/* GdkPixbuf library - Progressive loader object * * Copyright (C) 1999 The Free Software Foundation * * Authors: Mark Crichton * Miguel de Icaza * Federico Mena-Quintero * Jonathan Blandford * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2 of the License, or (at your option) any later version. * * This library 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 * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, write to the * Free Software Foundation, Inc., 59 Temple Place - Suite 330, * Boston, MA 02111-1307, USA. */ #include #include "gdk-pixbuf-private.h" #include "gdk-pixbuf-animation.h" #include "gdk-pixbuf-io.h" #include "gdk-pixbuf-loader.h" #include "gdk-pixbuf-marshal.h" enum { SIZE_PREPARED, AREA_PREPARED, AREA_UPDATED, CLOSED, LAST_SIGNAL }; static void gdk_pixbuf_loader_class_init (GdkPixbufLoaderClass *klass); static void gdk_pixbuf_loader_init (GdkPixbufLoader *loader); static void gdk_pixbuf_loader_finalize (GObject *loader); static gpointer parent_class = NULL; static guint pixbuf_loader_signals[LAST_SIGNAL] = { 0 }; /* Internal data */ #define LOADER_HEADER_SIZE 128 typedef struct { GdkPixbufAnimation *animation; gboolean closed; guchar header_buf[LOADER_HEADER_SIZE]; gint header_buf_offset; GdkPixbufModule *image_module; gpointer context; gint width; gint height; gboolean size_fixed; gboolean needs_scale; } GdkPixbufLoaderPrivate; /** * gdk_pixbuf_loader_get_type: * @void: * * Registers the #GdkPixbufLoader class if necessary, and returns the type ID * associated to it. * * Return value: The type ID of the #GdkPixbufLoader class. **/ GType gdk_pixbuf_loader_get_type (void) { static GType loader_type = 0; if (!loader_type) { static const GTypeInfo loader_info = { sizeof (GdkPixbufLoaderClass), (GBaseInitFunc) NULL, (GBaseFinalizeFunc) NULL, (GClassInitFunc) gdk_pixbuf_loader_class_init, NULL, /* class_finalize */ NULL, /* class_data */ sizeof (GdkPixbufLoader), 0, /* n_preallocs */ (GInstanceInitFunc) gdk_pixbuf_loader_init }; loader_type = g_type_register_static (G_TYPE_OBJECT, "GdkPixbufLoader", &loader_info, 0); } return loader_type; } static void gdk_pixbuf_loader_class_init (GdkPixbufLoaderClass *class) { GObjectClass *object_class; object_class = (GObjectClass *) class; parent_class = g_type_class_peek_parent (class); object_class->finalize = gdk_pixbuf_loader_finalize; pixbuf_loader_signals[SIZE_PREPARED] = g_signal_new ("size_prepared", G_TYPE_FROM_CLASS (object_class), G_SIGNAL_RUN_LAST, G_STRUCT_OFFSET (GdkPixbufLoaderClass, size_prepared), NULL, NULL, gdk_pixbuf_marshal_VOID__INT_INT, G_TYPE_NONE, 2, G_TYPE_INT, G_TYPE_INT); pixbuf_loader_signals[AREA_PREPARED] = g_signal_new ("area_prepared", G_TYPE_FROM_CLASS (object_class), G_SIGNAL_RUN_LAST, G_STRUCT_OFFSET (GdkPixbufLoaderClass, area_prepared), NULL, NULL, gdk_pixbuf_marshal_VOID__VOID, G_TYPE_NONE, 0); pixbuf_loader_signals[AREA_UPDATED] = g_signal_new ("area_updated", G_TYPE_FROM_CLASS (object_class), G_SIGNAL_RUN_LAST, G_STRUCT_OFFSET (GdkPixbufLoaderClass, area_updated), NULL, NULL, gdk_pixbuf_marshal_VOID__INT_INT_INT_INT, G_TYPE_NONE, 4, G_TYPE_INT, G_TYPE_INT, G_TYPE_INT, G_TYPE_INT); pixbuf_loader_signals[CLOSED] = g_signal_new ("closed", G_TYPE_FROM_CLASS (object_class), G_SIGNAL_RUN_LAST, G_STRUCT_OFFSET (GdkPixbufLoaderClass, closed), NULL, NULL, gdk_pixbuf_marshal_VOID__VOID, G_TYPE_NONE, 0); } static void gdk_pixbuf_loader_init (GdkPixbufLoader *loader) { GdkPixbufLoaderPrivate *priv; priv = g_new0 (GdkPixbufLoaderPrivate, 1); loader->priv = priv; } static void gdk_pixbuf_loader_finalize (GObject *object) { GdkPixbufLoader *loader; GdkPixbufLoaderPrivate *priv = NULL; loader = GDK_PIXBUF_LOADER (object); priv = loader->priv; if (!priv->closed) g_warning ("GdkPixbufLoader finalized without calling gdk_pixbuf_loader_close() - this is not allowed. You must explicitly end the data stream to the loader before dropping the last reference."); if (priv->animation) g_object_unref (priv->animation); g_free (priv); G_OBJECT_CLASS (parent_class)->finalize (object); } /** * gdk_pixbuf_loader_set_size: * @loader: A pixbuf loader. * @width: The desired width of the image being loaded. * @height: The desired height of the image being loaded. * * Causes the image to be scaled while it is loaded. The desired * image size can be determined relative to the original size of * the image by calling gdk_pixbuf_loader_set_size() from a * signal handler for the ::size_prepared signal. * * Attempts to set the desired image size are ignored after the * emission of the ::size_prepared signal. */ void gdk_pixbuf_loader_set_size (GdkPixbufLoader *loader, gint width, gint height) { GdkPixbufLoaderPrivate *priv = GDK_PIXBUF_LOADER (loader)->priv; g_return_if_fail (width > 0 && height > 0); if (!priv->size_fixed) { priv->width = width; priv->height = height; } } static void gdk_pixbuf_loader_size_func (gint *width, gint *height, gpointer loader) { GdkPixbufLoaderPrivate *priv = GDK_PIXBUF_LOADER (loader)->priv; /* allow calling gdk_pixbuf_loader_set_size() before the signal */ if (priv->width == 0 && priv->height == 0) { priv->width = *width; priv->height = *height; } g_signal_emit (loader, pixbuf_loader_signals[SIZE_PREPARED], 0, *width, *height); priv->size_fixed = TRUE; *width = priv->width; *height = priv->height; } static void gdk_pixbuf_loader_prepare (GdkPixbuf *pixbuf, GdkPixbufAnimation *anim, gpointer loader) { GdkPixbufLoaderPrivate *priv = GDK_PIXBUF_LOADER (loader)->priv; g_return_if_fail (pixbuf != NULL); if (!priv->size_fixed) { /* Defend against lazy loaders which don't call size_func */ gint width = gdk_pixbuf_get_width (pixbuf); gint height = gdk_pixbuf_get_height (pixbuf); gdk_pixbuf_loader_size_func (&width, &height, loader); } priv->needs_scale = FALSE; if (priv->width > 0 && priv->height > 0 && (priv->width != gdk_pixbuf_get_width (pixbuf) || priv->height != gdk_pixbuf_get_height (pixbuf))) priv->needs_scale = TRUE; if (anim) g_object_ref (anim); else anim = gdk_pixbuf_non_anim_new (pixbuf); priv->animation = anim; if (!priv->needs_scale) g_signal_emit (loader, pixbuf_loader_signals[AREA_PREPARED], 0); } static void gdk_pixbuf_loader_update (GdkPixbuf *pixbuf, gint x, gint y, gint width, gint height, gpointer loader) { GdkPixbufLoaderPrivate *priv = GDK_PIXBUF_LOADER (loader)->priv; if (!priv->needs_scale) g_signal_emit (loader, pixbuf_loader_signals[AREA_UPDATED], 0, x, y, /* sanity check in here. Defend against an errant loader */ MIN (width, gdk_pixbuf_animation_get_width (priv->animation)), MIN (height, gdk_pixbuf_animation_get_height (priv->animation))); } static gint gdk_pixbuf_loader_load_module (GdkPixbufLoader *loader, const char *image_type, GError **error) { GdkPixbufLoaderPrivate *priv = loader->priv; if (image_type) { priv->image_module = _gdk_pixbuf_get_named_module (image_type, error); } else { priv->image_module = _gdk_pixbuf_get_module (priv->header_buf, priv->header_buf_offset, NULL, error); } if (priv->image_module == NULL) return 0; if (priv->image_module->module == NULL) if (!_gdk_pixbuf_load_module (priv->image_module, error)) return 0; if (priv->image_module->module == NULL) return 0; if ((priv->image_module->begin_load == NULL) || (priv->image_module->stop_load == NULL) || (priv->image_module->load_increment == NULL)) { g_set_error (error, GDK_PIXBUF_ERROR, GDK_PIXBUF_ERROR_UNSUPPORTED_OPERATION, _("Incremental loading of image type '%s' is not supported"), priv->image_module->module_name); return 0; } priv->context = priv->image_module->begin_load (gdk_pixbuf_loader_size_func, gdk_pixbuf_loader_prepare, gdk_pixbuf_loader_update, loader, error); if (priv->context == NULL) { /* Defense against broken loaders; DO NOT take this as a GError * example */ if (error && *error == NULL) { g_warning ("Bug! loader '%s' didn't set an error on failure", priv->image_module->module_name); g_set_error (error, GDK_PIXBUF_ERROR, GDK_PIXBUF_ERROR_FAILED, _("Internal error: Image loader module '%s'" " failed to begin loading an image, but didn't" " give a reason for the failure"), priv->image_module->module_name); } return 0; } if (priv->header_buf_offset && priv->image_module->load_increment (priv->context, priv->header_buf, priv->header_buf_offset, error)) return priv->header_buf_offset; return 0; } static int gdk_pixbuf_loader_eat_header_write (GdkPixbufLoader *loader, const guchar *buf, gsize count, GError **error) { gint n_bytes; GdkPixbufLoaderPrivate *priv = loader->priv; n_bytes = MIN(LOADER_HEADER_SIZE - priv->header_buf_offset, count); memcpy (priv->header_buf + priv->header_buf_offset, buf, n_bytes); priv->header_buf_offset += n_bytes; if (priv->header_buf_offset >= LOADER_HEADER_SIZE) { if (gdk_pixbuf_loader_load_module (loader, NULL, error) == 0) return 0; } return n_bytes; } /** * gdk_pixbuf_loader_write: * @loader: A pixbuf loader. * @buf: Pointer to image data. * @count: Length of the @buf buffer in bytes. * @error: return location for errors * * This will cause a pixbuf loader to parse the next @count bytes of * an image. It will return %TRUE if the data was loaded successfully, * and %FALSE if an error occurred. In the latter case, the loader * will be closed, and will not accept further writes. If %FALSE is * returned, @error will be set to an error from the #GDK_PIXBUF_ERROR * or #G_FILE_ERROR domains. * * Return value: %TRUE if the write was successful, or %FALSE if the loader * cannot parse the buffer. **/ gboolean gdk_pixbuf_loader_write (GdkPixbufLoader *loader, const guchar *buf, gsize count, GError **error) { GdkPixbufLoaderPrivate *priv; g_return_val_if_fail (loader != NULL, FALSE); g_return_val_if_fail (GDK_IS_PIXBUF_LOADER (loader), FALSE); g_return_val_if_fail (buf != NULL, FALSE); g_return_val_if_fail (count >= 0, FALSE); priv = loader->priv; /* we expect it's not to be closed */ g_return_val_if_fail (priv->closed == FALSE, FALSE); if (priv->image_module == NULL) { gint eaten; eaten = gdk_pixbuf_loader_eat_header_write (loader, buf, count, error); if (eaten <= 0) return FALSE; count -= eaten; buf += eaten; } if (count > 0 && priv->image_module->load_increment) { gboolean retval; retval = priv->image_module->load_increment (priv->context, buf, count, error); if (!retval && error && *error == NULL) { /* Fix up busted image loader */ g_warning ("Bug! loader '%s' didn't set an error on failure", priv->image_module->module_name); g_set_error (error, GDK_PIXBUF_ERROR, GDK_PIXBUF_ERROR_FAILED, _("Internal error: Image loader module '%s'" " failed to begin loading an image, but didn't" " give a reason for the failure"), priv->image_module->module_name); } return retval; } return TRUE; } /** * gdk_pixbuf_loader_new: * * Creates a new pixbuf loader object. * * Return value: A newly-created pixbuf loader. **/ GdkPixbufLoader * gdk_pixbuf_loader_new (void) { return g_object_new (GDK_TYPE_PIXBUF_LOADER, NULL); } /** * gdk_pixbuf_loader_new_with_type: * @image_type: name of the image format to be loaded with the image * @error: return location for an allocated #GError, or %NULL to ignore errors * * Creates a new pixbuf loader object that always attempts to parse * image data as if it were an image of type @image_type, instead of * identifying the type automatically. Useful if you want an error if * the image isn't the expected type, for loading image formats * that can't be reliably identified by looking at the data, or if * the user manually forces a specific type. * * Return value: A newly-created pixbuf loader. **/ GdkPixbufLoader * gdk_pixbuf_loader_new_with_type (const char *image_type, GError **error) { GdkPixbufLoader *retval; GError *tmp; retval = g_object_new (GDK_TYPE_PIXBUF_LOADER, NULL); tmp = NULL; gdk_pixbuf_loader_load_module(retval, image_type, &tmp); if (tmp != NULL) { g_propagate_error (error, tmp); g_object_unref (retval); return NULL; } return retval; } /** * gdk_pixbuf_loader_get_pixbuf: * @loader: A pixbuf loader. * * Queries the #GdkPixbuf that a pixbuf loader is currently creating. * In general it only makes sense to call this function after the * "area_prepared" signal has been emitted by the loader; this means * that enough data has been read to know the size of the image that * will be allocated. If the loader has not received enough data via * gdk_pixbuf_loader_write(), then this function returns %NULL. The * returned pixbuf will be the same in all future calls to the loader, * so simply calling g_object_ref() should be sufficient to continue * using it. Additionally, if the loader is an animation, it will * return the "static image" of the animation * (see gdk_pixbuf_animation_get_static_image()). * * Return value: The #GdkPixbuf that the loader is creating, or %NULL if not * enough data has been read to determine how to create the image buffer. **/ GdkPixbuf * gdk_pixbuf_loader_get_pixbuf (GdkPixbufLoader *loader) { GdkPixbufLoaderPrivate *priv; g_return_val_if_fail (loader != NULL, NULL); g_return_val_if_fail (GDK_IS_PIXBUF_LOADER (loader), NULL); priv = loader->priv; if (priv->animation) return gdk_pixbuf_animation_get_static_image (priv->animation); else return NULL; } /** * gdk_pixbuf_loader_get_animation: * @loader: A pixbuf loader * * Queries the #GdkPixbufAnimation that a pixbuf loader is currently creating. * In general it only makes sense to call this function after the "area_prepared" * signal has been emitted by the loader. If the loader doesn't have enough * bytes yet (hasn't emitted the "area_prepared" signal) this function will * return %NULL. * * Return value: The #GdkPixbufAnimation that the loader is loading, or %NULL if not enough data has been read to determine the information. **/ GdkPixbufAnimation * gdk_pixbuf_loader_get_animation (GdkPixbufLoader *loader) { GdkPixbufLoaderPrivate *priv; g_return_val_if_fail (loader != NULL, NULL); g_return_val_if_fail (GDK_IS_PIXBUF_LOADER (loader), NULL); priv = loader->priv; return priv->animation; } /** * gdk_pixbuf_loader_close: * @loader: A pixbuf loader. * @error: return location for a #GError, or %NULL to ignore errors * * Informs a pixbuf loader that no further writes with * gdk_pixbuf_loader_write() will occur, so that it can free its * internal loading structures. Also, tries to parse any data that * hasn't yet been parsed; if the remaining data is partial or * corrupt, an error will be returned. If %FALSE is returned, @error * will be set to an error from the #GDK_PIXBUF_ERROR or #G_FILE_ERROR * domains. If you're just cancelling a load rather than expecting it * to be finished, passing %NULL for @error to ignore it is * reasonable. * * Returns: %TRUE if all image data written so far was successfully passed out via the update_area signal **/ gboolean gdk_pixbuf_loader_close (GdkPixbufLoader *loader, GError **error) { GdkPixbufLoaderPrivate *priv; gboolean retval = TRUE; g_return_val_if_fail (loader != NULL, TRUE); g_return_val_if_fail (GDK_IS_PIXBUF_LOADER (loader), TRUE); priv = loader->priv; /* we expect it's not closed */ g_return_val_if_fail (priv->closed == FALSE, TRUE); /* We have less the 128 bytes in the image. Flush it, and keep going. */ if (priv->image_module == NULL) { GError *tmp = NULL; gdk_pixbuf_loader_load_module (loader, NULL, &tmp); if (tmp != NULL) { g_propagate_error (error, tmp); retval = FALSE; } } if (priv->image_module && priv->image_module->stop_load && priv->context) { if (!priv->image_module->stop_load (priv->context, error)) retval = FALSE; } priv->closed = TRUE; if (priv->needs_scale) { GdkPixbuf *tmp, *pixbuf; tmp = gdk_pixbuf_animation_get_static_image (priv->animation); g_object_ref (tmp); pixbuf = gdk_pixbuf_new (GDK_COLORSPACE_RGB, tmp->has_alpha, 8, priv->width, priv->height); g_object_unref (priv->animation); priv->animation = gdk_pixbuf_non_anim_new (pixbuf); g_signal_emit (loader, pixbuf_loader_signals[AREA_PREPARED], 0); gdk_pixbuf_scale (tmp, pixbuf, 0, 0, priv->width, priv->height, 0, 0, (double) priv->width / tmp->width, (double) priv->height / tmp->height, GDK_INTERP_BILINEAR); g_object_unref (tmp); g_signal_emit (loader, pixbuf_loader_signals[AREA_UPDATED], 0, 0, 0, priv->width, priv->height); } g_signal_emit (loader, pixbuf_loader_signals[CLOSED], 0); return retval; } /** * gdk_pixbuf_loader_get_format: * @loader: A pixbuf loader. * * Obtains the available information about the format of the * currently loading image file. * * Returns: A #GdkPixbufFormat or %NULL. The return value is owned * by GdkPixbuf and should not be freed. */ GdkPixbufFormat * gdk_pixbuf_loader_get_format (GdkPixbufLoader *loader) { GdkPixbufLoaderPrivate *priv; g_return_val_if_fail (loader != NULL, NULL); g_return_val_if_fail (GDK_IS_PIXBUF_LOADER (loader), NULL); priv = loader->priv; if (priv->image_module) return _gdk_pixbuf_get_format (priv->image_module); else return NULL; }