SystemUI源码分析相关文章

Android8.1 MTK平台 SystemUI源码分析之 Notification流程

分析之前再贴一下 StatusBar 相关类图

电池图标刷新

从上篇的分析得到电池图标对应的布局为 SystemUI\src\com\android\systemui\BatteryMeterView.java

先从构造方法入手

public BatteryMeterView(Context context, AttributeSet attrs, int defStyle) {
    super(context, attrs, defStyle);
    setOrientation(LinearLayout.HORIZONTAL);
    setGravity(Gravity.CENTER_VERTICAL | Gravity.START);
    TypedArray atts = context.obtainStyledAttributes(attrs, R.styleable.BatteryMeterView,
            defStyle, 0);
    final int frameColor = atts.getColor(R.styleable.BatteryMeterView_frameColor,
            context.getColor(R.color.meter_background_color));
    mDrawable = new BatteryMeterDrawableBase(context, frameColor);
    atts.recycle();
    mSettingObserver = new SettingObserver(new Handler(context.getMainLooper()));
    mSlotBattery = context.getString(
            com.android.internal.R.string.status_bar_battery);
    mBatteryIconView = new ImageView(context);
    mBatteryIconView.setImageDrawable(mDrawable);
    final MarginLayoutParams mlp = new MarginLayoutParams(
            getResources().getDimensionPixelSize(R.dimen.status_bar_battery_icon_width),
            getResources().getDimensionPixelSize(R.dimen.status_bar_battery_icon_height));
    mlp.setMargins(0, 0, 0,
            getResources().getDimensionPixelOffset(R.dimen.battery_margin_bottom));
    addView(mBatteryIconView, mlp);
    updateShowPercent();
    Context dualToneDarkTheme = new ContextThemeWrapper(context,
            Utils.getThemeAttr(context, R.attr.darkIconTheme));
    Context dualToneLightTheme = new ContextThemeWrapper(context,
            Utils.getThemeAttr(context, R.attr.lightIconTheme));
    mDarkModeBackgroundColor = Utils.getColorAttr(dualToneDarkTheme, R.attr.backgroundColor);
    mDarkModeFillColor = Utils.getColorAttr(dualToneDarkTheme, R.attr.fillColor);
    mLightModeBackgroundColor = Utils.getColorAttr(dualToneLightTheme, R.attr.backgroundColor);
    mLightModeFillColor = Utils.getColorAttr(dualToneLightTheme, R.attr.fillColor);
    // Init to not dark at all.
    onDarkChanged(new Rect(), 0, DarkIconDispatcher.DEFAULT_ICON_TINT);
    mUserTracker = new CurrentUserTracker(mContext) {
        @Override
        public void onUserSwitched(int newUserId) {
            mUser = newUserId;
            getContext().getContentResolver().unregisterContentObserver(mSettingObserver);
            getContext().getContentResolver().registerContentObserver(
                    Settings.System.getUriFor(SHOW_BATTERY_PERCENT), false, mSettingObserver,
                    newUserId);
        }
    };
}

先说下 BatteryMeterView 继承自 LinearLayout，从上面的构造方法可以看出，我们看到的电池图标是由两部分组成的，

电量百分比(TextView)和电池等级(ImageView),构造方法主要做了如下几个操作

初始化电池等级icon，对应的drawable为 BatteryMeterDrawableBase，packages\apps\SettingsLib\src\com\android\settingslib\graph\BatteryMeterDrawableBase.java 将电池等级添加到父布局中
设置 Settings.System.SHOW_BATTERY_PERCENT 监听，当用户点击了显示电量百分比开关，则调用 updateShowPercent()方法在电池等级前添加电量百分比
通过onDarkChanged()设置默认的电池布局的主题色，当状态栏主题发生改变时，电池布局会做相应的更换(亮色和暗色切换)

在 PhoneStatusBarView 中添加了DarkReceiver监听，最终调用到 BatteryMeterView 的onDarkChanged()方法

修改百分比的字体颜色和电池等级的画笔颜色和背景颜色

// PhoneStatusBarView
@Override
protected void onAttachedToWindow() {
    super.onAttachedToWindow();
    // Always have Battery meters in the status bar observe the dark/light modes.
    Dependency.get(DarkIconDispatcher.class).addDarkReceiver(mBattery);
}
@Override
protected void onDetachedFromWindow() {
    super.onDetachedFromWindow();
    Dependency.get(DarkIconDispatcher.class).removeDarkReceiver(mBattery);
}
/BatteryMeterView
public void onDarkChanged(Rect area, float darkIntensity, int tint) {
    mDarkIntensity = darkIntensity;
    float intensity = DarkIconDispatcher.isInArea(area, this) ? darkIntensity : 0;
    int foreground = getColorForDarkIntensity(intensity, mLightModeFillColor,
            mDarkModeFillColor);
    int background = getColorForDarkIntensity(intensity, mLightModeBackgroundColor,
            mDarkModeBackgroundColor);
    mDrawable.setColors(foreground, background);
    setTextColor(foreground);
}

BatteryMeterDrawableBase 是一个自定义 Drawable，通过path来绘制电池图标，感兴趣的可自行研究

BatteryMeterView 中添加了电量改变监听，来看下 onBatteryLevelChanged()

 @Override
public void onBatteryLevelChanged(int level, boolean pluggedIn, boolean charging) {
    mDrawable.setBatteryLevel(level);
    // M: In case battery protection, it stop charging, but still plugged, it will
    // also wrongly show the charging icon.
    mDrawable.setCharging(pluggedIn && charging);
    mLevel = level;
    updatePercentText();
    setContentDescription(
            getContext().getString(charging ? R.string.accessibility_battery_level_charging
                    : R.string.accessibility_battery_level, level));
}
@Override
public void onPowerSaveChanged(boolean isPowerSave) {
    mDrawable.setPowerSave(isPowerSave);
}

setBatteryLevel()根据当前 level/100f 计算百分比绘制path，setCharging()是否绘制充电中闪电形状图标

电池状态改变流程

我们都知道电池状态改变是通过广播的方式接受的(Intent.ACTION_BATTERY_CHANGED),搜索找到 BatteryControllerImpl

SystemUI\src\com\android\systemui\statusbar\policy\BatteryControllerImpl.java

 @Override
public void onReceive(final Context context, Intent intent) {
    final String action = intent.getAction();
    if (action.equals(Intent.ACTION_BATTERY_CHANGED)) {
        if (mTestmode && !intent.getBooleanExtra("testmode", false)) return;
        mHasReceivedBattery = true;
        mLevel = (int)(100f
                * intent.getIntExtra(BatteryManager.EXTRA_LEVEL, 0)
                / intent.getIntExtra(BatteryManager.EXTRA_SCALE, 100));
        mPluggedIn = intent.getIntExtra(BatteryManager.EXTRA_PLUGGED, 0) != 0;
        final int status = intent.getIntExtra(BatteryManager.EXTRA_STATUS,
                BatteryManager.BATTERY_STATUS_UNKNOWN);
        mCharged = status == BatteryManager.BATTERY_STATUS_FULL;
        mCharging = mCharged || status == BatteryManager.BATTERY_STATUS_CHARGING;
        fireBatteryLevelChanged();
    }
  .......
}
 protected void fireBatteryLevelChanged() {
    synchronized (mChangeCallbacks) {
        final int N = mChangeCallbacks.size();
        for (int i = 0; i < N; i++) {
            mChangeCallbacks.get(i).onBatteryLevelChanged(mLevel, mPluggedIn, mCharging);
        }
    }
}

收到广播后通过 fireBatteryLevelChanged() 遍历回调监听，将状态参数发送。 BatteryMeterView实现了 BatteryStateChangeCallback,

收到改变监听 onBatteryLevelChanged()

android系统电池部分的驱动程序，继承了传统linux系统下的Power Supply驱动程序架构，Battery驱动程序通过Power Supply驱动程序生成相应的sys文件系统，

从而向用户空间提供电池各种属性的接口，然后遍历整个文件夹，查找各个能源供应设备的各种属性

Android的Linux 内核中的电池驱动会提供如下sysfs接口给framework：

/sys/class/power_supply/ac/onlineAC 电源连接状态

/sys/class/power_supply/usb/onlineUSB 电源连接状态

/sys/class/power_supply/battery/status 充电状态

/sys/class/power_supply/battery/health 电池状态

/sys/class/power_supply/battery/present 使用状态

/sys/class/power_supply/battery/capacity 电池 level

/sys/class/power_supply/battery/batt_vol 电池电压

/sys/class/power_supply/battery/batt_temp 电池温度

/sys/class/power_supply/battery/technology 电池技术

当供电设备的状态发生变化时，driver会更新这些文件，然后通过jni中的本地方法 android_server_BatteryService_update 向 java 层发送信息。

当监听到 power_supply 变化的消息后， nativeUpdate 函数就会重新读取以上sysfs文件获得当前状态。

而在用户层则是在 BatteryService.java 中通过广播的方式将电池相关的属性上报给上层app使用。

frameworks\base\services\core\java\com\android\server\BatteryService.java

BatteryService 在SystemServer.java 中创建，BatteryService 是在系统启动的时候就跑起来的，

为电池及充电相关的服务，主要作了如下几件事情: 监听 UEvent、读取sysfs 中的状态、发出广播 Intent.ACTION_BATTERY_CHANGED 通知上层

BatteryService 的 start()中注册 BatteryListener，当battery配置改变的时候，调用 update()

private final class BatteryListener extends IBatteryPropertiesListener.Stub {
    @Override public void batteryPropertiesChanged(BatteryProperties props) {
        final long identity = Binder.clearCallingIdentity();
        try {
            BatteryService.this.update(props);
        } finally {
            Binder.restoreCallingIdentity(identity);
        }
   }
}
private void update(BatteryProperties props) {
    synchronized (mLock) {
        if (!mUpdatesStopped) {
            mBatteryProps = props;
            // Process the new values.
            processValuesLocked(false);
        } else {
            mLastBatteryProps.set(props);
        }
    }
}
 private void processValuesLocked(boolean force) {
    boolean logOutlier = false;
    long dischargeDuration = 0;
  ...
  sendIntentLocked();
  .....
}
//发送 ACTION_BATTERY_CHANGED 广播
private void sendIntentLocked() {
    //  Pack up the values and broadcast them to everyone
    final Intent intent = new Intent(Intent.ACTION_BATTERY_CHANGED);
    intent.addFlags(Intent.FLAG_RECEIVER_REGISTERED_ONLY
            | Intent.FLAG_RECEIVER_REPLACE_PENDING);
    int icon = getIconLocked(mBatteryProps.batteryLevel);
    intent.putExtra(BatteryManager.EXTRA_SEQUENCE, mSequence);
    intent.putExtra(BatteryManager.EXTRA_STATUS, mBatteryProps.batteryStatus);
    intent.putExtra(BatteryManager.EXTRA_HEALTH, mBatteryProps.batteryHealth);
    intent.putExtra(BatteryManager.EXTRA_PRESENT, mBatteryProps.batteryPresent);
    intent.putExtra(BatteryManager.EXTRA_LEVEL, mBatteryProps.batteryLevel);
    intent.putExtra(BatteryManager.EXTRA_SCALE, BATTERY_SCALE);
    intent.putExtra(BatteryManager.EXTRA_ICON_SMALL, icon);
    intent.putExtra(BatteryManager.EXTRA_PLUGGED, mPlugType);
    intent.putExtra(BatteryManager.EXTRA_VOLTAGE, mBatteryProps.batteryVoltage);
    intent.putExtra(BatteryManager.EXTRA_TEMPERATURE, mBatteryProps.batteryTemperature);
    intent.putExtra(BatteryManager.EXTRA_TECHNOLOGY, mBatteryProps.batteryTechnology);
    intent.putExtra(BatteryManager.EXTRA_INVALID_CHARGER, mInvalidCharger);
    intent.putExtra(BatteryManager.EXTRA_MAX_CHARGING_CURRENT, mBatteryProps.maxChargingCurrent);
    intent.putExtra(BatteryManager.EXTRA_MAX_CHARGING_VOLTAGE, mBatteryProps.maxChargingVoltage);
    intent.putExtra(BatteryManager.EXTRA_CHARGE_COUNTER, mBatteryProps.batteryChargeCounter);
    mHandler.post(new Runnable() {
        @Override
        public void run() {
            ActivityManager.broadcastStickyIntent(intent, UserHandle.USER_ALL);
        }
    });
}

读取电池状态 cat /sys/class/power_supply/battery/uevent

时钟图标刷新

从 status_bar.xml 中看到时钟是一个自定义view， com.android.systemui.statusbar.policy.Clock

查看 Clock 源码知道继承自 TextView，时间内容更新通过setText()，通过监听如下5种广播修改时间显示

@Override
protected void onAttachedToWindow() {
    super.onAttachedToWindow();
    if (!mAttached) {
        mAttached = true;
        IntentFilter filter = new IntentFilter();
        filter.addAction(Intent.ACTION_TIME_TICK);
        filter.addAction(Intent.ACTION_TIME_CHANGED);
        filter.addAction(Intent.ACTION_TIMEZONE_CHANGED);
        filter.addAction(Intent.ACTION_CONFIGURATION_CHANGED);
        filter.addAction(Intent.ACTION_USER_SWITCHED);
        getContext().registerReceiverAsUser(mIntentReceiver, UserHandle.ALL, filter,
                null, Dependency.get(Dependency.TIME_TICK_HANDLER));
        Dependency.get(TunerService.class).addTunable(this, CLOCK_SECONDS,
                StatusBarIconController.ICON_BLACKLIST);
        SysUiServiceProvider.getComponent(getContext(), CommandQueue.class).addCallbacks(this);
        if (mShowDark) {
            Dependency.get(DarkIconDispatcher.class).addDarkReceiver(this);
        }
    }
    // NOTE: It's safe to do these after registering the receiver since the receiver always runs
    // in the main thread, therefore the receiver can't run before this method returns.
    // The time zone may have changed while the receiver wasn't registered, so update the Time
    mCalendar = Calendar.getInstance(TimeZone.getDefault());
    // Make sure we update to the current time
    updateClock();
    updateShowSeconds();
}

可以看到 mIntentReceiver 监听了5种类型的action

Intent.ACTION_TIME_TICK 时钟频率，1分钟一次

Intent.ACTION_TIME_CHANGED 时钟改变，用户在设置中修改了设置时间选项

Intent.ACTION_TIMEZONE_CHANGED 时区改变，用户在设置中修改了选择时区

Intent.ACTION_CONFIGURATION_CHANGED 系统配置改变，如修改系统语言、系统屏幕方向发生改变

Intent.ACTION_USER_SWITCHED 切换用户，机主或其它访客之间切换

我们看到系统设置界面中的使用24小时制开关，点击后时间会立马改变显示，就是通过发送 ACTION_TIME_CHANGED 广播，

携带 EXTRA_TIME_PREF_24_HOUR_FORMAT 参数，下面是核心代码

vendor\mediatek\proprietary\packages\apps\MtkSettings\src\com\android\settings\datetime\TimeFormatPreferenceController.java

private void set24Hour(boolean is24Hour) {
    Settings.System.putString(mContext.getContentResolver(),
            Settings.System.TIME_12_24,
            is24Hour ? HOURS_24 : HOURS_12);
}
private void timeUpdated(boolean is24Hour) {
    Intent timeChanged = new Intent(Intent.ACTION_TIME_CHANGED);
    int timeFormatPreference =
            is24Hour ? Intent.EXTRA_TIME_PREF_VALUE_USE_24_HOUR
                    : Intent.EXTRA_TIME_PREF_VALUE_USE_12_HOUR;
    timeChanged.putExtra(Intent.EXTRA_TIME_PREF_24_HOUR_FORMAT, timeFormatPreference);
    mContext.sendBroadcast(timeChanged);
}

回到 Clock.java 中，发现 EXTRA_TIME_PREF_24_HOUR_FORMAT 并没有被用上，继续深究代码

 final void updateClock() {
    if (mDemoMode) return;
    mCalendar.setTimeInMillis(System.currentTimeMillis());
    setText(getSmallTime());
    setContentDescription(mContentDescriptionFormat.format(mCalendar.getTime()));
}

收到广播最终都会调用 updateClock()，可以看到真正设置时间是通过 getSmallTime() 这个核心方法

private final CharSequence getSmallTime() {
    Context context = getContext();
    boolean is24 = DateFormat.is24HourFormat(context, ActivityManager.getCurrentUser());
    LocaleData d = LocaleData.get(context.getResources().getConfiguration().locale);
    final char MAGIC1 = '\uEF00';
    final char MAGIC2 = '\uEF01';
    SimpleDateFormat sdf;
    String format = mShowSeconds
            ? is24 ? d.timeFormat_Hms : d.timeFormat_hms
            : is24 ? d.timeFormat_Hm : d.timeFormat_hm;
    if (!format.equals(mClockFormatString)) {
        mContentDescriptionFormat = new SimpleDateFormat(format);
        /*
         * Search for an unquoted "a" in the format string, so we can
         * add dummy characters around it to let us find it again after
         * formatting and change its size.
         */
        if (mAmPmStyle != AM_PM_STYLE_NORMAL) {
            int a = -1;
            boolean quoted = false;
            for (int i = 0; i < format.length(); i++) {
                char c = format.charAt(i);
                if (c == '\'') {
                    quoted = !quoted;
                }
                if (!quoted && c == 'a') {
                    a = i;
                    break;
                }
            }
            if (a >= 0) {
                // Move a back so any whitespace before AM/PM is also in the alternate size.
                final int b = a;
                while (a > 0 && Character.isWhitespace(format.charAt(a-1))) {
                    a--;
                }
                format = format.substring(0, a) + MAGIC1 + format.substring(a, b)
                    + "a" + MAGIC2 + format.substring(b + 1);
            }
        }
        mClockFormat = sdf = new SimpleDateFormat(format);
        mClockFormatString = format;
    } else {
        sdf = mClockFormat;
    }
    String result = sdf.format(mCalendar.getTime());
    if (mAmPmStyle != AM_PM_STYLE_NORMAL) {
        int magic1 = result.indexOf(MAGIC1);
        int magic2 = result.indexOf(MAGIC2);
        if (magic1 >= 0 && magic2 > magic1) {
            SpannableStringBuilder formatted = new SpannableStringBuilder(result);
            if (mAmPmStyle == AM_PM_STYLE_GONE) {
                formatted.delete(magic1, magic2+1);
            } else {
                if (mAmPmStyle == AM_PM_STYLE_SMALL) {
                    CharacterStyle style = new RelativeSizeSpan(0.7f);
                    formatted.setSpan(style, magic1, magic2,
                                      Spannable.SPAN_EXCLUSIVE_INCLUSIVE);
                }
                formatted.delete(magic2, magic2 + 1);
                formatted.delete(magic1, magic1 + 1);
            }
            return formatted;
        }
    }
    return result;
}

方法有点长，我们挑主要的分析一下，DateFormat.is24HourFormat() 最终通过读取 Settings.System.TIME_12_24值，

这个值正好在上面的 TimeFormatPreferenceController 中点击24小时开关是改变，如果这个值为null，则通过获取本地时间

Local 来获取当前时间格式，如果等于24则返回true，该方法的源码可在AS中点进去查看，此处就不贴了。

LocaleData 是一个时间格式管理类，在 DateUtils.java 和 SimpleDateFormat.java 中都频繁使用

接下来获取到的 format 为 d.timeFormat_Hm，设置给 SimpleDateFormat(d.timeFormat_Hm)

String result = sdf.format(mCalendar.getTime());就是当前需要显示的时间，此处还需要做一下格式化

mAmPmStyle 是通过构造函数自定义属性赋值的，xml中并没有赋值，取默认值 AM_PM_STYLE_GONE，走这段代码

formatted.delete(magic1, magic2+1); 去除多余的 ‘\uEF00’ 和 ‘\uEF01’，最终显示的就是 formatted。

参考文章

https://blog.csdn.net/weilaideta/article/details/51760434

https://blog.csdn.net/W1107101310/article/details/80211885

Android8.1 MTK平台 SystemUI源码分析之电池时钟刷新

电池图标刷新

电池状态改变流程

时钟图标刷新

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Android8.1 MTK平台 SystemUI源码分析之电池时钟刷新