How to Open Files on the Mac OS X Lion Dock
Take a minute to look at the row of icons at the bottom of your display within OS X Lion. That row is the Dock, and those individual pictures are known as icons. One useful function of the Mac OS X Lion Dock is that you can use it to open icons easily.
Dock icons are odd ducks; you activate one with a single click. Most other icons in the Finder are selected (highlighted) when you single-click and are opened only when you double-click them.
Here’s the rundown on what happens when you click Dock icons:
If it’s an application icon, the application opens and becomes active. If the application is already open, it becomes active, which brings it and all its windows to the front.
If it’s a document icon, that document opens in its appropriate application, which becomes the active application. If that application is already open, it becomes the active application with this document in the front.
If it’s a folder or disk icon, a stack with its contents appears so you can pick an item. If you choose Show in Finder from this menu, the folder’s window opens in the Finder.
If the item is open already when you click its Dock icon, it becomes active.
The following tips explain several ways to open what you need from the Dock:
You can drag a document icon onto an application’s Dock icon, if the application knows how to handle that type of document, its Dock icon is highlighted, and the document opens in that application.
If the application can’t handle a document, try opening the document this way: Select the icon and choose File→Open With, or right- or Control+click the document icon and use the Open With menu to choose the application you want to open the document with.
If you hold down the Option key, the Open With command changes to Always Open With, which enables you to change the default application for this document permanently.
You can find the original icon of any item you see in the Dock by choosing Show in Finder from its Dock menu. This opens the window containing the item’s actual icon and selects that icon for you.