Help 2.0: rewritten code for the controls to support empty/broken collections without getting errors

git-svn-id: svn://svn.sharpdevelop.net/sharpdevelop/trunk@1526 1ccf3a8d-04fe-1044-b7c0-cef0b8235c61

src/AddIns/Misc/HtmlHelp2/Project/src/BaseControls/DynamicHelpPad.cs

@@ -114,7 +114,7 @@ namespace HtmlHelp2
 		
 		private bool CallDynamicHelp(string searchTerm, bool keywordSearch)
 		{
-			if (!HtmlHelp2Environment.IsReady || HtmlHelp2Environment.DynamicHelpIsBusy)
+			if (!HtmlHelp2Environment.SessionIsInitialized || HtmlHelp2Environment.DynamicHelpIsBusy)
 			{
 				return false;
 			}
@@ -363,7 +363,6 @@ namespace HtmlHelp2
 			dynamicHelpToolbar.AllowItemReorder          = false;
 			dynamicHelpToolbar.ShowItemToolTips          = false;
 			dynamicHelpToolbar.GripStyle                 = ToolStripGripStyle.Hidden;
-			dynamicHelpToolbar.Enabled                   = HtmlHelp2Environment.IsReady;
 			for (int i = 0; i < toolbarButtons.Length; i++)
 			{
 				ToolStripButton button = new ToolStripButton();
@@ -382,7 +381,7 @@ namespace HtmlHelp2
 			dynamicHelpToolbar.ImageList.Images.Add(ResourcesHelper.GetBitmap("HtmlHelp2.16x16.Index.png"));
 			dynamicHelpToolbar.ImageList.Images.Add(ResourcesHelper.GetBitmap("HtmlHelp2.16x16.Search.png"));
 
-			if (HtmlHelp2Environment.IsReady)
+			if (HtmlHelp2Environment.SessionIsInitialized)
 			{
 				HtmlHelp2Environment.NamespaceReloaded   += new EventHandler(this.NamespaceReloaded);
 			}
@@ -390,11 +389,6 @@ namespace HtmlHelp2
 
 		public void LoadDynamicHelpPage()
 		{
-			if (!HtmlHelp2Environment.IsReady)
-			{
-				return;
-			}
-
 			string url = String.Format("res://{0}/context", Assembly.GetExecutingAssembly().Location);
 			axWebBrowser.Navigate(url);
 		}

src/AddIns/Misc/HtmlHelp2/Project/src/BaseControls/IndexPad.cs

@@ -61,8 +61,9 @@ namespace HtmlHelp2
 		ComboBox searchTerm = new ComboBox();
 		Label label1 = new Label();
 		Label label2 = new Label();
+		Label infoLabel = new Label();
+		bool indexControlFailed = false;
 		bool itemClicked = false;
-		bool isEnabled = false;
 
 		protected override void Dispose(bool disposing)
 		{
@@ -75,10 +76,47 @@ namespace HtmlHelp2
 
 		public MsHelp2IndexControl()
 		{
-			this.isEnabled = (HtmlHelp2Environment.IsReady &&
-			                  Help2ControlsValidation.IsIndexControlRegistered);
+			this.InitializeComponents();
+			this.UpdateControls();
 
-			if (this.isEnabled)
+			HtmlHelp2Environment.FilterQueryChanged += new EventHandler(this.FilterQueryChanged);
+			HtmlHelp2Environment.NamespaceReloaded += new EventHandler(this.NamespaceReloaded);
+		}
+
+		private void UpdateControls()
+		{
+			filterCombobox.Enabled =
+				(HtmlHelp2Environment.SessionIsInitialized && !this.indexControlFailed);
+			searchTerm.Enabled =
+				(HtmlHelp2Environment.SessionIsInitialized && !this.indexControlFailed);
+			infoLabel.Visible = false;
+
+			if (this.indexControlFailed)
+			{
+				this.ShowInfoMessage
+					(StringParser.Parse("${res:AddIns.HtmlHelp2.HelpSystemNotAvailable}"));
+			}
+			else if (!HtmlHelp2Environment.SessionIsInitialized)
+			{
+				if (indexControl != null) indexControl.Visible = false;
+				this.ShowInfoMessage
+					("${res:AddIns.HtmlHelp2.HelpCollectionMayBeEmpty}");
+			}
+			else
+			{
+				indexControl.Visible = true;
+				this.LoadIndex();
+			}
+		}
+		
+		private void InitializeComponents()
+		{
+			infoLabel.Dock = DockStyle.Fill;
+			infoLabel.Visible = false;
+			infoLabel.TextAlign = ContentAlignment.MiddleCenter;
+			Controls.Add(infoLabel);
+
+			if (Help2ControlsValidation.IsIndexControlRegistered)
 			{
 				try
 				{
@@ -93,15 +131,16 @@ namespace HtmlHelp2
 					indexControl.BorderStyle = HxBorderStyle.HxBorderStyle_FixedSingle;
 					indexControl.FontSource = HxFontSourceConstant.HxFontExternal;
 				}
-				catch (Exception ex)
+				catch (System.Runtime.InteropServices.COMException ex)
 				{
 					LoggingService.Error("Help 2.0: Index control failed; " + ex.ToString());
-					this.FakeHelpControl();
+					this.indexControlFailed = true;
 				}
-			}
-			else
+				catch (Exception ex)
 				{
-				this.FakeHelpControl();
+					LoggingService.Error("Help 2.0: Index control failed; " + ex.ToString());
+					this.indexControlFailed = true;
+				}
 			}
 
 			Panel panel1 = new Panel();
@@ -113,14 +152,13 @@ namespace HtmlHelp2
 			filterCombobox.Dock = DockStyle.Top;
 			filterCombobox.DropDownStyle = ComboBoxStyle.DropDownList;
 			filterCombobox.Sorted = true;
-			filterCombobox.Enabled = this.isEnabled;
+			filterCombobox.Enabled = false;
 			filterCombobox.Font = new System.Drawing.Font("Tahoma", 8F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((byte)(0)));
 			filterCombobox.SelectedIndexChanged += new EventHandler(this.FilterChanged);
 
 			Controls.Add(label1);
 			label1.Dock = DockStyle.Top;
 			label1.TextAlign = ContentAlignment.MiddleLeft;
-			label1.Enabled = this.isEnabled;
 			label1.Font = new System.Drawing.Font("Tahoma", 8F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((byte)(0)));
 
 			Panel panel2 = new Panel();
@@ -130,7 +168,7 @@ namespace HtmlHelp2
 
 			panel2.Controls.Add(searchTerm);
 			searchTerm.Dock = DockStyle.Top;
-			searchTerm.Enabled = this.isEnabled;
+			searchTerm.Enabled = false;
 			searchTerm.Font = new System.Drawing.Font("Tahoma", 8F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((byte)(0)));
 			searchTerm.TextChanged += new EventHandler(this.SearchTextChanged);
 			searchTerm.KeyPress += new KeyPressEventHandler(this.SearchKeyPress);
@@ -138,30 +176,20 @@ namespace HtmlHelp2
 			Controls.Add(label2);
 			label2.Dock = DockStyle.Top;
 			label2.TextAlign = ContentAlignment.MiddleLeft;
-			label2.Enabled = this.isEnabled;
 			label2.Font = new System.Drawing.Font("Tahoma", 8F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((byte)(0)));
 
 			this.RedrawContent();
 
-			if (this.isEnabled)
-			{
-				HtmlHelp2Environment.FilterQueryChanged += new EventHandler(this.FilterQueryChanged);
-				HtmlHelp2Environment.NamespaceReloaded += new EventHandler(this.NamespaceReloaded);
-				this.LoadIndex();
-			}
+			this.indexControlFailed = (this.indexControlFailed || indexControl == null);
 		}
 
-		private void FakeHelpControl()
+		private void ShowInfoMessage(string infoText)
 		{
-			if (indexControl != null) indexControl.Dispose();
-			indexControl = null;
-
-			Controls.Clear();
-			Label nohelpLabel = new Label();
-			nohelpLabel.Dock = DockStyle.Fill;
-			nohelpLabel.Text = StringParser.Parse("${res:AddIns.HtmlHelp2.HelpSystemNotAvailable}");
-			nohelpLabel.TextAlign = ContentAlignment.MiddleCenter;
-			Controls.Add(nohelpLabel);
+			filterCombobox.Items.Clear();
+			searchTerm.Items.Clear();
+			searchTerm.Text = string.Empty;
+			infoLabel.Text = infoText;
+			infoLabel.Visible = true;
 		}
 
 		public void RedrawContent()
@@ -223,8 +251,7 @@ namespace HtmlHelp2
 	
 		private void LoadIndex()
 		{
-			this.SetIndex(HtmlHelp2Environment.CurrentFilterName);
-			if (this.isEnabled)
+			if (this.SetIndex(HtmlHelp2Environment.CurrentFilterName))
 			{
 				searchTerm.Text = string.Empty;
 				searchTerm.Items.Clear();
@@ -234,24 +261,18 @@ namespace HtmlHelp2
 			}
 		}
 
-		private void SetIndex(string filterName)
+		private bool SetIndex(string filterName)
 		{
-			if (!this.isEnabled) return;
 			try
 			{
 				indexControl.IndexData =
 					HtmlHelp2Environment.GetIndex(HtmlHelp2Environment.FindFilterQuery(filterName));
+				return true;
 			}
 			catch
 			{
-				this.isEnabled = false;
-				indexControl.Enabled = false;
-				indexControl.BackColor = SystemColors.ButtonFace;
-				filterCombobox.Enabled = false;
-				searchTerm.Enabled = false;
-				label1.Enabled = false;
-				label2.Enabled = false;
 				LoggingService.Error("Help 2.0: cannot connect to IHxIndex interface (Index)");
+				return false;
 			}
 		}
 
@@ -325,13 +346,8 @@ namespace HtmlHelp2
 
 		private void NamespaceReloaded(object sender, EventArgs e)
 		{
-			this.LoadIndex();
+			this.UpdateControls();
 		}
 		#endregion
-
-		public bool IsEnabled
-		{
-			get { return this.isEnabled; }
-		}
 	}
 }

src/AddIns/Misc/HtmlHelp2/Project/src/BaseControls/IndexResultsPad.cs

@@ -59,7 +59,6 @@ namespace HtmlHelp2
 			listView.Dock              = DockStyle.Fill;
 			listView.MultiSelect       = false;
 			listView.HideSelection     = false;
-			listView.Enabled           = HtmlHelp2Environment.IsReady;
 			listView.Font              = new System.Drawing.Font("Tahoma", 8F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((byte)(0)));
 			ListViewResize(this,null);
 

src/AddIns/Misc/HtmlHelp2/Project/src/BaseControls/SearchPad.cs

@@ -79,6 +79,27 @@ namespace HtmlHelp2
 		public HtmlHelp2SearchPad()
 		{
 			this.InitializeComponents();
+			this.UpdateControls();
+			
+			HtmlHelp2Environment.FilterQueryChanged += new EventHandler(FilterQueryChanged);
+			HtmlHelp2Environment.NamespaceReloaded  += new EventHandler(NamespaceReloaded);
+
+			ProjectService.SolutionLoaded        += this.SolutionLoaded;
+			ProjectService.SolutionClosed        += this.SolutionUnloaded;
+		}
+
+		private void UpdateControls()
+		{
+			titlesOnly.Enabled = HtmlHelp2Environment.SessionIsInitialized;
+			enableStemming.Enabled = HtmlHelp2Environment.SessionIsInitialized;
+			hiliteTopics.Enabled = HtmlHelp2Environment.SessionIsInitialized;
+			useCurrentLang.Enabled = HtmlHelp2Environment.SessionIsInitialized;
+			filterCombobox.Enabled = HtmlHelp2Environment.SessionIsInitialized;
+			searchTerm.Enabled = HtmlHelp2Environment.SessionIsInitialized;
+
+			searchTerm.Text = string.Empty;
+			searchTerm.Items.Clear();
+			filterCombobox.Items.Clear();
 		}
 
 		private void InitializeComponents()
@@ -102,13 +123,11 @@ namespace HtmlHelp2
 			titlesOnly.Width                      = pw;
 			titlesOnly.Top                        = searchButton.Top + searchButton.Height + 10;
 			titlesOnly.TextAlign                  = ContentAlignment.MiddleLeft;
-			titlesOnly.Enabled                    = HtmlHelp2Environment.IsReady;
 			titlesOnly.Font                       = new System.Drawing.Font("Tahoma", 8F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((byte)(0)));
 
 			enableStemming.Width                  = pw;
 			enableStemming.Top                    = titlesOnly.Top + titlesOnly.Height - 4;
 			enableStemming.TextAlign              = ContentAlignment.MiddleLeft;
-			enableStemming.Enabled                = HtmlHelp2Environment.IsReady;
 			enableStemming.Font                   = new System.Drawing.Font("Tahoma", 8F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((byte)(0)));
 
 			reuseMatches.Width                    = pw;
@@ -120,14 +139,12 @@ namespace HtmlHelp2
 			hiliteTopics.Width                    = pw;
 			hiliteTopics.Top                      = reuseMatches.Top + reuseMatches.Height - 4;
 			hiliteTopics.TextAlign                = ContentAlignment.MiddleLeft;
-			hiliteTopics.Enabled                  = HtmlHelp2Environment.IsReady;
 			hiliteTopics.Checked                  = true;
 			hiliteTopics.Font                     = new System.Drawing.Font("Tahoma", 8F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((byte)(0)));
 
 			useCurrentLang.Width                  = pw;
 			useCurrentLang.Top                    = hiliteTopics.Top + hiliteTopics.Height;
 			useCurrentLang.TextAlign              = ContentAlignment.MiddleLeft;
-			useCurrentLang.Enabled                = HtmlHelp2Environment.IsReady;
 			useCurrentLang.Visible                = ProjectService.CurrentProject != null;
 			useCurrentLang.Font                   = new System.Drawing.Font("Tahoma", 8F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((byte)(0)));
 
@@ -142,22 +159,18 @@ namespace HtmlHelp2
 			filterCombobox.Dock                   = DockStyle.Top;
 			filterCombobox.DropDownStyle          = ComboBoxStyle.DropDownList;
 			filterCombobox.Sorted                 = true;
-			filterCombobox.Enabled                = HtmlHelp2Environment.IsReady;
 			filterCombobox.Font                   = new System.Drawing.Font("Tahoma", 8F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((byte)(0)));
 			filterCombobox.SelectedIndexChanged  += new EventHandler(FilterChanged);
 			
-			if (HtmlHelp2Environment.IsReady)
+			if (HtmlHelp2Environment.SessionIsInitialized)
 			{
 				HtmlHelp2Environment.BuildFilterList(filterCombobox);
-				HtmlHelp2Environment.FilterQueryChanged += new EventHandler(FilterQueryChanged);
-				HtmlHelp2Environment.NamespaceReloaded  += new EventHandler(NamespaceReloaded);
 			}
 
 			// Filter label
 			mainPanel.Controls.Add(label1);
 			label1.Dock                           = DockStyle.Top;
 			label1.TextAlign                      = ContentAlignment.MiddleLeft;
-			label1.Enabled                        = HtmlHelp2Environment.IsReady;
 			label1.Font                           = new System.Drawing.Font("Tahoma", 8F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((byte)(0)));
 
 			// SearchTerm Combobox
@@ -169,19 +182,15 @@ namespace HtmlHelp2
 			searchTerm.Dock                       = DockStyle.Top;
 			searchTerm.TextChanged               += new EventHandler(SearchTextChanged);
 			searchTerm.KeyPress                  += new KeyPressEventHandler(KeyPressed);
-			searchTerm.Enabled                    = HtmlHelp2Environment.IsReady;
 			searchTerm.Font                       = new System.Drawing.Font("Tahoma", 8F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((byte)(0)));
 
 			mainPanel.Controls.Add(label2);
 			label2.Dock                           = DockStyle.Top;
 			label2.TextAlign                      = ContentAlignment.MiddleLeft;
-			label2.Enabled                        = HtmlHelp2Environment.IsReady;
 			label2.Font                           = new System.Drawing.Font("Tahoma", 8F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((byte)(0)));
 
 			this.RedrawContent();
 			
-			ProjectService.SolutionLoaded        += this.SolutionLoaded;
-			ProjectService.SolutionClosed        += this.SolutionUnloaded;
 		}
 
 		private void FilterChanged(object sender, EventArgs e)
@@ -210,12 +219,15 @@ namespace HtmlHelp2
 
 		private void NamespaceReloaded(object sender, EventArgs e)
 		{
-			searchTerm.Text                      = "";
-			searchTerm.Items.Clear();
+			this.UpdateControls();
+			
+			if (HtmlHelp2Environment.SessionIsInitialized)
+			{
 				filterCombobox.SelectedIndexChanged -= new EventHandler(FilterChanged);
 				HtmlHelp2Environment.BuildFilterList(filterCombobox);
 				filterCombobox.SelectedIndexChanged += new EventHandler(FilterChanged);
 			}
+		}
 		#endregion
 
 		private void SearchButtonClick(object sender, EventArgs e)
@@ -260,7 +272,7 @@ namespace HtmlHelp2
 
 		private void PerformFTS(string searchWord, bool useDynamicHelp)
 		{
-			if (!HtmlHelp2Environment.IsReady || string.IsNullOrEmpty(searchWord) || searchIsBusy)
+			if (!HtmlHelp2Environment.SessionIsInitialized || string.IsNullOrEmpty(searchWord) || searchIsBusy)
 			{
 				return;
 			}
@@ -344,7 +356,7 @@ namespace HtmlHelp2
 
 		public bool PerformF1FTS(string keyword, bool useDynamicHelp)
 		{
-			if (!HtmlHelp2Environment.IsReady || string.IsNullOrEmpty(keyword) || searchIsBusy)
+			if (!HtmlHelp2Environment.SessionIsInitialized || string.IsNullOrEmpty(keyword) || searchIsBusy)
 			{
 				return false;
 			}

src/AddIns/Misc/HtmlHelp2/Project/src/BaseControls/SearchResultsPad.cs

@@ -63,7 +63,6 @@ namespace HtmlHelp2
 
 			listView.FullRowSelect     = true;
 			listView.AutoArrange       = true;
-			listView.Enabled           = HtmlHelp2Environment.IsReady;
 			listView.Alignment         = ListViewAlignment.Left;
 			listView.View              = View.Details;
 			listView.Dock              = DockStyle.Fill;

src/AddIns/Misc/HtmlHelp2/Project/src/BaseControls/TocPad.cs

@@ -97,10 +97,11 @@ namespace HtmlHelp2
 		AxHxTocCtrl tocControl = null;
 		ComboBox filterCombobox = new ComboBox();
 		Label label1 = new Label();
+		Label infoLabel = new Label();
 		ContextMenuStrip printContextMenu = new ContextMenuStrip();
 		ToolStripMenuItem printTopic = new ToolStripMenuItem();
 		ToolStripMenuItem printTopicAndSubTopics = new ToolStripMenuItem();
-		bool isEnabled = false;
+		bool tocControlFailed = false;
 
 		protected override void Dispose(bool disposing)
 		{
@@ -113,9 +114,45 @@ namespace HtmlHelp2
 
 		public MsHelp2TocControl()
 		{
-			this.isEnabled = (HtmlHelp2Environment.IsReady && Help2ControlsValidation.IsTocControlRegistered);
+			this.InitializeComponents();
+			this.UpdateControl();
 
-			if (this.isEnabled)
+			HtmlHelp2Environment.FilterQueryChanged += new EventHandler(this.FilterQueryChanged);
+			HtmlHelp2Environment.NamespaceReloaded += new EventHandler(this.NamespaceReloaded);
+		}
+
+		private void UpdateControl()
+		{
+			filterCombobox.Enabled =
+				(HtmlHelp2Environment.SessionIsInitialized && !this.tocControlFailed);
+			infoLabel.Visible = false;
+
+			if (this.tocControlFailed)
+			{
+				this.ShowInfoMessage
+					(StringParser.Parse("${res:AddIns.HtmlHelp2.HelpSystemNotAvailable}"));
+			}
+			else if (!HtmlHelp2Environment.SessionIsInitialized)
+			{
+				if (tocControl != null) tocControl.Visible = false;
+				this.ShowInfoMessage
+					("${res:AddIns.HtmlHelp2.HelpCollectionMayBeEmpty}");
+			}
+			else
+			{
+				tocControl.Visible = true;
+				this.LoadToc();
+			}
+		}
+
+		private void InitializeComponents()
+		{
+			infoLabel.Dock = DockStyle.Fill;
+			infoLabel.Visible = false;
+			infoLabel.TextAlign = ContentAlignment.MiddleCenter;
+			Controls.Add(infoLabel);
+			
+			if (Help2ControlsValidation.IsTocControlRegistered)
 			{
 				try
 				{
@@ -130,6 +167,7 @@ namespace HtmlHelp2
 					Controls.Add(tocControl);
 					tocControl.CreateControl();
 	
+					tocControl.Visible = false;
 					tocControl.BorderStyle = HxBorderStyle.HxBorderStyle_FixedSingle;
 					tocControl.FontSource = HxFontSourceConstant.HxFontExternal;
 					tocControl.TreeStyle =
@@ -145,16 +183,16 @@ namespace HtmlHelp2
 					printTopicAndSubTopics.Click += new EventHandler(this.PrintTopicAndSubTopics);
 					printContextMenu.Items.Add(printTopicAndSubTopics);
 				}
+				catch (System.Runtime.InteropServices.COMException cEx)
+				{
+					LoggingService.Error("Help 2.0: TOC control failed: " + cEx.ToString());
+					this.tocControlFailed = true;
+				}
 				catch(Exception ex)
 				{
 					LoggingService.Error("Help 2.0: TOC control failed; " + ex.ToString());
-					this.isEnabled = false;
-					this.FakeHelpControl();
-				}
+					this.tocControlFailed = true;
 				}
-			else
-			{
-				this.FakeHelpControl();
 			}
 
 			Panel panel1 = new Panel();
@@ -166,36 +204,24 @@ namespace HtmlHelp2
 			filterCombobox.Dock = DockStyle.Top;
 			filterCombobox.DropDownStyle = ComboBoxStyle.DropDownList;
 			filterCombobox.Sorted = true;
-			filterCombobox.Enabled = this.isEnabled;
+			filterCombobox.Enabled = false;
 			filterCombobox.Font = new System.Drawing.Font("Tahoma", 8F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((byte)(0)));
 			filterCombobox.SelectedIndexChanged += new EventHandler(this.FilterChanged);
 
 			Controls.Add(label1);
 			label1.Dock = DockStyle.Top;
 			label1.TextAlign = ContentAlignment.MiddleLeft;
-			label1.Enabled = this.isEnabled;
 			label1.Font = new System.Drawing.Font("Tahoma", 8F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((byte)(0)));
 			this.RedrawContent();
 			
-			if (this.isEnabled)
-			{
-				HtmlHelp2Environment.FilterQueryChanged += new EventHandler(this.FilterQueryChanged);
-				HtmlHelp2Environment.NamespaceReloaded += new EventHandler(this.NamespaceReloaded);
-				this.LoadToc();
-			}
+			this.tocControlFailed = (this.tocControlFailed || tocControl == null);
 		}
 
-		private void FakeHelpControl()
+		private void ShowInfoMessage(string infoText)
 		{
-			if (tocControl != null) tocControl.Dispose();
-			tocControl = null;
-
-			Controls.Clear();
-			Label nohelpLabel = new Label();
-			nohelpLabel.Dock = DockStyle.Fill;
-			nohelpLabel.Text = StringParser.Parse("${res:AddIns.HtmlHelp2.HelpSystemNotAvailable}");
-			nohelpLabel.TextAlign = ContentAlignment.MiddleCenter;
-			Controls.Add(nohelpLabel);
+			filterCombobox.Items.Clear();
+			infoLabel.Text = infoText;
+			infoLabel.Visible = true;
 		}
 
 		public void RedrawContent()
@@ -244,7 +270,6 @@ namespace HtmlHelp2
 				tocControl.Hierarchy.PrintNode(0, tocControl.Selection, PrintOptions.HxHierarchy_PrintNode_Option_Children);
 			}
 		}
-		
 		#endregion
 
 		private void FilterChanged(object sender, EventArgs e)
@@ -260,8 +285,7 @@ namespace HtmlHelp2
 		
 		private void LoadToc()
 		{
-			this.SetToc(HtmlHelp2Environment.CurrentFilterName);
-			if (this.isEnabled)
+			if (this.SetToc(HtmlHelp2Environment.CurrentFilterName))
 			{
 				filterCombobox.SelectedIndexChanged -= new EventHandler(this.FilterChanged);
 				HtmlHelp2Environment.BuildFilterList(filterCombobox);
@@ -269,22 +293,18 @@ namespace HtmlHelp2
 			}
 		}
 	
-		private void SetToc(string filterName)
+		private bool SetToc(string filterName)
 		{
-			if (!this.isEnabled) return;
 			try
 			{
 				tocControl.Hierarchy =
 					HtmlHelp2Environment.GetTocHierarchy(HtmlHelp2Environment.FindFilterQuery(filterName));
+				return true;
 			}
 			catch
 			{
-				this.isEnabled = false;
-				tocControl.Enabled = false;
-				tocControl.BackColor = SystemColors.ButtonFace;
-				filterCombobox.Enabled = false;
-				label1.Enabled = false;
-				LoggingService.Error("Help 2.0: cannot connect to IHxHierarchy interface (Contents)");
+				LoggingService.Error("Help 2.0: Cannot connect to the IHxHierarchy interface.");
+				return false;
 			}
 		}
 
@@ -320,7 +340,7 @@ namespace HtmlHelp2
 
 		private void NamespaceReloaded(object sender, EventArgs e)
 		{
-			this.LoadToc();
+			this.UpdateControl();
 
 			tocControl.TreeStyle =
 				(HtmlHelp2Environment.Config.TocPictures)?TSC.HxTreeStyle_TreelinesPlusMinusPictureText:TSC.HxTreeStyle_TreelinesPlusMinusText;
@@ -330,7 +350,6 @@ namespace HtmlHelp2
 		#region Published Help 2.0 Commands
 		public void SynchronizeToc(string topicUrl)
 		{
-			if (!this.isEnabled) return;
 			try
 			{
 				tocControl.Synchronize(topicUrl);
@@ -343,15 +362,23 @@ namespace HtmlHelp2
 
 		public void GetNextFromNode()
 		{
-			if (!this.isEnabled) return;
+			try
+			{
 				int currentNode = tocControl.Hierarchy.GetNextFromNode(tocControl.Selection);
 				string topicUrl = tocControl.Hierarchy.GetURL(currentNode);
 				this.CallHelp(topicUrl, true);
 			}
+			catch (System.Runtime.InteropServices.COMException)
+			{
+			}
+			catch
+			{
+			}
+		}
 
 		public void GetNextFromUrl(string url)
 		{
-			if (!this.isEnabled || url == null || url.Length == 0) return;
+			if (url == null || url.Length == 0) return;
 			try
 			{
 				int currentNode = tocControl.Hierarchy.GetNextFromUrl(url);
@@ -369,15 +396,23 @@ namespace HtmlHelp2
 
 		public void GetPrevFromNode()
 		{
-			if (!this.isEnabled) return;
+			try
+			{
 				int currentNode = tocControl.Hierarchy.GetPrevFromNode(tocControl.Selection);
 				string topicUrl = tocControl.Hierarchy.GetURL(currentNode);
 				this.CallHelp(topicUrl, true);
 			}
+			catch (System.Runtime.InteropServices.COMException)
+			{
+			}
+			catch
+			{
+			}
+		}
 
 		public void GetPrevFromUrl(string url)
 		{
-			if (!this.isEnabled || url == null || url.Length == 0) return;
+			if (url == null || url.Length == 0) return;
 			try
 			{
 				int currentNode = tocControl.Hierarchy.GetPrevFromUrl(url);
@@ -424,11 +459,6 @@ namespace HtmlHelp2
 				}
 			}
 		}
-
-		public bool IsEnabled
-		{
-			get { return this.isEnabled; }
-		}
 		#endregion
 	}
 }

src/AddIns/Misc/HtmlHelp2/Project/src/Service/Help2RegistryWalker.cs

@@ -15,14 +15,15 @@ namespace HtmlHelp2.RegistryWalker
 
 	public sealed class Help2RegistryWalker
 	{
-		public static void BuildNamespacesList(ComboBox help2Collections, string selectedHelp2Collection)
+		public static bool BuildNamespacesList(ComboBox help2Collections, string selectedHelp2Collection)
 		{
 			if (help2Collections == null)
 			{
-				return;
+				return false;
 			}
 			help2Collections.Items.Clear();
 			help2Collections.BeginUpdate();
+			bool result = true;
 
 			try
 			{
@@ -48,14 +49,18 @@ namespace HtmlHelp2.RegistryWalker
 				else
 					help2Collections.SelectedIndex = 0;
 			}
-			catch(Exception ex)
+			catch
 			{
-				LoggingService.Error("Help 2.0: Cannot build namespaces list;", ex);
+				result = false;
 			}
-
+			finally
+			{
 				help2Collections.EndUpdate();
 			}
 
+			return result;
+		}
+
 		public static string GetNamespaceName(string description)
 		{
 			try

src/AddIns/Misc/HtmlHelp2/Project/src/Service/HtmlHelp2Options.cs

@@ -24,11 +24,12 @@ namespace HtmlHelp2.OptionsPanel
 	{
 		ComboBox help2Collections = null;
 		CheckBox tocPictures = null;
-		string selectedHelp2Collection = HtmlHelp2Environment.DefaultNamespaceName;
+		string selectedHelp2Collection = string.Empty;
 
 		public override void LoadPanelContents()
 		{
-			SetupFromXmlStream(this.GetType().Assembly.GetManifestResourceStream("HtmlHelp2.Resources.HtmlHelp2Options.xfrm"));
+			SetupFromXmlStream
+				(this.GetType().Assembly.GetManifestResourceStream("HtmlHelp2.Resources.HtmlHelp2Options.xfrm"));
 			this.InitializeComponents();
 		}
 
@@ -41,22 +42,18 @@ namespace HtmlHelp2.OptionsPanel
 
 		private void InitializeComponents()
 		{
-			try
-			{
+			selectedHelp2Collection = HtmlHelp2Environment.CurrentSelectedNamespace;
+
 			help2Collections = (ComboBox)ControlDictionary["help2Collections"];
-				help2Collections.Enabled = HtmlHelp2Environment.IsReady;
 			help2Collections.SelectedIndexChanged += new EventHandler(this.NamespaceNameChanged);
-				selectedHelp2Collection = HtmlHelp2Environment.CurrentSelectedNamespace;
 
 			tocPictures = (CheckBox)ControlDictionary["tocPictures"];
-				tocPictures.Enabled = HtmlHelp2Environment.IsReady;
 			tocPictures.Checked = HtmlHelp2Environment.Config.TocPictures;
 			
-				Help2RegistryWalker.BuildNamespacesList(help2Collections, selectedHelp2Collection);
-			}
-			catch(Exception ex)
+			if (!Help2RegistryWalker.BuildNamespacesList(help2Collections, selectedHelp2Collection))
 			{
-				LoggingService.Error("Help 2.0: Cannot initialize options panel; " + ex.Message);
+				help2Collections.Enabled = false;
+				tocPictures.Enabled = false;
 			}
 		}
 

src/AddIns/Misc/HtmlHelp2/Project/src/Service/HtmlHelp2Service.cs

@@ -45,7 +45,7 @@ namespace HtmlHelp2.Environment
 		}
 
 		#region Properties
-		public static bool IsReady
+		public static bool SessionIsInitialized
 		{
 			get { return session != null; }
 		}
@@ -195,34 +195,6 @@ namespace HtmlHelp2.Environment
 			{
 				return defaultValue;
 			}
-//			string resultString = "";
-//
-//			try
-//			{
-//				IHxIndex namedUrlIndex = (IHxIndex)session.GetNavigationInterface("!DefaultNamedUrlIndex",
-//				                                                                  "",
-//				                                                                  ref IndexGuid);
-//				IHxTopicList topics = null;
-//
-//				topics = namedUrlIndex.GetTopicsFromString(pageName, 0);
-//
-//				if(topics.Count == 0 && (alternatePageName != null && alternatePageName != ""))
-//				{
-//					topics = namedUrlIndex.GetTopicsFromString(alternatePageName, 0);
-//				}
-//
-//				if(topics.Count > 0)
-//					resultString = topics.ItemAt(1).URL;
-//
-//				if (resultString == null || resultString.Length == 0)
-//					resultString = defaultValue;
-//
-//				return resultString;
-//			}
-//			catch
-//			{
-//				return defaultValue;
-//			}
 		}
 
 		public static IHxHierarchy GetTocHierarchy(string filterQuery)
@@ -303,23 +275,6 @@ namespace HtmlHelp2.Environment
 			{
 				return string.Empty;
 			}
-//			try
-//			{
-//				IHxRegFilter filter        = namespaceFilters.FindFilter(filterName);
-//				currentSelectedFilterQuery = (string)filter.GetProperty(HxRegFilterPropId.HxRegFilterQuery);
-//				currentSelectedFilterName  = filterName;
-//
-//				OnFilterQueryChanged(EventArgs.Empty);
-//
-//				ReloadFTSSystem();
-//				ReloadDynamicHelpSystem();
-//				ReloadDefaultPages();
-//				return currentSelectedFilterQuery;
-//			}
-//			catch
-//			{
-//				return "";
-//			}
 		}
 
 		public static IHxTopicList GetMatchingTopicsForDynamicHelp(string searchTerm)