/* GDK - The GIMP Drawing Kit * Copyright (C) 1995-1999 Peter Mattis, Spencer Kimball and Josh MacDonald * * 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, see . */ /* * Modified by the GTK+ Team and others 1997-2000. See the AUTHORS * file for a list of people on the GTK+ Team. See the ChangeLog * files for a list of changes. These files are distributed with * GTK+ at ftp://ftp.gtk.org/pub/gtk/. */ #include "config.h" #include "gdkdndprivate.h" #include "gdkdisplay.h" #include "gdksurface.h" #include "gdkintl.h" #include "gdkcontentformats.h" #include "gdkcontentprovider.h" #include "gdkcontentserializer.h" #include "gdkcursor.h" #include "gdkenumtypes.h" #include "gdkeventsprivate.h" typedef struct _GdkDragContextPrivate GdkDragContextPrivate; struct _GdkDragContextPrivate { GdkDisplay *display; GdkDevice *device; }; static struct { GdkDragAction action; const gchar *name; GdkCursor *cursor; } drag_cursors[] = { { GDK_ACTION_DEFAULT, NULL, NULL }, { GDK_ACTION_ASK, "dnd-ask", NULL }, { GDK_ACTION_COPY, "dnd-copy", NULL }, { GDK_ACTION_MOVE, "dnd-move", NULL }, { GDK_ACTION_LINK, "dnd-link", NULL }, { 0, "dnd-none", NULL }, }; enum { PROP_0, PROP_CONTENT, PROP_DEVICE, PROP_DISPLAY, PROP_FORMATS, N_PROPERTIES }; enum { CANCEL, DROP_PERFORMED, DND_FINISHED, ACTION_CHANGED, N_SIGNALS }; static GParamSpec *properties[N_PROPERTIES] = { NULL, }; static guint signals[N_SIGNALS] = { 0 }; static GList *contexts = NULL; G_DEFINE_TYPE_WITH_PRIVATE (GdkDragContext, gdk_drag_context, G_TYPE_OBJECT) /** * SECTION:dnd * @title: Drag And Drop * @short_description: Functions for controlling drag and drop handling * * These functions provide a low level interface for drag and drop. * The X backend of GDK supports both the Xdnd and Motif drag and drop * protocols transparently, the Win32 backend supports the WM_DROPFILES * protocol. * * GTK+ provides a higher level abstraction based on top of these functions, * and so they are not normally needed in GTK+ applications. * See the [Drag and Drop][gtk3-Drag-and-Drop] section of * the GTK+ documentation for more information. */ /** * GdkDragContext: * * The GdkDragContext struct contains only private fields and * should not be accessed directly. */ /** * gdk_drag_context_get_display: * @context: a #GdkDragContext * * Gets the #GdkDisplay that the drag context was created for. * * Returns: (transfer none): a #GdkDisplay **/ GdkDisplay * gdk_drag_context_get_display (GdkDragContext *context) { GdkDragContextPrivate *priv = gdk_drag_context_get_instance_private (context); g_return_val_if_fail (GDK_IS_DRAG_CONTEXT (context), NULL); return priv->display; } /** * gdk_drag_context_get_formats: * @context: a #GdkDragContext * * Retrieves the formats supported by this context. * * Returns: (transfer none): a #GdkContentFormats **/ GdkContentFormats * gdk_drag_context_get_formats (GdkDragContext *context) { g_return_val_if_fail (GDK_IS_DRAG_CONTEXT (context), NULL); return context->formats; } /** * gdk_drag_context_get_actions: * @context: a #GdkDragContext * * Determines the bitmask of actions proposed by the source if * gdk_drag_context_get_suggested_action() returns %GDK_ACTION_ASK. * * Returns: the #GdkDragAction flags **/ GdkDragAction gdk_drag_context_get_actions (GdkDragContext *context) { g_return_val_if_fail (GDK_IS_DRAG_CONTEXT (context), GDK_ACTION_DEFAULT); return context->actions; } /** * gdk_drag_context_get_suggested_action: * @context: a #GdkDragContext * * Determines the suggested drag action of the context. * * Returns: a #GdkDragAction value **/ GdkDragAction gdk_drag_context_get_suggested_action (GdkDragContext *context) { g_return_val_if_fail (GDK_IS_DRAG_CONTEXT (context), 0); return context->suggested_action; } /** * gdk_drag_context_get_selected_action: * @context: a #GdkDragContext * * Determines the action chosen by the drag destination. * * Returns: a #GdkDragAction value **/ GdkDragAction gdk_drag_context_get_selected_action (GdkDragContext *context) { g_return_val_if_fail (GDK_IS_DRAG_CONTEXT (context), 0); return context->action; } /** * gdk_drag_context_get_source_surface: * @context: a #GdkDragContext * * Returns the #GdkSurface where the DND operation started. * * Returns: (transfer none): a #GdkSurface **/ GdkSurface * gdk_drag_context_get_source_surface (GdkDragContext *context) { g_return_val_if_fail (GDK_IS_DRAG_CONTEXT (context), NULL); return context->source_surface; } /** * gdk_drag_context_get_dest_surface: * @context: a #GdkDragContext * * Returns the destination surface for the DND operation. * * Returns: (transfer none): a #GdkSurface **/ GdkSurface * gdk_drag_context_get_dest_surface (GdkDragContext *context) { g_return_val_if_fail (GDK_IS_DRAG_CONTEXT (context), NULL); return context->dest_surface; } /** * gdk_drag_context_get_device: * @context: a #GdkDragContext * * Returns the #GdkDevice associated to the drag context. * * Returns: (transfer none): The #GdkDevice associated to @context. **/ GdkDevice * gdk_drag_context_get_device (GdkDragContext *context) { GdkDragContextPrivate *priv = gdk_drag_context_get_instance_private (context); g_return_val_if_fail (GDK_IS_DRAG_CONTEXT (context), NULL); return priv->device; } static void gdk_drag_context_init (GdkDragContext *context) { contexts = g_list_prepend (contexts, context); } static void gdk_drag_context_set_property (GObject *gobject, guint prop_id, const GValue *value, GParamSpec *pspec) { GdkDragContext *context = GDK_DRAG_CONTEXT (gobject); GdkDragContextPrivate *priv = gdk_drag_context_get_instance_private (context); switch (prop_id) { case PROP_CONTENT: context->content = g_value_dup_object (value); if (context->content) context->formats = gdk_content_provider_ref_formats (context->content); break; case PROP_DEVICE: priv->device = g_value_dup_object (value); g_assert (priv->device != NULL); priv->display = gdk_device_get_display (priv->device); break; default: G_OBJECT_WARN_INVALID_PROPERTY_ID (gobject, prop_id, pspec); break; } } static void gdk_drag_context_get_property (GObject *gobject, guint prop_id, GValue *value, GParamSpec *pspec) { GdkDragContext *context = GDK_DRAG_CONTEXT (gobject); GdkDragContextPrivate *priv = gdk_drag_context_get_instance_private (context); switch (prop_id) { case PROP_CONTENT: g_value_set_object (value, context->content); break; case PROP_DEVICE: g_value_set_object (value, priv->device); break; case PROP_DISPLAY: g_value_set_object (value, priv->display); break; case PROP_FORMATS: g_value_set_boxed (value, context->formats); break; default: G_OBJECT_WARN_INVALID_PROPERTY_ID (gobject, prop_id, pspec); break; } } static void gdk_drag_context_finalize (GObject *object) { GdkDragContext *context = GDK_DRAG_CONTEXT (object); contexts = g_list_remove (contexts, context); g_clear_object (&context->content); g_clear_pointer (&context->formats, gdk_content_formats_unref); if (context->source_surface) g_object_unref (context->source_surface); if (context->dest_surface) g_object_unref (context->dest_surface); G_OBJECT_CLASS (gdk_drag_context_parent_class)->finalize (object); } static void gdk_drag_context_read_local_async (GdkDragContext *context, GdkContentFormats *formats, int io_priority, GCancellable *cancellable, GAsyncReadyCallback callback, gpointer user_data) { GTask *task; task = g_task_new (context, cancellable, callback, user_data); g_task_set_priority (task, io_priority); g_task_set_source_tag (task, gdk_drag_context_read_local_async); g_task_return_new_error (task, G_IO_ERROR, G_IO_ERROR_NOT_SUPPORTED, _("Reading not implemented.")); g_object_unref (task); } static GInputStream * gdk_drag_context_read_local_finish (GdkDragContext *context, const char **out_mime_type, GAsyncResult *result, GError **error) { g_return_val_if_fail (g_task_is_valid (result, context), NULL); g_return_val_if_fail (g_task_get_source_tag (G_TASK (result)) == gdk_drag_context_read_local_async, NULL); if (out_mime_type) *out_mime_type = g_task_get_task_data (G_TASK (result)); return g_task_propagate_pointer (G_TASK (result), error); } static void gdk_drag_context_class_init (GdkDragContextClass *klass) { GObjectClass *object_class = G_OBJECT_CLASS (klass); object_class->get_property = gdk_drag_context_get_property; object_class->set_property = gdk_drag_context_set_property; object_class->finalize = gdk_drag_context_finalize; /** * GdkDragContext:content: * * The #GdkContentProvider or %NULL if the context is not a source-side * context. */ properties[PROP_CONTENT] = g_param_spec_object ("content", "Content", "The content being dragged", GDK_TYPE_CONTENT_PROVIDER, G_PARAM_READWRITE | G_PARAM_CONSTRUCT_ONLY | G_PARAM_STATIC_STRINGS | G_PARAM_EXPLICIT_NOTIFY); /** * GdkDragContext:device: * * The #GdkDevice that is performing the drag. */ properties[PROP_DEVICE] = g_param_spec_object ("device", "Device", "The device performing the drag", GDK_TYPE_DEVICE, G_PARAM_READWRITE | G_PARAM_CONSTRUCT_ONLY | G_PARAM_STATIC_STRINGS | G_PARAM_EXPLICIT_NOTIFY); /** * GdkDragContext:display: * * The #GdkDisplay that the drag context belongs to. */ properties[PROP_DISPLAY] = g_param_spec_object ("display", "Display", "Display this drag belongs to", GDK_TYPE_DISPLAY, G_PARAM_READABLE | G_PARAM_STATIC_STRINGS | G_PARAM_EXPLICIT_NOTIFY); /** * GdkDragContext:formats: * * The possible formats that the context can provide its data in. */ properties[PROP_FORMATS] = g_param_spec_boxed ("formats", "Formats", "The possible formats for data", GDK_TYPE_CONTENT_FORMATS, G_PARAM_READABLE | G_PARAM_STATIC_STRINGS | G_PARAM_EXPLICIT_NOTIFY); /** * GdkDragContext::cancel: * @context: The object on which the signal is emitted * @reason: The reason the context was cancelled * * The drag and drop operation was cancelled. */ signals[CANCEL] = g_signal_new (g_intern_static_string ("cancel"), G_TYPE_FROM_CLASS (object_class), G_SIGNAL_RUN_LAST, G_STRUCT_OFFSET (GdkDragContextClass, cancel), NULL, NULL, g_cclosure_marshal_VOID__ENUM, G_TYPE_NONE, 1, GDK_TYPE_DRAG_CANCEL_REASON); /** * GdkDragContext::drop-performed: * @context: The object on which the signal is emitted * @time: the time at which the drop happened. * * The drag and drop operation was performed on an accepting client. */ signals[DROP_PERFORMED] = g_signal_new (g_intern_static_string ("drop-performed"), G_TYPE_FROM_CLASS (object_class), G_SIGNAL_RUN_LAST, G_STRUCT_OFFSET (GdkDragContextClass, drop_performed), NULL, NULL, g_cclosure_marshal_VOID__INT, G_TYPE_NONE, 1, G_TYPE_INT); /** * GdkDragContext::dnd-finished: * @context: The object on which the signal is emitted * * The drag and drop operation was finished, the drag destination * finished reading all data. The drag source can now free all * miscellaneous data. */ signals[DND_FINISHED] = g_signal_new (g_intern_static_string ("dnd-finished"), G_TYPE_FROM_CLASS (object_class), G_SIGNAL_RUN_LAST, G_STRUCT_OFFSET (GdkDragContextClass, dnd_finished), NULL, NULL, g_cclosure_marshal_VOID__VOID, G_TYPE_NONE, 0); /** * GdkDragContext::action-changed: * @context: The object on which the signal is emitted * @action: The action currently chosen * * A new action is being chosen for the drag and drop operation. */ signals[ACTION_CHANGED] = g_signal_new (g_intern_static_string ("action-changed"), G_TYPE_FROM_CLASS (object_class), G_SIGNAL_RUN_LAST, G_STRUCT_OFFSET (GdkDragContextClass, action_changed), NULL, NULL, g_cclosure_marshal_VOID__FLAGS, G_TYPE_NONE, 1, GDK_TYPE_DRAG_ACTION); g_object_class_install_properties (object_class, N_PROPERTIES, properties); } /** * gdk_drag_status: * @context: a #GdkDragContext * @action: the selected action which will be taken when a drop happens, * or 0 to indicate that a drop will not be accepted * @time_: the timestamp for this operation * * Selects one of the actions offered by the drag source. * * This function is called by the drag destination in response to * gdk_drag_motion() called by the drag source. */ void gdk_drag_status (GdkDragContext *context, GdkDragAction action, guint32 time_) { g_return_if_fail (GDK_IS_DRAG_CONTEXT (context)); GDK_DRAG_CONTEXT_GET_CLASS (context)->drag_status (context, action, time_); } /* * gdk_drag_abort: * @context: a #GdkDragContext * @time_: the timestamp for this operation * * Aborts a drag without dropping. * * This function is called by the drag source. */ void gdk_drag_abort (GdkDragContext *context, guint32 time_) { g_return_if_fail (GDK_IS_DRAG_CONTEXT (context)); GDK_DRAG_CONTEXT_GET_CLASS (context)->drag_abort (context, time_); } /* * gdk_drag_drop: * @context: a #GdkDragContext * @time_: the timestamp for this operation * * Drops on the current destination. * * This function is called by the drag source. */ void gdk_drag_drop (GdkDragContext *context, guint32 time_) { g_return_if_fail (GDK_IS_DRAG_CONTEXT (context)); GDK_DRAG_CONTEXT_GET_CLASS (context)->drag_drop (context, time_); } /** * gdk_drop_finish: * @context: a #GdkDragContext * @success: %TRUE if the data was successfully received * @time_: the timestamp for this operation * * Ends the drag operation after a drop. * * This function is called by the drag destination. */ void gdk_drop_finish (GdkDragContext *context, gboolean success, guint32 time_) { g_return_if_fail (GDK_IS_DRAG_CONTEXT (context)); GDK_DRAG_CONTEXT_GET_CLASS (context)->drop_finish (context, success, time_); } static void gdk_drag_context_write_done (GObject *content, GAsyncResult *result, gpointer task) { GError *error = NULL; if (gdk_content_provider_write_mime_type_finish (GDK_CONTENT_PROVIDER (content), result, &error)) g_task_return_boolean (task, TRUE); else g_task_return_error (task, error); g_object_unref (task); } static void gdk_drag_context_write_serialize_done (GObject *content, GAsyncResult *result, gpointer task) { GError *error = NULL; if (gdk_content_serialize_finish (result, &error)) g_task_return_boolean (task, TRUE); else g_task_return_error (task, error); g_object_unref (task); } void gdk_drag_context_write_async (GdkDragContext *context, const char *mime_type, GOutputStream *stream, int io_priority, GCancellable *cancellable, GAsyncReadyCallback callback, gpointer user_data) { GdkContentFormats *formats, *mime_formats; GTask *task; GType gtype; g_return_if_fail (GDK_IS_DRAG_CONTEXT (context)); g_return_if_fail (context->content); g_return_if_fail (mime_type != NULL); g_return_if_fail (mime_type == g_intern_string (mime_type)); g_return_if_fail (G_IS_OUTPUT_STREAM (stream)); g_return_if_fail (cancellable == NULL || G_IS_CANCELLABLE (cancellable)); g_return_if_fail (callback != NULL); task = g_task_new (context, cancellable, callback, user_data); g_task_set_priority (task, io_priority); g_task_set_source_tag (task, gdk_drag_context_write_async); formats = gdk_content_provider_ref_formats (context->content); if (gdk_content_formats_contain_mime_type (formats, mime_type)) { gdk_content_provider_write_mime_type_async (context->content, mime_type, stream, io_priority, cancellable, gdk_drag_context_write_done, task); gdk_content_formats_unref (formats); return; } mime_formats = gdk_content_formats_new ((const gchar *[2]) { mime_type, NULL }, 1); mime_formats = gdk_content_formats_union_serialize_gtypes (mime_formats); gtype = gdk_content_formats_match_gtype (formats, mime_formats); if (gtype != G_TYPE_INVALID) { GValue value = G_VALUE_INIT; GError *error = NULL; g_assert (gtype != G_TYPE_INVALID); g_value_init (&value, gtype); if (gdk_content_provider_get_value (context->content, &value, &error)) { gdk_content_serialize_async (stream, mime_type, &value, io_priority, cancellable, gdk_drag_context_write_serialize_done, g_object_ref (task)); } else { g_task_return_error (task, error); } g_value_unset (&value); } else { g_task_return_new_error (task, G_IO_ERROR, G_IO_ERROR_NOT_SUPPORTED, _("No compatible formats to transfer clipboard contents.")); } gdk_content_formats_unref (mime_formats); gdk_content_formats_unref (formats); g_object_unref (task); } gboolean gdk_drag_context_write_finish (GdkDragContext *context, GAsyncResult *result, GError **error) { g_return_val_if_fail (g_task_is_valid (result, context), FALSE); g_return_val_if_fail (g_task_get_source_tag (G_TASK (result)) == gdk_drag_context_write_async, FALSE); return g_task_propagate_boolean (G_TASK (result), error); } /** * gdk_drop_read_async: * @context: a #GdkDragContext * @mime_types: (array zero-terminated=1) (element-type utf8): pointer to an array of mime types * @io_priority: the io priority for the read operation * @cancellable: (allow-none): optional #GCancellable object, %NULL to ignore * @callback: (scope async): a #GAsyncReadyCallback to call when the request is satisfied * @user_data: (closure): the data to pass to @callback * * Asynchronously read the dropped data from a DND context * in a format that complies with one of the mime types. */ void gdk_drop_read_async (GdkDragContext *context, const char **mime_types, int io_priority, GCancellable *cancellable, GAsyncReadyCallback callback, gpointer user_data) { GdkContentFormats *formats; g_return_if_fail (GDK_IS_DRAG_CONTEXT (context)); g_return_if_fail (mime_types != NULL && mime_types[0] != NULL); g_return_if_fail (cancellable == NULL || G_IS_CANCELLABLE (cancellable)); g_return_if_fail (callback != NULL); formats = gdk_content_formats_new (mime_types, g_strv_length ((char **) mime_types)); GDK_DRAG_CONTEXT_GET_CLASS (context)->read_async (context, formats, io_priority, cancellable, callback, user_data); gdk_content_formats_unref (formats); } /** * gdk_drop_read_finish: * @context: a #GdkDragContext * @out_mime_type: (out) (type utf8): return location for the used mime type * @result: a #GAsyncResult * @error: (allow-none): location to store error information on failure, or %NULL * * Finishes an async drop read operation, see gdk_drop_read_async(). * * Returns: (nullable) (transfer full): the #GInputStream, or %NULL */ GInputStream * gdk_drop_read_finish (GdkDragContext *context, const char **out_mime_type, GAsyncResult *result, GError **error) { g_return_val_if_fail (GDK_IS_DRAG_CONTEXT (context), NULL); g_return_val_if_fail (error == NULL || *error == NULL, NULL); if (g_async_result_is_tagged (result, gdk_drag_context_read_local_async)) { return gdk_drag_context_read_local_finish (context, out_mime_type, result, error); } else { return GDK_DRAG_CONTEXT_GET_CLASS (context)->read_finish (context, out_mime_type, result, error); } } /** * gdk_drag_context_get_drag_surface: * @context: a #GdkDragContext * * Returns the surface on which the drag icon should be rendered * during the drag operation. Note that the surface may not be * available until the drag operation has begun. GDK will move * the surface in accordance with the ongoing drag operation. * The surface is owned by @context and will be destroyed when * the drag operation is over. * * Returns: (nullable) (transfer none): the drag surface, or %NULL */ GdkSurface * gdk_drag_context_get_drag_surface (GdkDragContext *context) { g_return_val_if_fail (GDK_IS_DRAG_CONTEXT (context), NULL); if (GDK_DRAG_CONTEXT_GET_CLASS (context)->get_drag_surface) return GDK_DRAG_CONTEXT_GET_CLASS (context)->get_drag_surface (context); return NULL; } /** * gdk_drag_context_set_hotspot: * @context: a #GdkDragContext * @hot_x: x coordinate of the drag surface hotspot * @hot_y: y coordinate of the drag surface hotspot * * Sets the position of the drag surface that will be kept * under the cursor hotspot. Initially, the hotspot is at the * top left corner of the drag surface. */ void gdk_drag_context_set_hotspot (GdkDragContext *context, gint hot_x, gint hot_y) { g_return_if_fail (GDK_IS_DRAG_CONTEXT (context)); if (GDK_DRAG_CONTEXT_GET_CLASS (context)->set_hotspot) GDK_DRAG_CONTEXT_GET_CLASS (context)->set_hotspot (context, hot_x, hot_y); } /** * gdk_drag_drop_done: * @context: a #GdkDragContext * @success: whether the drag was ultimatively successful * * Inform GDK if the drop ended successfully. Passing %FALSE * for @success may trigger a drag cancellation animation. * * This function is called by the drag source, and should * be the last call before dropping the reference to the * @context. * * The #GdkDragContext will only take the first gdk_drag_drop_done() * call as effective, if this function is called multiple times, * all subsequent calls will be ignored. */ void gdk_drag_drop_done (GdkDragContext *context, gboolean success) { g_return_if_fail (GDK_IS_DRAG_CONTEXT (context)); if (context->drop_done) return; context->drop_done = TRUE; if (GDK_DRAG_CONTEXT_GET_CLASS (context)->drop_done) GDK_DRAG_CONTEXT_GET_CLASS (context)->drop_done (context, success); } void gdk_drag_context_set_cursor (GdkDragContext *context, GdkCursor *cursor) { g_return_if_fail (GDK_IS_DRAG_CONTEXT (context)); if (GDK_DRAG_CONTEXT_GET_CLASS (context)->set_cursor) GDK_DRAG_CONTEXT_GET_CLASS (context)->set_cursor (context, cursor); } void gdk_drag_context_cancel (GdkDragContext *context, GdkDragCancelReason reason) { g_return_if_fail (GDK_IS_DRAG_CONTEXT (context)); g_signal_emit (context, signals[CANCEL], 0, reason); } gboolean gdk_drag_context_handle_source_event (GdkEvent *event) { GdkDragContext *context; GList *l; for (l = contexts; l; l = l->next) { context = l->data; if (!context->is_source) continue; if (!GDK_DRAG_CONTEXT_GET_CLASS (context)->handle_event) continue; if (GDK_DRAG_CONTEXT_GET_CLASS (context)->handle_event (context, event)) return TRUE; } return FALSE; } GdkCursor * gdk_drag_get_cursor (GdkDragContext *context, GdkDragAction action) { gint i; for (i = 0 ; i < G_N_ELEMENTS (drag_cursors) - 1; i++) if (drag_cursors[i].action == action) break; if (drag_cursors[i].cursor == NULL) drag_cursors[i].cursor = gdk_cursor_new_from_name (drag_cursors[i].name, NULL); return drag_cursors[i].cursor; } static void gdk_drag_context_commit_drag_status (GdkDragContext *context) { GdkDragContextClass *context_class; g_return_if_fail (GDK_IS_DRAG_CONTEXT (context)); g_return_if_fail (!context->is_source); context_class = GDK_DRAG_CONTEXT_GET_CLASS (context); if (context_class->commit_drag_status) context_class->commit_drag_status (context); } gboolean gdk_drag_context_handle_dest_event (GdkEvent *event) { GdkDragContext *context = NULL; switch ((guint) event->any.type) { case GDK_DRAG_MOTION: case GDK_DROP_START: context = event->dnd.context; break; default: return FALSE; } if (!context) return FALSE; gdk_drag_context_commit_drag_status (context); return TRUE;; }