Android源码学习----状态栏（1）SignalClusterView

// Intimately tied to the design of res/layout/signal_cluster_view.xml
public class SignalClusterView extends LinearLayout implements NetworkControllerImpl.SignalCallback,
        SecurityController.SecurityControllerCallback, Tunable, DarkReceiver {
    //   Vpn  wifi 飞行模式图标 

    private final NetworkController mNetworkController;
    private final SecurityController mSecurityController;

    //省略
    private ArrayList mPhoneStates = new ArrayList();

    //省略
    ViewGroup mEthernetGroup, mWifiGroup;
    ImageView mVpn, mEthernet, mWifi, mAirplane, mEthernetDark, mWifiDark;
    ImageView mWifiActivityIn, mWifiActivityOut;
    View mWifiAirplaneSpacer, mWifiSignalSpacer;
    LinearLayout mMobileSignalGroup;

路径是 /frameworks/base/packages/SystemUI/src/com/android/systemui/statusbar/SignalClusterView.java

可以看出来是LineLayout的子类 ，里面重写了onLayout方法，onLayout调用了super.onLayout方法和applyIconTint()方法.

applyIconTint()方法里面就是对view的设置

private void applyIconTint() {
        setTint(mVpn, DarkIconDispatcher.getTint(mTintArea, mVpn, mIconTint));
        //省略
        applyDarkIntensity(
                DarkIconDispatcher.getDarkIntensity(mTintArea, mEthernet, mDarkIntensity),
                mEthernet, mEthernetDark);
        for (int i = 0; i < mPhoneStates.size(); i++) {
            mPhoneStates.get(i).setIconTint(mIconTint, mDarkIntensity, mTintArea);
        }
    }
    //设置透明度
    private void applyDarkIntensity(float darkIntensity, View lightIcon, View darkIcon) {
        lightIcon.setAlpha(1 - darkIntensity);
        darkIcon.setAlpha(darkIntensity);
    }
    // 为图片设置渲染颜色.
    private void setTint(ImageView v, int tint) {
        v.setImageTintList(ColorStateList.valueOf(tint));
    }

view的初始化：

 @Override
    protected void onFinishInflate() {
        super.onFinishInflate();
        //findview组件
        mVpn            = findViewById(R.id.);
        mEthernetGroup  = findViewById(R.id.ethernet_combo);
        mEthernet       = findViewById(R.id.ethernet);
        //省略
        maybeScaleVpnAndNoSimsIcons();
    }

    /**
     * Extracts the icon off of the VPN and no sims views and maybe scale them by
     * {@link #mIconScaleFactor}. Note that the other icons are not scaled here because         
     * they are  dynamic. As such, they need to be scaled each time the icon changes in {@link #apply()}. 
     */
    private void maybeScaleVpnAndNoSimsIcons() {
        if (mIconScaleFactor == 1.f) {
            return;
        }

        mVpn.setImageDrawable(new ScalingDrawableWrapper(mVpn.getDrawable(), mIconScaleFactor));
    }

maybeScaleVpnAndNoSimsIcons（）上面的注释是说：  从中提取图标，不显示sims视图，并按比例缩放 {@link miconscalefactor}。请注意，其他图标在此不缩放，因为它们是动态的因此，每次在{@link apply（）中更改图标时，都需要缩放它们。

   
  apply() 是一个私有方法，上面有一个注释   // Run after each indicator change. 也就是 每次指标变化后运行，里面内容就是对一些View的设置，那么调用apply()的地方有

    @Override
    public void setIsAirplaneMode(IconState icon) {//飞行模式
        mIsAirplaneMode = icon.visible && !mBlockAirplane;
        mAirplaneIconId = icon.icon;
        mAirplaneContentDescription = icon.contentDescription;

        apply();
    }
    @Override
    public void onRtlPropertiesChanged(int layoutDirection) {
    //省略
    }

    @Override
    protected void onAttachedToWindow() {//连接到window
        super.onAttachedToWindow();
        mVpnVisible = mSecurityController.isVpnEnabled();
        mVpnIconId = currentVpnIconId(mSecurityController.isVpnBranded());

        for (PhoneState state : mPhoneStates) {
            if (state.mMobileGroup.getParent() == null) {
                mMobileSignalGroup.addView(state.mMobileGroup);
            }
        }

        int endPadding = mMobileSignalGroup.getChildCount() > 0 ? mMobileSignalGroupEndPadding : 0;
        mMobileSignalGroup.setPaddingRelative(0, 0, endPadding, 0);

        Dependency.get(TunerService.class).addTunable(this, StatusBarIconController.ICON_BLACKLIST);

        apply();
        applyIconTint();
        mNetworkController.addCallback(this);
        mSecurityController.addCallback(this);
    }

    @Override
    public void setWifiIndicators(...) {//wifi
    }

    @Override
    public void setMobileDataIndicators(...); //信号等等数据
    }
    @Override
    public void setEthernetIndicators(IconState state) {//设置以太网指示器
    }

回到applyIconTint()方法，mPhoneStates是PhoneState的集合，源码里面PhoneState是内部类， 

 public PhoneState(int subId, Context context) {
            ViewGroup root = (ViewGroup) LayoutInflater.from(context)
                    .inflate(R.layout.mobile_signal_group, null);
            setViews(root);
            mSubId = subId;
        }

        public void setViews(ViewGroup root) {
            mMobileGroup    = root;
            mMobile         = root.findViewById(R.id.mobile_signal);
            mMobileType     = root.findViewById(R.id.mobile_type);
            mMobileRoaming  = root.findViewById(R.id.mobile_roaming);
            mMobileRoamingSpace  = root.findViewById(R.id.mobile_roaming_space);
            mMobileActivityIn = root.findViewById(R.id.mobile_in);
            mMobileActivityOut = root.findViewById(R.id.mobile_out);
            mMobileSignalDrawable = new SignalDrawable(mMobile.getContext());
            mMobile.setImageDrawable(mMobileSignalDrawable);
        }