Mac OS X how many NSNotification centers are there on a workstation-mac <h1>Short question</h1> <p>on a workstation-mac (MacPro) I found 3 NSNotification centers:</p> <h2>call (swift)</h2> <pre><code>// 1. NSWorkspace Center let theWorkspaceCenter = NSWorkspace.sharedWorkspace ().notificationCenter // 2. NSDistributedNotification Center let theNSDistributedNotificationCenter = NSDistributedNotificationCenter.defaultCenter () // 3. Default Center let theDefaultCenter = NSNotificationCenter.defaultCenter () </code></pre> <p>Are there any more NSNotification centers?</p> <hr> <h1>Longer description</h1> <p><strong>1. NSWorkspace Center</strong></p> <h2>call (swift)</h2> <pre><code>let theWorkspaceCenter = NSWorkspace.sharedWorkspace ().notificationCenter </code></pre> <ul> <li>Very few notifications</li> </ul> <h2>Typical notifications</h2> <ul> <li>Computer goes to sleep</li> <li>Computer wakes from sleep</li> <li>Volume gets mounted / unmounted</li> </ul> <h2>Example</h2> <pre><code>NSWorkspaceScreensDidWakeNotification NSWorkspaceWillUnmountNotification </code></pre> <hr> <p><strong>2. NSDistributedNotification Center</strong></p> <h2>call (swift)</h2> <pre><code>let theNSDistributedNotificationCenter = NSDistributedNotificationCenter.defaultCenter () </code></pre> <ul> <li>Regular notifications</li> </ul> <h2>Typical notifications</h2> <ul> <li>Menue tracking</li> <li>Application comes to foreground</li> <li>backup</li> <li>systemBeep</li> <li>0:00 dayChange</li> </ul> <h2>Example</h2> <pre><code>com.apple.HIToolbox.beginMenuTrackingNotification com.apple.HIToolbox.frontMenuBarShown com.apple.backupd.NewSystemBackupAvailableNotification com.apple.systemBeep com.apple.calendar.DayChanged </code></pre> <hr> <p><strong>3. Default Center</strong></p> <h2>call (swift)</h2> <pre><code>let theDefaultCenter = NSNotificationCenter.defaultCenter () </code></pre> <ul> <li>Very much notifications (hundreds / thousands within a few seconds)</li> </ul> <h2>Example</h2> <pre><code>NSApplicationDidUpdateNotification NSViewNeedsDisplayInRectNotification NSWindowDidUpdateNotification </code></pre> <p>Thanks for any hint!</p>