Android 12如何使锁屏界面状态栏ICON显示与桌面状态栏保持一致

1.相关类

• CollapsedStatusBarFragment.java
• StatusBar.java

2.原生隐藏控制逻辑
Android12 在锁屏界面开启时，状态栏显示电池电量，SIM状态和网络状态，隐藏掉了时间和通知等的显示(PanelView这些都会显示)
那么它是如何控制的呢？
在CollapsedStatusBarFragment.java中有一些flag可以控制，核心控制逻辑在adjustDisableFlags()方法中：

protected int adjustDisableFlags(int state) {
        boolean headsUpVisible = mStatusBarComponent.headsUpShouldBeVisible();
        if (headsUpVisible) {
            state |= DISABLE_CLOCK;
        }
		//下面的三个Flag就可以控制相关ICON显示
        if (!mKeyguardStateController.isLaunchTransitionFadingAway()
                && !mKeyguardStateController.isKeyguardFadingAway()
                && shouldHideNotificationIcons()
                && !(mStatusBarStateController.getState() == StatusBarState.KEYGUARD
                        && headsUpVisible)) {
            state |= DISABLE_NOTIFICATION_ICONS;
            state |= DISABLE_SYSTEM_INFO;
            state |= DISABLE_CLOCK;
        }


        if (mNetworkController != null && EncryptionHelper.IS_DATA_ENCRYPTED) {
            if (mNetworkController.hasEmergencyCryptKeeperText()) {
                state |= DISABLE_NOTIFICATION_ICONS;
            }
            if (!mNetworkController.isRadioOn()) {
                state |= DISABLE_SYSTEM_INFO;
            }
        }

        // The shelf will be hidden when dozing with a custom clock, we must show notification
        // icons in this occasion.
        if (mStatusBarStateController.isDozing()
                && mStatusBarComponent.getPanelController().hasCustomClock()) {
            state |= DISABLE_CLOCK | DISABLE_SYSTEM_INFO;
        }

        if (mOngoingCallController.hasOngoingCall()) {
            state &= ~DISABLE_ONGOING_CALL_CHIP;
        } else {
            state |= DISABLE_ONGOING_CALL_CHIP;
        }

        return state;
    }

那么它是如何被调用的呢？
StatusBar在初始化的时候，会调用makeStatusBarView()方法，而CollapsedStatusBarFragment就是在此时控制显示的：

	 protected void makeStatusBarView(@Nullable RegisterStatusBarResult result) {
 		... ...
 		FragmentHostManager.get(mPhoneStatusBarWindow)
                .addTagListener(CollapsedStatusBarFragment.TAG, (tag, fragment) -> {
                    CollapsedStatusBarFragment statusBarFragment =
                            (CollapsedStatusBarFragment) fragment;

                    PhoneStatusBarView oldStatusBarView = mStatusBarView;
                    mStatusBarView = (PhoneStatusBarView) statusBarFragment.getView();
                    mStatusBarView.setBar(this);
                    mStatusBarView.setPanel(mNotificationPanelViewController);
                    mStatusBarView.setScrimController(mScrimController);
                    mStatusBarView.setExpansionChangedListeners(mExpansionChangedListeners);
                    ... ...
                    }).getFragmentManager()
                .beginTransaction()
                .replace(R.id.status_bar_container,
                        new CollapsedStatusBarFragment(
                                mOngoingCallController,
                                mAnimationScheduler,
                                mStatusBarLocationPublisher,
                                mNotificationIconAreaController,
                                mFeatureFlags,
                                mStatusBarIconController,
                                mKeyguardStateController,
                                mNetworkController,
                                mStatusBarStateController,
                                this,
                                mCommandQueue
                        ),
                        CollapsedStatusBarFragment.TAG)
                .commit();
 }

而在显示过程中，会调用setPanelExpanded(boolean isExpanded)方法，该方法中updateHideIconsForBouncer(false );会通知CommandQueue控制Flag生效，调用到CollapsedStatusBarFragment的disable(…)方法，最后到核心逻辑adjustDisableFlags(…).

	public void setPanelExpanded(boolean isExpanded) {
        if (mPanelExpanded != isExpanded) {
            mNotificationLogger.onPanelExpandedChanged(isExpanded);
        }
        mPanelExpanded = isExpanded;
        updateHideIconsForBouncer(false );//控制隐藏
        mNotificationShadeWindowController.setPanelExpanded(isExpanded);
        mStatusBarStateController.setPanelExpanded(isExpanded);
        if (isExpanded && mStatusBarStateController.getState() != StatusBarState.KEYGUARD) {
            if (DEBUG) {
                Log.v(TAG, "clearing notification effects from Height");
            }
            clearNotificationEffects();
        }

        if (!isExpanded) {
            mRemoteInputManager.onPanelCollapsed();
        }
    }
    
	
    private void updateHideIconsForBouncer(boolean animate) {
        boolean hideBecauseApp = mTopHidesStatusBar && mIsOccluded
                && (mStatusBarWindowHidden || mBouncerShowing);
        boolean hideBecauseKeyguard = !mPanelExpanded && !mIsOccluded && mBouncerShowing;
        boolean shouldHideIconsForBouncer = hideBecauseApp || hideBecauseKeyguard;
        if (mHideIconsForBouncer != shouldHideIconsForBouncer) {
        	//注意这里将该值修改了，它会影响CollapsedStatusBarFragment:shouldHideNotificationIcons()
            mHideIconsForBouncer = shouldHideIconsForBouncer;

            if (!shouldHideIconsForBouncer && mBouncerWasShowingWhenHidden) {
                // We're delaying the showing, since most of the time the fullscreen app will
                // hide the icons again and we don't want them to fade in and out immediately again.
                mWereIconsJustHidden = true;
                mHandler.postDelayed(() -> {
                    mWereIconsJustHidden = false;
                    mCommandQueue.recomputeDisableFlags(mDisplayId, true);
                }, 500);
            } else {
                mCommandQueue.recomputeDisableFlags(mDisplayId, animate);//重新计算Flag并生效
            }
        }
        if (shouldHideIconsForBouncer) {
            mBouncerWasShowingWhenHidden = mBouncerShowing;
        }
    }

上面注释里提到的注意，会改变mStatusBarComponent.hideStatusBarIconsForBouncer()的值，也就会影响是否disable掉三种ICON显示

	private boolean shouldHideNotificationIcons() {
        if (!mStatusBar.isClosed() && mStatusBarComponent.hideStatusBarIconsWhenExpanded()) {
            return true;
        }
        if (mStatusBarComponent.hideStatusBarIconsForBouncer()) {
            return true;
        }
        return false;
    }

3.修改方法
上面的逻辑已经很清晰了，保证CollapsedStatusBarFragment.java不调用FLAG设置即可，具体如何还是看各位的需求。