android7.0锁屏（二）上锁流程

上锁的主要是两个步骤

• 设备加密，这块主要是与android管理设备密码服务相关
• 显示锁屏界面，即展开通知面板，同时加载密码界面的布局，但是会隐藏起来，等到向上划去锁屏界面才显示
• 更新activity stack的状态，锁屏下的activity会被置为onstop
  执行上锁的流程是调用KeyguardViewMediator的doKeyguardLocked函数来完成的

private void doKeyguardLocked(Bundle options) {
        if (!mExternallyEnabled) {
            return;
        }
        // if the keyguard is already showing, don't bother
        if (mStatusBarKeyguardViewManager.isShowing()) {
            resetStateLocked();
            return;
        }
        if (!mustNotUnlockCurrentUser()  || !mUpdateMonitor.isDeviceProvisioned()) {
            final boolean requireSim = !SystemProperties.getBoolean("keyguard.no_require_sim", false);
            final boolean absent = SubscriptionManager.isValidSubscriptionId(
                    mUpdateMonitor.getNextSubIdForState(IccCardConstants.State.ABSENT));
            final boolean disabled = SubscriptionManager.isValidSubscriptionId(
                    mUpdateMonitor.getNextSubIdForState(IccCardConstants.State.PERM_DISABLED));
            final boolean lockedOrMissing = mUpdateMonitor.isSimPinSecure()
                    || ((absent || disabled) && requireSim);
            if (!lockedOrMissing && shouldWaitForProvisioning()) {
                return;
            }
            if (mLockPatternUtils.isLockScreenDisabled(KeyguardUpdateMonitor.getCurrentUser())
                    && !lockedOrMissing) {
                return;
            }
            if (mLockPatternUtils.checkVoldPassword(KeyguardUpdateMonitor.getCurrentUser())) {
                setShowingLocked(false);
                hideLocked();
                mUpdateMonitor.reportSuccessfulStrongAuthUnlockAttempt();
                return;
            }
        }
        showLocked(options);
    }

重点看这个showLocked函数，经过handler的传递会调到handleShow

private void handleShow(Bundle options) {
        final int currentUser = KeyguardUpdateMonitor.getCurrentUser();
        if (mLockPatternUtils.isSecure(currentUser)) {
            mLockPatternUtils.getDevicePolicyManager().reportKeyguardSecured(currentUser);  //更新设备加密状态
        }
        synchronized (KeyguardViewMediator.this) {
            if (!mSystemReady) {
                return;
            } else {
            }
            setShowingLocked(true);
            mStatusBarKeyguardViewManager.show(options); // 显示锁屏界面和加载bouncer
            mHiding = false;
            mWakeAndUnlocking = false;
            resetKeyguardDonePendingLocked();
            mHideAnimationRun = false;
            updateActivityLockScreenState(); // 更新activitystack的状态
            adjustStatusBarLocked();
            userActivity();
            mShowKeyguardWakeLock.release();
        }
        mKeyguardDisplayManager.show();
    }

继续看显示锁屏的函数

public void show(Bundle options) {
        mShowing = true;
        mStatusBarWindowManager.setKeyguardShowing(true); // 调整状态栏的窗口状态
        mScrimController.abortKeyguardFadingOut();
        reset();
    }

public void reset() {
        if (mShowing) {
            if (mOccluded) {// 特殊情况，例如来电，音乐锁屏等显示在锁屏界面上的activity
                mPhoneStatusBar.hideKeyguard();
                mPhoneStatusBar.stopWaitingForKeyguardExit();
                mBouncer.hide(false /* destroyView */);
            } else {
                showBouncerOrKeyguard();
            }
            KeyguardUpdateMonitor.getInstance(mContext).sendKeyguardReset();
            updateStates();
        }
    }

正常情况下都会调用到showBouncerOrKeyguard()

protected void showBouncerOrKeyguard() {
        if (mBouncer.needsFullscreenBouncer()) { // 存在锁定的sim卡会走到这里
            // The keyguard might be showing (already). So we need to hide it.
            mPhoneStatusBar.hideKeyguard();
            mBouncer.show(true /* resetSecuritySelection */);
        } else {
            mPhoneStatusBar.showKeyguard(); // 展开下拉面板
            mBouncer.hide(false /* destroyView */); // 隐藏bouncer
            mBouncer.prepare(); // 加载bouncer的布局
        }
    }

所以正常情况下就会调用上面三段函数，主要关注bouncer布局的加载
经过一系列调用，会到达KeyguardSecurityContainer的showPrimarySecurityScreen

void showPrimarySecurityScreen(boolean turningOff) {
        SecurityMode securityMode = mSecurityModel.getSecurityMode(); // 获取锁屏密码样式
        if (DEBUG) Log.v(TAG, "showPrimarySecurityScreen(turningOff=" + turningOff + ")");
        showSecurityScreen(securityMode); // 加载具体的布局
    }

private void showSecurityScreen(SecurityMode securityMode) {
        if (securityMode == mCurrentSecuritySelection) return;
        KeyguardSecurityView oldView = getSecurityView(mCurrentSecuritySelection);
        KeyguardSecurityView newView = getSecurityView(securityMode);

        // Emulate Activity life cycle
        if (oldView != null) {
            oldView.onPause();
            oldView.setKeyguardCallback(mNullCallback); // ignore requests from old view
        }
        if (securityMode != SecurityMode.None) {
            newView.onResume(KeyguardSecurityView.VIEW_REVEALED);
            newView.setKeyguardCallback(mCallback);
        }
        // Find and show this child.
        final int childCount = mSecurityViewFlipper.getChildCount();
        final int securityViewIdForMode = getSecurityViewIdForMode(securityMode);
        for (int i = 0; i < childCount; i++) {
            if (mSecurityViewFlipper.getChildAt(i).getId() == securityViewIdForMode) {
                mSecurityViewFlipper.setDisplayedChild(i);
                break;
            }
        }
        mCurrentSecuritySelection = securityMode;
        mSecurityCallback.onSecurityModeChanged(securityMode,
                securityMode != SecurityMode.None && newView.needsInput());
    }

最后，通过锁定方式来找到对应的布局，就完成的bouncer的加载，划去锁屏界面后就可以看到了

private int getSecurityViewIdForMode(SecurityMode securityMode) {
        switch (securityMode) {
            case Pattern: return R.id.keyguard_pattern_view;
            case PIN: return R.id.keyguard_pin_view;
            case Password: return R.id.keyguard_password_view;
            case SimPin: return R.id.keyguard_sim_pin_view;
            case SimPuk: return R.id.keyguard_sim_puk_view;
        }
        return 0;
    }

放一张时序图

image.png