How to get character Width?

I am working on an application written using Flex converted  from Flex 3 to 4.5. It has bullet list functionality. I had seen one post (url is not remb now.) during development to include bullet in text flow. What that post suggesting is, include bullet character at first line and add indentation to first line and to paragraph. i.e. First line indentation is -18 and paragraph indent is 18. so that this will appear as bulleted paragraph.

My problem is, I am not able to manage number of spaces between bullet character and next character for different font-family and fontsize. I tried to find character width but no luck (not able to find api), I need expert advice.

Is there anything to get font matrix so that I can find width of space and adjust the spaces number and indentation.

Thanks,

Vikram