Toaster.java

package com.quickblox.sample.core.utils;

import android.graphics.Rect;
import android.support.annotation.IntDef;
import android.support.annotation.StringRes;
import android.util.DisplayMetrics;
import android.view.Gravity;
import android.view.View;
import android.view.Window;
import android.widget.Toast;

import com.quickblox.sample.core.CoreApp;

public class Toaster {

    @IntDef({Toast.LENGTH_LONG, Toast.LENGTH_SHORT})
    private @interface ToastLength {}

    public static void shortToast(View view, Window window, @StringRes int text) {
        Toast toast = makeToast(CoreApp.getInstance().getString(text), Toast.LENGTH_SHORT);

        Rect rect = new Rect();
        window.getDecorView().getWindowVisibleDisplayFrame(rect);
        int[] viewLocation = new int[2];
        view.getLocationInWindow(viewLocation);
        int viewLeft = viewLocation[0] - rect.left;
        int viewTop = viewLocation[1] - rect.top;

        DisplayMetrics metrics = new DisplayMetrics();
        window.getWindowManager().getDefaultDisplay().getMetrics(metrics);

        int widthMeasureSpec = View.MeasureSpec.makeMeasureSpec(metrics.widthPixels, View.MeasureSpec.UNSPECIFIED);
        int heightMeasureSpec = View.MeasureSpec.makeMeasureSpec(metrics.heightPixels, View.MeasureSpec.UNSPECIFIED);
        toast.getView().measure(widthMeasureSpec, heightMeasureSpec);

        int toastY = viewTop + view.getHeight();

        toast.setGravity(Gravity.TOP | Gravity.CENTER_VERTICAL, 0, toastY);
        toast.show();
    }

    public static void shortToast(@StringRes int text) {
        shortToast(CoreApp.getInstance().getString(text));
    }

    public static void shortToast(String text) {
        show(text, Toast.LENGTH_SHORT);
    }

    public static void longToast(@StringRes int text) {
        longToast(CoreApp.getInstance().getString(text));
    }

    public static void longToast(String text) {
        show(text, Toast.LENGTH_LONG);
    }

    private static Toast makeToast(String text, @ToastLength int length) {
        return Toast.makeText(CoreApp.getInstance(), text, length);
    }

    private static void show(String text, @ToastLength int length) {
        makeToast(text, length).show();
    }
}