简介

开发者选项中动画设置：

  • 窗口动画缩放(Windos animation scale)
  • 过渡动画缩放(Transition animation scale)
  • 动画程序时长缩放(Animation duration scale)
    分别对应Window动画(非Activity窗口。比如，Dialog、toast、自定义浮窗、输入法等窗口)、Activity动画(Activity窗口。Activity窗口)、View动画(比如View属性动画、水波纹背景动画)

原理

Setting设置动画

代码路径

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packages/apps/Settings/src/com/android/settings/DevelopmentSettings.java

WindowManagerService提供了setAnimationScale() API供Setting使用

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import android.os.RemoteException;
import android.os.ServiceManager;
import android.view.IWindowManager;

        IWindowManager mWindowManager = IWindowManager.Stub.asInterface(ServiceManager.getService("window"));
        try {
            float scale = 0;  //动画时长 [0,0.5,1,1.5,2,5,10]对应设置的[关闭,0.5x,1x.1.5x,2x,5x,10x]
            mWindowManager.setAnimationScale(0, scale); //设置窗口动画缩放
            mWindowManager.setAnimationScale(1, scale); //设置过渡动画缩放
            mWindowManager.setAnimationScale(2, scale); //动画程序时长缩放
        } catch (RemoteException e) {

        }

// 声明权限
        <uses-permission android:name="android.permission.SET_ANIMATION_SCALE"/>

setAnimationScale()函数

setAnimationScale()函数在frameworks/base/services/core/java/com/android/server/wm/WindowManagerService.java中

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@Override
   public void setAnimationScale(int which, float scale) {
       if (!checkCallingPermission(android.Manifest.permission.SET_ANIMATION_SCALE,
               "setAnimationScale()")) {
           throw new SecurityException("Requires SET_ANIMATION_SCALE permission");
       }

       scale = fixScale(scale);
       switch (which) {
           case 0: mWindowAnimationScaleSetting = scale; break;
           case 1: mTransitionAnimationScaleSetting = scale; break;
           case 2: mAnimatorDurationScaleSetting = scale; break;
       }

       // Persist setting
       mH.sendEmptyMessage(H.PERSIST_ANIMATION_SCALE);

打印dump信息

执行命令

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adb shell dumpsys window w -a

Window动画时长设置

Window动画的设置是通过frameworks\base\services\core\java\com\android\server\wm\WindowStateAnimator.java文件的setAnimation()函数来完成的

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public void setAnimation(Animation anim, long startTime) {
    ......
    mAnimation.scaleCurrentDuration(mService.getWindowAnimationScaleLocked());
    ......
}

调用Animation.scaleCurrentDuration()函数来重置动画时长为duration*scale

Activity动画时长设置

Activity切换动画的设置是通过frameworks\base\services\core\java\com\android\server\wm\AppWindowAnimator.java文件的setAnimation()函数来完成的

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public void setAnimation(Animation anim, int width, int height, boolean skipFirstFrame) {
    ......
    anim.scaleCurrentDuration(mService.getTransitionAnimationScaleLocked());
    ......
}

调用Animation.scaleCurrentDuration()函数来重置动画时长为duration*scale

View动画时长设置

View动画时长是通过ValueAnimator.sDurationScale静态变量来控制的

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public static IWindowManager getWindowManagerService() {
    synchronized (WindowManagerGlobal.class) {
        if (sWindowManagerService == null) {
            sWindowManagerService = IWindowManager.Stub.asInterface(
                    ServiceManager.getService("window"));
            try {
                sWindowManagerService = getWindowManagerService();
                ValueAnimator.setDurationScale(sWindowManagerService.getCurrentAnimatorScale());
            } catch (RemoteException e) {
                Log.e(TAG, "Failed to get WindowManagerService, cannot set animator scale", e);
            }
        }
        return sWindowManagerService;
    }
}

在进程启动后第一次调用getWindowManagerService()时便会从WMS中获取缩放值，然后保存到ValueAnimator.sDurationScale中
如果Setting中更新了View动画缩放因子，那么WMS中调用dispatchNewAnimatorScaleLocked()函数后会回调上层应用的onAnimatorScaleChanged()接口，通知应用View的动画时长Scale更新

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 public static IWindowSession getWindowSession() {
    synchronized (WindowManagerGlobal.class) {
        if (sWindowSession == null) {
            try {
                InputMethodManager imm = InputMethodManager.getInstance();
                IWindowManager windowManager = getWindowManagerService();
                sWindowSession = windowManager.openSession(
                        new IWindowSessionCallback.Stub() {
                            @Override
                            public void onAnimatorScaleChanged(float scale) {
                                ValueAnimator.setDurationScale(scale);
                            }
                        },
                        imm.getClient(), imm.getInputContext());
            } catch (RemoteException e) {
                Log.e(TAG, "Failed to open window session", e);
            }
        }
        return sWindowSession;
    }
}

对于View动画，如果动画时长使用了ValueAnimator.sDurationScale，那么必然受”Animator duration scale”控制