Power Manager — notification agent.


Power Manager is a per-session application responsible for Power Manager's essential user interface.

Power Manager is included with every edition of Power Manager. Each user session should include a running instance of Power Manager Without Power Manager the user will not be kept informed of pending or executing events.

You can safely kill and relaunch Power Manager without affecting Power Manager Engine, or your schedule.


Power Manager provides three major interface elements:

Status menu


Warnings are displayed moments before a host affecting action is performed. A warning should explain two things to the user: what action is about to occur and what is responsible for the action.

The default warning is a large action or event specific icon accompanied by a short message. The message is typically the event name.

A warning is displayed for no less that 2 seconds before the action begins. This is enough time to register with the active user. There is no expectation of the user being able to stop or affect the action; notifications are provided earlier to allow the user to affect the action.

A warning needs to reassure users that an action is planned, predictable, and appropriate. Power Manager Engine can be used to shut down the user's computer. If the user sees their Mac shutting down without obvious reason, expect the user to be upset. A warning provides the user with a reason and culprit for the shut down; even then some users will be upset if their work is interrupted, but they now have a cause.

As a Power Manager client Power Manager observes the notifications.warnings variable.


Notifications are typically displayed minutes before an event is triggered. A notification is a polite reminder of a pending event.

Notifications are displayed for events whose trigger time and date can be calculated. These include the date and time trigger and daily trigger.

A notification should raise the user's awareness of a pending event. Notifications should not interrupt the workflow of the active user. Pending events may not be critical to the user, and in most cases the event is unlikely to affect the user's situation.

However, some events will affect the user. These events include those with shut down actions and other host affecting actions. The notification must always give the user an opportunity to secure their work. Notifications should provide the opportunity for the appropriately privileged user to adjust or cancel the pending event.

Events without time and date based triggers do not display notifications.

As a Power Manager client Power Manager observes the notifications.current variable.

Status Menu

The status menu is an ever present display of pending triggers. The status menu provides a quick glance guide to the next pending trigger.

Displaying the status menu's contents shows the user a list of pending triggers. The status menu can provide a means of adjusting or cancelling pending triggers.

Users should have the option of disabling the status menu. In some environments, a status menu showing pending triggers may not be appropriate.

As a Power Manager client Power Manager observes the notifications.pending variable.


Power Manager's non-critical notifiers may be enabled and disabled on a per-user basis. This allows users to choose which notification methods best suit their needs.

To enable or disable a notifier, use the defaults command line tool. Each notifier has an associated key and boolean value.

Power Manager inspects the defaults on launch, and after seeing a distributed notification matching the Power Manager preference domain (

Table 2.1. Available Defaults

Key Purpose Type Default
notifier.status-menu Show the status menu boolean true
notifier.notifications Show notification panel boolean true
notifier.notifications.simplify Pre-authorise notification panel's buttons boolean false
notifier.growl Enable Growl notification support boolean true
notifier.notification-center Enable Notification Center support boolean true

bash$ defaults write notifier.status-menu -bool no

Hide the status menu. The change will take affect next log in, or after a distributed notification matching the Power Manager preference domain is posted.

Simplified Notification

Power Manager offers the ability to show a "simplified" notification panel. You need to turn on this feature by setting the default notifier.notifications.simplify in the domain
bash$ defaults write notifier.notifications.simplify YES

Enable the simplified notification option for the current user.

bash$ sudo defaults write /Library/Preferences/ notifier.notifications.simplify YES

Enable the simplified notification option for all users of the computer.

With this default set, the notification panel will pre-authorise for adjust and cancel rights. If the rights can not be authorised, the appropriate button will be disabled:

A user without adjust or cancel rights, will only be able to click OK;
A user with only cancel rights, will only be able click Cancel or OK;
A user with cancel and adjust rights, will be able to click, Adjust, Cancel, or OK.

When simplified, the notification interface removes the potential password warning and simplifies the button labels.

Login Window

Power Manager shows a notification within the Login Window. The position of this notification is controlled by the computer wide preference notifier.login.position-vertical in the domain
bash$ sudo defaults write /Library/Preferences/ notifier.login.position-vertical -float 10.5

Place the Login Window notification at the base of the main screen.

notifier.login.position-vertical must be a float value between 1.5 and 11.5. Where 1.5 is a positioned at the bottom and 11.5 at the top of the screen.


Power Manager