Android4.4电源管理——屏幕亮度设置

最新推荐文章于 2021-05-27 11:13:16 发布

Vincent_ywj

最新推荐文章于 2021-05-27 11:13:16 发布

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CC 4.0 BY-SA版权

本文链接：https://blog.youkuaiyun.com/u010681466/article/details/19897851

本文详细阐述了屏幕状态切换及亮度调整的核心机制，包括显示功率状态管理、屏幕开闭控制、背光亮度设置等关键步骤，以及同步更新流程与状态通知机制。

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    private void initialize() {
    mPowerState = new DisplayPowerState(
                new ElectronBeam(mDisplayManager), mDisplayBlanker,
                mLights.getLight(LightsService.LIGHT_ID_BACKLIGHT));

}

private void setScreenOn(boolean on) {

        if (!mPowerState.isScreenOn() == on) {
            mPowerState.setScreenOn(on);
            if (on) {
                mNotifier.onScreenOn();
            } else {

mNotifier.onScreenOff();

}

    /**
     * Sets whether the screen is on or off.
     */
    public void setScreenOn(boolean on) {
        if (mScreenOn != on) {
            if (DEBUG) {
                Slog.d(TAG, "setScreenOn: on=" + on);
            }

            mScreenOn = on;
            mScreenReady = false;
            scheduleScreenUpdate();
        }
    }

    private void scheduleScreenUpdate() {
        if (!mScreenUpdatePending) {
            mScreenUpdatePending = true;
            postScreenUpdateThreadSafe();
        }
    }

    private void postScreenUpdateThreadSafe() {
        mHandler.removeCallbacks(mScreenUpdateRunnable);
        mHandler.post(mScreenUpdateRunnable);
    }

    private final Runnable mScreenUpdateRunnable = new Runnable() {
        @Override
        public void run() {
            mScreenUpdatePending = false;

            int brightness = mScreenOn && mElectronBeamLevel > 0f ? mScreenBrightness : 0;
            if (mPhotonicModulator.setState(mScreenOn, brightness)) {
                mScreenReady = true;
                invokeCleanListenerIfNeeded();
            }
        }
    };

        public boolean setState(boolean on, int backlight) {
            synchronized (mLock) {
                if (on != mPendingOn || backlight != mPendingBacklight) {
                    if (DEBUG) {
                        Slog.d(TAG, "Requesting new screen state: on=" + on
                                + ", backlight=" + backlight);
                    }

                    if (YulongFeature.FEATURE_YULONG) {
                        Slog.d(TAG, "Requesting new screen state: on=" + on
                                + ", backlight=" + backlight + ", mChangeInProgress=" + mChangeInProgress);
                    }

                    mPendingOn = on;
                    mPendingBacklight = backlight;

                    if (!mChangeInProgress) {
                        mChangeInProgress = true;
                        Slog.i(TAG, "setState : AsyncTask.THREAD_POOL_EXECUTOR.execute(mTask)");
                        AsyncTask.THREAD_POOL_EXECUTOR.execute(mTask);
                    }
                }
                return mChangeInProgress;
            }
        }

private final Runnable mTask = new Runnable() {

@Override

public void run() {

// Apply pending changes untildone.

for (;;) {

final boolean on;

final boolean onChanged;

final int backlight;

final booleanbacklightChanged;

synchronized (mLock) {

on = mPendingOn;

onChanged = (on !=mActualOn);

backlight = mPendingBacklight;

backlightChanged =(backlight != mActualBacklight);

if (!onChanged&& !backlightChanged) {

mChangeInProgress =false;

break;

}

mActualOn = on;

mActualBacklight =backlight;

}

if (onChanged &&on) {

mDisplayBlanker.unblankAllDisplays();

}

if (backlightChanged) {

mBacklight.setBrightness(backlight);

}

if (onChanged &&!on) {

mDisplayBlanker.blankAllDisplays();

}

// Let the outer class knowthat all changes have been applied.

postScreenUpdateThreadSafe();

}

};

        public void setBrightness(int brightness) {
            setBrightness(brightness, BRIGHTNESS_MODE_USER);
        }

        public void setBrightness(int brightness, int brightnessMode) {
            synchronized (this) {
                int color = brightness & 0x000000ff;
                color = 0xff000000 | (color << 16) | (color << 8) | color;
                setLightLocked(color, LIGHT_FLASH_NONE, 0, 0, brightnessMode);
            }
        }