Uses the twilight service to determine the hours of
sunrise and sunset. Shortly after sunset or before sunrise
gradually start to apply a gamma correction factor to the
auto-brightness calculations to make the screen a little
dimmer at night.
The effect is relatively small and is mostly noticeable
in dark rooms. This is just a first pass at the algorithm,
we can tweak the adjustment later to ensure that it has even less
impact in moderate or bright environments.
Change-Id: Idf89022a5d0bb52975e04779352d53fa63371178
Auto-brightness adjustment applies a gamma correction factor
between 1/3 and 3 depending on the setting. This feature
is disabled for now.
Change-Id: I2b300b5c455da545bea56b2bae5bc7903e30f30e
The major goal of this rewrite is to make it easier to implement
power management policies correctly. According, the new
implementation primarily uses state-based rather than event-based
triggers for applying changes to the current power state.
For example, when an application requests that the proximity
sensor be used to manage the screen state (by way of a wake lock),
the power manager makes note of the fact that the set of
wake locks changed. Then it executes a common update function
that recalculates the entire state, first looking at wake locks,
then considering user activity, and eventually determining whether
the screen should be turned on or off. At this point it may
make a request to a component called the DisplayPowerController
to asynchronously update the display's powe state. Likewise,
DisplayPowerController makes note of the updated power request
and schedules its own update function to figure out what needs
to be changed.
The big benefit of this approach is that it's easy to mutate
multiple properties of the power state simultaneously then
apply their joint effects together all at once. Transitions
between states are detected and resolved by the update in
a consistent manner.
The new power manager service has is implemented as a set of
loosely coupled components. For the most part, information
only flows one way through these components (by issuing a
request to that component) although some components support
sending a message back to indicate when the work has been
completed. For example, the DisplayPowerController posts
a callback runnable asynchronously to tell the PowerManagerService
when the display is ready. An important feature of this
approach is that each component neatly encapsulates its
state and maintains its own invariants. Moreover, we do
not need to worry about deadlocks or awkward mutual exclusion
semantics because most of the requests are asynchronous.
The benefits of this design are especially apparent in
the implementation of the screen on / off and brightness
control animations which are able to take advantage of
framework features like properties, ObjectAnimator
and Choreographer.
The screen on / off animation is now the responsibility
of the power manager (instead of surface flinger). This change
makes it much easier to ensure that the animation is properly
coordinated with other power state changes and eliminates
the cause of race conditions in the older implementation.
The because of the userActivity() function has been changed
so that it never wakes the device from sleep. This change
removes ambiguity around forcing or disabling user activity
for various purposes. To wake the device, use wakeUp().
To put it to sleep, use goToSleep(). Simple.
The power manager service interface and API has been significantly
simplified and consolidated. Also fixed some inconsistencies
related to how the minimum and maximum screen brightness setting
was presented in brightness control widgets and enforced behind
the scenes.
At present the following features are implemented:
- Wake locks.
- User activity.
- Wake up / go to sleep.
- Power state broadcasts.
- Battery stats and event log notifications.
- Dreams.
- Proximity screen off.
- Animated screen on / off transitions.
- Auto-dimming.
- Auto-brightness control for the screen backlight with
different timeouts for ramping up versus ramping down.
- Auto-on when plugged or unplugged.
- Stay on when plugged.
- Device administration maximum user activity timeout.
- Application controlled brightness via window manager.
The following features are not yet implemented:
- Reduced user activity timeout for the key guard.
- Reduced user activity timeout for the phone application.
- Coordinating screen on barriers with the window manager.
- Preventing auto-rotation during power state changes.
- Auto-brightness adjustment setting (feature was disabled
in previous version of the power manager service pending
an improved UI design so leaving it out for now).
- Interpolated brightness control (a proposed new scheme
for more compactly specifying auto-brightness levels
in config.xml).
- Button / keyboard backlight control.
- Change window manager to associated WorkSource with
KEEP_SCREEN_ON_FLAG wake lock instead of talking
directly to the battery stats service.
- Optionally support animating screen brightness when
turning on/off instead of playing electron beam animation
(config_animateScreenLights).
Change-Id: I1d7a52e98f0449f76d70bf421f6a7f245957d1d7
It turns out OFF_BECAUSE_OF_TIMEOUT is not the best indicator
of actual screen timeout.
For example, it is the reason passed down when acquiring a wake lock.
This was causing us to launch Dreams in the wrong situations, and
deadlocking on calls to WindowManager.
This fix simply adds an additional check ensuring the intention is to
turn the screen off.
Change-Id: If8adff446b5b1fcb19424b45878b75bfd0552b90
Enable feature in config. Expose Dream in public api for unbundled apps.
Unhide package. Add isDreaming() method to service.
Re-arrange the Dream api a bit. (use onStart as hook for subclasses).
Coordinate properly with power manager.
Replace old dock mode (don't fire old intent).
Change-Id: I1318d20cc1613e5d862f2913f2fcdc9719302cf7
Bug: 6921930
The purpose of this change is to remove direct reliance on
SurfaceFlinger for describing the size and characteristics of
displays.
This patch also starts to make a distinction between logical displays
and physical display devices. Currently, the window manager owns
the concept of a logical display whereas the new display
manager owns the concept of a physical display device.
Change-Id: I7e0761f83f033be6c06fd1041280c21500bcabc0
