"Smarter" Navigation side bar with mouse

It has happend to me a lot of times when I click _SQL Query_ on the Navigation side bar, and I press ⌘+A to select all text in the Query Window. Instead, all items of the Navigation side bar are selected.

I now (when I think of it) click within the SQL Query editor, before pressing ⌘+A. An alternative is hitting the TAB key twice before pressing ⌘+A.

I also see the use case of using the arrow-keys after one selects an item from the Navigation side bar, so automatically select the contents would be not what you want.

One solution to the problem would be if you click on the icon of an item, the _contents_ of the item would be selected. TextMate does this with the project explorer. When you hover the mouse above the cursor, you will get a hand-pointer, so the user knows it will do something different. It also includes a small animation when you click on it (the open-animation, borrowed from Finder).

PS: sorry for the title; I couldn't come up with a better one. Don't hesitate to make it more clear.

No files, tests, or entry points are named. Start by reproducing the ⌘+A behavior after selecting SQL Query in the navigation sidebar, then trace the sidebar selection and SQL Query editor focus handling. Done should distinguish sidebar selection from editor text selection while preserving keyboard navigation.

Written by the indexing model from the issue text.