feat: Implement dynamic cursor height for double-height characters

.gitea/workflows/build-windows.yaml

@@ -23,7 +23,7 @@ jobs:
 
       - name: Build Executable
         run: |
-          wine pyinstaller --onefile --windowed --name TeletextEditor_Windows.exe --paths src --add-data "app_icon.png;." --icon=app_icon.ico src/main.py
+          wine pyinstaller --onefile --windowed --hidden-import=pkgutil --hidden-import=PyQt6.sip --collect-all PyQt6 --name TeletextEditor_Windows.exe --paths src --add-data "app_icon.png;." --icon=app_icon.ico src/main.py
 
       - name: Upload Artifact
         uses: actions/upload-artifact@v3

build_app.py

@@ -27,6 +27,9 @@ def build():
         sys.executable, "-m", "PyInstaller",
         "--onefile",
         "--windowed",
+        "--hidden-import=pkgutil",
+        "--hidden-import=PyQt6.sip",
+        "--collect-all", "PyQt6",
         "--paths", "src",
         f"--add-data=app_icon.png{sep}.",
         "src/main.py"

src/teletext/io.py

@@ -228,3 +228,65 @@ def parse_header(data: bytearray):
     language = ((c_bits_2 & 1) << 1) | ((c_bits_2 & 2) >> 1) | (c_bits_2 & 4)
     
     return page_num, sub_code, language
+
+def save_tti(file_path: str, page: Page):
+    """
+    Saves a single Page object to a TTI file.
+    """
+    with open(file_path, 'w', encoding='latin-1') as f:
+        # Header Info
+        # DS - Source? Description?
+        f.write(f"DS,Teletext Editor Export\n")
+        f.write(f"SP,{file_path}\n")
+        
+        # PN - Page Number mpp00
+        # Typically TTI uses decimal integer for mppss? 
+        # Or mppss as hex digits? 
+        # Standard convention: mppss where m is 1-8, pp is 00-FF, ss is 00-99
+        # Example: Page 100 -> PN,10000
+        # Example: Page 1F0 -> PN,1F000
+        f.write(f"PN,{page.magazine}{page.page_number:02X}00\n")
+        
+        # SC - Subcode ssss
+        f.write(f"SC,{page.sub_code:04X}\n")
+        
+        # PS - Page Status
+        # 8000 is typical for "Transmission"
+        f.write(f"PS,8000\n")
+        
+        # RE - Region (Language)
+        f.write(f"RE,{page.language}\n")
+        
+        # Lines
+        # We need to construct the 40-char string for each row
+        # Row 0 is special (Header)
+        
+        # Get all packets for this page
+        # Map row -> packet
+        rows = {}
+        for p in page.packets:
+            rows[p.row] = p
+            
+        for r in range(26): # 0 to 25
+            if r in rows:
+                packet = rows[r]
+                # Packet data is 40 bytes (after the 2-byte header we stripped in Packet class? No wait)
+                # Packet.data in our model IS the 40 bytes of character data (we strip MRAG in __post_init__)
+                # So we just decode it as latin-1 to get the chars
+                
+                # However, we must ensure we don't have newlines or nulls breaking the text file structure
+                # TTI format usually accepts raw bytes 0x00-0xFF if strictly handled, but often expects
+                # mapped control codes.
+                # Standard VBIT2 TTI handling treats it as a binary-safe string if mapped to char.
+                
+                # Row 0 special handling: The first 8 bytes of Row 0 are usually header flags in the packet,
+                # but visually they are "P100    ".
+                # TTI usually expects the visual representation for the line content.
+                # But for transmission, we want the raw bytes.
+                # OL,r,String
+                
+                data_str = packet.data.decode('latin-1')
+                f.write(f"OL,{r},{data_str}\n")
+            else:
+                # Empty line? Usually omitted or written as empty
+                pass

src/teletext/renderer.py

@@ -252,6 +252,9 @@ class TeletextCanvas(QWidget):
         held_char = 0x20 # Space
         double_height = False
         
+        last_visible_idx = -1
+        bg_segments = [(0, bg)] # Track BG changes: (index, color)
+        
         y = row * self.cell_h
         
         data = b''
@@ -263,7 +266,7 @@ class TeletextCanvas(QWidget):
         # Header string for Row 0 columns 0-7
         header_prefix = ""
         if row == 0 and self.page:
-            header_prefix = f"P{self.page.magazine}{self.page.page_number:02d}"
+            header_prefix = f"P{self.page.magazine}{self.page.page_number:02X}"
             # Pad to 8 chars
             header_prefix = header_prefix.ljust(8)
             
@@ -311,12 +314,33 @@ class TeletextCanvas(QWidget):
                     graphics_mode = True
                 elif byte_val == 0x1C: # Black BG
                     bg = COLORS[0]
+                    bg_segments.append((c, bg))
                 elif byte_val == 0x1D: # New BG
                     bg = fg
+                    bg_segments.append((c, bg))
+                    
                 elif byte_val == 0x0C: # Normal Height
                     double_height = False
                 elif byte_val == 0x0D: # Double Height
                     double_height = True
+                    # Backfill Height if we are in leading controls
+                    if last_visible_idx == -1:
+                        # Update occlusion mask for 0..c-1
+                        for k in range(c):
+                            next_occlusion_mask[k] = True
+                            
+                        # Repaint 0..c-1 with DH
+                        if draw_bg:
+                            # Repaint each cell with its historical BG
+                            for k in range(c):
+                                # Resolve BG for k
+                                cell_bg = bg_segments[0][1]
+                                for idx, color in reversed(bg_segments):
+                                    if idx <= k:
+                                        cell_bg = color
+                                        break
+                                painter.fillRect(k * self.cell_w, y, self.cell_w, self.cell_h * 2, cell_bg)
+
                 elif byte_val == 0x19: # Contiguous Graphics
                     contiguous = True
                 elif byte_val == 0x1A: # Separated Graphics
@@ -326,6 +350,23 @@ class TeletextCanvas(QWidget):
                 elif byte_val == 0x1F: # Release Graphics
                     hold_graphics = False
             
+            # Update visibility tracker
+            # If it's a control code, it's "invisible" (space) UNLESS Held Graphics draws something
+            visible_content = False
+            if is_control:
+                if hold_graphics and graphics_mode:
+                    visible_content = True
+            else:
+                 # Treat Space (0x20) as "invisible" for backfill purposes
+                 # This allows backfilling height over leading spaces in banners
+                 if byte_val > 0x20:
+                     visible_content = True
+                 
+            if visible_content:
+                # If this is the first visible char, mark it
+                if last_visible_idx == -1:
+                    last_visible_idx = c
+
             # Record Double Height for next row
             if double_height and not is_occluded:
                 next_occlusion_mask[c] = True
@@ -398,8 +439,8 @@ class TeletextCanvas(QWidget):
             if draw_fg and self.cursor_visible and c == self.cursor_x and row == self.cursor_y:
                  painter.setCompositionMode(QPainter.CompositionMode.CompositionMode_Difference)
                  # Difference with white creates inversion
-                 # Note: Cursor follows double height? Probably just the active cell.
-                 painter.fillRect(x, y, self.cell_w, self.cell_h, QColor(255, 255, 255))
+                 h_cursor = self.cell_h * 2 if double_height else self.cell_h
+                 painter.fillRect(x, y, self.cell_w, h_cursor, QColor(255, 255, 255))
                  painter.setCompositionMode(QPainter.CompositionMode.CompositionMode_SourceOver)
         
         return next_occlusion_mask

src/teletext/ui.py

@@ -8,7 +8,7 @@ from PyQt6.QtWidgets import (
 from PyQt6.QtGui import QAction, QKeyEvent, QPainter, QBrush, QColor
 from PyQt6.QtCore import Qt, QRect, QTimer
 
-from .io import load_t42, save_t42
+from .io import load_t42, save_t42, save_tti, decode_hamming_8_4, encode_hamming_8_4
 from .renderer import TeletextCanvas, create_blank_packet
 import copy
 import sys
@@ -121,10 +121,14 @@ class MainWindow(QMainWindow):
         
         self.service = TeletextService()
         self.current_page: Page = None
+        self.current_file_path = None
         self.clipboard = [] # List of (row, data_bytes)
         self.undo_stack = []
         self.redo_stack = []
         self.is_modified = False
+        self.language_overrides = {} # Session-based viewer overrides: (mag, pnum) -> lang_idx
+        
+        self.language_names = ["English", "German", "Swedish/Finnish", "Italian", "French", "Portuguese/Spanish", "Turkish", "Romania"]
 
         # UI Components
         self.central_widget = QWidget()
@@ -296,6 +300,26 @@ class MainWindow(QMainWindow):
         btn_release.clicked.connect(lambda: self.insert_char(0x1F))
         right_layout.addWidget(btn_release)
         
+        right_layout.addSpacing(10)
+
+        # Page Language Setting
+        lang_group_label = QLabel("Page Language:")
+        right_layout.addWidget(lang_group_label)
+        
+        lang_layout = QHBoxLayout()
+        self.lang_combo = QComboBox()
+        self.lang_combo.addItems(self.language_names)
+        self.lang_combo.setToolTip("Select the National Option Character Set for this page.")
+        
+        btn_set_lang = QPushButton("Set")
+        btn_set_lang.setFixedWidth(40)
+        btn_set_lang.clicked.connect(self.apply_language_change)
+        btn_set_lang.setToolTip("Apply this language setting to the page header.")
+        
+        lang_layout.addWidget(self.lang_combo)
+        lang_layout.addWidget(btn_set_lang)
+        right_layout.addLayout(lang_layout)
+        
         right_layout.addStretch()
         
         self.layout.addLayout(center_layout, 1)
@@ -319,8 +343,6 @@ class MainWindow(QMainWindow):
         self.language_label = QLabel("Lang: English")
         self.status_bar.addPermanentWidget(self.language_label)
 
-        self.language_names = ["English", "German", "Swedish/Finnish", "Italian", "French", "Portuguese/Spanish", "Turkish", "Romania"]
-
         # Menus
         self.create_menus()
 
@@ -328,6 +350,7 @@ class MainWindow(QMainWindow):
         idx = self.canvas.subset_idx
         if 0 <= idx < len(self.language_names):
             self.language_label.setText(f"Lang: {self.language_names[idx]}")
+            self.lang_combo.setCurrentIndex(idx)
         else:
             self.language_label.setText(f"Lang: Unknown ({idx})")
 
@@ -386,6 +409,10 @@ class MainWindow(QMainWindow):
         save_as_action.triggered.connect(self.save_as_file)
         file_menu.addAction(save_as_action)
         
+        export_tti_action = QAction("Export to TTI...", self)
+        export_tti_action.triggered.connect(self.export_tti)
+        file_menu.addAction(export_tti_action)
+        
         close_action = QAction("Close File", self)
         close_action.triggered.connect(self.close_file)
         file_menu.addAction(close_action)
@@ -437,6 +464,79 @@ class MainWindow(QMainWindow):
         if action:
             idx = action.data()
             self.canvas.subset_idx = idx
+            
+            # Store session override for the current page (magazine + page number)
+            if self.current_page:
+                key = (self.current_page.magazine, self.current_page.page_number)
+                self.language_overrides[key] = idx
+                
+            self.canvas.redraw()
+            self.canvas.update()
+            self.update_language_label()
+
+    def apply_language_change(self):
+        if not self.current_page:
+            return
+            
+        idx = self.lang_combo.currentIndex()
+        if idx < 0: return
+        
+        # Update the model
+        self.current_page.language = idx
+        
+        # Also update the session override/viewer to match
+        self.canvas.subset_idx = idx
+        key = (self.current_page.magazine, self.current_page.page_number)
+        self.language_overrides[key] = idx
+        
+        # Patch Row 0 packet data to persist language selection to file
+        # Language bits are in Byte 8 (Control Bits 2): C12, C13, C14
+        # We need to preserve C11 (bit 3 of encoded 4-bit val) which is "Inhibit Display" usually 0
+        
+        # Find Row 0 packet
+        header_packet = None
+        for p in self.current_page.packets:
+            if p.row == 0:
+                header_packet = p
+                break
+        
+        if header_packet and len(header_packet.data) > 8:
+            try:
+                old_val = decode_hamming_8_4(header_packet.data[8])
+                # Encoded nibble structure: D1(b0), D2(b1), D3(b2), D4(b3)
+                # D1 maps to C12
+                # D2 maps to C13
+                # D3 maps to C14
+                # D4 maps to C11
+                
+                # io.py logic for reading:
+                # language = ((c_bits_2 & 1) << 1) | ((c_bits_2 & 2) >> 1) | (c_bits_2 & 4)
+                # i.e. Lang Bit 0 comes from D2, Lang Bit 1 comes from D1, Lang Bit 2 comes from D3
+                
+                # So for writing:
+                # D1 = Lang Bit 1
+                # D2 = Lang Bit 0
+                # D3 = Lang Bit 2
+                
+                l0 = (idx >> 0) & 1
+                l1 = (idx >> 1) & 1
+                l2 = (idx >> 2) & 1
+                
+                d1 = l1
+                d2 = l0
+                d3 = l2
+                d4 = (old_val >> 3) & 1 # Preserve C11
+                
+                new_val = d1 | (d2 << 1) | (d3 << 2) | (d4 << 3)
+                
+                header_packet.data[8] = encode_hamming_8_4(new_val)
+                self.set_modified(True)
+                self.status_label.setText(f"Language set to {self.language_names[idx]} (saved to header).")
+            except Exception as e:
+                self.status_label.setText(f"Error setting language: {e}")
+        else:
+            self.status_label.setText("No header packet found to update.")
+            
         self.canvas.redraw()
         self.canvas.update()
         self.update_language_label()
@@ -475,6 +575,7 @@ class MainWindow(QMainWindow):
         
         self.undo_stack.clear()
         self.redo_stack.clear()
+        self.language_overrides.clear()
         
         self.status_label.setText("File closed.")
         QTimer.singleShot(3000, lambda: self.status_label.setText("Ready"))
@@ -516,9 +617,9 @@ class MainWindow(QMainWindow):
 
     def save_file(self) -> bool:
         if not self.current_file_path:
-             fname, _ = QFileDialog.getSaveFileName(self, "Save T42", "", "Teletext Files (*.t42)")
-             if not fname: return False
-             self.current_file_path = fname
+             # User requested status message instead of Save As behavior for empty state
+             self.status_label.setText("No file loaded to save. Please use 'Save As...' or 'Open' first.")
+             return False
         
         try:
             self.progress_bar.setVisible(True)
@@ -544,6 +645,20 @@ class MainWindow(QMainWindow):
             self.status_label.setText("Error saving file")
             return False
 
+    def export_tti(self):
+        if not self.current_page:
+            QMessageBox.warning(self, "Export TTI", "No page selected to export.")
+            return
+            
+        fname, _ = QFileDialog.getSaveFileName(self, "Export to TTI", "", "Teletext Text Image (*.tti)")
+        if not fname: return
+        
+        try:
+            save_tti(fname, self.current_page)
+            QMessageBox.information(self, "Export Successful", f"Page exported to {os.path.basename(fname)}")
+        except Exception as e:
+            QMessageBox.critical(self, "Export Failed", f"Failed to export TTI: {e}")
+
     def copy_page_content(self):
         if not self.current_page:
             return
@@ -751,6 +866,14 @@ class MainWindow(QMainWindow):
         if isinstance(page, Page):
             self.current_page = page
             self.canvas.set_page(page)
+            
+            # Apply session language override if it exists for this page
+            key = (page.magazine, page.page_number)
+            if key in self.language_overrides:
+                self.canvas.subset_idx = self.language_overrides[key]
+                self.canvas.redraw()
+                self.canvas.update()
+                
             self.update_language_label()
             self.canvas.setFocus()