MAC OS X Mountain Lion: Shortcuts for taking pictures of the screen

source link

Pictures of the screen (screenshots) are saved as files on the desktop, but if you prefer to put a screenshot in the Clipboard, hold down the Control key while you press the other keys. You can then paste the picture into a document.

Action	Shortcut
Take a picture of the whole screen	Command (⌘)-Shift-3
Take a picture of part of the screen	Command (⌘)-Shift-4, and then drag the crosshair pointer to select the area. Continue to press the mouse button, release the keys, and then press Shift, Option, or the Space bar while you drag to resize the selection area. When you are ready to take a picture, release the mouse button. To cancel, press Escape before you release the mouse button.
Take a picture of a window or the menu bar	Command (⌘)-Shift-4, press the Space bar, move the camera pointer over the area to highlight it, and then click. To cancel, press Escape before you click.
Take a picture of a menu, including the title	Click the menu to display the menu commands, press Command (⌘)-Shift-4, and drag the crosshair pointer over the area. To cancel, press Escape before you click.
Take a picture of the menu without its title	Click the menu to display the menu commands, press Command (⌘)-Shift-4, press the Space Bar, move the camera pointer over the menu to highlight it, and then click. To cancel, press Escape before you click.

You can also take pictures of the screen using the Grab app.
Some apps, such as DVD Player, may not let you take pictures of the screen.

Fix the “App can’t be opened because it is from an unidentified developer” Error in Mac OS X

source

Since OS X Mountain Lion, the Mac defaults to preventing applications from unidentified developers or sources from being launched. You’ll discover the message in OS X 10.8 when you try to launch a Mac app that didn’t come from a verified source or from the Mac App Store, and you’ll get an alert dialog that says “[App name] can’t be opened because it is from an unidentified developer”.

This new security feature is called GateKeeper, and it doesn’t mean you can’t run those unverified apps on the Mac, you just have to either temporarily skirt the security blanket of GateKeeper, or turn off the app limitations entirely.

Temporarily Get Around “App Can’t Be Opened” Gatekeeper Alert Message

This is probably the best option for most users, since it maintains some security:

1. Right-click (or control-click) the application in question and choose “Open”
2. Click the “Open” button at the next dialog warning to launch the app anyway

You can do this with any third party app that gives you this warning dialog and open it anyway.

If you get tired of constantly right-clicking apps to open them, return to pre-Mountain Lion levels of app security by turning off Gatekeepers app verification completely.

Disable GateKeeper’s Unidentified App Developer Prevention Completely

This is generally best for advanced users who know what apps to trust and not to trust:

1. Launch System Preferences from the Apple  menu
2. Choose “Security & Privacy” and then click the “General” tab, followed by clicking the lock icon in the corner to unlock the settings
3. Look for “Allow applications downloaded from:” and choose “Anywhere”
4. Accept the security warning and allow
5. You can now launch any app from any location or developer