/* 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 "gdkdragprivate.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" static struct { GdkDragAction action; const char *name; GdkCursor *cursor; } drag_cursors[] = { { 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, PROP_SELECTED_ACTION, PROP_ACTIONS, PROP_SURFACE, N_PROPERTIES }; enum { CANCEL, DROP_PERFORMED, DND_FINISHED, N_SIGNALS }; typedef struct _GdkDragPrivate GdkDragPrivate; struct _GdkDragPrivate { GdkSurface *surface; GdkDisplay *display; GdkDevice *device; GdkContentFormats *formats; GdkContentProvider *content; GdkDragAction actions; GdkDragAction selected_action; guint drop_done : 1; /* Whether gdk_drag_drop_done() was performed */ }; static GParamSpec *properties[N_PROPERTIES] = { NULL, }; static guint signals[N_SIGNALS] = { 0 }; static GList *drags = NULL; G_DEFINE_ABSTRACT_TYPE_WITH_PRIVATE (GdkDrag, gdk_drag, 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 GdkDrag object represents the source side of an ongoing DND operation. * It is created when a drag is started, and stays alive for duration of * the DND operation. After a drag has been started with gdk_drag_begin(), * the caller gets informed about the status of the ongoing drag operation * with signals on the #GdkDrag object. * * The GdkDrop object represents the target side of an ongoing DND operation. * Possible drop sites get informed about the status of the ongoing drag operation * with events of type %GDK_DRAG_ENTER, %GDK_DRAG_LEAVE, %GDK_DRAG_MOTION and * %GDK_DROP_START. The #GdkDrop object can be obtained from these #GdkEvents * using gdk_event_get_drop(). * * The actual data transfer is initiated from the target side via an async * read, using one of the GdkDrop functions for this purpose: gdk_drop_read_async() * or gdk_drop_read_value_async(). * * 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][gtk4-Drag-and-Drop] section of the GTK documentation * for more information. */ /** * GdkDrag: * * The GdkDrag struct contains only private fields and * should not be accessed directly. */ /** * gdk_drag_get_display: * @drag: a #GdkDrag * * Gets the #GdkDisplay that the drag object was created for. * * Returns: (transfer none): a #GdkDisplay **/ GdkDisplay * gdk_drag_get_display (GdkDrag *drag) { GdkDragPrivate *priv = gdk_drag_get_instance_private (drag); g_return_val_if_fail (GDK_IS_DRAG (drag), NULL); return priv->display; } /** * gdk_drag_get_formats: * @drag: a #GdkDrag * * Retrieves the formats supported by this GdkDrag object. * * Returns: (transfer none): a #GdkContentFormats **/ GdkContentFormats * gdk_drag_get_formats (GdkDrag *drag) { GdkDragPrivate *priv = gdk_drag_get_instance_private (drag); g_return_val_if_fail (GDK_IS_DRAG (drag), NULL); return priv->formats; } /** * gdk_drag_get_actions: * @drag: a #GdkDrag * * Determines the bitmask of possible actions proposed by the source. * * Returns: the #GdkDragAction flags **/ GdkDragAction gdk_drag_get_actions (GdkDrag *drag) { GdkDragPrivate *priv = gdk_drag_get_instance_private (drag); g_return_val_if_fail (GDK_IS_DRAG (drag), 0); return priv->actions; } /** * gdk_drag_get_selected_action: * @drag: a #GdkDrag * * Determines the action chosen by the drag destination. * * Returns: a #GdkDragAction value **/ GdkDragAction gdk_drag_get_selected_action (GdkDrag *drag) { GdkDragPrivate *priv = gdk_drag_get_instance_private (drag); g_return_val_if_fail (GDK_IS_DRAG (drag), 0); return priv->selected_action; } /** * gdk_drag_get_device: * @drag: a #GdkDrag * * Returns the #GdkDevice associated to the GdkDrag object. * * Returns: (transfer none): The #GdkDevice associated to @drag. **/ GdkDevice * gdk_drag_get_device (GdkDrag *drag) { GdkDragPrivate *priv = gdk_drag_get_instance_private (drag); g_return_val_if_fail (GDK_IS_DRAG (drag), NULL); return priv->device; } /** * gdk_drag_get_content: * @drag: a #GdkDrag * * Returns the #GdkContentProvider associated to the GdkDrag object. * * Returns: (transfer none): The #GdkContentProvider associated to @drag. **/ GdkContentProvider * gdk_drag_get_content (GdkDrag *drag) { GdkDragPrivate *priv = gdk_drag_get_instance_private (drag); g_return_val_if_fail (GDK_IS_DRAG (drag), NULL); return priv->content; } /** * gdk_drag_get_surface: * @drag: a #GdkDrag * * Returns the #GdkSurface where the drag originates. * * Returns: (transfer none): The #GdkSurface where the drag originates **/ GdkSurface * gdk_drag_get_surface (GdkDrag *drag) { GdkDragPrivate *priv = gdk_drag_get_instance_private (drag); g_return_val_if_fail (GDK_IS_DRAG (drag), NULL); return priv->surface; } static void gdk_drag_init (GdkDrag *drag) { drags = g_list_prepend (drags, drag); } static void gdk_drag_set_property (GObject *gobject, guint prop_id, const GValue *value, GParamSpec *pspec) { GdkDrag *drag = GDK_DRAG (gobject); GdkDragPrivate *priv = gdk_drag_get_instance_private (drag); switch (prop_id) { case PROP_CONTENT: priv->content = g_value_dup_object (value); if (priv->content) { g_assert (priv->formats == NULL); priv->formats = gdk_content_provider_ref_formats (priv->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; case PROP_FORMATS: if (priv->formats) { GdkContentFormats *override = g_value_dup_boxed (value); if (override) { gdk_content_formats_unref (priv->formats); priv->formats = override; } } else { priv->formats = g_value_dup_boxed (value); g_assert (priv->formats != NULL); } break; case PROP_SELECTED_ACTION: { GdkDragAction action = g_value_get_flags (value); gdk_drag_set_selected_action (drag, action); } break; case PROP_ACTIONS: { GdkDragAction actions = g_value_get_flags (value); gdk_drag_set_actions (drag, actions); } break; case PROP_SURFACE: priv->surface = g_value_dup_object (value); g_assert (priv->surface != NULL); break; default: G_OBJECT_WARN_INVALID_PROPERTY_ID (gobject, prop_id, pspec); break; } } static void gdk_drag_get_property (GObject *gobject, guint prop_id, GValue *value, GParamSpec *pspec) { GdkDrag *drag = GDK_DRAG (gobject); GdkDragPrivate *priv = gdk_drag_get_instance_private (drag); switch (prop_id) { case PROP_CONTENT: g_value_set_object (value, priv->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, priv->formats); break; case PROP_SELECTED_ACTION: g_value_set_flags (value, priv->selected_action); break; case PROP_ACTIONS: g_value_set_flags (value, priv->actions); break; case PROP_SURFACE: g_value_set_object (value, priv->surface); break; default: G_OBJECT_WARN_INVALID_PROPERTY_ID (gobject, prop_id, pspec); break; } } static void gdk_drag_finalize (GObject *object) { GdkDrag *drag = GDK_DRAG (object); GdkDragPrivate *priv = gdk_drag_get_instance_private (drag); drags = g_list_remove (drags, drag); g_clear_object (&priv->content); g_clear_pointer (&priv->formats, gdk_content_formats_unref); g_clear_object (&priv->surface); G_OBJECT_CLASS (gdk_drag_parent_class)->finalize (object); } static void gdk_drag_class_init (GdkDragClass *klass) { GObjectClass *object_class = G_OBJECT_CLASS (klass); object_class->get_property = gdk_drag_get_property; object_class->set_property = gdk_drag_set_property; object_class->finalize = gdk_drag_finalize; /** * GdkDrag:content: * * The #GdkContentProvider. */ 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); /** * GdkDrag: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); /** * GdkDrag:display: * * The #GdkDisplay that the drag 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); /** * GdkDrag:formats: * * The possible formats that the drag 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_READWRITE | G_PARAM_CONSTRUCT_ONLY | G_PARAM_STATIC_STRINGS | G_PARAM_EXPLICIT_NOTIFY); properties[PROP_SELECTED_ACTION] = g_param_spec_flags ("selected-action", "Selected action", "The currently selected action", GDK_TYPE_DRAG_ACTION, 0, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS | G_PARAM_EXPLICIT_NOTIFY); properties[PROP_ACTIONS] = g_param_spec_flags ("actions", "Actions", "The possible actions", GDK_TYPE_DRAG_ACTION, 0, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS | G_PARAM_EXPLICIT_NOTIFY); properties[PROP_SURFACE] = g_param_spec_object ("surface", "Surface", "The surface where the drag originates", GDK_TYPE_SURFACE, G_PARAM_READWRITE | G_PARAM_CONSTRUCT_ONLY | G_PARAM_STATIC_STRINGS | G_PARAM_EXPLICIT_NOTIFY); /** * GdkDrag::cancel: * @drag: The object on which the signal is emitted * @reason: The reason the drag was cancelled * * The drag 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 (GdkDragClass, cancel), NULL, NULL, NULL, G_TYPE_NONE, 1, GDK_TYPE_DRAG_CANCEL_REASON); /** * GdkDrag::drop-performed: * @drag: The object on which the signal is emitted * * The drag 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 (GdkDragClass, drop_performed), NULL, NULL, NULL, G_TYPE_NONE, 0); /** * GdkDrag::dnd-finished: * @drag: The object on which the signal is emitted * * The drag operation was finished, the destination * finished reading all data. The drag object 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 (GdkDragClass, dnd_finished), NULL, NULL, NULL, G_TYPE_NONE, 0); g_object_class_install_properties (object_class, N_PROPERTIES, properties); } static void gdk_drag_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_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_write_async (GdkDrag *drag, const char *mime_type, GOutputStream *stream, int io_priority, GCancellable *cancellable, GAsyncReadyCallback callback, gpointer user_data) { GdkDragPrivate *priv = gdk_drag_get_instance_private (drag); GdkContentFormats *formats, *mime_formats; GTask *task; GType gtype; g_return_if_fail (GDK_IS_DRAG (drag)); g_return_if_fail (priv->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 (drag, cancellable, callback, user_data); g_task_set_priority (task, io_priority); g_task_set_source_tag (task, gdk_drag_write_async); formats = gdk_content_provider_ref_formats (priv->content); if (gdk_content_formats_contain_mime_type (formats, mime_type)) { gdk_content_provider_write_mime_type_async (priv->content, mime_type, stream, io_priority, cancellable, gdk_drag_write_done, task); gdk_content_formats_unref (formats); return; } mime_formats = gdk_content_formats_new ((const char *[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 (priv->content, &value, &error)) { gdk_content_serialize_async (stream, mime_type, &value, io_priority, cancellable, gdk_drag_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_write_finish (GdkDrag *drag, GAsyncResult *result, GError **error) { g_return_val_if_fail (g_task_is_valid (result, drag), FALSE); g_return_val_if_fail (g_task_get_source_tag (G_TASK (result)) == gdk_drag_write_async, FALSE); return g_task_propagate_boolean (G_TASK (result), error); } void gdk_drag_set_actions (GdkDrag *drag, GdkDragAction actions) { GdkDragPrivate *priv = gdk_drag_get_instance_private (drag); if (priv->actions == actions) return; priv->actions = actions; g_object_notify_by_pspec (G_OBJECT (drag), properties[PROP_ACTIONS]); } void gdk_drag_set_selected_action (GdkDrag *drag, GdkDragAction action) { GdkDragPrivate *priv = gdk_drag_get_instance_private (drag); GdkCursor *cursor; if (priv->selected_action == action) return; priv->selected_action = action; cursor = gdk_drag_get_cursor (drag, action); gdk_drag_set_cursor (drag, cursor); g_object_notify_by_pspec (G_OBJECT (drag), properties[PROP_SELECTED_ACTION]); } /** * gdk_drag_get_drag_surface: * @drag: a #GdkDrag * * 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 @drag and will be destroyed when * the drag operation is over. * * Returns: (nullable) (transfer none): the drag surface, or %NULL */ GdkSurface * gdk_drag_get_drag_surface (GdkDrag *drag) { g_return_val_if_fail (GDK_IS_DRAG (drag), NULL); if (GDK_DRAG_GET_CLASS (drag)->get_drag_surface) return GDK_DRAG_GET_CLASS (drag)->get_drag_surface (drag); return NULL; } /** * gdk_drag_set_hotspot: * @drag: a #GdkDrag * @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_set_hotspot (GdkDrag *drag, int hot_x, int hot_y) { g_return_if_fail (GDK_IS_DRAG (drag)); if (GDK_DRAG_GET_CLASS (drag)->set_hotspot) GDK_DRAG_GET_CLASS (drag)->set_hotspot (drag, hot_x, hot_y); } /** * gdk_drag_drop_done: * @drag: a #GdkDrag * @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 * @drag. * * The #GdkDrag 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 (GdkDrag *drag, gboolean success) { GdkDragPrivate *priv = gdk_drag_get_instance_private (drag); g_return_if_fail (GDK_IS_DRAG (drag)); if (priv->drop_done) return; priv->drop_done = TRUE; if (GDK_DRAG_GET_CLASS (drag)->drop_done) GDK_DRAG_GET_CLASS (drag)->drop_done (drag, success); } void gdk_drag_set_cursor (GdkDrag *drag, GdkCursor *cursor) { g_return_if_fail (GDK_IS_DRAG (drag)); if (GDK_DRAG_GET_CLASS (drag)->set_cursor) GDK_DRAG_GET_CLASS (drag)->set_cursor (drag, cursor); } void gdk_drag_cancel (GdkDrag *drag, GdkDragCancelReason reason) { g_return_if_fail (GDK_IS_DRAG (drag)); g_signal_emit (drag, signals[CANCEL], 0, reason); } gboolean gdk_drag_handle_source_event (GdkEvent *event) { GdkDrag *drag; GList *l; for (l = drags; l; l = l->next) { drag = l->data; if (!GDK_DRAG_GET_CLASS (drag)->handle_event) continue; if (GDK_DRAG_GET_CLASS (drag)->handle_event (drag, event)) return TRUE; } return FALSE; } GdkCursor * gdk_drag_get_cursor (GdkDrag *drag, GdkDragAction action) { int 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; } /** * gdk_drag_action_is_unique: * @action: a #GdkDragAction * * Checks if @action represents a single action or if it * includes multiple flags that can be selected from. * * When @action is 0 - ie no action was given, %TRUE * is returned. * * Returns: %TRUE if exactly one action was given **/ gboolean gdk_drag_action_is_unique (GdkDragAction action) { return (action & (action - 1)) == 0; }