Added unload feature to unload current pdfs

Author: reliak

Diff for: src/MoonPdf/Properties/AssemblyInfo.cs

@@ -64,5 +64,5 @@ You should have received a copy of the GNU General Public License
 // You can specify all the values or you can default the Build and Revision Numbers 
 // by using the '*' as shown below:
 // [assembly: AssemblyVersion("1.0.*")]
-[assembly: AssemblyVersion("0.3.0.0")]
-[assembly: AssemblyFileVersion("0.3.0.0")]
+[assembly: AssemblyVersion("0.3.1.0")]
+[assembly: AssemblyFileVersion("0.3.1.0")]

Diff for: src/MoonPdfLib/ContinuousMoonPdfPanel.xaml.cs

@@ -75,9 +75,28 @@ public void Load(IPdfSource source, string password = null)
                 this.ZoomToWidth();
 
             if (this.scrollViewer != null)
+            {
+                this.scrollViewer.Visibility = System.Windows.Visibility.Visible;
                 this.scrollViewer.ScrollToTop();
+            }
         }
-        
+
+        public void Unload()
+        {
+            this.scrollViewer.Visibility = System.Windows.Visibility.Collapsed;
+            this.scrollViewer.ScrollToHorizontalOffset(0);
+            this.scrollViewer.ScrollToVerticalOffset(0);
+            this.imageProvider = null;
+
+            if (this.virtualizingPdfPages != null)
+            {
+                this.virtualizingPdfPages.CleanUpAllPages();
+                this.virtualizingPdfPages = null;
+            }
+
+            this.itemsControl.ItemsSource = null;
+        }
+
 		private void CreateNewItemsSource()
 		{
 			var pageTimeout = TimeSpan.FromSeconds(2);

Diff for: src/MoonPdfLib/IMoonPdfPanel.cs

@@ -33,6 +33,7 @@ internal interface IMoonPdfPanel
 		UserControl Instance { get; }
 		float CurrentZoom { get; }
 		void Load(IPdfSource source, string password = null);
+        void Unload();
         void Zoom(double zoomFactor);
 		void ZoomIn();
 		void ZoomOut();

Diff for: src/MoonPdfLib/MoonPdfPanel.xaml.cs

@@ -211,7 +211,19 @@ public void Open(IPdfSource source, string password = null)
 			if (this.PdfLoaded != null)
 				this.PdfLoaded(this, EventArgs.Empty);
 		}
-        
+
+        public void Unload()
+        {
+            this.CurrentSource = null;
+            this.CurrentPassword = null;
+            this.TotalPages = 0;
+
+            this.innerPanel.Unload();
+
+            if (this.PdfLoaded != null)
+                this.PdfLoaded(this, EventArgs.Empty);
+        }
+
         private void LoadPdf(IPdfSource source, string password)
         {
             var pageBounds = MuPdfWrapper.GetPageBounds(source, this.Rotation, password);

Diff for: src/MoonPdfLib/Properties/AssemblyInfo.cs

@@ -45,5 +45,5 @@ You should have received a copy of the GNU General Public License
 // You can specify all the values or you can default the Build and Revision Numbers 
 // by using the '*' as shown below:
 // [assembly: AssemblyVersion("1.0.*")]
-[assembly: AssemblyVersion("0.3.0.0")]
-[assembly: AssemblyFileVersion("0.3.0.0")]
+[assembly: AssemblyVersion("0.3.1.0")]
+[assembly: AssemblyFileVersion("0.3.1.0")]

Diff for: src/MoonPdfLib/SinglePageMoonPdfPanel.xaml.cs

@@ -59,14 +59,27 @@ public void Load(IPdfSource source, string password = null)
 
             currentPageIndex = 0;
 
+            if (this.scrollViewer != null)
+                this.scrollViewer.Visibility = System.Windows.Visibility.Visible;
+
             if (this.parent.ZoomType == ZoomType.Fixed)
                 this.SetItemsSource();
             else if (this.parent.ZoomType == ZoomType.FitToHeight)
                 this.ZoomToHeight();
             else if (this.parent.ZoomType == ZoomType.FitToWidth)
                 this.ZoomToWidth();
         }
-        
+
+        public void Unload()
+        {
+            this.scrollViewer.Visibility = System.Windows.Visibility.Collapsed;
+            this.scrollViewer.ScrollToHorizontalOffset(0);
+            this.scrollViewer.ScrollToVerticalOffset(0);
+            currentPageIndex = 0;
+
+            this.imageProvider = null;
+        }
+
 		ScrollViewer IMoonPdfPanel.ScrollViewer
 		{
 			get { return this.scrollViewer; }