added crosshair cursor and better cursor position display

src/gui/DamarisGUI.py

@@ -2322,6 +2322,24 @@ class MonitorWidgets:
         # Matplot Toolbar hinzufuegen (Display_Table, 2. Zeile)
         self.matplot_toolbar = matplotlib.backends.backend_gtk3.NavigationToolbar2GTK3( self.matplot_canvas )
 
+        # Make cursor position text bigger and bold - access message label directly
+        try:
+            # The coordinate label is stored in the toolbar's message attribute
+            if hasattr(self.matplot_toolbar, 'message'):
+                self.matplot_toolbar.message.modify_font(pango.FontDescription("sans bold 16"))
+        except:
+            pass
+
+        # Add cursor toggle button to toolbar
+        self.matplot_cursor = None
+        separator = gtk.SeparatorToolItem()
+        self.matplot_toolbar.insert(separator, self.matplot_toolbar.get_n_items())
+        cursor_btn = gtk.ToggleToolButton()
+        cursor_btn.set_label("Cursor")
+        cursor_btn.set_tooltip_text("Toggle crosshair cursor")
+        cursor_btn.connect("toggled", self.toggle_cursor)
+        self.matplot_toolbar.insert(cursor_btn, self.matplot_toolbar.get_n_items())
+
         self.display_table.attach( self.matplot_toolbar, 0, 1, 1, 2, gtk.AttachOptions.FILL | gtk.AttachOptions.EXPAND, 0, 0, 0 )
         self.matplot_toolbar.show( )
 
@@ -2743,6 +2761,15 @@ class MonitorWidgets:
 
         return True
 
+    def toggle_cursor(self, widget):
+        """Toggle matplotlib crosshair cursor"""
+        from matplotlib.widgets import Cursor
+        if widget.get_active():
+            self.matplot_cursor = Cursor(self.matplot_axes, useblit=False, color='red', linewidth=1)
+        else:
+            self.matplot_cursor = None
+        self.matplot_canvas.draw()
+
     def on_canvas_button_press(self, widget, event):
         """Handle button press events on matplotlib canvas"""
         if event.button == 3:  # Right click