Android 镜像模式和扩展模式区别探讨-Android14

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1、副屏锁屏界面模式

属于 扩展模式 ，非镜像模式。LogicalDisplay.java#configureDisplayLocked 添加日志显示mHasContent=true，表明副屏添加了单独的界面。

2、副屏锁屏界面

SystemUI中KeyguardDisplayManager.java里 isKeyguardShowable 判断锁屏界面是否添加KeyguardPresentation；默认主屏DEFAULT_DISPLAY不会添加

frameworks/base/packages/SystemUI/src/com/android/keyguard/KeyguardDisplayManager.java

private boolean isKeyguardShowable(Display display) {if (display == null) {if (DEBUG) Log.i(TAG, "Cannot show Keyguard on null display");return false;}if (display.getDisplayId() == mDisplayTracker.getDefaultDisplayId()) {if (DEBUG) Log.i(TAG, "Do not show KeyguardPresentation on the default display");return false;}display.getDisplayInfo(mTmpDisplayInfo);if ((mTmpDisplayInfo.flags & Display.FLAG_PRIVATE) != 0) {if (DEBUG) Log.i(TAG, "Do not show KeyguardPresentation on a private display");return false;}if ((mTmpDisplayInfo.flags & Display.FLAG_ALWAYS_UNLOCKED) != 0) {if (DEBUG) {Log.i(TAG, "Do not show KeyguardPresentation on an unlocked display");}return false;}if (mKeyguardStateController.isOccluded()&& mDeviceStateHelper.isConcurrentDisplayActive(display)) {if (DEBUG) {// When activities with FLAG_SHOW_WHEN_LOCKED are shown on top of Keyguard, the// Keyguard state becomes "occluded". In this case, we should not show the// KeyguardPresentation, since the activity is presenting content onto the// non-default display.Log.i(TAG, "Do not show KeyguardPresentation when occluded and concurrent"+ " display is active");}return false;}return true;
}/**
* @param display The display to show the presentation on.
* @return {@code true} if a presentation was added.
*         {@code false} if the presentation cannot be added on that display or the presentation
*         was already there.
*/
private boolean showPresentation(Display display) {if (!isKeyguardShowable(display)) return false;if (DEBUG) Log.i(TAG, "Keyguard enabled on display: " + display);final int displayId = display.getDisplayId();Presentation presentation = mPresentations.get(displayId);if (presentation == null) {final Presentation newPresentation = createPresentation(display);newPresentation.setOnDismissListener(dialog -> {if (newPresentation.equals(mPresentations.get(displayId))) {mPresentations.remove(displayId);}});presentation = newPresentation;try {presentation.show();} catch (WindowManager.InvalidDisplayException ex) {Log.w(TAG, "Invalid display:", ex);presentation = null;}if (presentation != null) {mPresentations.append(displayId, presentation);return true;}}return false;
}

KeyguardPresentation_83">2.1 添加KeyguardPresentation

KeyguardPresentation继承Presentation，根据副屏对应Display信息 createDisplayContext 创建对应的Context添加对应的副屏上。

frameworks/base/packages/SystemUI/src/com/android/keyguard/KeyguardDisplayManager.java

KeyguardPresentation createPresentation(Display display) {return new KeyguardPresentation(mContext, display, mKeyguardStatusViewComponentFactory);
}

frameworks/base/core/java/android/app/Presentation.java

private static Context createPresentationContext(Context outerContext, Display display, int theme, @WindowType int type) {if (outerContext == null) {throw new IllegalArgumentException("outerContext must not be null");}if (display == null) {throw new IllegalArgumentException("display must not be null");}Context windowContext = outerContext.createDisplayContext(display).createWindowContext(getWindowType(type, display), null /* options */);if (theme == 0) {TypedValue outValue = new TypedValue();windowContext.getTheme().resolveAttribute(com.android.internal.R.attr.presentationTheme, outValue, true);theme = outValue.resourceId;}return new ContextThemeWrapper(windowContext, theme);
}

2.2 副屏同步主屏锁屏界面

副屏同步主屏锁屏界面就不需要显示KeyguardPresentation，需要在KeyguardDisplayManager.java#isKeyguardShowable判断，可以判断display.getDisplayId() > mDisplayTracker.getDefaultDisplayId()副屏返回false不添加界面；这里需要注意 CTS会失败 。