.wmclass_name = NULL;
  attrs.wmclass_class = NULL;
  attrs.override_redirect = FALSE;

  attrs.width  = width;
  attrs.height = height;

  attributes_mask = GDK_WA_X | GDK_WA_Y | GDK_WA_VISUAL;

  /* We make an assumption that gdk_window_new() is going to call
   * XCreateWindow as it's first operation; this seems to be true currently
   * as long as you pass in a colormap.
   */
  if (create_serial)
    *create_serial = XNextRequest (xdisplay);
  window =
    gdk_window_new (gdk_screen_get_root_window(screen),
		    &attrs, attributes_mask);

  gdk_window_resize (window, width, height);
  set_background_none (xdisplay, GDK_WINDOW_XID (window));

  return meta_frames_manage_window (ui->frames, GDK_WINDOW_XID (window), window);
}

void
meta_ui_map_frame   (MetaUI *ui,
                     Window  xwindow)
{
  GdkWindow *window;
  GdkDisplay *display;

  display = gdk_x11_lookup_xdisplay (ui->xdisplay);
  window = gdk_x11_window_lookup_for_display (display, xwindow);

  if (window)
    gdk_window_show_unraised (window);
}

void
meta_ui_unmap_frame (MetaUI *ui,
                     Window  xwindow)
{
  GdkWindow *window;
  GdkDisplay *display;

  display = gdk_x11_lookup_xdisplay (ui->xdisplay);
  window = gdk_x11_window_lookup_for_display (display, xwindow);

  if (window)
    gdk_window_hide (window);
}

gboolean
meta_ui_window_should_not_cause_focus (Display *xdisplay,
                                       Window   xwindow)
{
  GdkWindow *window;
  GdkDisplay *display;

  display = gdk_x11_lookup_xdisplay (xdisplay);
  window = gdk_x11_window_lookup_for_display (display, xwindow);

  /* we shouldn't cause focus if we're an override redirect
   * toplevel which is not foreign
   */
  if (window && gdk_window_get_window_type (window) == GDK_WINDOW_TEMP)
    return TRUE;
  else
    return FALSE;
}

void
meta_ui_theme_get_frame_borders (MetaUI *ui,
                                 MetaFrameType      type,
                                 MetaFrameFlags     flags,
                                 MetaFrameBorders  *borders)
{
  int text_height;
  MetaStyleInfo *style_info = NULL;
  PangoContext *context;
  const PangoFontDescription *font_desc;
  PangoFontDescription *free_font_desc = NULL;

  GdkDisplay *display = gdk_x11_lookup_xdisplay (ui->xdisplay);
  GdkScreen *screen = gdk_display_get_screen (display, XScreenNumberOfScreen (ui->xscreen));

  style_info = meta_theme_create_style_info (screen, NULL);

  context = gtk_widget_get_pango_context (GTK_WIDGET (ui->frames));
  font_desc = meta_prefs_get_titlebar_font ();

  if (!font_desc)
    {
      free_font_desc = meta_style_info_create_font_desc (style_info);
      font_desc = (const PangoFontDescription *) free_font_desc;
    }

  text_height = meta_pango_font_desc_get_text_height (font_desc, context);

  meta_theme_get_frame_borders (meta_theme_get_default (),
                                style_info, type, text_height, flags,
                                borders);

  if (free_font_desc)
    pango_font_description_free (free_font_desc);

  if (style_info != NULL)
    meta_style_info_unref (style_info);
}

gboolean
meta_ui_window_is_widget (MetaUI *ui,
                          Window  xwindow)
{
  GdkDisplay *display;
  GdkWindow *window;

  display = gdk_x11_lookup_xdisplay (ui->xdisplay);
  window = gdk_x11_window_lookup_for_display (display, xwindow);

  if (window)
    {
      void *user_data = NULL;
      gdk_window_get_user_data (window, &user_data);
      return user_data != NULL && user_data != ui->frames;
    }
  else
    return FALSE;
}

gboolean
meta_ui_window_is_dummy (MetaUI *ui,
                         Window  xwindow)
{
  GdkWindow *frames_window = gtk_widget_get_window (GTK_WIDGET (ui->frames));
  return xwindow == gdk_x11_window_get_xid (frames_window);
}