AIS_TextLabel - new public class to display simple text labels (based on MyTextClass private class from Draw Harness).
ViewerTest::Display() - add more reliable replacement for VDisplayAISObject() with no viewer update flag.
vdrawtext command redesign:
- Use new AIS_TextLabel class instead of private MyTextClass.
- Take object name and allow to clear labels from the Viewer.
- Use parameter name + parameter value syntax instead of strict list of mandatory arguments.
- Use [0; 1] range for colors and accept names.
- Drop redundant argument "isMultiByte".
- Support argument -noupdate to skip Viewer update.
Update test cases to new syntax of vdrawtext.
Unstable test cases were reviewed
Modified test cases using checktrend command
Modified test cases for Linux platform
Modified test cases for Debug mode
