Add IElementFinder implementation (#27)

* Add IElementFinder to resolve #23

Author: mialeska

Aquality.Selenium/src/Aquality.Selenium/Elements/ElementFinder.cs

@@ -0,0 +1,99 @@
+using System;
+using System.Collections.Generic;
+using System.Collections.ObjectModel;
+using System.Linq;
+using System.Threading;
+using Aquality.Selenium.Browsers;
+using Aquality.Selenium.Configurations;
+using Aquality.Selenium.Elements.Interfaces;
+using Aquality.Selenium.Waitings;
+using OpenQA.Selenium;
+
+namespace Aquality.Selenium.Elements
+{
+    internal sealed class ElementFinder : IElementFinder
+    {
+        private static readonly ThreadLocal<ElementFinder> InstanceHolder = new ThreadLocal<ElementFinder>();
+
+        private ElementFinder()
+        {
+        }
+
+        public static ElementFinder Instance
+        {
+            get
+            {
+                if (!InstanceHolder.IsValueCreated)
+                {
+                    InstanceHolder.Value = new ElementFinder();
+                }
+
+                return InstanceHolder.Value;
+            }
+        }
+
+        private ITimeoutConfiguration TimeoutConfiguration => Configuration.Instance.TimeoutConfiguration;
+
+        private TimeSpan DefaultTimeout => TimeoutConfiguration.Condition;
+
+        private Browser Browser => BrowserManager.Browser;
+
+        public IWebElement FindElement(By locator, TimeSpan? timeout = null, ElementState state = ElementState.ExistsInAnyState)
+        {
+            var clearTimeout = timeout ?? DefaultTimeout;
+            var elements = FindElements(locator, clearTimeout, state);
+            if (elements.Any())
+            {
+                return elements.First();
+            }
+
+            throw new NoSuchElementException($"Element was not found in {clearTimeout.Seconds} seconds in state {state} by locator {locator}");
+        }
+
+        public IWebElement FindElement(By by)
+        {
+            return FindElement(by, timeout: null);
+        }
+
+        public ReadOnlyCollection<IWebElement> FindElements(By locator, TimeSpan? timeout = null, ElementState state = ElementState.ExistsInAnyState)
+        {
+            var resultElements = new List<IWebElement>();
+            Browser.ImplicitWaitTimeout = TimeSpan.Zero;
+            ConditionalWait.WaitForTrue(driver =>
+            {
+                var foundElements = driver.FindElements(locator);
+                var filteredElements = FilterByState(foundElements, state);
+                resultElements.AddRange(filteredElements);
+                return filteredElements.Any();
+            }, timeout ?? DefaultTimeout);
+            Browser.ImplicitWaitTimeout = TimeoutConfiguration.Implicit;
+            return resultElements.ToList().AsReadOnly();
+        }
+
+        private IList<IWebElement> FilterByState(IList<IWebElement> foundElements, ElementState state)
+        {
+            var filteredElements = new List<IWebElement>();
+            if (foundElements.Any())
+            {
+                switch (state)
+                {
+                    case ElementState.Displayed:
+                        filteredElements.AddRange(foundElements.Where(element => element.Displayed));
+                        break;
+                    case ElementState.ExistsInAnyState:
+                        filteredElements.AddRange(foundElements);
+                        break;
+                    default:
+                        throw new InvalidOperationException($"{state} state is not recognized");
+                }
+            }
+
+            return filteredElements;
+        }
+
+        public ReadOnlyCollection<IWebElement> FindElements(By by)
+        {
+            return FindElements(by, timeout: null);
+        }
+    }
+}

Aquality.Selenium/src/Aquality.Selenium/Elements/Interfaces/IElementFinder.cs

@@ -0,0 +1,31 @@
+using OpenQA.Selenium;
+using System;
+using System.Collections.ObjectModel;
+
+namespace Aquality.Selenium.Elements.Interfaces
+{
+    /// <summary>
+    /// Provides ability to find elements in desired ElementState
+    /// </summary>
+    public interface IElementFinder : ISearchContext
+    {
+        /// <summary>
+        /// Finds elements in desired ElementState
+        /// </summary>
+        /// <param name="locator">elements locator</param>
+        /// <param name="timeout">timeout for search</param>
+        /// <param name="state">desired ElementState</param>
+        /// <returns>List of found elements</returns>
+        ReadOnlyCollection<IWebElement> FindElements(By locator, TimeSpan? timeout = null, ElementState state = ElementState.ExistsInAnyState);
+
+        /// <summary>
+        /// Finds element in desired ElementState
+        /// </summary>
+        /// <param name="locator">elements locator</param>
+        /// <param name="timeout">timeout for search</param>
+        /// <param name="state">desired ElementState</param>
+        /// <exception cref="OpenQA.Selenium.NoSuchElementException">Thrown if element was not found in time in desired state</exception> 
+        /// <returns>Found element</returns>
+        IWebElement FindElement(By locator, TimeSpan? timeout = null, ElementState state = ElementState.ExistsInAnyState);
+    }
+}