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package com.android.internal.policy.impl;
import android.app.AlarmManager;
import android.app.PendingIntent;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.content.res.Resources;
import android.hardware.display.DisplayManager;
import android.hardware.display.DisplayManagerInternal;
import android.os.Handler;
import android.os.SystemClock;
import android.util.Log;
import android.view.Display;
import com.android.server.LocalServices;
import java.io.PrintWriter;
import java.util.concurrent.TimeUnit;
public class BurnInProtectionHelper implements DisplayManager.DisplayListener {
private static final String TAG = "BurnInProtection";
// Default value when max burnin radius is not set.
public static final int BURN_IN_RADIUS_MAX_DEFAULT = -1;
private static final long BURNIN_PROTECTION_WAKEUP_INTERVAL_MS = TimeUnit.MINUTES.toMillis(1);
private static final long BURNIN_PROTECTION_MINIMAL_INTERVAL_MS = TimeUnit.SECONDS.toMillis(10);
private static final String ACTION_BURN_IN_PROTECTION =
"android.internal.policy.action.BURN_IN_PROTECTION";
private static final int BURN_IN_SHIFT_STEP = 2;
private boolean mBurnInProtectionActive;
private final int mMinHorizontalBurnInOffset;
private final int mMaxHorizontalBurnInOffset;
private final int mMinVerticalBurnInOffset;
private final int mMaxVerticalBurnInOffset;
private final int mBurnInRadiusMaxSquared;
private int mLastBurnInXOffset = 0;
/* 1 means increasing, -1 means decreasing */
private int mXOffsetDirection = 1;
private int mLastBurnInYOffset = 0;
/* 1 means increasing, -1 means decreasing */
private int mYOffsetDirection = 1;
private final AlarmManager mAlarmManager;
private final PendingIntent mBurnInProtectionIntent;
private final DisplayManagerInternal mDisplayManagerInternal;
private final Display mDisplay;
private BroadcastReceiver mBurnInProtectionReceiver = new BroadcastReceiver() {
@Override
public void onReceive(Context context, Intent intent) {
updateBurnInProtection();
}
};
public BurnInProtectionHelper(Context context) {
final Resources resources = context.getResources();
mMinHorizontalBurnInOffset = resources.getInteger(
com.android.internal.R.integer.config_burnInProtectionMinHorizontalOffset);
mMaxHorizontalBurnInOffset = resources.getInteger(
com.android.internal.R.integer.config_burnInProtectionMaxHorizontalOffset);
mMinVerticalBurnInOffset = resources.getInteger(
com.android.internal.R.integer.config_burnInProtectionMinVerticalOffset);
mMaxVerticalBurnInOffset = resources.getInteger(
com.android.internal.R.integer.config_burnInProtectionMaxVerticalOffset);
int burnInRadiusMax = resources.getInteger(
com.android.internal.R.integer.config_burnInProtectionMaxRadius);
if (burnInRadiusMax != BURN_IN_RADIUS_MAX_DEFAULT) {
mBurnInRadiusMaxSquared = burnInRadiusMax * burnInRadiusMax;
} else {
mBurnInRadiusMaxSquared = BURN_IN_RADIUS_MAX_DEFAULT;
}
mDisplayManagerInternal = LocalServices.getService(DisplayManagerInternal.class);
mAlarmManager = (AlarmManager) context.getSystemService(Context.ALARM_SERVICE);
context.registerReceiver(mBurnInProtectionReceiver,
new IntentFilter(ACTION_BURN_IN_PROTECTION));
Intent intent = new Intent(ACTION_BURN_IN_PROTECTION);
intent.setPackage(context.getPackageName());
intent.setFlags(Intent.FLAG_RECEIVER_REGISTERED_ONLY);
mBurnInProtectionIntent = PendingIntent.getBroadcast(context, 0,
intent, PendingIntent.FLAG_UPDATE_CURRENT);
DisplayManager displayManager =
(DisplayManager) context.getSystemService(Context.DISPLAY_SERVICE);
mDisplay = displayManager.getDisplay(Display.DEFAULT_DISPLAY);
displayManager.registerDisplayListener(this, null /* handler */);
}
public void startBurnInProtection() {
if (!mBurnInProtectionActive) {
mBurnInProtectionActive = true;
updateBurnInProtection();
}
}
private void updateBurnInProtection() {
if (mBurnInProtectionActive) {
adjustOffsets();
mDisplayManagerInternal.setDisplayOffsets(mDisplay.getDisplayId(),
mLastBurnInXOffset, mLastBurnInYOffset);
// Next adjustment at least ten seconds in the future.
long next = SystemClock.elapsedRealtime() + BURNIN_PROTECTION_MINIMAL_INTERVAL_MS;
// And aligned to the minute.
next = next - next % BURNIN_PROTECTION_WAKEUP_INTERVAL_MS
+ BURNIN_PROTECTION_WAKEUP_INTERVAL_MS;
mAlarmManager.set(AlarmManager.ELAPSED_REALTIME, next, mBurnInProtectionIntent);
} else {
mAlarmManager.cancel(mBurnInProtectionIntent);
mDisplayManagerInternal.setDisplayOffsets(mDisplay.getDisplayId(), 0, 0);
}
}
public void cancelBurnInProtection() {
if (mBurnInProtectionActive) {
mBurnInProtectionActive = false;
updateBurnInProtection();
}
}
/**
* Gently shifts current burn-in offsets, minimizing the change for the user.
*
* Shifts are applied in following fashion:
* 1) shift horizontally from minimum to the maximum;
* 2) shift vertically by one from minimum to the maximum;
* 3) shift horizontally from maximum to the minimum;
* 4) shift vertically by one from minimum to the maximum.
* 5) if you reach the maximum vertically, start shifting back by one from maximum to minimum.
*
* On top of that, stay within specified radius. If the shift distance from the center is
* higher than the radius, skip these values and go the next position that is within the radius.
*/
private void adjustOffsets() {
do {
// By default, let's just shift the X offset.
final int xChange = mXOffsetDirection * BURN_IN_SHIFT_STEP;
mLastBurnInXOffset += xChange;
if (mLastBurnInXOffset > mMaxHorizontalBurnInOffset
|| mLastBurnInXOffset < mMinHorizontalBurnInOffset) {
// Whoops, we went too far horizontally. Let's retract..
mLastBurnInXOffset -= xChange;
// change horizontal direction..
mXOffsetDirection *= -1;
// and let's shift the Y offset.
final int yChange = mYOffsetDirection * BURN_IN_SHIFT_STEP;
mLastBurnInYOffset += yChange;
if (mLastBurnInYOffset > mMaxVerticalBurnInOffset
|| mLastBurnInYOffset < mMinVerticalBurnInOffset) {
// Whoops, we went to far vertically. Let's retract..
mLastBurnInYOffset -= yChange;
// and change vertical direction.
mYOffsetDirection *= -1;
}
}
// If we are outside of the radius, let's try again.
} while (mBurnInRadiusMaxSquared != BURN_IN_RADIUS_MAX_DEFAULT
&& mLastBurnInXOffset * mLastBurnInXOffset + mLastBurnInYOffset * mLastBurnInYOffset
> mBurnInRadiusMaxSquared);
}
public void dump(String prefix, PrintWriter pw) {
pw.println(prefix + TAG);
prefix += " ";
pw.println(prefix + "mBurnInProtectionActive=" + mBurnInProtectionActive);
pw.println(prefix + "mHorizontalBurnInOffsetsBounds=(" + mMinHorizontalBurnInOffset + ", "
+ mMaxHorizontalBurnInOffset + ")");
pw.println(prefix + "mVerticalBurnInOffsetsBounds=(" + mMinVerticalBurnInOffset + ", "
+ mMaxVerticalBurnInOffset + ")");
pw.println(prefix + "mBurnInRadiusMaxSquared=" + mBurnInRadiusMaxSquared);
pw.println(prefix + "mLastBurnInOffset=(" + mLastBurnInXOffset + ", "
+ mLastBurnInYOffset + ")");
pw.println(prefix + "mOfsetChangeDirections=(" + mXOffsetDirection + ", "
+ mYOffsetDirection + ")");
}
@Override
public void onDisplayAdded(int i) {
}
@Override
public void onDisplayRemoved(int i) {
}
@Override
public void onDisplayChanged(int displayId) {
if (displayId == mDisplay.getDisplayId()) {
if (mDisplay.getState() == Display.STATE_DOZE
|| mDisplay.getState() == Display.STATE_DOZE_SUSPEND) {
startBurnInProtection();
} else {
cancelBurnInProtection();
}
}
}
}
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