|Tip 228||Switch Which App Edits a File You’re Working On|
Let’s say you’re tweaking a photo in Preview and decide you need the full power of Adobe Photoshop.
Look at Preview’s title bar. You’ll see the name of the file currently being worked upon. To the left of this will be a small icon representing the file. This is known as the proxy icon. Click and hold it for a few seconds, and then drag and drop the icon to the Photoshop icon on your Dock or to the Photoshop icon in Applications. The most recent version of the file will open in Photoshop (to learn about versions, see Exploring OS X: Autosave and Versions).
It’s a good idea to close Preview following this. Otherwise, attempting to save the file in Photoshop will show an error message saying the file is in use.
Instead of dropping the proxy icon onto the Dock icon, while still in the process of dragging the icon you can tap Command+Tab to bring up the application switcher and drop the proxy icon on top of the program’s icon in the switcher display.
Note that this same technique of dragging and dropping the proxy icon also works if you want to insert an image you’re working on into a word processing document (although this example could be any file type and any kind of document). In the image editor, save the file if you haven’t already, and then drag the proxy icon on top of the word processor or layout program’s window where you’d like to insert it. It will be inserted instantly.