SourceManager.cs :  » 2.6.4-mono-.net-core » System.Windows » System » Windows » Automation » C# / CSharp Open Source

// Permission is hereby granted, free of charge, to any person obtaining 
// a copy of this software and associated documentation files (the 
// "Software"), to deal in the Software without restriction, including 
// without limitation the rights to use, copy, modify, merge, publish, 
// distribute, sublicense, and/or sell copies of the Software, and to 
// permit persons to whom the Software is furnished to do so, subject to 
// the following conditions: 
//  
// The above copyright notice and this permission notice shall be 
// included in all copies or substantial portions of the Software. 
//  
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF 
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE 
// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION 
// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION 
// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. 
// 
// Copyright (c) 2009 Novell, Inc. (http://www.novell.com) 
// 
// Authors: 
//      Sandy Armstrong <sanfordarmstrong@gmail.com>
// 

using System;
using System.Collections.Generic;
using System.Reflection;

using Mono.UIAutomation.Source;
using Mono.UIAutomation.Services;

namespace System.Windows.Automation{
  internal static class SourceManager
  {
    private const string AtspiUiaSourceAssembly =
      "AtspiUiaSource, Version=1.0.0.0, Culture=neutral, PublicKeyToken=f4ceacb585d99812";
    private const string UiaDbusSourceAssembly =
      "UiaDbusSource, Version=1.0.0.0, Culture=neutral, PublicKeyToken=f4ceacb585d99812";
    private static IAutomationSource [] sources = null;
    private static object sourcesLock = new object ();

    internal static IAutomationSource [] GetAutomationSources ()
    {
      if (sources == null) {
        lock (sourcesLock) {
          if (sources == null) {
            var sourcesList = new List<IAutomationSource> ();

            // Let MONO_UIA_SOURCE env var override default source
            string sourceAssemblyNames =
              Environment.GetEnvironmentVariable ("MONO_UIA_SOURCE");

            if (string.IsNullOrEmpty (sourceAssemblyNames))
              sourceAssemblyNames =
                UiaDbusSourceAssembly + ";" + AtspiUiaSourceAssembly;

            foreach (string sourceAssembly in sourceAssemblyNames.Split (';')) {
              if (string.IsNullOrEmpty (sourceAssembly))
                continue;
              IAutomationSource source = GetAutomationSource (sourceAssembly);
              if (source != null)
                sourcesList.Add (source);
            }
            sources = sourcesList.ToArray ();
          }
        }
      }
      return sources;
    }

    // TODO: Rename to GetAutomationElement
    // Note: this method could be invoked by multiple threads simultaneously
    internal static AutomationElement GetOrCreateAutomationElement (IElement sourceElement)
    {
      if (sourceElement == null)
        return null;
      return new AutomationElement (sourceElement);
    }

    // TODO: Rename to GetAutomationElements
    internal static AutomationElement [] GetOrCreateAutomationElements (IElement [] sourceElements)
    {
      AutomationElement [] ret = new AutomationElement [sourceElements.Length];
      for (int i = 0; i < sourceElements.Length; i++)
        ret [i] = GetOrCreateAutomationElement (sourceElements [i]);
      return ret;
    }

    private static IAutomationSource GetAutomationSource (string sourceAssemblyName)
    {
      Assembly sourceAssembly = null;
      try {
        sourceAssembly = Assembly.Load (sourceAssemblyName);
      } catch (Exception e){
        Log.Warn (string.Format ("Error loading UIA source ({0}): {1}",
                                          sourceAssemblyName,
                                          e));
        return null;
      }

      Type sourceType = null;

      // Quickie inefficent implementation
      Type sourceInterfaceType = typeof (IAutomationSource);
      foreach (Type type in sourceAssembly.GetTypes ()) {
        if (sourceInterfaceType.IsAssignableFrom (type)) {
          sourceType = type;
          break;
        }
      }
      if (sourceType == null) {
        Log.Error ("No UIA source found in assembly: " +
                           sourceAssemblyName);
        return null;
      }

      try {
        IAutomationSource source
          = (IAutomationSource) Activator.CreateInstance (sourceType);
        if (!source.IsAccessibilityEnabled)
          return null;

        source.Initialize ();
        return source;
      } catch (Exception e) {
        Log.Error ("Failed to load UIA source: " + e);
        return null;
      }
    }
  }
}