This change is the initial check in of the screen magnification
feature. This feature enables magnification of the screen via
global gestures (assuming it has been enabled from settings)
to allow a low vision user to efficiently use an Android device.
Interaction model:
1. Triple tap toggles permanent screen magnification which is magnifying
the area around the location of the triple tap. One can think of the
location of the triple tap as the center of the magnified viewport.
For example, a triple tap when not magnified would magnify the screen
and leave it in a magnified state. A triple tapping when magnified would
clear magnification and leave the screen in a not magnified state.
2. Triple tap and hold would magnify the screen if not magnified and enable
viewport dragging mode until the finger goes up. One can think of this
mode as a way to move the magnified viewport since the area around the
moving finger will be magnified to fit the screen. For example, if the
screen was not magnified and the user triple taps and holds the screen
would magnify and the viewport will follow the user's finger. When the
finger goes up the screen will clear zoom out. If the same user interaction
is performed when the screen is magnified, the viewport movement will
be the same but when the finger goes up the screen will stay magnified.
In other words, the initial magnified state is sticky.
3. Pinching with any number of additional fingers when viewport dragging
is enabled, i.e. the user triple tapped and holds, would adjust the
magnification scale which will become the current default magnification
scale. The next time the user magnifies the same magnification scale
would be used.
4. When in a permanent magnified state the user can use two or more fingers
to pan the viewport. Note that in this mode the content is panned as
opposed to the viewport dragging mode in which the viewport is moved.
5. When in a permanent magnified state the user can use three or more
fingers to change the magnification scale which will become the current
default magnification scale. The next time the user magnifies the same
magnification scale would be used.
6. The magnification scale will be persisted in settings and in the cloud.
Note: Since two fingers are used to pan the content in a permanently magnified
state no other two finger gestures in touch exploration or applications
will work unless the uses zooms out to normal state where all gestures
works as expected. This is an intentional tradeoff to allow efficient
panning since in a permanently magnified state this would be the dominant
action to be performed.
Design:
1. The window manager exposes APIs for setting accessibility transformation
which is a scale and offsets for X and Y axis. The window manager queries
the window policy for which windows will not be magnified. For example,
the IME windows and the navigation bar are not magnified including windows
that are attached to them.
2. The accessibility features such a screen magnification and touch
exploration are now impemented as a sequence of transformations on the
event stream. The accessibility manager service may request each
of these features or both. The behavior of the features is not changed
based on the fact that another one is enabled.
3. The screen magnifier keeps a viewport of the content that is magnified
which is surrounded by a glow in a magnified state. Interactions outside
of the viewport are delegated directly to the application without
interpretation. For example, a triple tap on the letter 'a' of the IME
would type three letters instead of toggling magnified state. The viewport
is updated on screen rotation and on window transitions. For example,
when the IME pops up the viewport shrinks.
4. The glow around the viewport is implemented as a special type of window
that does not take input focus, cannot be touched, is laid out in the
screen coordiates with width and height matching these of the screen.
When the magnified region changes the root view of the window draws the
hightlight but the size of the window does not change - unless a rotation
happens. All changes in the viewport size or showing or hiding it are
animated.
5. The viewport is encapsulated in a class that knows how to show,
hide, and resize the viewport - potentially animating that.
This class uses the new animation framework for animations.
6. The magnification is handled by a magnification controller that
keeps track of the current trnasformation to be applied to the screen
content and the desired such. If these two are not the same it is
responsibility of the magnification controller to reconcile them by
potentially animating the transition from one to the other.
7. A dipslay content observer wathces for winodw transitions, screen
rotations, and when a rectange on the screen has been reqeusted. This
class is responsible for handling interesting state changes such
as changing the viewport bounds on IME pop up or screen rotation,
panning the content to make a requested rectangle visible on the
screen, etc.
8. To implement viewport updates the window manger was updated with APIs
to watch for window transitions and when a rectangle has been requested
on the screen. These APIs are protected by a signature level permission.
Also a parcelable and poolable window info class has been added with
APIs for getting the window info given the window token. This enables
getting some useful information about a window. There APIs are also
signature protected.
bug:6795382
Change-Id: Iec93da8bf6376beebbd4f5167ab7723dc7d9bd00
This fixes showing the emergency dialer on devices without telephony.
Two fixes were required: 1. Move emergency dialer code to the view
that contains it (KeyguardSelectorView). 2. Always call onPause()
or onResume() in onScreenTurnedOff() and onScreenTurnedOn(), respectively.
Fixes bug 7117895
Change-Id: I96769fdda8478b6b60f46f7470bed2279ea2de72
Each user has its own Settings.System.* and Settings.Secure.* namespace now. In
addition, this CL introduces the new Settings.Global.* namespace, which contains
a number of previously-elsewhere named settings entities; these Global.* entities
are common to all users. Because these elements have been moved from their prior
existence in the other namespaces, attempts to access them under their old names
and namespaces are detected and redirected (with appropriate compile-time and
logging messages) to their new homes.
The new Global.* namespace can only be written by system-level code, just like
the existing Secure.* namespace. If an app attempts to write a key that was
previously in the System.* namespace but has been moved to the Global.* namespace,
then a warning is logged and no write is performed; the action is a no-op. (The
app is explicitly not crashed, to avoid breaking well-behaved apps that can't
know any better.)
There is also now a hidden API for getting/setting settings entities associated
with a user other than the caller's. Reading/writing data for a user other than
yourself requires the signature-level INTERACT_ACROSS_USERS_FULL permission.
Manipulating data for a different user cannot be done via the ContentProvider
query() / insert() APIs; you must use the Settings.get/put APIs for that degree
of control. In general, use of the get/set API is *strongly* preferred over
query-type access to Settings.
Bug 6985398
Change-Id: Ibee54ddff99fb847c8c2479c23b50f1e7524d724
When the BaseIWindow.resized method got switched from taking (int x,
int y, ...) to taking (Rect, ...) the SurfaceView.MyWindow override
never got updated.
Fixes bug 6992324.
Change-Id: Id0b9625559ae0100336f4573f09d313138c8a6e7
Large software layers won't draw if they're larger than the size of the drawing
cache, in which case this log will be triggered.
bug:7078391
Change-Id: Ib42a060b8e3b3642417df9243a086aa15b2989b1
