added a list of suggested commands based on what's been typed so far (#…

…68)

src/console.rs

@@ -235,6 +235,8 @@ pub struct ConsoleConfiguration {
     pub background_color: Color32,
     /// Foreground (text) color
     pub foreground_color: Color32,
+    /// Number of suggested commands to show
+    pub num_suggestions: usize,
 }
 
 impl Default for ConsoleConfiguration {
@@ -255,6 +257,7 @@ impl Default for ConsoleConfiguration {
             show_title_bar: true,
             background_color: Color32::from_black_alpha(102),
             foreground_color: Color32::LIGHT_GRAY,
+            num_suggestions: 4
         }
     }
 }
@@ -421,8 +424,44 @@ pub(crate) fn console_ui(
                         .lock_focus(true)
                         .font(egui::TextStyle::Monospace);
 
-                    // Handle enter
                     let text_edit_response = ui.add(text_edit);
+
+                    // show a few suggestions
+                    if text_edit_response.has_focus() && !state.buf.is_empty() {
+                        // create the area to show suggestions
+                        let suggestions_area = 
+                            egui::Area::new(ui.auto_id_with("suggestions"))
+                                .fixed_pos(ui.next_widget_position())
+                                .movable(false);
+                        suggestions_area.show(ui.ctx(), |ui| {
+
+                            // collect the given number of commands starting
+                            // with the given text
+                            let command_names = &config.commands.iter()
+                                .map(|c| *c.0 )
+                                .filter(|c| c.starts_with(&state.buf))
+                                .collect::<Vec<_>>();
+
+                            // show each command in the list
+                            for command in command_names.iter().take(config.num_suggestions) {
+                                let mut layout_job = egui::text::LayoutJob::default();
+                                layout_job.append(state.buf.as_str(), 0.0, TextFormat {
+                                    font_id: FontId::new(14.0, egui::FontFamily::Monospace),
+                                    underline: egui::Stroke::new(1., Color32::WHITE),
+                                    color: Color32::WHITE,
+                                    ..default()
+                                });
+                                layout_job.append(&command[state.buf.len()..], 0.0, TextFormat {
+                                    font_id: FontId::new(14.0, egui::FontFamily::Monospace),
+                                    color: Color32::LIGHT_GRAY,
+                                    ..default()
+                                });
+                                ui.label(layout_job);
+                            }
+                        });
+                    }
+
+                    // Handle enter
                     if text_edit_response.lost_focus()
                         && ui.input(|i| i.key_pressed(egui::Key::Enter))
                     {