When you say opened do you mean brought up from a minimized state?
As far as I am aware you can not trigger other events on this happening. What I would suggest is using buttons to show or hide the chart - that way you can attach other actions (such as Select In Field).
I've uploaded a couple of examples to the community that may be helpful in implementing this:
You will not get an action to fire when you minimise or maximise an object. You will need to have some kind of button or text area with actions to trigger things. If you do not want to go with the Show/Hide method (as per the links I posted) you could put a transparent text box over the top of the minimised icon which does the maximise and fires the Select In Field action. This could be confusing to users though - as it would require a single click rather than a double click (like other minimised objects).
If you do go with a transparent text box over the top of something else then make sure you set the layers correctly on the objects so the text area stays on top. I have to say I try to avoid transparent objects - as it is quite easy to get in a tangle with them.