Handle orientation changes more systematically.

Bug: 4981385

Simplify the orientation changing code path in the
WindowManager.  Instead of the policy calling setRotation()
when the sensor determined orientation changes, it calls
updateRotation(), which figures everything out.  For the most
part, the rotation actually passed to setRotation() was
more or less ignored and just added confusion, particularly
when handling deferred orientation changes.

Ensure that 180 degree rotations are disallowed even when
the application specifies SCREEN_ORIENTATION_SENSOR_*.
These rotations are only enabled when docked upside-down for
some reason or when the application specifies
SCREEN_ORIENTATION_FULL_SENSOR.

Ensure that special modes like HDMI connected, lid switch,
dock and rotation lock all cause the sensor to be ignored
even when the application asks for sensor-based orientation
changes.  The sensor is not relevant in these modes because
some external factor (or the user) is determining the
preferred rotation.

Currently, applications can still override the preferred
rotation even when there are special modes in play that
might say otherwise.  We could tweak this so that some
special modes trump application choices completely
(resulting in a letter-boxed application, perhaps).
I tested this sort of tweak (not included in the patch)
and it seems to work fine, including transitions between
applications with varying orientation.

Delete dead code related to animFlags.

Handle pausing/resuming orientation changes more precisely.
Ensure that a deferred orientation change is performed when
a drag completes, even if endDragLw() is not called because the
drag was aborted before the drop happened.  We pause
the orientation change in register() and resume in unregister()
because those methods appear to always be called as needed.

Change-Id: If0a31de3d057251e581fdee64819f2b19e676e9a

4 files changed, 31 insertions, 35 deletions

diff --git a/core/java/android/view/IWindowManager.aidl b/core/java/android/view/IWindowManager.aidl
index 335c66b..55c821d 100644
--- a/core/java/android/view/IWindowManager.aidl
+++ b/core/java/android/view/IWindowManager.aidl
@@ -163,15 +163,13 @@ interface IWindowManager
 
     // These can only be called with the SET_ORIENTATION permission.
     /**
-     * Change the current screen rotation, constants as per
-     * {@link android.view.Surface}.
-     * @param rotation the intended rotation.
+     * Update the current screen rotation based on the current state of
+     * the world.
      * @param alwaysSendConfiguration Flag to force a new configuration to
      * be evaluated.  This can be used when there are other parameters in
      * configuration that are changing.
-     * @param animFlags Animation flags as per {@link android.view.Surface}.
      */
-    void setRotation(int rotation, boolean alwaysSendConfiguration, int animFlags);
+    void updateRotation(boolean alwaysSendConfiguration);
 
     /**
      * Retrieve the current screen orientation, constants as per
diff --git a/core/java/android/view/Surface.java b/core/java/android/view/Surface.java
index 3880bc4..64d3d31 100644
--- a/core/java/android/view/Surface.java
+++ b/core/java/android/view/Surface.java
@@ -207,9 +207,6 @@ public class Surface implements Parcelable {
 
     /** Enable dithering when compositing this surface @hide */
     public static final int SURFACE_DITHER    = 0x04;
-    
-    /** Disable the orientation animation @hide */
-    public static final int FLAGS_ORIENTATION_ANIMATION_DISABLE = 0x000000001;
 
     // The mSurfaceControl will only be present for Surfaces used by the window
     // server or system processes. When this class is parceled we defer to the
@@ -393,7 +390,7 @@ public class Surface implements Parcelable {
      * set the orientation of the given display.
      * @param display
      * @param orientation
-     * @param flags
+     * @param flags Currently unused, set to 0.
      * @hide
      */
     public static native   void setOrientation(int display, int orientation, int flags);
diff --git a/core/java/android/view/WindowManagerPolicy.java b/core/java/android/view/WindowManagerPolicy.java
index c07faf6..1dbb083 100644
--- a/core/java/android/view/WindowManagerPolicy.java
+++ b/core/java/android/view/WindowManagerPolicy.java
@@ -375,12 +375,6 @@ public interface WindowManagerPolicy {
     /** Screen turned off because of proximity sensor */
     public final int OFF_BECAUSE_OF_PROX_SENSOR = 4;
 
-    /**
-     * Magic constant to {@link IWindowManager#setRotation} to not actually
-     * modify the rotation.
-     */
-    public final int USE_LAST_ROTATION = -1000;
-
     /** When not otherwise specified by the activity's screenOrientation, rotation should be
      * determined by the system (that is, using sensors). */
     public final int USER_ROTATION_FREE = 0;
@@ -856,22 +850,30 @@ public interface WindowManagerPolicy {
     public boolean inKeyguardRestrictedKeyInputMode();
 
     /**
-     * Given an orientation constant
-     * ({@link android.content.pm.ActivityInfo#SCREEN_ORIENTATION_LANDSCAPE
-     * ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE} or
-     * {@link android.content.pm.ActivityInfo#SCREEN_ORIENTATION_PORTRAIT
-     * ActivityInfo.SCREEN_ORIENTATION_PORTRAIT}), return a surface
-     * rotation.
+     * Given an orientation constant, returns the appropriate surface rotation,
+     * taking into account sensors, docking mode, rotation lock, and other factors.
+     *
+     * @param orientation An orientation constant, such as
+     * {@link android.content.pm.ActivityInfo#SCREEN_ORIENTATION_LANDSCAPE}.
+     * @param lastRotation The most recently used rotation.
+     * @return The surface rotation to use.
      */
-    public int rotationForOrientationLw(int orientation, int lastRotation,
-            boolean displayEnabled);
-    
+    public int rotationForOrientationLw(int orientation, int lastRotation);
+
     /**
-     * Return the currently locked screen rotation, if any.  Return
-     * Surface.ROTATION_0, Surface.ROTATION_90, Surface.ROTATION_180, or
-     * Surface.ROTATION_270 if locked; return -1 if not locked.
+     * Given an orientation constant and a rotation, returns true if the rotation
+     * has compatible metrics to the requested orientation.  For example, if
+     * the application requested landscape and got seascape, then the rotation
+     * has compatible metrics; if the application requested portrait and got landscape,
+     * then the rotation has incompatible metrics; if the application did not specify
+     * a preference, then anything goes.
+     *
+     * @param orientation An orientation constant, such as
+     * {@link android.content.pm.ActivityInfo#SCREEN_ORIENTATION_LANDSCAPE}.
+     * @param rotation The rotation to check.
+     * @return True if the rotation is compatible with the requested orientation.
      */
-    public int getLockedRotationLw();
+    public boolean rotationHasCompatibleMetricsLw(int orientation, int rotation);
 
     /**
      * Called when the system is mostly done booting to determine whether
diff --git a/core/java/android/view/WindowOrientationListener.java b/core/java/android/view/WindowOrientationListener.java
index 76b47ca..726bf4a 100755
--- a/core/java/android/view/WindowOrientationListener.java
+++ b/core/java/android/view/WindowOrientationListener.java
@@ -118,14 +118,13 @@ public abstract class WindowOrientationListener {
 
     /**
      * Gets the current orientation.
-     * @param lastRotation
-     * @return
+     * @return The current rotation, or -1 if unknown.
      */
-    public int getCurrentRotation(int lastRotation) {
+    public int getCurrentRotation() {
         if (mEnabled) {
-            return mSensorEventListener.getCurrentRotation(lastRotation);
+            return mSensorEventListener.getCurrentRotation();
         }
-        return lastRotation;
+        return -1;
     }
 
     /**
@@ -342,8 +341,8 @@ public abstract class WindowOrientationListener {
             mOrientationListener = orientationListener;
         }
 
-        public int getCurrentRotation(int lastRotation) {
-            return mRotation != ROTATION_UNKNOWN ? mRotation : lastRotation;
+        public int getCurrentRotation() {
+            return mRotation; // may be -1, if unknown
         }
 
         @Override