mutter/src/core/meta-cursor-tracker.c

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

/* 
 * Copyright 2013 Red Hat, Inc.
 * 
 * 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, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
 * 02111-1307, USA.
 *
 * Author: Giovanni Campagna <gcampagn@redhat.com>
 */

/**
 * SECTION:cursor-tracker
 * @title: MetaCursorTracker
 * @short_description: Mutter cursor tracking helper. Originally only
 *                     tracking the cursor image, now more of a "core
 *                     pointer abstraction"
 */

#include <config.h>
#include <meta/main.h>
#include <meta/util.h>
#include <meta/errors.h>

#include <cogl/cogl.h>
#include <clutter/clutter.h>

#include <gdk/gdk.h>

#include <X11/extensions/Xfixes.h>

#include "meta-cursor-tracker-private.h"
#include "screen-private.h"

#ifdef HAVE_WAYLAND
#include "meta-wayland-private.h"
#endif

#define META_WAYLAND_DEFAULT_CURSOR_HOTSPOT_X 7
#define META_WAYLAND_DEFAULT_CURSOR_HOTSPOT_Y 4

struct _MetaCursorTracker {
  GObject parent_instance;

  MetaScreen *screen;

  gboolean is_showing;

  CoglTexture2D *sprite;
  int hot_x, hot_y;

  CoglTexture2D *root_cursor;
  int root_hot_x, root_hot_y;

  CoglTexture2D *default_cursor;

  int current_x, current_y;
  cairo_rectangle_int_t current_rect;
  cairo_rectangle_int_t previous_rect;
  gboolean previous_is_valid;

  CoglPipeline *pipeline;
};

struct _MetaCursorTrackerClass {
  GObjectClass parent_class;
};

G_DEFINE_TYPE (MetaCursorTracker, meta_cursor_tracker, G_TYPE_OBJECT);

enum {
    CURSOR_CHANGED,
    LAST_SIGNAL
};

static guint signals[LAST_SIGNAL];

static void
meta_cursor_tracker_init (MetaCursorTracker *self)
{
  /* (JS) Best (?) that can be assumed since XFixes doesn't provide a way of
     detecting if the system mouse cursor is showing or not.

     On wayland we start with the cursor showing
  */
  self->is_showing = TRUE;
}

static void
meta_cursor_tracker_finalize (GObject *object)
{
  MetaCursorTracker *self = META_CURSOR_TRACKER (object);

  if (self->sprite)
    cogl_object_unref (self->sprite);
  if (self->root_cursor)
    cogl_object_unref (self->root_cursor);
  if (self->default_cursor)
    cogl_object_unref (self->default_cursor);
  if (self->pipeline)
    cogl_object_unref (self->pipeline);

  G_OBJECT_CLASS (meta_cursor_tracker_parent_class)->finalize (object);
}

static void
meta_cursor_tracker_class_init (MetaCursorTrackerClass *klass)
{
  GObjectClass *object_class = G_OBJECT_CLASS (klass);

  object_class->finalize = meta_cursor_tracker_finalize;

  signals[CURSOR_CHANGED] = g_signal_new ("cursor-changed",
                                          G_TYPE_FROM_CLASS (klass),
                                          G_SIGNAL_RUN_LAST,
                                          0,
                                          NULL, NULL, NULL,
                                          G_TYPE_NONE, 0);
}

#ifdef HAVE_WAYLAND
static MetaCursorTracker *
make_wayland_cursor_tracker (MetaScreen *screen)
{
  MetaWaylandCompositor *compositor;
  CoglContext *ctx;
  MetaCursorTracker *self = g_object_new (META_TYPE_CURSOR_TRACKER, NULL);
  self->screen = screen;

  ctx = clutter_backend_get_cogl_context (clutter_get_default_backend ());
  self->pipeline = cogl_pipeline_new (ctx);

  compositor = meta_wayland_compositor_get_default ();
  compositor->seat->cursor_tracker = self;

  return self;
}
#endif

static MetaCursorTracker *
make_x11_cursor_tracker (MetaScreen *screen)
{
  MetaCursorTracker *self = g_object_new (META_TYPE_CURSOR_TRACKER, NULL);
  self->screen = screen;

  XFixesSelectCursorInput (screen->display->xdisplay,
                           screen->xroot,
                           XFixesDisplayCursorNotifyMask);

  return self;
}

/**
 * meta_cursor_tracker_get_for_screen:
 * @screen: the #MetaScreen
 *
 * Retrieves the cursor tracker object for @screen.
 *
 * Returns: (transfer none):
 */
MetaCursorTracker *
meta_cursor_tracker_get_for_screen (MetaScreen *screen)
{
  MetaCursorTracker *self;

  if (screen->cursor_tracker)
    return screen->cursor_tracker;

#ifdef HAVE_WAYLAND
  if (meta_is_wayland_compositor ())
    self = make_wayland_cursor_tracker (screen);
  else
#endif
    self = make_x11_cursor_tracker (screen);

  screen->cursor_tracker = self;
  return self;
}

gboolean
meta_cursor_tracker_handle_xevent (MetaCursorTracker *tracker,
                                   XEvent            *xevent)
{
  XFixesCursorNotifyEvent *notify_event;

  if (meta_is_wayland_compositor ())
    return FALSE;

  if (xevent->xany.type != tracker->screen->display->xfixes_event_base + XFixesCursorNotify)
    return FALSE;

  notify_event = (XFixesCursorNotifyEvent *)xevent;
  if (notify_event->subtype != XFixesDisplayCursorNotify)
    return FALSE;

  g_clear_pointer (&tracker->sprite, cogl_object_unref);
  g_signal_emit (tracker, signals[CURSOR_CHANGED], 0);

  return TRUE;
}

static void
ensure_xfixes_cursor (MetaCursorTracker *tracker)
{
  XFixesCursorImage *cursor_image;
  CoglTexture2D *sprite;
  guint8 *cursor_data;
  gboolean free_cursor_data;
  CoglContext *ctx;

  if (tracker->sprite)
    return;

  cursor_image = XFixesGetCursorImage (tracker->screen->display->xdisplay);
  if (!cursor_image)
    return;

  /* Like all X APIs, XFixesGetCursorImage() returns arrays of 32-bit
   * quantities as arrays of long; we need to convert on 64 bit */
  if (sizeof(long) == 4)
    {
      cursor_data = (guint8 *)cursor_image->pixels;
      free_cursor_data = FALSE;
    }
  else
    {
      int i, j;
      guint32 *cursor_words;
      gulong *p;
      guint32 *q;

      cursor_words = g_new (guint32, cursor_image->width * cursor_image->height);
      cursor_data = (guint8 *)cursor_words;

      p = cursor_image->pixels;
      q = cursor_words;
      for (j = 0; j < cursor_image->height; j++)
        for (i = 0; i < cursor_image->width; i++)
          *(q++) = *(p++);

      free_cursor_data = TRUE;
    }

  ctx = clutter_backend_get_cogl_context (clutter_get_default_backend ());
  sprite = cogl_texture_2d_new_from_data (ctx,
                                          cursor_image->width,
                                          cursor_image->height,
                                          CLUTTER_CAIRO_FORMAT_ARGB32,
                                          COGL_PIXEL_FORMAT_ANY,
                                          cursor_image->width * 4, /* stride */
                                          cursor_data,
                                          NULL);

  if (free_cursor_data)
    g_free (cursor_data);

  if (sprite != NULL)
    {
      tracker->sprite = sprite;
      tracker->hot_x = cursor_image->xhot;
      tracker->hot_y = cursor_image->yhot;
    }
  XFree (cursor_image);
}

/**
 * meta_cursor_tracker_get_sprite:
 *
 * Returns: (transfer none):
 */
CoglTexture *
meta_cursor_tracker_get_sprite (MetaCursorTracker *tracker)
{
  g_return_val_if_fail (META_IS_CURSOR_TRACKER (tracker), NULL);

  if (!meta_is_wayland_compositor ())
    ensure_xfixes_cursor (tracker);

  return COGL_TEXTURE (tracker->sprite);
}

/**
 * meta_cursor_tracker_get_hot:
 * @tracker:
 * @x: (out):
 * @y: (out):
 *
 */
void
meta_cursor_tracker_get_hot (MetaCursorTracker *tracker,
                             int               *x,
                             int               *y)
{
  g_return_if_fail (META_IS_CURSOR_TRACKER (tracker));

  if (!meta_is_wayland_compositor ())
    ensure_xfixes_cursor (tracker);

  if (x)
    *x = tracker->hot_x;
  if (y)
    *y = tracker->hot_y;
}

static void
ensure_wayland_cursor (MetaCursorTracker *tracker)
{
  CoglBitmap *bitmap;
  char *filename;

  if (tracker->default_cursor)
    return;

  filename = g_build_filename (MUTTER_PKGDATADIR,
                               "cursors/left_ptr.png",
                               NULL);

  bitmap = cogl_bitmap_new_from_file (filename, NULL);
  tracker->default_cursor = cogl_texture_2d_new_from_bitmap (bitmap,
                                                             COGL_PIXEL_FORMAT_ANY,
                                                             NULL);

  cogl_object_unref (bitmap);
  g_free (filename);
}

void
meta_cursor_tracker_set_root_cursor (MetaCursorTracker *tracker,
                                     MetaCursor         cursor)
{
  Cursor xcursor;
  MetaDisplay *display = tracker->screen->display;

  /* First create a cursor for X11 applications that don't specify their own */
  xcursor = meta_display_create_x_cursor (display, cursor);

  XDefineCursor (display->xdisplay, tracker->screen->xroot, xcursor);
  XFlush (display->xdisplay);
  XFreeCursor (display->xdisplay, xcursor);

  /* Now update the real root cursor */
  if (meta_is_wayland_compositor ())
    {
      /* FIXME! We need to load all the other cursors too */
      ensure_wayland_cursor (tracker);

      g_clear_pointer (&tracker->root_cursor, cogl_object_unref);
      tracker->root_cursor = cogl_object_ref (tracker->default_cursor);
      tracker->root_hot_x = META_WAYLAND_DEFAULT_CURSOR_HOTSPOT_X;
      tracker->root_hot_y = META_WAYLAND_DEFAULT_CURSOR_HOTSPOT_Y;
    }
}

void
meta_cursor_tracker_revert_root (MetaCursorTracker *tracker)
{
  meta_cursor_tracker_set_sprite (tracker,
                                  tracker->root_cursor,
                                  tracker->root_hot_x,
                                  tracker->root_hot_y);
}

void
meta_cursor_tracker_set_sprite (MetaCursorTracker *tracker,
                                CoglTexture2D     *sprite,
                                int                hot_x,
                                int                hot_y)
{
  g_assert (meta_is_wayland_compositor ());

  g_clear_pointer (&tracker->sprite, cogl_object_unref);

  if (sprite)
    {
      tracker->sprite = cogl_object_ref (sprite);
      tracker->hot_x = hot_x;
      tracker->hot_y = hot_y;
      cogl_pipeline_set_layer_texture (tracker->pipeline, 0, COGL_TEXTURE (tracker->sprite));
    }
  else
    cogl_pipeline_set_layer_texture (tracker->pipeline, 0, NULL);

  g_signal_emit (tracker, signals[CURSOR_CHANGED], 0);

  meta_cursor_tracker_update_position (tracker, tracker->current_x, tracker->current_y);
}

void
meta_cursor_tracker_update_position (MetaCursorTracker *tracker,
                                     int                new_x,
                                     int                new_y)
{
  g_assert (meta_is_wayland_compositor ());

  tracker->current_x = new_x;
  tracker->current_y = new_y;
  tracker->current_rect.x = tracker->current_x - tracker->hot_x;
  tracker->current_rect.y = tracker->current_y - tracker->hot_y;

  if (tracker->sprite)
    {
      tracker->current_rect.width = cogl_texture_get_width (COGL_TEXTURE (tracker->sprite));
      tracker->current_rect.height = cogl_texture_get_height (COGL_TEXTURE (tracker->sprite));
    }
  else
    {
      tracker->current_rect.width = 0;
      tracker->current_rect.height = 0;
    }
}

void
meta_cursor_tracker_paint (MetaCursorTracker *tracker)
{
  g_assert (meta_is_wayland_compositor ());

  if (tracker->sprite == NULL)
    return;

  /* FIXME: try to use a DRM cursor when possible */
  cogl_framebuffer_draw_rectangle (cogl_get_draw_framebuffer (),
                                   tracker->pipeline,
                                   tracker->current_rect.x,
                                   tracker->current_rect.y,
                                   tracker->current_rect.x +
                                   tracker->current_rect.width,
                                   tracker->current_rect.y +
                                   tracker->current_rect.height);

  tracker->previous_rect = tracker->current_rect;
  tracker->previous_is_valid = TRUE;
}

void
meta_cursor_tracker_queue_redraw (MetaCursorTracker *tracker,
                                  ClutterActor      *stage)
{
  g_assert (meta_is_wayland_compositor ());

  if (tracker->previous_is_valid)
    {
      clutter_actor_queue_redraw_with_clip (stage, &tracker->previous_rect);
      tracker->previous_is_valid = FALSE;
    }

  if (tracker->sprite == NULL)
    return;

  clutter_actor_queue_redraw_with_clip (stage, &tracker->current_rect);
}

static void
get_pointer_position_gdk (int         *x,
                          int         *y,
                          int         *mods)
{
  GdkDeviceManager *gmanager;
  GdkDevice *gdevice;
  GdkScreen *gscreen;

  gmanager = gdk_display_get_device_manager (gdk_display_get_default ());
  gdevice = gdk_device_manager_get_client_pointer (gmanager);

  gdk_device_get_position (gdevice, &gscreen, x, y);
  gdk_device_get_state (gdevice,
                        gdk_screen_get_root_window (gscreen),
                        NULL, (GdkModifierType*)mods);
}

static void
get_pointer_position_clutter (int         *x,
                              int         *y,
                              int         *mods)
{
  ClutterDeviceManager *cmanager;
  ClutterInputDevice *cdevice;
  ClutterPoint point;

  cmanager = clutter_device_manager_get_default ();
  cdevice = clutter_device_manager_get_core_device (cmanager, CLUTTER_POINTER_DEVICE);

  clutter_input_device_get_coords (cdevice, NULL, &point);
  *x = point.x;
  *y = point.y;
  *mods = clutter_input_device_get_modifier_state (cdevice);
}

void
meta_cursor_tracker_get_pointer (MetaCursorTracker   *tracker,
                                 int                 *x,
                                 int                 *y,
                                 ClutterModifierType *mods)
{
  /* We can't use the clutter interface when not running as a wayland compositor,
     because we need to query the server, rather than using the last cached value.
     OTOH, on wayland we can't use GDK, because that only sees the events
     we forward to xwayland.
  */
  if (meta_is_wayland_compositor ())
    get_pointer_position_clutter (x, y, (int*)mods);
  else
    get_pointer_position_gdk (x, y, (int*)mods);
}