gdkcursor-x11.c

linux下电话本所依赖的一些图形库

#ifdef HAVE_XCURSOR

static XcursorImage*
create_cursor_image (GdkPixbuf *pixbuf,
		     gint       x,
		     gint       y)
{
  guint width, height, rowstride, n_channels;
  guchar *pixels, *src;
  XcursorImage *xcimage;
  XcursorPixel *dest;

  width = gdk_pixbuf_get_width (pixbuf);
  height = gdk_pixbuf_get_height (pixbuf);

  n_channels = gdk_pixbuf_get_n_channels (pixbuf);
  rowstride = gdk_pixbuf_get_rowstride (pixbuf);
  pixels = gdk_pixbuf_get_pixels (pixbuf);

  xcimage = XcursorImageCreate (width, height);

  xcimage->xhot = x;
  xcimage->yhot = y;

  dest = xcimage->pixels;

  if (n_channels == 3)
    {
      gint i, j;

      for (j = 0; j < height; j++)
        {
          src = pixels + j * rowstride;
          for (i = 0; i < width; i++)
            {
              *dest = (0xff << 24) | (src[0] << 16) | (src[1] << 8) | src[2];
            }

	  src += n_channels;
	  dest++;
	}
    }
  else
    {
      _gdk_x11_convert_to_format (pixels, rowstride,
                                  (guchar *) dest, 4 * width,
                                  GDK_X11_FORMAT_ARGB,
                                  (G_BYTE_ORDER == G_BIG_ENDIAN) ?
                                  GDK_MSB_FIRST : GDK_LSB_FIRST,
                                  width, height);
    }

  return xcimage;
}


/**
 * gdk_cursor_new_from_pixbuf:
 * @display: the #GdkDisplay for which the cursor will be created
 * @pixbuf: the #GdkPixbuf containing the cursor image
 * @x: the horizontal offset of the 'hotspot' of the cursor. 
 * @y: the vertical offset of the 'hotspot' of the cursor.
 *
 * Creates a new cursor from a pixbuf. 
 *
 * Not all GDK backends support RGBA cursors. If they are not 
 * supported, a monochrome approximation will be displayed. 
 * The functions gdk_display_supports_cursor_alpha() and 
 * gdk_display_supports_cursor_color() can be used to determine
 * whether RGBA cursors are supported; 
 * gdk_display_get_default_cursor_size() and 
 * gdk_display_get_maximal_cursor_size() give information about 
 * cursor sizes.
 *
 * On the X backend, support for RGBA cursors requires a
 * sufficently new version of the X Render extension. 
 *
 * Returns: a new #GdkCursor.
 * 
 * Since: 2.4
 */
GdkCursor *
gdk_cursor_new_from_pixbuf (GdkDisplay *display, 
			    GdkPixbuf  *pixbuf,
			    gint        x,
			    gint        y)
{
  XcursorImage *xcimage;
  Cursor xcursor;
  GdkCursorPrivate *private;
  GdkCursor *cursor;

  g_return_val_if_fail (GDK_IS_DISPLAY (display), NULL);
  g_return_val_if_fail (GDK_IS_PIXBUF (pixbuf), NULL);
  g_return_val_if_fail (0 <= x && x < gdk_pixbuf_get_width (pixbuf), NULL);
  g_return_val_if_fail (0 <= y && y < gdk_pixbuf_get_height (pixbuf), NULL);

  if (display->closed)
    xcursor = None;
  else 
    {
      xcimage = create_cursor_image (pixbuf, x, y);
      xcursor = XcursorImageLoadCursor (GDK_DISPLAY_XDISPLAY (display), xcimage);
      XcursorImageDestroy (xcimage);
    }

  private = g_new (GdkCursorPrivate, 1);
  private->display = display;
  private->xcursor = xcursor;
  cursor = (GdkCursor *) private;
  cursor->type = GDK_CURSOR_IS_PIXMAP;
  cursor->ref_count = 1;
  
  return cursor;
}

/**
 * gdk_display_supports_cursor_alpha:
 * @display: a #GdkDisplay
 *
 * Returns %TRUE if cursors can use an 8bit alpha channel 
 * on @display. Otherwise, cursors are restricted to bilevel 
 * alpha (i.e. a mask).
 *
 * Returns: whether cursors can have alpha channels.
 *
 * Since: 2.4
 */
gboolean 
gdk_display_supports_cursor_alpha (GdkDisplay *display)
{
  g_return_val_if_fail (GDK_IS_DISPLAY (display), FALSE);

  return XcursorSupportsARGB (GDK_DISPLAY_XDISPLAY (display));
}

/**
 * gdk_display_supports_cursor_color:
 * @display: a #GdkDisplay
 *
 * Returns %TRUE if multicolored cursors are supported
 * on @display. Otherwise, cursors have only a forground
 * and a background color.
 *
 * Returns: whether cursors can have multiple colors.
 *
 * Since: 2.4
 */
gboolean 
gdk_display_supports_cursor_color (GdkDisplay *display)
{
  g_return_val_if_fail (GDK_IS_DISPLAY (display), FALSE);

  return XcursorSupportsARGB (GDK_DISPLAY_XDISPLAY (display));
}

/**
 * gdk_display_get_default_cursor_size:
 * @display: a #GdkDisplay
 *
 * Returns the default size to use for cursors on @display.
 *
 * Returns: the default cursor size.
 *
 * Since: 2.4
 */
guint     
gdk_display_get_default_cursor_size (GdkDisplay *display)
{
  g_return_val_if_fail (GDK_IS_DISPLAY (display), FALSE);

  return XcursorGetDefaultSize (GDK_DISPLAY_XDISPLAY (display));
}

#else

GdkCursor *
gdk_cursor_new_from_pixbuf (GdkDisplay *display, 
			    GdkPixbuf  *pixbuf,
			    gint        x,
			    gint        y)
{
  GdkCursor *cursor;
  GdkPixmap *pixmap, *mask;
  guint width, height, n_channels, rowstride, i, j;
  guint8 *data, *mask_data, *pixels;
  GdkColor fg = { 0, 0, 0, 0 };
  GdkColor bg = { 0, 0xffff, 0xffff, 0xffff };
  GdkScreen *screen;

  g_return_val_if_fail (GDK_IS_DISPLAY (display), NULL);
  g_return_val_if_fail (GDK_IS_PIXBUF (pixbuf), NULL);

  width = gdk_pixbuf_get_width (pixbuf);
  height = gdk_pixbuf_get_height (pixbuf);

  g_return_val_if_fail (0 <= x && x < width, NULL);
  g_return_val_if_fail (0 <= y && y < height, NULL);

  n_channels = gdk_pixbuf_get_n_channels (pixbuf);
  rowstride = gdk_pixbuf_get_rowstride (pixbuf);
  pixels = gdk_pixbuf_get_pixels (pixbuf);

  data = g_new0 (guint8, (width + 7) / 8 * height);
  mask_data = g_new0 (guint8, (width + 7) / 8 * height);

  for (j = 0; j < height; j++)
    {
      guint8 *src = pixels + j * rowstride;
      guint8 *d = data + (width + 7) / 8 * j;
      guint8 *md = mask_data + (width + 7) / 8 * j;
	
      for (i = 0; i < width; i++)
	{
	  if (src[1] < 0x80)
	    *d |= 1 << (i % 8);
	  
	  if (n_channels == 3 || src[3] >= 0x80)
	    *md |= 1 << (i % 8);
	  
	  src += n_channels;
	  if (i % 8 == 7)
	    {
	      d++; 
	      md++;
	    }
	}
    }
      
  screen = gdk_display_get_default_screen (display);
  pixmap = gdk_bitmap_create_from_data (gdk_screen_get_root_window (screen), 
					data, width, height);
 
  mask = gdk_bitmap_create_from_data (gdk_screen_get_root_window (screen),
				      mask_data, width, height);
   
  cursor = gdk_cursor_new_from_pixmap (pixmap, mask, &fg, &bg, x, y);
   
  g_object_unref (pixmap);
  g_object_unref (mask);

  g_free (data);
  g_free (mask_data);
  
  return cursor;
}

gboolean 
gdk_display_supports_cursor_alpha (GdkDisplay    *display)
{
  g_return_val_if_fail (GDK_IS_DISPLAY (display), FALSE);

  return FALSE;
}

gboolean 
gdk_display_supports_cursor_color (GdkDisplay    *display)
{
  g_return_val_if_fail (GDK_IS_DISPLAY (display), FALSE);

  return FALSE;
}

guint     
gdk_display_get_default_cursor_size (GdkDisplay    *display)
{
  g_return_val_if_fail (GDK_IS_DISPLAY (display), 0);
  
  /* no idea, really */
  return 20; 
}

#endif


/**
 * gdk_display_get_maximal_cursor_size:
 * @display: a #GdkDisplay
 * @width: the return location for the maximal cursor width
 * @height: the return location for the maximal cursor height
 *
 * Gets the maximal size to use for cursors on @display.
 *
 * Since: 2.4
 */
void     
gdk_display_get_maximal_cursor_size (GdkDisplay *display,
				     guint       *width,
				     guint       *height)
{
  GdkScreen *screen;
  GdkWindow *window;

  g_return_if_fail (GDK_IS_DISPLAY (display));
  
  screen = gdk_display_get_default_screen (display);
  window = gdk_screen_get_root_window (screen);
  XQueryBestCursor (GDK_DISPLAY_XDISPLAY (display), 
		    GDK_WINDOW_XWINDOW (window), 
		    128, 128, width, height);
}

#define __GDK_CURSOR_X11_C__
#include "gdkaliasdef.c"