Method WinGetText

Source/script2.cpp:3723–3781

ResultType Line::WinGetText(char *aTitle, char *aText, char *aExcludeTitle, char *aExcludeText)
{
	Var *output_var = ResolveVarOfArg(0);
	if (!output_var)
		return FAIL;
	g_ErrorLevel->Assign(ERRORLEVEL_ERROR); // Set default ErrorLevel.
	HWND target_window = DetermineTargetWindow(aTitle, aText, aExcludeTitle, aExcludeText);
	// Even if target_window is NULL, we want to continue on so that the output
	// variables are set to be the empty string, which is the proper thing to do
	// rather than leaving whatever was in there before:
	if (!target_window)
		return output_var->Assign(); // Tell it not to free the memory by not calling with "".

	length_and_buf_type sab;
	sab.buf = NULL; // Tell it just to calculate the length this time around.
	sab.total_length = sab.capacity = 0; // Init
	EnumChildWindows(target_window, EnumChildGetText, (LPARAM)&sab);

	if (!sab.total_length) // No text in window.
	{
		g_ErrorLevel->Assign(ERRORLEVEL_NONE); // Indicate success.
		return output_var->Assign(); // Tell it not to free the memory by omitting all params.
	}
	// This adjustment was added because someone reported that max variable capacity was being
	// exceeded in some cases (perhaps custom controls that retrieve large amounts of text
	// from the disk in response to the "get text" message):
	if (sab.total_length >= g_MaxVarCapacity)    // Allow the command to succeed by truncating the text.
		sab.total_length = g_MaxVarCapacity - 1; // And this length will be used to limit the retrieval capacity below.

	// Set up the var, enlarging it if necessary.  If the output_var is of type VAR_CLIPBOARD,
	// this call will set up the clipboard for writing:
	if (output_var->Assign(NULL, (VarSizeType)sab.total_length) != OK)
		return FAIL;  // It already displayed the error.

	// Fetch the text directly into the var.  Also set the length explicitly
	// in case actual size written was off from the esimated size (since
	// GetWindowTextLength() can return more space that will actually be required
	// in certain circumstances, see MSDN):
	sab.buf = output_var->Contents();
	sab.total_length = 0; // Init
	// Note: The capacity member below exists because granted capacity might be a little larger than we asked for,
	// which allows the actual text fetched to be larger than the length estimate retrieved by the first pass
	// (which generally shouldn't happen since MSDN docs say that the actual length can be less, but never greater,
	// than the estimate length):
	sab.capacity = output_var->Capacity(); // Capacity includes the zero terminator, i.e. it's the size of the memory area.
	EnumChildWindows(target_window, EnumChildGetText, (LPARAM)&sab); // Get the text.

	// Length is set explicitly below in case it wound up being smaller than expected/estimated.
	// MSDN says that can happen generally, and also specifically because: "ANSI applications may have
	// the string in the buffer reduced in size (to a minimum of half that of the wParam value) due to
	// conversion from ANSI to Unicode."
	output_var->Length() = (VarSizeType)sab.total_length;
	if (sab.total_length)
		g_ErrorLevel->Assign(ERRORLEVEL_NONE); // Indicate success.
	else
		// Something went wrong, so make sure we set to empty string.
		*output_var->Contents() = '\0';  // Safe because Assign() gave us a non-constant memory area.
	return output_var->Close();  // In case it's the clipboard.