Reworked how we handle keyboard input.

src/MainForm.cs

@@ -31,6 +31,7 @@ public partial class MainForm : Form
     private Tuple<int,int> mScrollDragAnchor ;
     private double mCurrZoom, mMinZoom, mMaxZoom ;
     private DateTime mLastKeyPressTimeStamp = DateTime.Now ;
+    private bool mDisableProcessCmdKey = false ;
 
     public MainForm()
     {

src/MainForm.ui.cs

@@ -88,9 +88,6 @@ public partial class MainForm : Form
         this.FormClosing += new FormClosingEventHandler( this.MainForm_FormClosing ) ;
         this.Resize += new EventHandler( this.MainForm_Resize ) ;
         this.mSearchQuery.TextChanged += new EventHandler( this.SearchQuery_TextChanged ) ;
-        this.mSearchQuery.KeyPress += new KeyPressEventHandler( this.SearchQuery_KeyPress ) ;
-        this.mSearchQuery.KeyDown += new KeyEventHandler( this.SearchQuery_KeyDown ) ;
-        this.mSearchResults.KeyPress += new KeyPressEventHandler( this.SearchResults_KeyPress ) ;
         this.mSearchResults.SelectionChanged += new EventHandler( this.SearchResults_SelectionChanged ) ;
 
         mChartImagePictureBox.MouseDown += new MouseEventHandler( this.ChartImagePictureBox_MouseDown ) ;
@@ -121,6 +118,80 @@ public partial class MainForm : Form
         return false ;
     }
 
+    protected override bool ProcessCmdKey( ref Message msg, Keys keyData )
+    {
+        // prevent recursive calls
+        if ( mDisableProcessCmdKey )
+            return false ;
+
+        // initialize
+        Keys modifierKeys = Control.ModifierKeys & (Keys.Control | Keys.Shift | Keys.Alt) ;
+        Keys keyCode = keyData & ~(Keys.Control | Keys.Shift | Keys.Alt) ;
+
+        // check for special keypresses
+        if ( keyCode == Keys.Left || keyCode == Keys.Right ) {
+            // send the keypress to the search results
+            mSearchResults.Focus() ;
+            mDisableProcessCmdKey = true ;
+            SendKeys.SendWait( "{" + keyCode.ToString() + "}" ) ;
+            mDisableProcessCmdKey = false ;
+            return true ;
+        }
+        if ( keyCode == Keys.Escape ) {
+            // clear the search query
+            mSearchQuery.Text = "" ;
+            loadSearchResults( mChartImages.Values, "SHOW-ALL" ) ;
+            return true ;
+        }
+        if ( keyCode == Keys.Return )
+            return true ; // nb: stop Windows from beeping :-/
+
+        // check for ChartImage shortcuts
+        List<ChartImage> chartImages = ChartImage.checkShortcut( modifierKeys, keyCode ) ;
+        if ( chartImages != null ) {
+            // yup - show them as search results
+            ILog logger = LogManager.GetLogger( "shortcuts" ) ;
+            logger.Info( $"Found ChartImage's for shortcut: {ChartImage.shortcutString(modifierKeys,keyCode)}" ) ;
+            foreach ( ChartImage chartImage in chartImages )
+                logger.Info( $"- {chartImage.caption()}" ) ;
+            mSearchQuery.Text = "" ;
+            loadSearchResults( chartImages, "HOTKEY:"+modifierKeys+":"+keyCode ) ;
+            return true ;
+        }
+
+        // check if we should update the search query
+        // FUDGE! This is incredibly annoying :-/ We get a *key code*, which is not the same as an ASCII character,
+        // so we only recognize a very limited set of characters here. Other characters will still be recognized
+        // and added to the search query *if* the textbox has focus (since the code here won't fire, we end up
+        // flagging the message as "not processed", and the textbox will receive the message normally), so it's
+        // only an issue when the user is typing a search query and something else has focus. We could perhaps
+        // translate things like Keys.OemXXX key codes here, but it's not worth the effort, since search queries
+        // will almost always consist of only letters and/or numbers.
+        int ch = (int) keyCode ;
+        string sendKey = "" ;
+        if ( (ch >= 65 && ch <= 90) || ch == 32 )
+            sendKey = ((char)ch).ToString().ToLower() ;
+        else if ( ch >= 48 && ch <= 57 )
+            sendKey = keyCode.ToString().Substring( 1 ) ;
+        else if ( keyCode == Keys.Back )
+            sendKey = "{BKSP}" ;
+        if ( sendKey != "" ) {
+            // check if it's time to start a new search query
+            int ttl = Program.appConfig.getIntVal( new string[]{"SearchQueryTTL"}, 5 ) ;
+            if ( (DateTime.Now - mLastKeyPressTimeStamp).TotalSeconds > ttl )
+                mSearchQuery.Text = "" ;
+            mLastKeyPressTimeStamp = DateTime.Now ;
+            // send the keypress to the search query textbox
+            mSearchQuery.Focus() ;
+            mDisableProcessCmdKey = true ;
+            SendKeys.SendWait( sendKey ) ;
+            mDisableProcessCmdKey = false ;
+            return true ;
+        }
+
+        return false ;
+    }
+
     private int ChartImagePanel_MaxScrollX() { return mChartImagePanel.HorizontalScroll.Maximum - mChartImagePanel.Width + 17 ; }
     private int ChartImagePanel_MaxScrollY() { return mChartImagePanel.VerticalScroll.Maximum - mChartImagePanel.Height + 17 ; }
 
@@ -359,62 +430,4 @@ public partial class MainForm : Form
         updateSearchResults( mSearchQuery.Text.Trim() ) ;
     }
 
-    private void SearchQuery_KeyPress( object sender, KeyPressEventArgs e )
-    {
-        // check how much time has passed since the last keypress
-        int ch = (int) e.KeyChar ;
-        if ( ch >= 32 && ch < 127 ) {
-            int ttl = Program.appConfig.getIntVal( new string[]{"SearchQueryTTL"}, 5 ) ;
-            if ( (DateTime.Now - mLastKeyPressTimeStamp).TotalSeconds > ttl ) {
-                // it's been a while - start a new search query
-                mSearchQuery.Text = "" ;
-            }
-            mLastKeyPressTimeStamp = DateTime.Now ;
-        }
-    }
-
-    private void SearchQuery_KeyDown( object sender, KeyEventArgs e )
-    {
-        // check if there are any ChartImage's associated with the keypress
-        List<ChartImage> chartImages = ChartImage.checkShortcut( e.Modifiers, e.KeyCode ) ;
-        if ( chartImages != null ) {
-            // yup - show them as search results
-            ILog logger = LogManager.GetLogger( "shortcuts" ) ;
-            logger.Info( $"Found ChartImage's for shortcut: {ChartImage.shortcutString(e.Modifiers,e.KeyCode)}" ) ;
-            foreach ( ChartImage chartImage in chartImages )
-                logger.Info( $"- {chartImage.caption()}" ) ;
-            mSearchQuery.Text = "" ;
-            loadSearchResults( chartImages, "HOTKEY:"+e.Modifiers+":"+e.KeyCode ) ;
-            e.Handled = true ;
-            return ;
-        }
-
-        // check if we should apply the keypress to the search results
-        if ( e.KeyCode == Keys.Escape ) {
-            mSearchQuery.Text = "" ;
-            loadSearchResults( mChartImages.Values, "SHOW-ALL" ) ;
-            e.SuppressKeyPress = true ;
-            e.Handled = true ;
-        } else if ( e.KeyCode == Keys.Return ) {
-            e.SuppressKeyPress = true ;
-            e.Handled = true ;
-        } else if ( e.KeyCode == Keys.Left || e.KeyCode == Keys.Right ) {
-            mSearchResults.Focus() ;
-            SendKeys.SendWait( "{" + e.KeyCode.ToString() + "}" ) ;
-            mSearchQuery.Focus() ;
-            e.Handled = true ;
-        }
-    }
-
-    private void SearchResults_KeyPress( object sender, KeyPressEventArgs e )
-    {
-        // check if we should apply the keypress to the search query
-        int ch = (int) e.KeyChar ;
-        if ( ch == 27 )
-            mSearchQuery.Text = "" ;
-        else if ( ch >= 32 && ch < 127 ) {
-            mSearchQuery.Focus() ;
-            SendKeys.Send( e.KeyChar.ToString() ) ;
-        }
-    }
 }