Method getRootCommand

librecad/src/ui/forms/qg_commandwidget.cpp:274–314

}

QString QG_CommandWidget::getRootCommand( const QStringList & cmdList, const QString & typed ) {
	//do we have to check for empty cmdList?
	if(cmdList.empty()) return QString();

	//find the shortest string in cmdList
	auto const& shortestString = * std::min_element(cmdList.begin(), cmdList.end(),
													[](QString const& a, QString const& b) -> bool
			{
				return a.size() < b.size();
			}
			);
	int const lengthShortestString = shortestString.size();

	// Now we parse the cmdList list, character of each item by character.
	int low = typed.length();
	int high = lengthShortestString + 1;

    while(high > low + 1) {
		int mid = (high + low)/2;
		bool common = true;

		QString const& proposal = shortestString.left(mid);
        for(auto const& substring: cmdList) {
            if(!substring.startsWith(proposal)) {
                common = false;
                break;
            }
        }
        if(common) {
            low = mid;
        }
        else {
            high = mid;
        }
    }

    // As we assign just before mid value to low (if strings are common), we can use it as parameter for left.
    // If not common -> low value does not changes, even if escaping from the while. This avoids weird behaviors like continuing completion when pressing tab.
	return shortestString.left(low);

}

void QG_CommandWidget::chooseCommandFile()
{