Update the UI as images are loaded during startup.

src/MainForm.cs

@@ -1,5 +1,6 @@
 using System ;
 using System.IO ;
+using System.Threading ;
 using System.Drawing ;
 using System.Collections.Generic ;
 using System.Windows.Forms ;
@@ -46,6 +47,8 @@ public partial class MainForm : Form
             dataDir, "*.*", SearchOption.AllDirectories
         ) ;
         foreach( string fname in files ) {
+
+            // load the next image
             string extn = Path.GetExtension( fname ).ToLower() ;
             if ( ! mValidImageExtensions.Contains( extn ) )
                 continue ;
@@ -61,8 +64,20 @@ public partial class MainForm : Form
                 key = fullPath ;
             }
             logger.Debug( $"Loading image: {key}" ) ;
-            mChartImages[ key ] = new ChartImage( key, fullPath ) ;
+            ChartImage chartImage = new ChartImage( key, fullPath ) ;
+            mChartImages[ key ] = chartImage ;
+
+            // add the image to the list
+            ImageListViewItem item = chartImage.imageListViewItem ;
+            mSearchResults.Invoke( (MethodInvoker) ( () => mSearchResults.Items.Add( item ) ) ) ;
         }
+
+        // everything has been loaded, allow searches
+        mSearchQuery.Invoke( (MethodInvoker) ( () => {
+            mSearchLabel.Enabled = true ;
+            mSearchQuery.Enabled = true ;
+            mSearchQuery.Focus() ;
+        } ) ) ;
     }
 
     private void updateSearchResults( string searchQuery )

src/MainForm.ui.cs

@@ -2,6 +2,7 @@ using System ;
 using System.Text ;
 using System.Drawing ;
 using System.IO ;
+using System.Threading ;
 using System.Runtime.InteropServices ;
 using System.Collections.Generic ;
 using System.Windows.Forms ;
@@ -131,8 +132,11 @@ public partial class MainForm : Form
         doMainFormResize( null ) ;
 
         // load the chart images
-        loadChartImages() ;
-        loadSearchResults( mChartImages.Values, "" ) ;
+        // NOTE: This can take some time, so we update the UI as they are loaded.
+        mSearchLabel.Enabled = false ;
+        mSearchQuery.Enabled = false ;
+        Thread thread = new Thread( () => loadChartImages() ) ;
+        thread.Start() ;
     }
 
     private void MainForm_FormClosing( object sender, FormClosingEventArgs e )