Handle case where libenchant.dll is not present more gracefully. Creating a broker in that case makes a broker which functions like a null object (returning no providers and no dictionaries).

git-svn-id: svn+ssh://svn.abisource.com/svnroot/enchant/trunk@24319 bcba8976-2d24-0410-9c9c-aab3bd5fdfd6

1 files changed, 82 insertions, 30 deletions

diff --git a/src/bindings/Enchant.Net/Broker.cs b/src/bindings/Enchant.Net/Broker.cs
index 186c860..c944777 100644
--- a/src/bindings/Enchant.Net/Broker.cs
+++ b/src/bindings/Enchant.Net/Broker.cs
@@ -33,6 +33,7 @@ namespace Enchant
 	    private readonly Dictionary<string, WeakReference> _dictionaryCache;

 	    private readonly Dictionary<string, WeakReference> _pwlDictionaryCache;

 	    private bool _cacheDictionaries = true;

+	    private static Nullable<bool> _isLibEnchantAvailable;

 

 	    private static Broker _defaultBroker;

         /// <summary>

@@ -50,19 +51,46 @@ namespace Enchant
 	        }

 	    }

 

+        public static bool IsLibEnchantAvailable

+        {

+            get

+            {

+                if (_isLibEnchantAvailable == null)

+                {

+                    // force a broker to be created and thus trying to

+                    // us libenchant and setting our status

+                    Broker broker = Default;

+                }

+                return _isLibEnchantAvailable??false;

+            }

+        }

+

+

 		public Broker()

 		{

-			_handle = Bindings.enchant_broker_init();

-			VerifyNoErrors();

-			if (_handle.IsInvalid)

-			{

-				throw new ApplicationException("Unable to initialize broker");

-			}

-            _dictionaryCache = new Dictionary<string, WeakReference>();

+            try

+            {

+                _handle = Bindings.enchant_broker_init();

+                _isLibEnchantAvailable = true;

+            }

+            catch (DllNotFoundException)

+            {

+                _isLibEnchantAvailable = false;

+            }

+            if (_isLibEnchantAvailable == true)

+            {

+                VerifyNoErrors();

+                if (_handle.IsInvalid)

+                {

+                    throw new ApplicationException("Unable to initialize broker");

+                }

+            }

+		    _dictionaryCache = new Dictionary<string, WeakReference>();

             _pwlDictionaryCache = new Dictionary<string, WeakReference>();

 		}

 

-		public IEnumerable<ProviderInfo> Providers

+

+	    public IEnumerable<ProviderInfo> Providers

 		{

 			get

 			{

@@ -78,12 +106,13 @@ namespace Enchant
         private void InitializeProviderList()

         {

           _providers = new List<ProviderInfo>();

-          Bindings.enchant_broker_describe(_handle,

-                                           delegate(ProviderInfo provider)

-                                           {

-                                             _providers.Add(provider);

-                                           });

-          VerifyNoErrors();

+          if (_isLibEnchantAvailable == true)

+          {

+              Bindings.enchant_broker_describe(_handle,

+                                               delegate(ProviderInfo provider)

+                                               { _providers.Add(provider); });

+              VerifyNoErrors();

+          }

         }

 

         public IEnumerable<DictionaryInfo> Dictionaries

@@ -108,12 +137,13 @@ namespace Enchant
 	    private void InitializeDictionaryList()

         {

           _dictionaries = new List<DictionaryInfo>();

-          Bindings.enchant_broker_list_dicts(_handle,

-                                             delegate(DictionaryInfo dictionary)

-                                             {

-                                               _dictionaries.Add(dictionary);

-                                             });

-          VerifyNoErrors();

+          if (_isLibEnchantAvailable == true)

+          {

+              Bindings.enchant_broker_list_dicts(_handle,

+                                                 delegate(DictionaryInfo dictionary)

+                                                 { _dictionaries.Add(dictionary); });

+              VerifyNoErrors();

+          }

         }

 

 	    #region IDisposable Members

@@ -133,7 +163,10 @@ namespace Enchant
             if (disposing)

             {

                 // dispose-only, i.e. non-finalizable logic

-                _handle.Dispose();

+                if(_handle != null)

+                {

+                    _handle.Dispose();

+                }

                 DisposeAllDictionariesFromCache(_dictionaryCache);

                 DisposeAllDictionariesFromCache(_pwlDictionaryCache);

             }

@@ -174,6 +207,11 @@ namespace Enchant
 		    {

 			    throw new ArgumentNullException("language_tag");

 		    }

+            if(_isLibEnchantAvailable != true)

+            {

+                throw new InvalidOperationException("LibEnchant is not available");

+            }

+

             Dictionary dictionary = GetDictionaryFromCache(this._dictionaryCache, language_tag);

             if(dictionary != null)

             {

@@ -253,6 +291,11 @@ namespace Enchant
           {

             throw new ArgumentNullException("language_tag");

           }

+          if (_isLibEnchantAvailable != true)

+          {

+              return false;

+          }

+

           int result = Bindings.enchant_broker_dict_exists(_handle, language_tag);

           VerifyNoErrors();

           if (result != 0 && result != 1)

@@ -270,7 +313,10 @@ namespace Enchant
 			{

 				throw new ArgumentNullException("pwlFile");

 			}

-

+            if (_isLibEnchantAvailable != true)

+            {

+                throw new InvalidOperationException("LibEnchant is not available");

+            }

             Dictionary dictionary = GetDictionaryFromCache(this._pwlDictionaryCache, pwlFile);

             if (dictionary != null)

             {

@@ -293,17 +339,23 @@ namespace Enchant
 	    public void SetOrdering(string language_tag, string ordering)

 		{

 			VerifyNotDisposed();

-			Bindings.enchant_broker_set_ordering(_handle, language_tag, ordering);

-			VerifyNoErrors();

+            if (_isLibEnchantAvailable == true)

+            {

+                Bindings.enchant_broker_set_ordering(_handle, language_tag, ordering);

+            }

+	        VerifyNoErrors();

 		}

 

 		private void VerifyNoErrors()

 		{

-			string message = Bindings.enchant_broker_get_error(_handle);

-			if (!string.IsNullOrEmpty(message))

-			{

-				throw new ApplicationException(message);

-			}

+            if (_isLibEnchantAvailable == true)

+            {

+                string message = Bindings.enchant_broker_get_error(_handle);

+                if (!string.IsNullOrEmpty(message))

+                {

+                    throw new ApplicationException(message);

+                }

+            }

 		}

 	}

-}
\ No newline at end of file
+}