+/* If F's terminal is not capable of displaying a popup dialog,
+ emulate it with a menu. */
+
+static Lisp_Object
+emulate_dialog_with_menu (struct frame *f, Lisp_Object contents)
+{
+ Lisp_Object x, y, frame, newpos, prompt = Fcar (contents);
+ int x_coord, y_coord;
+
+ if (FRAME_WINDOW_P (f))
+ {
+ x_coord = FRAME_PIXEL_WIDTH (f);
+ y_coord = FRAME_PIXEL_HEIGHT (f);
+ }
+ else
+ {
+ x_coord = FRAME_COLS (f);
+ /* Center the title at frame middle. (TTY menus have
+ their upper-left corner at the given position.) */
+ if (STRINGP (prompt))
+ x_coord -= SCHARS (prompt);
+ y_coord = FRAME_LINES (f);
+ }
+
+ XSETFRAME (frame, f);
+ XSETINT (x, x_coord / 2);
+ XSETINT (y, y_coord / 2);
+ newpos = list2 (list2 (x, y), frame);
+
+ return Fx_popup_menu (newpos, list2 (prompt, contents));
+}
+
+DEFUN ("x-popup-dialog", Fx_popup_dialog, Sx_popup_dialog, 2, 3, 0,
+ doc: /* Pop up a dialog box and return user's selection.
+POSITION specifies which frame to use.
+This is normally a mouse button event or a window or frame.
+If POSITION is t, it means to use the frame the mouse is on.
+The dialog box appears in the middle of the specified frame.
+
+CONTENTS specifies the alternatives to display in the dialog box.
+It is a list of the form (DIALOG ITEM1 ITEM2...).
+Each ITEM is a cons cell (STRING . VALUE).
+The return value is VALUE from the chosen item.
+
+An ITEM may also be just a string--that makes a nonselectable item.
+An ITEM may also be nil--that means to put all preceding items
+on the left of the dialog box and all following items on the right.
+\(By default, approximately half appear on each side.)
+
+If HEADER is non-nil, the frame title for the box is "Information",
+otherwise it is "Question".
+
+If the user gets rid of the dialog box without making a valid choice,
+for instance using the window manager, then this produces a quit and
+`x-popup-dialog' does not return. */)
+ (Lisp_Object position, Lisp_Object contents, Lisp_Object header)
+{
+ struct frame *f = NULL;
+ Lisp_Object window;
+
+ /* Decode the first argument: find the window or frame to use. */
+ if (EQ (position, Qt)
+ || (CONSP (position) && (EQ (XCAR (position), Qmenu_bar)
+ || EQ (XCAR (position), Qtool_bar))))
+ window = selected_window;
+ else if (CONSP (position))
+ {
+ Lisp_Object tem = XCAR (position);
+ if (CONSP (tem))
+ window = Fcar (XCDR (position));
+ else
+ {
+ tem = Fcar (XCDR (position)); /* EVENT_START (position) */
+ window = Fcar (tem); /* POSN_WINDOW (tem) */
+ }
+ }
+ else if (WINDOWP (position) || FRAMEP (position))
+ window = position;
+ else
+ window = Qnil;
+
+ /* Decode where to put the menu. */
+
+ if (FRAMEP (window))
+ f = XFRAME (window);
+ else if (WINDOWP (window))
+ {
+ CHECK_LIVE_WINDOW (window);
+ f = XFRAME (WINDOW_FRAME (XWINDOW (window)));
+ }
+ else
+ /* ??? Not really clean; should be CHECK_WINDOW_OR_FRAME,
+ but I don't want to make one now. */
+ CHECK_WINDOW (window);
+
+ /* Force a redisplay before showing the dialog. If a frame is created
+ just before showing the dialog, its contents may not have been fully
+ drawn, as this depends on timing of events from the X server. Redisplay
+ is not done when a dialog is shown. If redisplay could be done in the
+ X event loop (i.e. the X event loop does not run in a signal handler)
+ this would not be needed.
+
+ Do this before creating the widget value that points to Lisp
+ string contents, because Fredisplay may GC and relocate them. */
+ Fredisplay (Qt);
+
+ /* Display the popup dialog by a terminal-specific hook ... */
+ if (FRAME_TERMINAL (f)->popup_dialog_hook)
+ {
+ Lisp_Object selection
+ = FRAME_TERMINAL (f)->popup_dialog_hook (f, header, contents);
+#ifdef HAVE_NTGUI
+ /* NTGUI supports only simple dialogs with Yes/No choices. For
+ other dialogs, it returns the symbol 'unsupported--w32-dialog',
+ as a signal for the caller to fall back to the emulation code. */
+ if (!EQ (selection, Qunsupported__w32_dialog))
+#endif
+ return selection;
+ }
+ /* ... or emulate it with a menu. */
+ return emulate_dialog_with_menu (f, contents);
+}
+