Make a ruler through selected rectangle on screen by mouse, help!

[qingtianyu9]

I'm a web developer, I want to do following:

1. I want to make a ruler that can measuring on screen, when the left mouse button pressed and make a selected rectangle to draw a ruler.

2. I also want to make some reference-lines on screen and set top, those reference-lines can vertical or horizontal show on screen, just like photoshop reference-lines, and the reference-line can drag and delete.

3. Ruler can adsorbent reference-lines.

How should I do it? Any source code or anyone or any idea can help me? thanks very much.

[wakillon]

Take a look to :