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Feature: Enhanced Editing, Hex Inspector, Color Shortcuts

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- 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.
This commit is contained in:
Daniel Dybing
2025-12-28 21:57:44 +01:00
parent e2ed4dd1e2
commit 088ad1a320
6 changed files with 265 additions and 20 deletions
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src/teletext/__pycache__/io.cpython-312.pyc
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src/teletext/__pycache__/renderer.cpython-312.pyc
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src/teletext/__pycache__/ui.cpython-312.pyc
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74
src/teletext/io.py
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@@ -62,24 +62,74 @@ def load_t42(file_path: str) -> TeletextService:
return service
def encode_hamming_8_4(value):
# Value is 4 bits (0-15)
d1 = (value >> 0) & 1
d2 = (value >> 1) & 1
d3 = (value >> 2) & 1
d4 = (value >> 3) & 1
# Parity bits (Odd parity default? Or standard Hamming?)
# Teletext spec:
# P1 = 1 + D1 + D2 + D4 (mod 2) -> Inverse of even parity check?
# Actually, simpler to look up or calculate.
# Let's match typical implementation:
# P1 (b0) covers 1,3,7 (D1, D2, D4)
# P2 (b2) covers 1,5,7 (D1, D3, D4)
# P3 (b4) covers 3,5,7 (D2, D3, D4)
# P4 (b6) covers all.
# Teletext uses ODD parity for the hamming bits usually?
# "Hamming 8/4 with odd parity"
p1 = 1 ^ d1 ^ d2 ^ d4
p2 = 1 ^ d1 ^ d3 ^ d4
p3 = 1 ^ d2 ^ d3 ^ d4
res = (p1 << 0) | (d1 << 1) | \
(p2 << 2) | (d2 << 3) | \
(p3 << 4) | (d3 << 5) | \
(d4 << 7)
# P4 (bit 6) makes total bits odd
# Count set bits so far
set_bits = bin(res).count('1')
p4 = 1 if (set_bits % 2 == 0) else 0
res |= (p4 << 6)
return res
def save_t42(file_path: str, service: TeletextService):
with open(file_path, 'wb') as f:
# User requirement: "without rearranging the order of the packets"
# Implies we should iterate the original list.
# However, if we edit data, we modify the Packet objects in place.
# If we Add/Delete packets, we need to handle that.
for packet in service.all_packets:
# Reconstruct the 42 bytes from the packet fields
# The packet.data (bytearray) should be mutable and edited by the UI.
# packet.original_data (first 2 bytes) + packet.data
# Reconstruct header bytes from packet.magazine and packet.row
# Byte 1: M1 M2 M3 R1
# Byte 2: R2 R3 R4 R5
# Note: If we changed Magazine or Row, we'd need to re-encode the first 2 bytes.
# For now, assume we primarily edit content (bytes 2-41).
mag = packet.magazine
if mag == 8: mag = 0 # 0 encoded as 8
header = packet.original_data[:2] # Keep original address for now
# TODO: regenerating header if Mag/Row changed
# Bits:
# B1 data: M1(0) M2(1) M3(2) R1(3)
m1 = (mag >> 0) & 1
m2 = (mag >> 1) & 1
m3 = (mag >> 2) & 1
r1 = (packet.row >> 0) & 1
b1_val = m1 | (m2 << 1) | (m3 << 2) | (r1 << 3)
b1_enc = encode_hamming_8_4(b1_val)
# B2 data: R2(0) R3(1) R4(2) R5(3)
r2 = (packet.row >> 1) & 1
r3 = (packet.row >> 2) & 1
r4 = (packet.row >> 3) & 1
r5 = (packet.row >> 4) & 1
b2_val = r2 | (r3 << 1) | (r4 << 2) | (r5 << 3)
b2_enc = encode_hamming_8_4(b2_val)
header = bytes([b1_enc, b2_enc])
f.write(header + packet.data)
def decode_hamming_8_4(byte_val):

143
src/teletext/renderer.py
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@@ -6,6 +6,40 @@ from PyQt6.QtCore import Qt, QRect, QSize, pyqtSignal
from .models import Page, Packet
from .charsets import get_char
# Helper to create a blank packet
def create_blank_packet(magazine: int, row: int) -> Packet:
# 42 bytes
# Bytes 0-1: Address (Hamming encoded)
# We need to compute Hamming for M and R.
# For now, let's just make a placeholder that "looks" okay or use 0x00 and let a future saver fix it.
# But wait, `Packet` expects 42 bytes input.
# Ideally we should implement the hamming encoder from `io.py` or similar.
# For now, we will create a Packet with dummy address bytes and correct mag/row properties set manually if needed,
# OR we just construct the bytes.
# Let's rely on the Packet class parsing... which is annoying if we can't easily encode.
# Hack: default to 0x00 0x00, then manually set .magazine and .row
data = bytearray(42)
# Set spaces
data[2:] = b'\x20' * 40
p = Packet(bytes(data))
# Override
p.magazine = magazine
p.row = row
p.data = bytearray(b'\x20' * 40)
# We really should set the address bytes correctly so saving works "naturally".
# But `save_t42` uses `packet.original_data[:2]`.
# So we MUST encode properly or `save_t42` needs to regenerate headers.
# Let's defer proper Hamming encoding to the Save step (as noted in TODO in io.py).
# For in-memory editing, this is fine.
return p
# Teletext Palette
COLORS = [
QColor(0, 0, 0), # Black
@@ -19,8 +53,11 @@ COLORS = [
]
class TeletextCanvas(QWidget):
cursorChanged = pyqtSignal(int, int, int) # x, y, byte_val
def __init__(self, parent=None):
super().__init__(parent)
self.setMouseTracking(True) # Just in case
self.setMinimumSize(480, 500) # 40x12 * 25x20 approx
self.page: Page = None
self.subset_idx = 0 # Default English
@@ -48,22 +85,65 @@ class TeletextCanvas(QWidget):
self.cursor_visible = True
# Blinking cursor timer could be added, for now static inverted is fine or toggle on timer elsewhere
def get_byte_at(self, x, y):
if not self.page: return 0
# Row 0 special logic (header) - returning what is displayed or raw?
# User probably wants RAW byte for editing.
packet = None
for p in self.page.packets:
if p.row == y:
packet = p
break
if packet and 0 <= x < 40:
return packet.data[x]
return 0
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)
def set_cursor(self, x, y):
self.cursor_x = max(0, min(self.cols - 1, x))
self.cursor_y = max(0, min(self.rows - 1, y))
self.redraw()
self.update()
self.emit_cursor_change()
def move_cursor(self, dx, dy):
self.cursor_x = max(0, min(self.cols - 1, self.cursor_x + dx))
self.cursor_y = max(0, min(self.rows - 1, self.cursor_y + dy))
self.redraw()
self.update()
self.emit_cursor_change()
def set_byte_at_cursor(self, byte_val):
if not self.page: return
packet = None
for p in self.page.packets:
if p.row == self.cursor_y:
packet = p
break
if packet:
if 0 <= self.cursor_x < 40:
packet.data[self.cursor_x] = byte_val
self.redraw()
self.emit_cursor_change()
else:
# Create packet if missing
self.handle_input(chr(byte_val)) # Lazy reuse or duplicate create logic
def set_page(self, page: Page):
self.page = page
self.cursor_x = 0
self.cursor_y = 0
self.redraw()
self.update()
self.emit_cursor_change()
def handle_input(self, text):
if not self.page:
@@ -96,10 +176,24 @@ class TeletextCanvas(QWidget):
self.redraw()
self.move_cursor(1, 0)
else:
# Create a packet if it doesn't exist for this row?
# Creating new packets in a T42 stream is tricky (insertion).
# For now, only edit existing rows.
pass
# Create a packet if it doesn't exist for this row
if 0 <= self.cursor_x < 40:
# Check if we should create it
# Only if input is valid char?
if len(text) == 1:
# Create new packet
new_packet = create_blank_packet(self.page.magazine, self.cursor_y)
self.page.packets.append(new_packet)
# Sort packets by row? Or just append. Renderer handles unordered.
# But for sanity, let's just append.
# Write the char
byte_val = ord(text)
if byte_val > 255: byte_val = 0x3F
new_packet.data[self.cursor_x] = byte_val
self.redraw()
self.move_cursor(1, 0)
def redraw(self):
self.buffer.fill(Qt.GlobalColor.black)
@@ -223,11 +317,48 @@ class TeletextCanvas(QWidget):
# Draw Cursor
# Invert the cell at cursor position
if self.cursor_visible and c == self.cursor_x and row == self.cursor_y:
painter.setCompositionMode(QPainter.CompositionMode.RasterOp_NotSourceXorDestination)
# XOR with white (creates inversion)
painter.setCompositionMode(QPainter.CompositionMode.CompositionMode_Difference)
# Difference with white creates inversion
painter.fillRect(x, y, self.cell_w, self.cell_h, QColor(255, 255, 255))
painter.setCompositionMode(QPainter.CompositionMode.CompositionMode_SourceOver)
def mousePressEvent(self, event):
self.setFocus()
# Calculate cell from mouse position
# Need to account for scaling?
# The widget sizes to fit, but we render to a fixed buffer then scale up.
# paintEvent scales buffer to self.rect().
# This is a bit tricky because paintEvent uses aspect-ratio scaling and centering.
# We need to reverse the mapping.
target_rect = self.rect()
# Re-calc scale and offset
# Note: This logic duplicates paintEvent, commonize?
# Simple approximation for MVP:
# If the window is roughly aspect ratio correct, direct mapping works.
# If not, we need offset.
# Let's get the exact rect used in paintEvent
scale_x = target_rect.width() / self.img_w
scale_y = target_rect.height() / self.img_h
scale = min(scale_x, scale_y)
dw = self.img_w * scale
dh = self.img_h * scale
ox = (target_rect.width() - dw) / 2
oy = (target_rect.height() - dh) / 2
mx = event.pos().x() - ox
my = event.pos().y() - oy
if 0 <= mx < dw and 0 <= my < dh:
col = int(mx / (self.cell_w * scale))
row = int(my / (self.cell_h * scale))
self.set_cursor(col, row)
def draw_mosaic(self, painter, x, y, char_code, color, contiguous):
val = char_code & 0x7F
bits = 0

68
src/teletext/ui.py
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@@ -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