Function ControlGetListView

source/script2.cpp:1813–2094

void ControlGetListView(ResultToken &aResultToken, HWND aHwnd, LPTSTR aOptions)
// Called by ControlGet() below.  It has ensured that aHwnd is a valid handle to a ListView.
{
	// GET ROW COUNT
	LRESULT row_count;
	if (!SendMessageTimeout(aHwnd, LVM_GETITEMCOUNT, 0, 0, SMTO_ABORTIFHUNG, 2000, (PDWORD_PTR)&row_count)) // Timed out or failed.
		goto error;

	// GET COLUMN COUNT
	// Through testing, could probably get to a level of 90% certainty that a ListView for which
	// InsertColumn() was never called (or was called only once) might lack a header control if the LV is
	// created in List/Icon view-mode and/or with LVS_NOCOLUMNHEADER. The problem is that 90% doesn't
	// seem to be enough to justify elimination of the code for "undetermined column count" mode.  If it
	// ever does become a certainty, the following could be changed:
	// 1) The extra code for "undetermined" mode rather than simply forcing col_count to be 1.
	// 2) Probably should be kept for compatibility: -1 being returned when undetermined "col count".
	//
	// The following approach might be the only simple yet reliable way to get the column count (sending
	// LVM_GETITEM until it returns false doesn't work because it apparently returns true even for
	// nonexistent subitems -- the same is reported to happen with LVM_GETCOLUMN and such, though I seem
	// to remember that LVM_SETCOLUMN fails on non-existent columns -- but calling that on a ListView
	// that isn't in Report view has been known to traumatize the control).
	// Fix for v1.0.37.01: It appears that the header doesn't always exist.  For example, when an
	// Explorer window opens and is *initially* in icon or list mode vs. details/tiles mode, testing
	// shows that there is no header control.  Testing also shows that there is exactly one column
	// in such cases but only for Explorer and other things that avoid creating the invisible columns.
	// For example, a script can create a ListView in Icon-mode and give it retrievable column data for
	// columns beyond the first.  Thus, having the undetermined-col-count mode preserves flexibility
	// by allowing individual columns beyond the first to be retrieved.  On a related note, testing shows
	// that attempts to explicitly retrieve columns (i.e. fields/subitems) other than the first in the
	// case of Explorer's Icon/List view modes behave the same as fetching the first column (i.e. Col3
	// would retrieve the same text as specifying Col1 or not having the Col option at all).
	// Obsolete because not always true: Testing shows that a ListView always has a header control
	// (at least on XP), even if you can't see it (such as when the view is Icon/Tile or when -Hdr has
	// been specified in the options).
	HWND header_control;
	LRESULT col_count = -1;  // Fix for v1.0.37.01: Use -1 to indicate "undetermined col count".
	if (SendMessageTimeout(aHwnd, LVM_GETHEADER, 0, 0, SMTO_ABORTIFHUNG, 2000, (PDWORD_PTR)&header_control)
		&& header_control) // Relies on short-circuit boolean order.
		SendMessageTimeout(header_control, HDM_GETITEMCOUNT, 0, 0, SMTO_ABORTIFHUNG, 2000, (PDWORD_PTR)&col_count);
		// Return value is not checked because if it fails, col_count is left at its default of -1 set above.
		// In fact, if any of the above conditions made it impossible to determine col_count, col_count stays
		// at -1 to indicate "undetermined".

	// PARSE OPTIONS (a simple vs. strict method is used to reduce code size)
	bool get_count = tcscasestr(aOptions, _T("Count"));
	bool include_selected_only = tcscasestr(aOptions, _T("Selected")); // Explicit "ed" to reserve "Select" for possible future use.
	bool include_focused_only = tcscasestr(aOptions, _T("Focused"));  // Same.
	LPTSTR col_option = tcscasestr(aOptions, _T("Col")); // Also used for mode "Count Col"
	int requested_col = col_option ? ATOI(col_option + 3) - 1 : -1;
	if (col_count > -1 && col_option && (requested_col < 0 || requested_col >= col_count)) // Specified column does not exist.
		_f_throw_value(ERR_PARAM1_INVALID, col_option);

	// IF THE "COUNT" OPTION IS PRESENT, FULLY HANDLE THAT AND RETURN
	if (get_count)
	{
		int result; // Must be signed to support writing a col count of -1 to aOutputVar.
		if (include_focused_only) // Listed first so that it takes precedence over include_selected_only.