Drag-n-drop support on Linux

This commit implements drag-n-drop support from external applications into Blender.
Used xdnd implementation from Paul Sheer.

1 files changed, 221 insertions, 0 deletions

diff --git a/extern/xdnd/xdnd.h b/extern/xdnd/xdnd.h
new file mode 100644
index 00000000000..c903b51c8d0
--- /dev/null
+++ b/extern/xdnd/xdnd.h
@@ -0,0 +1,221 @@
+/* xdnd.c, xdnd.h - C program library for handling the Xdnd protocol
+   Copyright (C) 1996-2000 Paul Sheer
+
+   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.
+ */
+
+#ifndef _X_DND_H
+#define _X_DND_H
+
+#ifdef  __cplusplus
+extern "C" {
+#endif
+
+/* you can set this to either 2 (which support 0 and 1 as well) or 3 */
+/* #define XDND_VERSION 2 */
+#define XDND_VERSION 3
+
+
+/* XdndEnter */
+#define XDND_THREE 3
+#define XDND_ENTER_SOURCE_WIN(e)	((e)->xclient.data.l[0])
+#define XDND_ENTER_THREE_TYPES(e)	(((e)->xclient.data.l[1] & 0x1UL) == 0)
+#define XDND_ENTER_THREE_TYPES_SET(e,b)	(e)->xclient.data.l[1] = ((e)->xclient.data.l[1] & ~0x1UL) | (((b) == 0) ? 0 : 0x1UL)
+#define XDND_ENTER_VERSION(e)		((e)->xclient.data.l[1] >> 24)
+#define XDND_ENTER_VERSION_SET(e,v)	(e)->xclient.data.l[1] = ((e)->xclient.data.l[1] & ~(0xFF << 24)) | ((v) << 24)
+#define XDND_ENTER_TYPE(e,i)		((e)->xclient.data.l[2 + i])	/* i => (0, 1, 2) */
+
+/* XdndPosition */
+#define XDND_POSITION_SOURCE_WIN(e)	((e)->xclient.data.l[0])
+#define XDND_POSITION_ROOT_X(e)		((e)->xclient.data.l[2] >> 16)
+#define XDND_POSITION_ROOT_Y(e)		((e)->xclient.data.l[2] & 0xFFFFUL)
+#define XDND_POSITION_ROOT_SET(e,x,y)	(e)->xclient.data.l[2]  = ((x) << 16) | ((y) & 0xFFFFUL)
+#define XDND_POSITION_TIME(e)		((e)->xclient.data.l[3])
+#define XDND_POSITION_ACTION(e)		((e)->xclient.data.l[4])
+
+/* XdndStatus */
+#define XDND_STATUS_TARGET_WIN(e)	((e)->xclient.data.l[0])
+#define XDND_STATUS_WILL_ACCEPT(e)	((e)->xclient.data.l[1] & 0x1L)
+#define XDND_STATUS_WILL_ACCEPT_SET(e,b) (e)->xclient.data.l[1] = ((e)->xclient.data.l[1] & ~0x1UL) | (((b) == 0) ? 0 : 0x1UL)
+#define XDND_STATUS_WANT_POSITION(e)	((e)->xclient.data.l[1] & 0x2UL)
+#define XDND_STATUS_WANT_POSITION_SET(e,b) (e)->xclient.data.l[1] = ((e)->xclient.data.l[1] & ~0x2UL) | (((b) == 0) ? 0 : 0x2UL)
+#define XDND_STATUS_RECT_X(e)		((e)->xclient.data.l[2] >> 16)
+#define XDND_STATUS_RECT_Y(e)		((e)->xclient.data.l[2] & 0xFFFFL)
+#define XDND_STATUS_RECT_WIDTH(e)	((e)->xclient.data.l[3] >> 16)
+#define XDND_STATUS_RECT_HEIGHT(e)	((e)->xclient.data.l[3] & 0xFFFFL)
+#define XDND_STATUS_RECT_SET(e,x,y,w,h)	{(e)->xclient.data.l[2] = ((x) << 16) | ((y) & 0xFFFFUL); (e)->xclient.data.l[3] = ((w) << 16) | ((h) & 0xFFFFUL); }
+#define XDND_STATUS_ACTION(e)		((e)->xclient.data.l[4])
+
+/* XdndLeave */
+#define XDND_LEAVE_SOURCE_WIN(e)	((e)->xclient.data.l[0])
+
+/* XdndDrop */
+#define XDND_DROP_SOURCE_WIN(e)		((e)->xclient.data.l[0])
+#define XDND_DROP_TIME(e)		((e)->xclient.data.l[2])
+
+/* XdndFinished */
+#define XDND_FINISHED_TARGET_WIN(e)	((e)->xclient.data.l[0])
+
+struct _DndCursor {
+    int width, height;
+    int x, y;
+    unsigned char *image_data, *mask_data;
+    char *_action;
+    Pixmap image_pixmap, mask_pixmap;
+    Cursor cursor;
+    Atom action;
+};
+
+typedef struct _DndCursor DndCursor;
+typedef struct _DndClass DndClass;
+
+struct _DndClass {
+/* insert chars sequentionally into the target widget, type will be the same as `desired_type'
+   returned from widget_apply_position. This may be called several times in succession 
+   with sequention blocks of data. Must return non-zero on failure */
+    int (*widget_insert_drop) (DndClass * dnd, unsigned char *data, int length, int remaining, Window into, Window from, Atom type);
+
+/* In response to DELETE requests : FIXME - not yet used */
+    int (*widget_delete_selection) (DndClass * dnd, Window window, Window from);
+
+/* returns 1 if widget exists, zero otherwise. If this method is not 
+   set then the code assumes that no widgets have support for recieving drops.
+   In this case none of the widget methods need be set. */
+    int (*widget_exists) (DndClass * dnd, Window window);
+
+/* must update the widgets border to its default appearance */
+    void (*widget_apply_leave) (DndClass * dnd, Window widgets_window);
+
+/* must update the widgets border to give the appearance of being able to recieve a drop,
+   plus return all data to pointers. As per the protocol, if the widget cannot
+   perform the action specified by `action' then it should return either XdndActionPrivate
+   or XdndActionCopy into supported_action (leaving 0 supported_action unchanged is equivalent
+   to XdndActionCopy). Returns 1 if ready to ok drop */
+    int (*widget_apply_position) (DndClass * dnd, Window widgets_window, Window from,
+                                  Atom action, int x, int y, Time t, Atom * typelist,
+                                  int *want_position, Atom * supported_action, Atom * desired_type,
+                                  XRectangle * rectangle);
+
+/* returns drag data of the specified type. This will be one of `typelist' given to xdnd_drag */
+    void (*widget_get_data) (DndClass * dnd, Window window, unsigned char **data, int *length, Atom type);
+
+/* this is called from with the main event loop if an expose event is recieved and is optional */
+    void (*handle_expose_events) (DndClass * dnd, XEvent * xevent);
+
+/* creates a chooser dialog if the action is XdndActionAsk. Returns non-zero on cancel */
+    int (*action_choose_dialog) (DndClass * dnd, char **descriptions, Atom * actions, Atom * result);
+
+#if 0 /* implemented internally */
+/* returns a widget that is dnd aware within a parent widget that lies under the point x, y */
+    Window (*widget_get_child_widget) (DndClass * dnd, Window parent, int x, int y);
+#endif
+
+    void *pad1[8];
+
+    DndCursor *cursors;
+
+    Display *display;
+
+    Atom XdndAware;
+    Atom XdndSelection;
+    Atom XdndEnter;
+    Atom XdndLeave;
+    Atom XdndPosition;
+    Atom XdndDrop;
+    Atom XdndFinished;
+    Atom XdndStatus;
+    Atom XdndActionCopy;
+    Atom XdndActionMove;
+    Atom XdndActionLink;
+    Atom XdndActionAsk;
+    Atom XdndActionPrivate;
+    Atom XdndTypeList;
+    Atom XdndActionList;
+    Atom XdndActionDescription;
+
+    Atom Xdnd_NON_PROTOCOL_ATOM;
+    Atom version;
+
+    Atom pad2[16];
+
+    Window root_window;
+
+#define XDND_DROP_STAGE_IDLE		0
+#define XDND_DRAG_STAGE_DRAGGING	1
+#define XDND_DRAG_STAGE_ENTERED		2
+#define XDND_DROP_STAGE_CONVERTING	3
+#define XDND_DROP_STAGE_ENTERED		4
+    int stage;
+    int dragging_version;
+    int internal_drag;
+    int want_position;
+    int ready_to_drop;
+    int will_accept;
+    XRectangle rectangle;
+    Window dropper_window, dragger_window;
+    Atom *dragger_typelist;
+    Atom desired_type;
+    Atom supported_action;
+    Time time;
+/* drop position from last XdndPosition */
+    int x, y;
+    int pad3[16];
+
+/* move euclidian pixels before considering this to be an actual drag */
+    float drag_threshold;
+
+/* block for only this many seconds on not receiving a XdndFinished from target, default : 10 */
+    int time_out;
+
+#define XDND_OPTION_NO_HYSTERESIS (1<<0)
+    int options;
+
+/* user hooks */
+    void *user_hook1;
+    void *user_hook2;
+    void *user_hook3;
+    Window dropper_toplevel;
+    void *pad4[15];
+};
+
+
+void xdnd_init (DndClass * dnd, Display * display);
+void xdnd_shut (DndClass * dnd);
+/* for nested widgets where parent and child receive drops of different
+types; then always pass typelist as null */
+void xdnd_set_dnd_aware (DndClass * dnd, Window window, Atom * typelist);
+int xdnd_is_dnd_aware (DndClass * dnd, Window window, int *version, Atom * typelist);
+void xdnd_set_type_list (DndClass * dnd, Window window, Atom * typelist);
+void xdnd_set_actions (DndClass * dnd, Window window, Atom * actions, char **descriptions);
+int xdnd_get_actions (DndClass * dnd, Window window, Atom ** actions, char ***descriptions);
+int xdnd_choose_action_dialog (DndClass * dnd, Atom * actions, char **descriptions, Atom * result);
+Atom xdnd_drag (DndClass * dnd, Window from, Atom action, Atom * typelist);
+
+/* Returns 1 if event is handled, This must be placed in the widget
+libraries main event loop and be called if the event type is
+ClientMessage or SelectionNotify */
+int xdnd_handle_drop_events (DndClass * dnd, XEvent * xevent);
+Atom xdnd_get_drop (Display * display, XEvent * xevent, Atom * typelist, Atom * actionlist,
+                    unsigned char **data, int *length, Atom * type, int *x, int *y);
+
+
+#ifdef  __cplusplus
+}
+#endif
+
+#endif 	/* !_X_DND_H */
+
+