Refactor UI: Replace Page Tree with List+Dropdown. Fix header rendering and crash.

src/teletext/ui.py

@@ -1,7 +1,7 @@
 
 import os
 from PyQt6.QtWidgets import (QMainWindow, QWidget, QVBoxLayout, QHBoxLayout, 
-                             QTreeWidget, QTreeWidgetItem, QFileDialog, QMenuBar, QMenu, QMessageBox)
+                             QListWidget, QListWidgetItem, QComboBox, QLabel, QFileDialog, QMenuBar, QMenu, QMessageBox)
 from PyQt6.QtGui import QAction, QKeyEvent
 from PyQt6.QtCore import Qt
 
@@ -24,16 +24,38 @@ class MainWindow(QMainWindow):
         
         self.layout = QHBoxLayout(self.central_widget)
         
-        # Left Panel: Page Tree
-        self.tree = QTreeWidget()
-        self.tree.setHeaderLabel("Pages")
-        self.tree.setFixedWidth(200)
-        self.tree.itemClicked.connect(self.on_page_selected)
-        self.layout.addWidget(self.tree)
+        # Left Panel: Page List
+        left_layout = QVBoxLayout()
+        left_label = QLabel("Pages")
+        left_layout.addWidget(left_label)
         
-        # Center: Teletext Canvas
+        self.page_list = QListWidget()
+        self.page_list.setFixedWidth(150)
+        self.page_list.itemClicked.connect(self.on_page_selected)
+        left_layout.addWidget(self.page_list)
+        
+        self.layout.addLayout(left_layout)
+        
+        # Center Area Layout (Top Bar + Canvas)
+        center_layout = QVBoxLayout()
+        
+        # Top Bar: Subpage Selector
+        top_bar = QHBoxLayout()
+        self.subpage_label = QLabel("Subpage:")
+        self.subpage_combo = QComboBox()
+        self.subpage_combo.setMinimumWidth(250)
+        self.subpage_combo.currentIndexChanged.connect(self.on_subpage_changed)
+        top_bar.addWidget(self.subpage_label)
+        top_bar.addWidget(self.subpage_combo)
+        top_bar.addStretch()
+        
+        center_layout.addLayout(top_bar)
+        
+        # Canvas
         self.canvas = TeletextCanvas()
-        self.layout.addWidget(self.canvas, 1) # Expand
+        center_layout.addWidget(self.canvas, 1) # Expand
+        
+        self.layout.addLayout(center_layout, 1)
         
         # Menus
         self.create_menus()
@@ -78,7 +100,7 @@ class MainWindow(QMainWindow):
         if fname:
             try:
                 self.service = load_t42(fname)
-                self.populate_tree()
+                self.populate_list()
                 QMessageBox.information(self, "Loaded", f"Loaded {len(self.service.pages)} pages.")
             except Exception as e:
                 QMessageBox.critical(self, "Error", f"Failed to load file: {e}")
@@ -92,34 +114,55 @@ class MainWindow(QMainWindow):
             except Exception as e:
                 QMessageBox.critical(self, "Error", f"Failed to save file: {e}")
 
-    def populate_tree(self):
-        self.tree.clear()
+    def populate_list(self):
+        self.page_list.clear()
+        
+        # Group pages by Mag+PageNum
+        # We want unique list items
+        self.page_groups = {} # Key: (mag, page_num) -> List[Page]
         
-        # Group by Magazine
-        mags = {}
         for p in self.service.pages:
-            if p.magazine not in mags:
-                mags[p.magazine] = QTreeWidgetItem([f"Magazine {p.magazine}"])
-                self.tree.addTopLevelItem(mags[p.magazine])
+            key = (p.magazine, p.page_number)
+            if key not in self.page_groups:
+                self.page_groups[key] = []
+            self.page_groups[key].append(p)
             
-            # Format: PPP-SS (Page-Subcode)
-            # Create Item
-            # Subcode is complicated to display "nicely" without decoding, 
-            # let's just show hex or raw for now if not standard 0000.
+        # Sort keys
+        sorted_keys = sorted(self.page_groups.keys())
         
-            label = f"{p.page_number:02d} (Sub: {p.sub_code:04X})"
-            item = QTreeWidgetItem([label])
-            item.setData(0, Qt.ItemDataRole.UserRole, p)
-            mags[p.magazine].addChild(item)
+        for mag, pnum in sorted_keys:
+            label = f"{mag}{pnum:02d}"
+            item = QListWidgetItem(label)
+            item.setData(Qt.ItemDataRole.UserRole, (mag, pnum))
+            self.page_list.addItem(item)
 
-        self.tree.expandAll()
+    def on_page_selected(self, item):
+        mag, pnum = item.data(Qt.ItemDataRole.UserRole)
+        pages = self.page_groups.get((mag, pnum), [])
         
-    def on_page_selected(self, item, column):
-        page = item.data(0, Qt.ItemDataRole.UserRole)
+        # Populate Subpage Combo
+        self.subpage_combo.blockSignals(True)
+        self.subpage_combo.clear()
+        
+        for i, p in enumerate(pages):
+            # Display format: Index or Subcode?
+            # Subcode is often 0000. Index 1/N is clearer for editing.
+            label = f"{i+1}/{len(pages)} (Sub {p.sub_code:04X})"
+            self.subpage_combo.addItem(label, p)
+            
+        self.subpage_combo.blockSignals(False)
+        
+        if pages:
+            self.subpage_combo.setCurrentIndex(0)
+            # Trigger update (manual because blockSignals)
+            self.on_subpage_changed(0)
+            
+    def on_subpage_changed(self, index):
+        if index < 0: return
+        page = self.subpage_combo.itemData(index)
         if isinstance(page, Page):
             self.current_page = page
             self.canvas.set_page(page)
-            # Also set window focus to canvas or handle key events?
             self.canvas.setFocus()
             
     # Input Handling (Editor Logic)