feat: add Mosaic Graphics support and fix char rendering

- Added Mosaic Picker dialog with visual previews
- Added 'Graphics' mode toggle to UI
- Implemented status bar mode indicator (Text/Graphics)
- Corrected English character mapping for 0x60 to Hyphen (-)
- Verified German and Swedish/Finnish character sets against ETSI spec

src/teletext/charsets.py

@@ -9,7 +9,7 @@ to Unicode characters based on the National Option (3 bits).
 ENGLISH = {
     0x23: '#', 0x24: '$', 0x40: '@', 
     0x5B: '[', 0x5C: '\\', 0x5D: ']', 0x5E: '^', 
-    0x5F: '_', 0x60: '`', 
+    0x5F: '_', 0x60: '-', 
     0x7B: '{', 0x7C: '|', 0x7D: '}', 0x7E: '~'
 }
 

src/teletext/renderer.py

@@ -53,7 +53,7 @@ COLORS = [
 ]
 
 class TeletextCanvas(QWidget):
-    cursorChanged = pyqtSignal(int, int, int) # x, y, byte_val
+    cursorChanged = pyqtSignal(int, int, int, bool) # x, y, byte_val, is_graphics
 
     def __init__(self, parent=None):
         super().__init__(parent)
@@ -83,6 +83,7 @@ class TeletextCanvas(QWidget):
         self.cursor_x = 0
         self.cursor_y = 0
         self.cursor_visible = True
+        self.cursor_is_graphics = False # Tracked during draw
         # Blinking cursor timer could be added, for now static inverted is fine or toggle on timer elsewhere
 
     def get_byte_at(self, x, y):
@@ -103,7 +104,7 @@ class TeletextCanvas(QWidget):
 
     def emit_cursor_change(self):
         val = self.get_byte_at(self.cursor_x, self.cursor_y)
-        self.cursorChanged.emit(self.cursor_x, self.cursor_y, val)
+        self.cursorChanged.emit(self.cursor_x, self.cursor_y, val, self.cursor_is_graphics)
 
     def set_cursor(self, x, y):
         self.cursor_x = max(0, min(self.cols - 1, x))
@@ -329,6 +330,10 @@ class TeletextCanvas(QWidget):
             if double_height and not is_occluded:
                 next_occlusion_mask[c] = True
 
+            # Capture cursor state if this is the cursor position
+            if c == self.cursor_x and row == self.cursor_y:
+                self.cursor_is_graphics = graphics_mode
+
             # If occluded, do not draw anything for this cell
             if is_occluded:
                 continue

src/teletext/ui.py

@@ -2,14 +2,11 @@
 from PyQt6.QtWidgets import (
     QMainWindow, QWidget, QVBoxLayout, QHBoxLayout, 
     QListWidget, QListWidgetItem, QComboBox, QLabel, QLineEdit, QPushButton, 
-    QFileDialog, QMenuBar, QMenu, QMessageBox, QStatusBar, QProgressBar, QApplication
+    QFileDialog, QMenuBar, QMenu, QMessageBox, QStatusBar, QProgressBar, QApplication,
+    QCheckBox, QDialog, QGridLayout
 )
-
+from PyQt6.QtGui import QAction, QKeyEvent, QPainter, QBrush, QColor
-# ... (imports remain)
+from PyQt6.QtCore import Qt, QRect
-
-# ... (imports remain)
-from PyQt6.QtGui import QAction, QKeyEvent
-from PyQt6.QtCore import Qt
 
 from .io import load_t42, save_t42
 from .renderer import TeletextCanvas, create_blank_packet
@@ -18,6 +15,104 @@ import sys
 import os
 from .models import TeletextService, Page, Packet
 
+class MosaicButton(QPushButton):
+    def __init__(self, code, main_window):
+        super().__init__()
+        self.code = code
+        self.main_window = main_window
+        self.setFixedSize(32, 32)
+        self.setToolTip(f"Hex: {code:02X}")
+        self.clicked.connect(self.on_click)
+
+    def on_click(self):
+        self.main_window.insert_char(self.code)
+
+    def paintEvent(self, event):
+        super().paintEvent(event)
+        painter = QPainter(self)
+        
+        # Draw content area (centered, smaller than button)
+        w = self.width()
+        h = self.height()
+        m = 4
+        rect = QRect(m, m, w - 2*m, h - 2*m)
+        
+        # Background (Black)
+        painter.fillRect(rect, Qt.GlobalColor.black)
+        
+        # Foreground (White)
+        painter.setBrush(QBrush(Qt.GlobalColor.white))
+        painter.setPen(Qt.PenStyle.NoPen)
+        
+        # Mosaic Logic
+        val = self.code & 0x7F
+        bits = 0
+        if val >= 0x20:
+            bits = val - 0x20
+            
+        # 2x3 grid
+        cw = rect.width()
+        ch = rect.height()
+        
+        x_splits = [0, cw // 2, cw]
+        y_splits = [0, ch // 3, (2 * ch) // 3, ch]
+        
+        # bit 0: TL, 1: TR, 2: ML, 3: MR, 4: BL, 6: BR
+        block_indices = [
+            (0, 0), (1, 0), # Top
+            (0, 1), (1, 1), # Mid
+            (0, 2), (1, 2)  # Bot
+        ]
+        bit_mask = [1, 2, 4, 8, 16, 64]
+        
+        for i in range(6):
+            if bits & bit_mask[i]:
+                c, r = block_indices[i]
+                bx = rect.x() + x_splits[c]
+                by = rect.y() + y_splits[r]
+                bw = x_splits[c+1] - x_splits[c]
+                bh = y_splits[r+1] - y_splits[r]
+                painter.drawRect(bx, by, bw, bh)
+
+class MosaicDialog(QDialog):
+    def __init__(self, main_window):
+        super().__init__(main_window)
+        self.setWindowTitle("Insert Mosaic")
+        self.main_window = main_window
+        self.setLayout(QVBoxLayout())
+        
+        lbl = QLabel("Click to insert mosaic character:")
+        self.layout().addWidget(lbl)
+
+        hint = QLabel("Note: Mosaics only appear if the line segment is in Graphics Mode.\n"
+                      "Insert a Graphics Color code (e.g. Red Graphics 0x11) first.")
+        hint.setStyleSheet("color: gray; font-style: italic;")
+        self.layout().addWidget(hint)
+        
+        grid = QGridLayout()
+        self.layout().addLayout(grid)
+        
+        # Ranges: 0x20-0x3F, 0x60-0x7F
+        codes = []
+        codes.extend(range(0x20, 0x40))
+        codes.extend(range(0x60, 0x80))
+        
+        row = 0
+        col = 0
+        max_cols = 8
+        
+        for code in codes:
+            btn = MosaicButton(code, main_window)
+            grid.addWidget(btn, row, col)
+            col += 1
+            if col >= max_cols:
+                col = 0
+                row += 1
+                
+        close_btn = QPushButton("Close")
+        close_btn.clicked.connect(self.accept)
+        self.layout().addWidget(close_btn)
+
 class MainWindow(QMainWindow):
     def __init__(self):
         super().__init__()
@@ -90,6 +185,12 @@ class MainWindow(QMainWindow):
         
         # Color Shortcuts
         color_layout = QHBoxLayout()
+        
+        # Graphics Mode Toggle
+        self.chk_graphics = QCheckBox("Graphics")
+        self.chk_graphics.setToolTip("If checked, inserts Graphics Color codes (e.g. Red Graphics 0x11) instead of Alpha (0x01)")
+        color_layout.addWidget(self.chk_graphics)
+
         colors = [
             ("Red", 0x01, "#FF0000"),
             ("Green", 0x02, "#00FF00"),
@@ -103,9 +204,15 @@ class MainWindow(QMainWindow):
         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))
+            # Use separate method to handle graphics check
+            btn.clicked.connect(lambda checked, c=code: self.insert_color(c))
             color_layout.addWidget(btn)
             
+        # Mosaics Button
+        btn_mosaic = QPushButton("Mosaics...")
+        btn_mosaic.clicked.connect(self.open_mosaic_dialog)
+        color_layout.addWidget(btn_mosaic)
+            
         color_layout.addStretch()
         center_layout.addLayout(color_layout)
 
@@ -128,6 +235,10 @@ class MainWindow(QMainWindow):
         self.status_label = QLabel("Ready")
         self.status_bar.addWidget(self.status_label)
 
+        self.mode_label = QLabel("Mode: Text")
+        self.mode_label.setFixedWidth(120)
+        self.status_bar.addPermanentWidget(self.mode_label)
+        
         self.language_label = QLabel("Lang: English")
         self.status_bar.addPermanentWidget(self.language_label)
 
@@ -539,8 +650,21 @@ class MainWindow(QMainWindow):
         self.canvas.move_cursor(1, 0)
         self.canvas.setFocus()
 
-    def on_cursor_changed(self, x, y, val):
+    def insert_color(self, base_code):
+        code = base_code
+        if self.chk_graphics.isChecked():
+            # Convert 0x01..0x07 to 0x11..0x17
+            code += 0x10
+        self.insert_char(code)
+
+    def open_mosaic_dialog(self):
+        dlg = MosaicDialog(self)
+        dlg.exec()
+            
+    def on_cursor_changed(self, x, y, val, is_graphics):
         self.hex_input.setText(f"{val:02X}")
+        mode_str = "Graphics" if is_graphics else "Text"
+        self.mode_label.setText(f"Mode: {mode_str}")
         
     def on_hex_entered(self):
         text = self.hex_input.text()