ToastCompat, make toast shown when user disabled notification permission

ToastCompat.java

import android.app.Activity;
import android.content.Context;
import android.content.res.Resources;
import android.graphics.PixelFormat;
import android.support.annotation.StringRes;
import android.support.v4.app.NotificationManagerCompat;
import android.util.Log;
import android.view.Gravity;
import android.view.View;
import android.view.ViewGroup;
import android.view.WindowManager;
import android.widget.FrameLayout;
import android.widget.Toast;

/**
 * 替代系统Toast，防止用户禁用通知栏权限导致Toast不显示问题.必须在Activity Context下才有效
 *
 * @author CJL
 * @since 2017-11-24
 */
public class ToastCompat {
    private Toast mToast;
    private FrameLayout mToastView;
    private WindowManager.LayoutParams mLayoutParams;
    private Runnable mCancelRun;

    private boolean useSystemToast = false;
    private static ToastCompat mLastToast;


    private ToastCompat(Context context, CharSequence text, int duration) {
        mToast = Toast.makeText(context.getApplicationContext(), text, duration);
        useSystemToast = !(context instanceof Activity) || NotificationManagerCompat.from(context).areNotificationsEnabled();

        if (useSystemToast) {
            return;
        }

        mToastView = new FrameLayout(context) {
            @Override
            protected void onWindowVisibilityChanged(int visibility) {
                super.onWindowVisibilityChanged(visibility);
                if (visibility != View.VISIBLE) {
                    cancel();
                }
            }
        };
        mToastView.addView(mToast.getView(), ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT);

        mLayoutParams = new WindowManager.LayoutParams();
        mLayoutParams.height = WindowManager.LayoutParams.WRAP_CONTENT;
        mLayoutParams.width = WindowManager.LayoutParams.WRAP_CONTENT;
        mLayoutParams.format = PixelFormat.TRANSLUCENT;
        mLayoutParams.windowAnimations = -1;
        mLayoutParams.type = WindowManager.LayoutParams.TYPE_APPLICATION_PANEL;
        mLayoutParams.flags = WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON
                | WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE
                | WindowManager.LayoutParams.FLAG_NOT_TOUCHABLE;
        mLayoutParams.gravity = Gravity.CENTER_HORIZONTAL | Gravity.BOTTOM;
        mLayoutParams.y = 200;

        mCancelRun = new Runnable() {
            @Override
            public void run() {
                cancel();
            }
        };
    }

    public void cancel() {
        if (useSystemToast || mCancelRun == null || mToastView == null) {
            return;
        }
        mToastView.removeCallbacks(mCancelRun);

        WindowManager windowManager = (WindowManager) mToastView.getContext().getSystemService(Context.WINDOW_SERVICE);
        if (windowManager != null && mToastView.getParent() != null) {
            try {
                windowManager.removeView(mToastView);
            } catch (Throwable e) {
                Log.e("ToastCompat", "Cancel toast failed!", e);
            }
        }

        mToastView = null;
        mCancelRun = null;
        mLayoutParams = null;
        mLastToast = null;
    }

    public void show() {
        if (useSystemToast) {
            mToast.show();
            return;
        }
        if (mLastToast != null) {
            mLastToast.cancel();
        }

        WindowManager windowManager = (WindowManager) mToastView.getContext().getSystemService(Context.WINDOW_SERVICE);
        if (windowManager == null) {
            return;
        }

        try {
            windowManager.addView(mToastView, mLayoutParams);
            int delayTime = mToast.getDuration() == Toast.LENGTH_SHORT ? 2000 : 3000;
            mToastView.postDelayed(mCancelRun, delayTime);
            mLastToast = this;
        } catch (Throwable e) {
            Log.e("ToastCompat", "show Toast failed!", e);
        }
    }

    public void setText(CharSequence text) {
        mToast.setText(text);
    }

    public void setText(@StringRes int res) {
        setText(mToastView.getContext().getResources().getString(res));
    }

    public void setGravity(int gravity, int xOffset, int yOffset) {
        if (useSystemToast) {
            mToast.setGravity(gravity, xOffset, yOffset);
            return;
        }
        mLayoutParams.gravity = gravity;
        mLayoutParams.x = xOffset;
        mLayoutParams.y = yOffset;
    }

    public View getView() {
        return mToast.getView();
    }

    public void setDuration(int duration) {
        mToast.setDuration(duration);
    }

    public static ToastCompat makeText(Context context, CharSequence text, int duration) {
        return new ToastCompat(context, text, duration);
    }

    public static ToastCompat makeText(Context context, @StringRes int resId, int duration)
            throws Resources.NotFoundException {
        return makeText(context, context.getResources().getText(resId), duration);
    }
}