//-----------------------------------------------------------------------
// <copyright file="GvrUIHelpers.cs" company="Google Inc.">
// Copyright 2017 Google Inc. All rights reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// </copyright>
//-----------------------------------------------------------------------

using System.Collections;
using UnityEngine;
using UnityEngine.UI;

/// <summary>Helper class for dealing with canvas UI.</summary>
public static class GvrUIHelpers
{
    /// <summary>
    /// Finds the meters scale for the local coordinate system of the root canvas that contains the
    /// canvasObject passed in.
    /// </summary>
    /// <param name="canvasObject">The UI canvas object for which to find the scale.</param>
    /// <returns>The meters scale for the local coordinate system of the root UI canvas.</returns>
    public static float GetMetersToCanvasScale(Transform canvasObject)
    {
        Canvas canvas = canvasObject.GetComponentInParent<Canvas>();
        if (canvas == null)
        {
            return 0.0f;
        }

        if (!canvas.isRootCanvas)
        {
            canvas = canvas.rootCanvas;
        }

        float metersToCanvasScale = canvas.transform.localScale.x;
        return metersToCanvasScale;
    }
}