Method FindGroup

source/script_gui.cpp:7920–7953

int GuiType::FindGroup(GuiIndexType aControlIndex, GuiIndexType &aGroupStart, GuiIndexType &aGroupEnd)
// Caller must provide a valid aControlIndex for an existing control.
// Returns the number of radio buttons inside the group. In addition, it provides start and end
// values to the caller via aGroupStart/End, where Start is the index of the first control in
// the group and End is the index of the control *after* the last control in the group (if none,
// aGroupEnd is set to mControlCount).
// NOTE: This returns the range covering the entire group, and it is possible for the group
// to contain non-radio type controls.  Thus, the caller should check each control inside the
// returned range to make sure it's a radio before operating upon it.
{
	// Work backwards in the control array until the first member of the group is found or the
	// first array index, whichever comes first (the first array index is the top control in the
	// Z-Order and thus treated by the OS as an implicit start of a new group):
	int group_radios = 0; // This and next are both init'd to 0 not 1 because the first loop checks aControlIndex itself.
	for (aGroupStart = aControlIndex;; --aGroupStart)
	{
		if (mControl[aGroupStart]->type == GUI_CONTROL_RADIO)
			++group_radios;
		if (!aGroupStart || GetWindowLong(mControl[aGroupStart]->hwnd, GWL_STYLE) & WS_GROUP)
			break;
	}
	// Now find the control after the last control (or mControlCount if none).  Must start at +1
	// because if aControlIndex's control has the WS_GROUP style, we don't want to count that
	// as the end of the group (because in fact that would be the beginning of the group).
	for (aGroupEnd = aControlIndex + 1; aGroupEnd < mControlCount; ++aGroupEnd)
	{
		// Unlike the previous loop, this one must do this check prior to the next one:
		if (GetWindowLong(mControl[aGroupEnd]->hwnd, GWL_STYLE) & WS_GROUP)
			break;
		if (mControl[aGroupEnd]->type == GUI_CONTROL_RADIO)
			++group_radios;
	}
	return group_radios;
}