Method GetGuiControlEvent

Source/script.cpp:11282–11351

VarSizeType Script::GetGuiControlEvent(char *aBuf)
// We're returning the length of the var's contents, not the size.
{
	if (g.GuiEvent == GUI_EVENT_DROPFILES)
	{
		GuiType *pgui;
		UINT u, file_count;
		// GUI_EVENT_DROPFILES should mean that g.GuiWindowIndex < MAX_GUI_WINDOWS, but the below will double check
		// that in case g.GuiEvent can ever be set to that value as a result of receiving a bogus message in the queue.
		if (g.GuiWindowIndex >= MAX_GUI_WINDOWS  // The current thread was not launched as a result of GUI action or this is a bogus msg.
			|| !(pgui = g_gui[g.GuiWindowIndex]) // Gui window no longer exists.  Relies on short-circuit boolean.
			|| !pgui->mHdrop // No HDROP (probably impossible unless g.GuiEvent was given a bogus value somehow).
			|| !(file_count = DragQueryFile(pgui->mHdrop, 0xFFFFFFFF, NULL, 0))) // No files in the drop (not sure if this is possible).
			// All of the above rely on short-circuit boolean order.
		{
			// Make the dropped-files list blank since there is no HDROP to query (or no files in it).
			if (aBuf)
				*aBuf = '\0';
			return 0;
		}
		// Above has ensured that file_count > 0
		if (aBuf)
		{
			char *cp = aBuf;
			for (u = 0; u < file_count; ++u)
			{
				cp += DragQueryFile(pgui->mHdrop, u, cp, MAX_PATH); // MAX_PATH is arbitrary since aBuf is already known to be large enough.
				if (u < file_count - 1) // i.e omit the LF after the last file to make parsing via "Loop, Parse" easier.
					*cp++ = '\n';
				// Although the transcription of files on the clipboard into their text filenames is done
				// with \r\n (so that they're in the right format to be pasted to other apps as a plain text
				// list), it seems best to use a plain linefeed for dropped files since they won't be going
				// onto the clipboard nearly as often, and `n is easier to parse.  Also, a script array isn't
				// used because large file lists would then consume a lot more of memory because arrays
				// are permanent once created, and also there would be wasted space due to the part of each
				// variable's capacity not used by the filename.
			}
			// No need for final termination of string because the last item lacks a newline.
			return (VarSizeType)(cp - aBuf); // This is the length of what's in the buffer.
		}
		else
		{
			VarSizeType total_length = 0;
			for (u = 0; u < file_count; ++u)
				total_length += DragQueryFile(pgui->mHdrop, u, NULL, 0);
				// Above: MSDN: "If the lpszFile buffer address is NULL, the return value is the required size,
				// in characters, of the buffer, not including the terminating null character."
			return total_length + file_count - 1; // Include space for a linefeed after each filename except the last.
		}
		// Don't call DragFinish() because this variable might be referred to again before this thread
		// is done.  DragFinish() is called by MsgSleep() when the current thread finishes.
	}

	// Otherwise, this event is not GUI_EVENT_DROPFILES, so use standard modes of operation.
	static char *names[] = GUI_EVENT_NAMES;
	if (!aBuf)
		return (g.GuiEvent < GUI_EVENT_ILLEGAL) ? (VarSizeType)strlen(names[g.GuiEvent]) : 1;
	// Otherwise: