一）需求-场景

Android13 实现允许桌面自动旋转
Android13 版本开始后，支持屏幕自动旋转，优化体验和兼容性，适配不同屏幕 主界面可自动旋转

二）参考资料

android framework13-launcher3【06手机旋转问题】
Launcher默认支持旋转
Launcher默认支持旋转
Launcher3 布局
Launcher3 版本变化
展讯Android9.0 Launcher 简介：

三）遇到问题

定制化屏幕旋转遇到两个核心问题

• 屏幕自动旋转后，最近历史任务并没有旋转，方向异常。
• 定制的好多案子，比如平板产品中旋转没有问题，但是好多手机方案新品来做平板产品。就遇到好多问题了，当成手机了，需要默认为平板。无法解决最近历史任务异常问题。
• 在GMS 产品中，是存在配置是存在覆盖问题的。

四） 修改点

/packages/apps/Launcher3/quickstep/src/com/android/quickstep/util/RecentsOrientedState.java
/packages/apps/Launcher3/src/com/android/launcher3/states/RotationHelper.java
/packages/apps/Launcher3/src/com/android/launcher3/util/window/WindowManagerProxy.java

/packages/apps/Launcher3/quickstep/res/xml/indexable_launcher_prefs.xml 
/packages/apps/Launcher3/res/xml/launcher_preferences.xml
/vendor/google/apps/SearchLauncher/res/xml/launcher_preferences.xm

备注：仅针对大多数产品，各家平台需要根据自己的实际产品类型和方案类型来实际更改。思路是没问题的

五）属性Launcher3 种类及构成

为什么要了解这个，一方面搞清楚源码里面好多个Launcher，或者 Launcher 相关的究竟是什么。特别是GMS 版本，需要怎么改，不然改了还是会覆盖的。【暂不分析源码配置哪个Launcher】
总之：如果是GMS项目，先搞清楚自己Launcher构成，如何组合编译的，然后配置相关的建议都修改。

六）实现方案

主要解决三个问题：

修改默认配置,自动旋转改为true

/packages/apps/Launcher3/res/xml/launcher_preferences.xml
/vendor/google/apps/SearchLauncher/res/xml/launcher_preferences.xm

defaultValue 默认值改为ture 

 <SwitchPreference
        android:key="pref_allowRotation"
        android:title="@string/allow_rotation_title"
        android:summary="@string/allow_rotation_desc"
        android:defaultValue="false"
        android:persistent="true"
        launcher:logIdOn="615"
        launcher:logIdOff="616" />

 <SwitchPreference
        android:key="pref_allowRotation"
        android:title="@string/allow_rotation_title"
        android:summary="@string/allow_rotation_desc"
        android:defaultValue="false"
        android:persistent="true" />

RecentsOrientedState 允许桌面旋转设置

直接设置为true

  private void updateHomeRotationSetting() {
        boolean homeRotationEnabled = true;//mSharedPrefs.getBoolean(ALLOW_ROTATION_PREFERENCE_KEY, true);//huanghb modify
        setFlag(FLAG_HOME_ROTATION_ALLOWED_IN_PREFS, homeRotationEnabled);
        SystemUiProxy.INSTANCE.get(mContext).setHomeRotationEnabled(homeRotationEnabled);
    }

手机方案适配平板方案，模拟为平板方案

RotationHelper.java getAllowRotationDefaultValue 判断当前是否允许旋转，不用计算，直接返回 true

    /**
     * Returns the default value of {@link #ALLOW_ROTATION_PREFERENCE_KEY} preference.
     */
    public static boolean getAllowRotationDefaultValue(DeviceProfile deviceProfile) {
        // If the device's pixel density was scaled (usually via settings for A11y), use the
        // original dimensions to determine if rotation is allowed of not.
        float originalSmallestWidth = dpiFromPx(
                Math.min(deviceProfile.widthPx, deviceProfile.heightPx), DENSITY_DEVICE_STABLE);
        return true;
    }

WindowManagerProxy.java 判断当前是平板的的判断。

public static final int MIN_TABLET_WIDTH = 1

        boolean isTablet = swDp >= MIN_TABLET_WIDTH;
        boolean isTablet = config.smallestScreenWidthDp > MIN_TABLET_WIDTH;
这样在判断的时候，就直接以平板的方式来判断了，就满足自动旋转要求了。

分享部分git 修改记录

diff --git a/packages/apps/Launcher3/quickstep/res/xml/indexable_launcher_prefs.xml b/packages/apps/Launcher3/quickstep/res/xml/indexable_launcher_prefs.xml
old mode 100644
new mode 100755
index b4740e5..aa1fd4d
--- a/packages/apps/Launcher3/quickstep/res/xml/indexable_launcher_prefs.xml
+++ b/packages/apps/Launcher3/quickstep/res/xml/indexable_launcher_prefs.xml
@@ -26,7 +26,7 @@
         android:key="pref_allowRotation"
         android:title="@string/allow_rotation_title"
         android:summary="@string/allow_rotation_desc"
-        android:defaultValue="false"
+        android:defaultValue="true"
         android:persistent="true" />
 
 </PreferenceScreen>
diff --git a/packages/apps/Launcher3/quickstep/src/com/android/quickstep/util/RecentsOrientedState.java b/packages/apps/Launcher3/quickstep/src/com/android/quickstep/util/RecentsOrientedState.jav
old mode 100644
new mode 100755
index 6038a22..76dd118
--- a/packages/apps/Launcher3/quickstep/src/com/android/quickstep/util/RecentsOrientedState.java
+++ b/packages/apps/Launcher3/quickstep/src/com/android/quickstep/util/RecentsOrientedState.java
@@ -291,7 +291,7 @@ public class RecentsOrientedState implements
     }
 
     private void updateHomeRotationSetting() {
-        boolean homeRotationEnabled = mSharedPrefs.getBoolean(ALLOW_ROTATION_PREFERENCE_KEY, false);
+        boolean homeRotationEnabled = true;//mSharedPrefs.getBoolean(ALLOW_ROTATION_PREFERENCE_KEY, true);//huanghb modify
         setFlag(FLAG_HOME_ROTATION_ALLOWED_IN_PREFS, homeRotationEnabled);
         SystemUiProxy.INSTANCE.get(mContext).setHomeRotationEnabled(homeRotationEnabled);
     }
diff --git a/packages/apps/Launcher3/res/xml/launcher_preferences.xml b/packages/apps/Launcher3/res/xml/launcher_preferences.xml
old mode 100644
new mode 100755
index 8a0c909..171eeb2
--- a/packages/apps/Launcher3/res/xml/launcher_preferences.xml
+++ b/packages/apps/Launcher3/res/xml/launcher_preferences.xml
@@ -45,7 +45,7 @@
         android:key="pref_allowRotation"
         android:title="@string/allow_rotation_title"
         android:summary="@string/allow_rotation_desc"
-        android:defaultValue="false"
+        android:defaultValue="true"
         android:persistent="true"
         launcher:logIdOn="615"
         launcher:logIdOff="616" />
diff --git a/packages/apps/Launcher3/src/com/android/launcher3/states/RotationHelper.java b/packages/apps/Launcher3/src/com/android/launcher3/states/RotationHelper.java
old mode 100644
new mode 100755
index 38b62d4..bf88c9d
--- a/packages/apps/Launcher3/src/com/android/launcher3/states/RotationHelper.java
+++ b/packages/apps/Launcher3/src/com/android/launcher3/states/RotationHelper.java
@@ -49,7 +49,7 @@ public class RotationHelper implements OnSharedPreferenceChangeListener,
         // original dimensions to determine if rotation is allowed of not.
         float originalSmallestWidth = dpiFromPx(
                 Math.min(deviceProfile.widthPx, deviceProfile.heightPx), DENSITY_DEVICE_STABLE);
-        return originalSmallestWidth >= MIN_TABLET_WIDTH;
+        return true;
     }
 
     public static final int REQUEST_NONE = 0;
diff --git a/packages/apps/Launcher3/src/com/android/launcher3/util/window/WindowManagerProxy.java b/packages/apps/Launcher3/src/com/android/launcher3/util/window/WindowManagerProxy.java
old mode 100644
new mode 100755
index 9665bf9..d81565c
--- a/packages/apps/Launcher3/src/com/android/launcher3/util/window/WindowManagerProxy.java
+++ b/packages/apps/Launcher3/src/com/android/launcher3/util/window/WindowManagerProxy.java
@@ -61,7 +61,7 @@ import com.android.launcher3.util.WindowBounds;
  */
 public class WindowManagerProxy implements ResourceBasedOverride {
 
-    public static final int MIN_TABLET_WIDTH = 600;
+    public static final int MIN_TABLET_WIDTH = 1;//huanghb modify
 
     public static final MainThreadInitializedObject<WindowManagerProxy> INSTANCE =
             forOverride(WindowManagerProxy.class, R.string.window_manager_proxy_class);
diff --git a/vendor/google/apps/SearchLauncher/res/xml/launcher_preferences.xml b/vendor/google/apps/SearchLauncher/res/xml/launcher_preferences.xml
old mode 100644
new mode 100755
index a70bb30..f95219b
--- a/vendor/google/apps/SearchLauncher/res/xml/launcher_preferences.xml
+++ b/vendor/google/apps/SearchLauncher/res/xml/launcher_preferences.xml
@@ -50,7 +50,7 @@
         android:title="@string/title_show_google_app"/>
 
     <SwitchPreference
-        android:defaultValue="false"
+        android:defaultValue="true"
         android:key="pref_allowRotation"
         android:persistent="true"
         android:summary="@string/allow_rotation_desc"
(END)

七）总结：

如需要解决的问题一样
1）更改配置
2）解决最近历史任务允许旋转设置
3）把产品当做pad 来，判断是否pad 地方判断，更改逻辑判断条件实现