view位置小坑

getLocationOnScreen() will get the location based on the phone screen.

getLocationInWindow() will get the location based on the activity window. 水滴屏获取位置用这种

|--phone screen--------------------- |
|--------status bar---------------------|
|                                                      |
|-------------------------------------------|
|--------activity window------ -------|
|                                                      |
|                                                      |
|                                                      |
|                                                      |
|                                                      |
|                                                      |
|-------------------------------------------|

2.statusBarHeight会随着有无通知改变

3.是否有刘海屏 水滴屏

 /**
     * 是否有刘海屏
     *
     * @return
     */
    public static boolean hasNotchInScreen(Activity activity) {
        if (activity == null || activity.isFinishing()) return false;

        boolean result = false;

        // 通过其他方式判断是否有刘海屏  目前官方提供有开发文档的就 小米，vivo，华为（荣耀），oppo
        String manufacturer = Build.MANUFACTURER;

        Log.i("cchen", "manufacturer " + manufacturer);
        if (TextUtils.isEmpty(manufacturer)) {
            return false;
        } else if (manufacturer.equalsIgnoreCase("HUAWEI")) {
            result = hasNotchHw(activity);
        } else if (manufacturer.equalsIgnoreCase("xiaomi")) {
            result = hasNotchXiaoMi(activity);
        } else if (manufacturer.equalsIgnoreCase("oppo")) {
            result = hasNotchOPPO(activity);
        } else if (manufacturer.equalsIgnoreCase("vivo")) {
            result = hasNotchVIVO(activity);
        }

        if(result) return true;

        // android  P 以上有标准 API 来判断是否有刘海屏
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.P) {
            DisplayCutout displayCutout = activity.getWindow().getDecorView().getRootWindowInsets().getDisplayCutout();
            Log.i("cchen", "displayCutout " + displayCutout);
            if (displayCutout != null) {
                // 说明有刘海屏
                return true;
            }
        }
        return false;
    }

    /**
     * 判断vivo是否有刘海屏
     * https://swsdl.vivo.com.cn/appstore/developer/uploadfile/20180328/20180328152252602.pdf
     *
     * @param activity
     * @return
     */
    private static boolean hasNotchVIVO(Activity activity) {
        try {
            Class<?> c = Class.forName("android.util.FtFeature");
            Method get = c.getMethod("isFeatureSupport", int.class);
            return (boolean) (get.invoke(c, 0x20));
        } catch (Exception e) {
            e.printStackTrace();
            return false;
        }
    }

    /**
     * 判断oppo是否有刘海屏
     * https://open.oppomobile.com/wiki/doc#id=10159
     *
     * @param activity
     * @return
     */
    private static boolean hasNotchOPPO(Activity activity) {
        return activity.getPackageManager().hasSystemFeature("com.oppo.feature.screen.heteromorphism");
    }

    /**
     * 判断xiaomi是否有刘海屏
     * https://dev.mi.com/console/doc/detail?pId=1293
     *
     * @param activity
     * @return
     */
    private static boolean hasNotchXiaoMi(Activity activity) {
        try {
            Class<?> c = Class.forName("android.os.SystemProperties");
            Method get = c.getMethod("getInt", String.class, int.class);
            return (int) (get.invoke(c, "ro.miui.notch", 0)) == 1;
        } catch (Exception e) {
            e.printStackTrace();
            return false;
        }
    }

    /**
     * 判断华为是否有刘海屏
     * https://devcenter-test.huawei.com/consumer/cn/devservice/doc/50114
     *
     * @param activity
     * @return
     */
    private static boolean hasNotchHw(Activity activity) {

        try {
            ClassLoader cl = activity.getClassLoader();
            Class HwNotchSizeUtil = cl.loadClass("com.huawei.android.util.HwNotchSizeUtil");
            Method get = HwNotchSizeUtil.getMethod("hasNotchInScreen");
            return (boolean) get.invoke(HwNotchSizeUtil);
        } catch (Exception e) {
            return false;
        }
    }

4.Button在约束布局中挡住其他view，是因为button自带elevation，在Z轴上高于其他view。
Button和TextView的不同
Button 有背景，点击，按下都有相应的效果。
可点击。
默认有焦点。
样式不同，比如颜色，位置等

5.removeView由于有LayoutTransition而删除失败

6.弹出dialog时，window不退出全屏，虚拟键不弹出
在show 之前 ，getWindow().setFlags(WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE,
WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE);