am f9205adb: am 3a8effb8: am 9302251e: Merge "Reduce screen on latency, eliminate flashes." into jb-mr1-dev

* commit 'f9205adb415cf87a9c4956e0b850c831801cc1f3':
  Reduce screen on latency, eliminate flashes.

5 files changed, 116 insertions, 70 deletions

diff --git a/services/java/com/android/server/power/DisplayPowerController.java b/services/java/com/android/server/power/DisplayPowerController.java
index a1c1fa6..25d2944 100644
--- a/services/java/com/android/server/power/DisplayPowerController.java
+++ b/services/java/com/android/server/power/DisplayPowerController.java
@@ -271,6 +271,12 @@ final class DisplayPowerController {
     // When the screen turns on again, we report user activity to the power manager.
     private boolean mScreenOffBecauseOfProximity;
 
+    // True if the screen on is being blocked.
+    private boolean mScreenOnWasBlocked;
+
+    // The elapsed real time when the screen on was blocked.
+    private long mScreenOnBlockStartRealTime;
+
     // Set to true if the light sensor is enabled.
     private boolean mLightSensorEnabled;
 
@@ -513,7 +519,7 @@ final class DisplayPowerController {
         final Executor executor = AsyncTask.THREAD_POOL_EXECUTOR;
         Display display = mDisplayManager.getDisplay(Display.DEFAULT_DISPLAY);
         mPowerState = new DisplayPowerState(
-                mElectronBeamAnimatesBacklightConfig ? null : new ElectronBeam(display),
+                new ElectronBeam(display),
                 new PhotonicModulator(executor,
                         mLights.getLight(LightsService.LIGHT_ID_BACKLIGHT),
                         mSuspendBlocker));
@@ -553,7 +559,6 @@ final class DisplayPowerController {
         final boolean mustNotify;
         boolean mustInitialize = false;
         boolean updateAutoBrightness = mTwilightChanged;
-        boolean screenOnWasBlocked = false;
         mTwilightChanged = false;
 
         synchronized (mLock) {
@@ -662,18 +667,24 @@ final class DisplayPowerController {
                 // It is relatively short but if we cancel it and switch to the
                 // on animation immediately then the results are pretty ugly.
                 if (!mElectronBeamOffAnimator.isStarted()) {
-                    if (mPowerRequest.blockScreenOn && !mPowerState.isScreenOn()) {
-                        if (DEBUG) {
-                            Slog.d(TAG, "Blocked screen on while screen currently off.");
-                        }
-                        screenOnWasBlocked = true;
+                    // Turn the screen on.  The contents of the screen may not yet
+                    // be visible if the electron beam has not been dismissed because
+                    // its last frame of animation is solid black.
+                    setScreenOn(true);
+
+                    if (mPowerRequest.blockScreenOn
+                            && mPowerState.getElectronBeamLevel() == 0.0f) {
+                        blockScreenOn();
                     } else {
-                        setScreenOn(true);
+                        unblockScreenOn();
                         if (USE_ELECTRON_BEAM_ON_ANIMATION) {
                             if (!mElectronBeamOnAnimator.isStarted()) {
                                 if (mPowerState.getElectronBeamLevel() == 1.0f) {
                                     mPowerState.dismissElectronBeam();
-                                } else if (mPowerState.prepareElectronBeam(true)) {
+                                } else if (mPowerState.prepareElectronBeam(
+                                        mElectronBeamAnimatesBacklightConfig ?
+                                                ElectronBeam.MODE_BLANK :
+                                                        ElectronBeam.MODE_WARM_UP)) {
                                     mElectronBeamOnAnimator.start();
                                 } else {
                                     mElectronBeamOnAnimator.end();
@@ -684,22 +695,6 @@ final class DisplayPowerController {
                             mPowerState.dismissElectronBeam();
                         }
                     }
-                } else {
-                    // FIXME: If the electron beam off animation is playing then we have a bit
-                    // of a problem.  The window manager policy would only have requested
-                    // to block screen on if it was about to start preparing the keyguard.
-                    // It's already too late to do anything about that.  Ideally we would
-                    // let the animation play out first but that would require making
-                    // some pretty deep changes to the power manager and we don't have
-                    // time just now.  For now, short-circuit the animation and get ready.
-                    if (mPowerRequest.blockScreenOn) {
-                        if (DEBUG) {
-                            Slog.d(TAG, "Blocked screen on while screen off animation running.");
-                        }
-                        screenOnWasBlocked = true;
-                        setScreenOn(false);
-                        mElectronBeamOffAnimator.end();
-                    }
                 }
             } else {
                 // Want screen off.
@@ -708,7 +703,10 @@ final class DisplayPowerController {
                     if (!mElectronBeamOffAnimator.isStarted()) {
                         if (mPowerState.getElectronBeamLevel() == 0.0f) {
                             setScreenOn(false);
-                        } else if (mPowerState.prepareElectronBeam(false)
+                        } else if (mPowerState.prepareElectronBeam(
+                                mElectronBeamAnimatesBacklightConfig ?
+                                        ElectronBeam.MODE_BLANK :
+                                                ElectronBeam.MODE_COOL_DOWN)
                                 && mPowerState.isScreenOn()) {
                             mElectronBeamOffAnimator.start();
                         } else {
@@ -723,7 +721,7 @@ final class DisplayPowerController {
         // We mostly care about the screen state here, ignoring brightness changes
         // which will be handled asynchronously.
         if (mustNotify
-                && !screenOnWasBlocked
+                && !mScreenOnWasBlocked
                 && !mElectronBeamOnAnimator.isStarted()
                 && !mElectronBeamOffAnimator.isStarted()
                 && mPowerState.waitUntilClean(mCleanListener)) {
@@ -740,6 +738,26 @@ final class DisplayPowerController {
         }
     }
 
+    private void blockScreenOn() {
+        if (!mScreenOnWasBlocked) {
+            mScreenOnWasBlocked = true;
+            if (DEBUG) {
+                Slog.d(TAG, "Blocked screen on.");
+                mScreenOnBlockStartRealTime = SystemClock.elapsedRealtime();
+            }
+        }
+    }
+
+    private void unblockScreenOn() {
+        if (mScreenOnWasBlocked) {
+            mScreenOnWasBlocked = false;
+            if (DEBUG) {
+                Slog.d(TAG, "Unblocked screen on after " +
+                        (SystemClock.elapsedRealtime() - mScreenOnBlockStartRealTime) + " ms");
+            }
+        }
+    }
+
     private void setScreenOn(boolean on) {
         if (!mPowerState.isScreenOn() == on) {
             mPowerState.setScreenOn(on);
diff --git a/services/java/com/android/server/power/DisplayPowerRequest.java b/services/java/com/android/server/power/DisplayPowerRequest.java
index 5f94414..22f17d7 100644
--- a/services/java/com/android/server/power/DisplayPowerRequest.java
+++ b/services/java/com/android/server/power/DisplayPowerRequest.java
@@ -52,11 +52,14 @@ final class DisplayPowerRequest {
     // If true, enables automatic brightness control.
     public boolean useAutoBrightness;
 
-    // If true, prevents the screen from turning on if it is currently off.
-    // The display does not enter a "ready" state if this flag is true and the screen
-    // is off and is being prevented from turning on.  The window manager policy blocks
-    // screen on while it prepares the keyguard to prevent the user from seeing
-    // intermediate updates.
+    // If true, prevents the screen from completely turning on if it is currently off.
+    // The display does not enter a "ready" state if this flag is true and screen on is
+    // blocked.  The window manager policy blocks screen on while it prepares the keyguard to
+    // prevent the user from seeing intermediate updates.
+    //
+    // Technically, we may not block the screen itself from turning on (because that introduces
+    // extra unnecessary latency) but we do prevent content on screen from becoming
+    // visible to the user.
     public boolean blockScreenOn;
 
     public DisplayPowerRequest() {
diff --git a/services/java/com/android/server/power/DisplayPowerState.java b/services/java/com/android/server/power/DisplayPowerState.java
index dba45b3..f6ce7a7 100644
--- a/services/java/com/android/server/power/DisplayPowerState.java
+++ b/services/java/com/android/server/power/DisplayPowerState.java
@@ -50,7 +50,7 @@ final class DisplayPowerState {
     private static final int DIRTY_BRIGHTNESS = 1 << 2;
 
     private final Choreographer mChoreographer;
-    private final ElectronBeam mElectronBeam; // may be null if only animating backlights
+    private final ElectronBeam mElectronBeam;
     private final PhotonicModulator mScreenBrightnessModulator;
 
     private int mDirty;
@@ -130,26 +130,19 @@ final class DisplayPowerState {
      * This method should be called before starting an animation because it
      * can take a fair amount of time to prepare the electron beam surface.
      *
-     * @param warmUp True if the electron beam should start warming up.
+     * @param mode The electron beam animation mode to prepare.
      * @return True if the electron beam was prepared.
      */
-    public boolean prepareElectronBeam(boolean warmUp) {
-        if (mElectronBeam != null) {
-            boolean success = mElectronBeam.prepare(warmUp);
-            invalidate(DIRTY_ELECTRON_BEAM);
-            return success;
-        } else {
-            return true;
-        }
+    public boolean prepareElectronBeam(int mode) {
+        invalidate(DIRTY_ELECTRON_BEAM);
+        return mElectronBeam.prepare(mode);
     }
 
     /**
      * Dismisses the electron beam surface.
      */
     public void dismissElectronBeam() {
-        if (mElectronBeam != null) {
-            mElectronBeam.dismiss();
-        }
+        mElectronBeam.dismiss();
     }
 
     /**
@@ -230,9 +223,7 @@ final class DisplayPowerState {
         pw.println("  mScreenBrightness=" + mScreenBrightness);
         pw.println("  mElectronBeamLevel=" + mElectronBeamLevel);
 
-        if (mElectronBeam != null) {
-            mElectronBeam.dump(pw);
-        }
+        mElectronBeam.dump(pw);
     }
 
     private void invalidate(int dirty) {
@@ -251,7 +242,7 @@ final class DisplayPowerState {
                 PowerManagerService.nativeSetScreenState(false);
             }
 
-            if ((mDirty & DIRTY_ELECTRON_BEAM) != 0 && mElectronBeam != null) {
+            if ((mDirty & DIRTY_ELECTRON_BEAM) != 0) {
                 mElectronBeam.draw(mElectronBeamLevel);
             }
 
diff --git a/services/java/com/android/server/power/ElectronBeam.java b/services/java/com/android/server/power/ElectronBeam.java
index 0c68997..8c242f7 100644
--- a/services/java/com/android/server/power/ElectronBeam.java
+++ b/services/java/com/android/server/power/ElectronBeam.java
@@ -26,7 +26,6 @@ import android.opengl.EGLSurface;
 import android.opengl.GLES10;
 import android.opengl.GLUtils;
 import android.os.Looper;
-import android.os.Process;
 import android.util.FloatMath;
 import android.util.Slog;
 import android.view.Display;
@@ -41,12 +40,13 @@ import java.nio.FloatBuffer;
 
 /**
  * Bzzzoooop!  *crackle*
- *
+ * <p>
  * Animates a screen transition from on to off or off to on by applying
  * some GL transformations to a screenshot.
- *
+ * </p><p>
  * This component must only be created or accessed by the {@link Looper} thread
  * that belongs to the {@link DisplayPowerController}.
+ * </p>
  */
 final class ElectronBeam {
     private static final String TAG = "ElectronBeam";
@@ -65,7 +65,7 @@ final class ElectronBeam {
 
     // Set to true when the animation context has been fully prepared.
     private boolean mPrepared;
-    private boolean mWarmUp;
+    private int mMode;
 
     private final Display mDisplay;
     private final DisplayInfo mDisplayInfo = new DisplayInfo();
@@ -90,6 +90,10 @@ final class ElectronBeam {
     private final FloatBuffer mVertexBuffer = createNativeFloatBuffer(8);
     private final FloatBuffer mTexCoordBuffer = createNativeFloatBuffer(8);
 
+    public static final int MODE_WARM_UP = 0;
+    public static final int MODE_COOL_DOWN = 1;
+    public static final int MODE_BLANK = 2;
+
     public ElectronBeam(Display display) {
         mDisplay = display;
     }
@@ -98,16 +102,15 @@ final class ElectronBeam {
      * Warms up the electron beam in preparation for turning on or off.
      * This method prepares a GL context, and captures a screen shot.
      *
-     * @param warmUp True if the electron beam is about to be turned on, false if
-     * it is about to be turned off.
+     * @param mode The desired mode for the upcoming animation.
      * @return True if the electron beam is ready, false if it is uncontrollable.
      */
-    public boolean prepare(boolean warmUp) {
+    public boolean prepare(int mode) {
         if (DEBUG) {
-            Slog.d(TAG, "prepare: warmUp=" + warmUp);
+            Slog.d(TAG, "prepare: mode=" + mode);
         }
 
-        mWarmUp = warmUp;
+        mMode = mode;
 
         // Get the display size and adjust it for rotation.
         mDisplay.getDisplayInfo(mDisplayInfo);
@@ -123,17 +126,28 @@ final class ElectronBeam {
         }
 
         // Prepare the surface for drawing.
-        if (!createEglContext()
-                || !createEglSurface()
-                || !captureScreenshotTextureAndSetViewport()) {
+        if (!tryPrepare()) {
             dismiss();
             return false;
         }
 
+        // Done.
         mPrepared = true;
         return true;
     }
 
+    private boolean tryPrepare() {
+        if (createSurface()) {
+            if (mMode == MODE_BLANK) {
+                return true;
+            }
+            return createEglContext()
+                    && createEglSurface()
+                    && captureScreenshotTextureAndSetViewport();
+        }
+        return false;
+    }
+
     /**
      * Dismisses the electron beam animation surface and cleans up.
      *
@@ -148,6 +162,7 @@ final class ElectronBeam {
 
         destroyScreenshotTexture();
         destroyEglSurface();
+        destroySurface();
         mPrepared = false;
     }
 
@@ -163,6 +178,14 @@ final class ElectronBeam {
             Slog.d(TAG, "drawFrame: level=" + level);
         }
 
+        if (!mPrepared) {
+            return false;
+        }
+
+        if (mMode == MODE_BLANK) {
+            return showSurface(1.0f - level);
+        }
+
         if (!attachEglContext()) {
             return false;
         }
@@ -185,8 +208,7 @@ final class ElectronBeam {
         } finally {
             detachEglContext();
         }
-
-        return showEglSurface();
+        return showSurface(1.0f);
     }
 
     /**
@@ -217,7 +239,7 @@ final class ElectronBeam {
         // bind texture and set blending for drawing planes
         GLES10.glBindTexture(GLES10.GL_TEXTURE_2D, mTexNames[0]);
         GLES10.glTexEnvx(GLES10.GL_TEXTURE_ENV, GLES10.GL_TEXTURE_ENV_MODE,
-                mWarmUp ? GLES10.GL_MODULATE : GLES10.GL_REPLACE);
+                mMode == MODE_WARM_UP ? GLES10.GL_MODULATE : GLES10.GL_REPLACE);
         GLES10.glTexParameterx(GLES10.GL_TEXTURE_2D,
                 GLES10.GL_TEXTURE_MAG_FILTER, GLES10.GL_LINEAR);
         GLES10.glTexParameterx(GLES10.GL_TEXTURE_2D,
@@ -251,7 +273,7 @@ final class ElectronBeam {
         GLES10.glColorMask(true, true, true, true);
 
         // draw the white highlight (we use the last vertices)
-        if (!mWarmUp) {
+        if (mMode == MODE_COOL_DOWN) {
             GLES10.glColor4f(ag, ag, ag, 1.0f);
             GLES10.glDrawArrays(GLES10.GL_TRIANGLE_FAN, 0, 4);
         }
@@ -472,7 +494,7 @@ final class ElectronBeam {
         }
     }*/
 
-    private boolean createEglSurface() {
+    private boolean createSurface() {
         if (mSurfaceSession == null) {
             mSurfaceSession = new SurfaceSession();
         }
@@ -481,9 +503,15 @@ final class ElectronBeam {
         try {
             if (mSurface == null) {
                 try {
+                    int flags;
+                    if (mMode == MODE_BLANK) {
+                        flags = Surface.FX_SURFACE_DIM | Surface.HIDDEN;
+                    } else {
+                        flags = Surface.OPAQUE | Surface.HIDDEN;
+                    }
                     mSurface = new Surface(mSurfaceSession,
                             "ElectronBeam", mDisplayWidth, mDisplayHeight,
-                            PixelFormat.OPAQUE, Surface.OPAQUE | Surface.HIDDEN);
+                            PixelFormat.OPAQUE, flags);
                 } catch (Surface.OutOfResourcesException ex) {
                     Slog.e(TAG, "Unable to create surface.", ex);
                     return false;
@@ -514,7 +542,10 @@ final class ElectronBeam {
         } finally {
             Surface.closeTransaction();
         }
+        return true;
+    }
 
+    private boolean createEglSurface() {
         if (mEglSurface == null) {
             int[] eglSurfaceAttribList = new int[] {
                     EGL14.EGL_NONE
@@ -536,7 +567,9 @@ final class ElectronBeam {
             }
             mEglSurface = null;
         }
+    }
 
+    private void destroySurface() {
         if (mSurface != null) {
             Surface.openTransaction();
             try {
@@ -549,11 +582,12 @@ final class ElectronBeam {
         }
     }
 
-    private boolean showEglSurface() {
+    private boolean showSurface(float alpha) {
         if (!mSurfaceVisible) {
             Surface.openTransaction();
             try {
                 mSurface.setLayer(ELECTRON_BEAM_LAYER);
+                mSurface.setAlpha(alpha);
                 mSurface.show();
             } finally {
                 Surface.closeTransaction();
@@ -643,7 +677,7 @@ final class ElectronBeam {
         pw.println();
         pw.println("Electron Beam State:");
         pw.println("  mPrepared=" + mPrepared);
-        pw.println("  mWarmUp=" + mWarmUp);
+        pw.println("  mMode=" + mMode);
         pw.println("  mDisplayLayerStack=" + mDisplayLayerStack);
         pw.println("  mDisplayRotation=" + mDisplayRotation);
         pw.println("  mDisplayWidth=" + mDisplayWidth);
diff --git a/services/java/com/android/server/power/ScreenOnBlocker.java b/services/java/com/android/server/power/ScreenOnBlocker.java
index 2bf0bcf..dbbbc6d 100644
--- a/services/java/com/android/server/power/ScreenOnBlocker.java
+++ b/services/java/com/android/server/power/ScreenOnBlocker.java
@@ -18,7 +18,7 @@ package com.android.server.power;
 
 /**
  * Low-level screen on blocker mechanism which is used to keep the screen off
- * until the window manager is ready to show new content.
+ * or the contents of the screen hidden until the window manager is ready to show new content.
  */
 interface ScreenOnBlocker {
     /**