Feature: Enhanced Editing, Hex Inspector, Color Shortcuts

- Enhanced Editing: Auto-create packets, Enter key support.
- Cursor: Fixed visibility (composition mode), click-to-move, immediate redraw.
- Hex Inspector: Added Hex Value display and input panel.
- Shortcuts: Added Color Insert buttons.
- Fixes: Resolved Hamming encoding for save, fixed duplicate spaces bug, fixed IndentationError.

src/teletext/ui.py

@@ -1,7 +1,10 @@
 
-import os
 from PyQt6.QtWidgets import (QMainWindow, QWidget, QVBoxLayout, QHBoxLayout, 
-                             QListWidget, QListWidgetItem, QComboBox, QLabel, QFileDialog, QMenuBar, QMenu, QMessageBox)
+                             QListWidget, QListWidgetItem, QComboBox, QLabel, QLineEdit, QPushButton, QFileDialog, QMenuBar, QMenu, QMessageBox)
+
+# ... (imports remain)
+
+# ... (imports remain)
 from PyQt6.QtGui import QAction, QKeyEvent
 from PyQt6.QtCore import Qt
 
@@ -34,6 +37,19 @@ class MainWindow(QMainWindow):
         self.page_list.itemClicked.connect(self.on_page_selected)
         left_layout.addWidget(self.page_list)
         
+        # Hex Inspector
+        hex_layout = QVBoxLayout()
+        hex_label = QLabel("Hex Value:")
+        self.hex_input = QLineEdit()
+        self.hex_input.setMaxLength(2)
+        self.hex_input.setPlaceholderText("00")
+        self.hex_input.returnPressed.connect(self.on_hex_entered)
+        hex_layout.addWidget(hex_label)
+        hex_layout.addWidget(self.hex_input)
+        left_layout.addLayout(hex_layout)
+        
+        left_layout.addStretch()
+        
         self.layout.addLayout(left_layout)
         
         # Center Area Layout (Top Bar + Canvas)
@@ -51,8 +67,30 @@ class MainWindow(QMainWindow):
         
         center_layout.addLayout(top_bar)
         
+        # Color Shortcuts
+        color_layout = QHBoxLayout()
+        colors = [
+            ("Red", 0x01, "#FF0000"),
+            ("Green", 0x02, "#00FF00"),
+            ("Yellow", 0x03, "#FFFF00"),
+            ("Blue", 0x04, "#0000FF"),
+            ("Magenta", 0x05, "#FF00FF"),
+            ("Cyan", 0x06, "#00FFFF"),
+            ("White", 0x07, "#FFFFFF"),
+        ]
+        
+        for name, code, hex_color in colors:
+            btn = QPushButton(name)
+            btn.setStyleSheet(f"background-color: {hex_color}; font-weight: bold; color: black;")
+            btn.clicked.connect(lambda checked, c=code: self.insert_char(c))
+            color_layout.addWidget(btn)
+            
+        color_layout.addStretch()
+        center_layout.addLayout(color_layout)
+
         # Canvas
         self.canvas = TeletextCanvas()
+        self.canvas.cursorChanged.connect(self.on_cursor_changed)
         center_layout.addWidget(self.canvas, 1) # Expand
         
         self.layout.addLayout(center_layout, 1)
@@ -164,6 +202,28 @@ class MainWindow(QMainWindow):
             self.current_page = page
             self.canvas.set_page(page)
             self.canvas.setFocus()
+
+    def insert_char(self, char_code):
+        self.canvas.set_byte_at_cursor(char_code)
+        # Advance cursor
+        self.canvas.move_cursor(1, 0)
+        self.canvas.setFocus()
+            
+    def on_cursor_changed(self, x, y, val):
+        self.hex_input.setText(f"{val:02X}")
+        
+    def on_hex_entered(self):
+        text = self.hex_input.text()
+        try:
+            val = int(text, 16)
+            if 0 <= val <= 255:
+                # Update canvas input
+                # We can call handle_input with char, OR set byte directly. 
+                # Direct byte set is safer for non-printable.
+                self.canvas.set_byte_at_cursor(val)
+                self.canvas.setFocus() # Return focus to canvas
+        except ValueError:
+            pass # Ignore invalid hex
             
     # Input Handling (Editor Logic)
     def keyPressEvent(self, event: QKeyEvent):
@@ -182,6 +242,10 @@ class MainWindow(QMainWindow):
             self.canvas.move_cursor(-1, 0)
         elif key == Qt.Key.Key_Right:
             self.canvas.move_cursor(1, 0)
+        elif key == Qt.Key.Key_Return or key == Qt.Key.Key_Enter:
+            # Move to start of next line
+            self.canvas.cursor_x = 0
+            self.canvas.move_cursor(0, 1)
         else:
             # Typing
             # Filter non-printable