install isort and black for code formatting

With the old solution I replaced tabs with four spaces and then did
some calculations to get the correct byte positions for a coordinate.
With the new solution (using FontMetric.horizontalAdvance) this is not
necessary anymore and we can use tha native tab.
But I cannot change the tab width. It is always 8 characters.
You can set tabStopDistance on horizontalAdvance(), but not on
elided_text() and I did not find a way to use it while rendering text.

.envrc

@@ -0,0 +1 @@
+PATH=$(pwd)/venv312/bin:$PATH

.gitignore

@@ -6,3 +6,4 @@ testbed
 icons-not-used
 venv*
 *.spec
+/version.txt

.idea/misc.xml

@@ -1,6 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project version="4">
   <component name="Black">
+    <option name="enabledOnSave" value="true" />
     <option name="sdkName" value="Python 3.12 (krowlog)" />
   </component>
   <component name="ProjectRootManager" version="2" project-jdk-name="Python 3.12 (krowlog)" project-jdk-type="Python SDK" />

README.md

@@ -17,7 +17,7 @@ KrowLog is a viewer for text files of arbitrary size.
 * Select arbitrary strings (not just full lines).
 * Double click selects word.
 * Triple click selects line.
-* Copy protection: Users is warned before creating a clipboard more than 5 MB in size. They can choose to copy the
+* Copy protection: Users are warned before creating a clipboard more than 5 MB in size. They can choose to copy the
   selection into a new file instead.
 * Optionally open a new tab when saving selection as file.
 * Panel for temporary notes

changelog.txt

@@ -0,0 +1,16 @@
+
+Next Version
+* Feature: Add changelog.
+* Fix:     When the range sliders are overlapping the end slider cannot be moved.
+* Feature: Get version number from git tags.
+* Feature: You can now "follow" a file. When enabled the file is automatically reloaded
+           and scrolled to the end. Any manual scroll action disables "follow" mode.
+* Feature: Better support for fonts and characters with non-uniform width.
+* Fix:     Cannot scroll to arbitrary positions in a file if the file is larger than 2GB
+* Feature: File type specific highlighters.
+
+0.2.1
+* Feature: Show how many bytes are selected.
+* Feature: Highlighters can be disabled.
+* Feature: If a regex contains a group, then only the group is highlighted.
+           Using a filter expression like '(\d+)ms' will only hightlight the number.

constants.py

@@ -1,6 +1,8 @@
 import os
 
 krow_icon = "icons" + os.sep + "krowlog.svg"
+qt_icon = "icons" + os.sep + "qt-logo.png"
 license_file = os.path.dirname(os.path.realpath(__file__)) + os.sep + "LICENSE"
+changelog_file = os.path.dirname(os.path.realpath(__file__)) + os.sep + "changelog.txt"
 
 tab_width = 4

instructions.md

@@ -8,12 +8,12 @@ Just run `make_installer.py` with the following command. The distribution can be
 to run this on all target platforms.
 
 ```
-venv311/bin/python make_installer.py
+venv312/bin/python make_installer.py
 ```
 
 ## Update Python
 
 1. install the latest python version. We need the dev version, because PyInstaller requires it.
-   `sudo apt install python-3.11-dev python-3.11-venv`
-2. create new virtual environment with `python3.11 -m venv /path/to/venv`
+   `sudo apt install python-3.12-dev python-3.12-venv`
+2. create new virtual environment with `python3.12 -m venv /path/to/venv`
 3. select the venv in PyCharm

krowlog.py

@@ -1,21 +1,26 @@
 import argparse
+import gettext
 import logging
+import os
 import signal
-from PySide6 import QtCore
-from PySide6.QtWidgets import QApplication
-from PySide6.QtCore import QTimer
 import sys
+from pathlib import Path
+
+from PySide6 import QtCore
+from PySide6.QtCore import QTimer
+from PySide6.QtWidgets import QApplication
+
 import constants
 from src import install
 from src.pluginregistry import PluginRegistry
-import gettext
 from src.ui.icon import Icon
-from pathlib import Path
-import os
 
-__version__ = Path(os.path.dirname(os.path.realpath(__file__)) + os.sep + "version.txt").read_text()
+version_file = Path(
+    os.path.dirname(os.path.realpath(__file__)) + os.sep + "version.txt"
+)
+__version__ = version_file.read_text() if version_file.is_file() else "0.0.0"
 
-gettext.install('krowlog', 'locale')
+gettext.install("krowlog", "locale")
 
 logging.basicConfig(level=logging.INFO)
 log = logging.getLogger("main")
@@ -67,7 +72,9 @@ class CmdArgs:
 
 def parse_command_line_parameters() -> CmdArgs:
     parser = argparse.ArgumentParser()
-    parser.add_argument('files', metavar='F', type=str, nargs='*', help='file(s) to open')
+    parser.add_argument(
+        "files", metavar="F", type=str, nargs="*", help="file(s) to open"
+    )
     namespace = parser.parse_args()
     return CmdArgs(files=namespace.files)
 
@@ -76,7 +83,9 @@ if __name__ == "__main__":
     cmd_args = parse_command_line_parameters()
 
     app = QApplication(sys.argv)
-    app.setWindowIcon(Icon(constants.krow_icon))  # works only for Linux (but only X11, not Wayland)
+    app.setWindowIcon(
+        Icon(constants.krow_icon)
+    )  # works only for Linux (but only X11, not Wayland)
 
     # install stuff, e.g. a desktop file, set icon on Windows
     install.install()

make_installer.py

@@ -1,9 +1,10 @@
 import PyInstaller.__main__
 import os
+import sys
 
 os.system("git -C . describe --match \"*.*.*\" --tags > version.txt")
 
-PyInstaller.__main__.run([
+arguments = [
     'krowlog.py',
     # '--onefile',
     '--noconfirm',
@@ -14,10 +15,14 @@ PyInstaller.__main__.run([
     '--add-binary', 'icons' + os.pathsep + 'icons',
     '--add-binary', 'locales' + os.pathsep + 'locales',
     '--add-binary', 'LICENSE' + os.pathsep + '.',
+    '--add-binary', 'changelog.txt' + os.pathsep + '.',
     '--add-binary', 'version.txt' + os.pathsep + '.',
     '--hidden-import=krowlog',
-    '--hidden-import=watchdog',
-    '--hidden-import=watchdog.observers',
-    '--hidden-import=watchdog.version',
+    '--hidden-import=__future__',
     '--hidden-import=configparser'
-])
+]
+
+if sys.platform == 'win32' or sys.platform == 'cygwin':
+    arguments.append('--version-file=version.py')
+
+PyInstaller.__main__.run(arguments)

requirements.txt

@@ -1,5 +1,6 @@
 pip==25.0.1
 PySide6_Essentials==6.8.2.1
 setuptools==77.0.3
-watchdog==6.0.0
 pyinstaller==6.12.0
+isort==6.0.1
+black==25.1.0

src/plugins/krowlog/about_qt_dialog.py

@@ -0,0 +1,79 @@
+import textwrap
+
+import PySide6
+from PySide6.QtCore import Qt
+from PySide6.QtGui import QFont, QPalette
+from PySide6.QtWidgets import *
+
+import constants
+
+import krowlog
+from src.ui.icon import Icon
+from src.ui.label import Label
+from src.ui.vbox import VBox
+from src.i18n import _
+
+
+class AboutQTDialog(QDialog):
+    """Dialog for showing info about KrowLog"""
+
+    def __init__(self, parent=None):
+        super(AboutQTDialog, self).__init__(parent)
+        self.setWindowTitle(_("About QT"))
+        self.setModal(True)
+        # self.setMinimumWidth(850)
+        # self.setFixedHeight(400)
+
+        self.layout = QVBoxLayout(self)
+
+        text = f"""
+               <b>About QT</b>
+               <p>This program uses QT version {PySide6.QtCore.__version__}.</p>
+               
+               <p>QT is a C++ toolkit for cross-platform application development.</p>
+               
+               <p>Qt provides single-source portability across all major desktop 
+               operating systems. It is also available for embedded Linux and other 
+               embedded and mobile operating systems.</p>
+               
+               <p>Qt is available under multiple licensing options designed to accommodate 
+               the needs of our various users.</p>
+               
+               <p>Qt licensed under our commercial license agreement is appropriate for 
+               development of proprietary/commercial software where you do not want to 
+               share any source code with third parties or otherwise cannot comply with 
+               the terms of GNU (L)GPL.</p>
+               
+               <p>Qt licensed under GNU (L)GPL is appropriate for the development of Qt
+               applications provided you can comply with the terms and conditions of the 
+               respective licenses.</p>
+               
+               Please see <a href="http://qt.io/licensing">qt.io/licensing</a> for an<
+               overview of Qt licensing.
+               
+               <p>Copyright (C) 2025 The Qt Company Ltd and other contributors.</p>
+               
+               <p>Qt and the Qt logo are trademarks of The Qt Company Ltd.</p>
+               
+               <p>Qt is The Qt Company Ltd product developed as an open source project.
+               See <a href="http://qt.io">qt.io</a> for more information.</p>
+               """
+        label = Label(text)
+        label.setWordWrap(True)
+
+        app_icon = QLabel()
+        app_icon.setPixmap(Icon(constants.qt_icon).pixmap(64, 64))
+        heading = QWidget(self)
+        hbox = QHBoxLayout(heading)
+        hbox.addWidget(app_icon)
+        hbox.addWidget(label)
+        hbox.addSpacerItem(QSpacerItem(1, 1, hData=QSizePolicy.Policy.Expanding))
+
+        heading.layout = hbox
+        self.layout.addWidget(heading)
+
+        buttons = QDialogButtonBox(self)
+        buttons.setStandardButtons(QDialogButtonBox.StandardButton.Close)
+        buttons.rejected.connect(self.close)
+        self.layout.addWidget(buttons)
+        self.setSizePolicy(QSizePolicy.Policy.MinimumExpanding, QSizePolicy.Policy.MinimumExpanding)

src/plugins/krowlog/aboutdialog.py

@@ -1,7 +1,6 @@
 import textwrap
 
 import PySide6
-from watchdog import version as watchdog_version
 from PySide6.QtCore import Qt
 from PySide6.QtGui import QFont, QPalette
 from PySide6.QtWidgets import *
@@ -22,8 +21,8 @@ class AboutDialog(QDialog):
         super(AboutDialog, self).__init__(parent)
         self.setWindowTitle(_("About KrowLog"))
         self.setModal(True)
-        self.setMinimumWidth(650)
-        self.setFixedHeight(300)
+        self.setMinimumWidth(850)
+        self.setFixedHeight(400)
 
         self.layout = QVBoxLayout(self)
 
@@ -50,6 +49,7 @@ class AboutDialog(QDialog):
         tabs.addTab(self._about(), _("About"))
         tabs.addTab(self._libraries(), _("Libraries"))
         tabs.addTab(self._license(), _("License"))
+        tabs.addTab(self._changelog(), _("Changelog"))
 
         self.layout.addWidget(tabs)
 
@@ -74,11 +74,9 @@ class AboutDialog(QDialog):
         <ul>
         <li>PySide6-Essentials {pyside} (LGPL v3) - <a href="https://doc.qt.io/qtforpython-6/">https://doc.qt.io/qtforpython-6/</a></li>
         <li>Qt6 {qt} (LGPL v3) - <a href="https://code.qt.io/cgit/qt/qtbase.git/">https://code.qt.io/cgit/qt/qtbase.git/</a></li>
-        <li>watchdog {watchdog} (Apache 2.0) - <a href="https://github.com/gorakhargosh/watchdog">https://github.com/gorakhargosh/watchdog</a></li>
         </ul>""".format(
             pyside=PySide6.__version__,
-            qt=PySide6.QtCore.__version__,
-            watchdog=watchdog_version.VERSION_STRING)
+            qt=PySide6.QtCore.__version__)
         label = textwrap.dedent(dependencies)
 
         result = QWidget()
@@ -106,3 +104,25 @@ class AboutDialog(QDialog):
         panel.setBackgroundRole(QPalette.ColorRole.Light)
         result.layout.addWidget(panel)
         return result
+
+    def _changelog(self) -> QWidget:
+        with open(constants.changelog_file, 'r') as file:
+            text = file.read()
+
+        result = QWidget()
+        result.layout = QVBoxLayout(result)
+        result.layout.setContentsMargins(0, 0, 0, 0)
+        result.setSizePolicy(QSizePolicy.Policy.MinimumExpanding, QSizePolicy.Policy.MinimumExpanding)
+
+        label = Label(text)
+        label.setFont(QFont("Monospace"))
+        label.setSizePolicy(QSizePolicy.Policy.MinimumExpanding, QSizePolicy.Policy.MinimumExpanding)
+
+        panel = QScrollArea(result)
+        panel.setContentsMargins(0, 0, 0, 0)
+        panel.setViewportMargins(0, 0, 0, 0)
+        panel.setSizePolicy(QSizePolicy.Policy.MinimumExpanding, QSizePolicy.Policy.MinimumExpanding)
+        panel.setWidget(label)
+        panel.setBackgroundRole(QPalette.ColorRole.Light)
+        result.layout.addWidget(panel)
+        return result

src/plugins/krowlogplugin.py

@@ -5,6 +5,7 @@ from PySide6.QtCore import Qt
 from PySide6.QtWidgets import QDockWidget, QMessageBox
 
 import constants
+from src.plugins.krowlog.about_qt_dialog import AboutQTDialog
 from src.plugins.krowlog.aboutdialog import AboutDialog
 from src.mainwindow import MainWindow
 from src.pluginbase import PluginBase
@@ -36,6 +37,7 @@ class KrowLogPlugin(PluginBase):
         return [
             MenuContribution("file", action=self._action_close(), action_id="close application", after="<last>"),
             MenuContribution("help", action=self._action_about(), action_id="open about dialog", after="<last>"),
+            MenuContribution("help", action=self._action_about_qt(), action_id="open about QT dialog", after="<last>"),
             MenuContribution("settings", menu=self._sub_menu_languages(), action_id="recent files menu"),
         ]
 
@@ -108,6 +110,14 @@ class KrowLogPlugin(PluginBase):
         )
         return about_action
 
+    def _action_about_qt(self) -> RAction:
+        action = RAction(
+            _("&About QT"),
+            action=lambda: AboutQTDialog().exec(),
+            icon_file=constants.qt_icon
+        )
+        return action
+
     def _action_close(self) -> RAction:
         icon = "close" if sys.platform == 'win32' or sys.platform == 'cygwin' else "exit"
         close_action = RAction(_("E&xit"), action=lambda: self.main_window.destruct(), shortcut='Ctrl+X',

src/plugins/logfile/filterwidget.py

@@ -279,6 +279,7 @@ class FilterWidget(QWidget):
 
     def destruct(self):
         self._cancel_search()
+        self.hits_view.destruct()
         os.remove(self.tmp_filename)
 
     def _cancel_search(self):

src/ui/bigtext/bigtext.py

@@ -23,55 +23,31 @@ from src.ui.icon import Icon
 from src.ui.rangeslider import RangeSlider
 from src.util.conversion import humanbytes
 from src.pluginregistry import PluginRegistry
+from threading import Event
 
-from src.settings.settings import Settings
-from watchdog.observers import Observer
-from watchdog.events import FileSystemEventHandler
 from src.i18n import _
 
 log = logging.getLogger("bigtext")
 
-
-class FileObserver(FileSystemEventHandler):
-
-    def __init__(self, big_text):
-        super(FileObserver, self).__init__()
-        self.big_text = big_text
-        self._last_mtime = -1
-
-    def on_modified(self, event):
-        # slow down the updates. This is needed, because the file is modified
-        # constantly, which would lead to constant re-rendering, which would
-        # block the UI thread and make the UI unresponsive.
-        # Note: we don't miss events, because they are queued and de-duplicated
-        if not event.is_directory:
-            try:
-                mtime = os.stat(event.src_path).st_mtime
-                if mtime != self._last_mtime:
-                    self._last_mtime = mtime
-                    time.sleep(0.5)
-                    self.big_text.trigger_update.emit()
-            except FileNotFoundError:
-                # ignore: happens when closing the application, because tmp files are deleted,
-                # which triggers a modification event
-                pass
-
-
 class FileWatchdogThread(QRunnable):
 
     def __init__(self, big_text, file: str):
         super(FileWatchdogThread, self).__init__()
         self.file = file
         self.big_text = big_text
-        self.observer = Observer()
+        self.stop = Event()
 
     def run(self) -> None:
-        self.observer.schedule(FileObserver(self.big_text), self.file)
-        self.observer.start()
+        _last_mtime = None
+        while not self.stop.is_set():
+            mtime = os.stat(self.file).st_mtime
+            if mtime != _last_mtime:
+                _last_mtime = mtime
+                self.big_text.trigger_update.emit()
+            self.stop.wait(0.5)
 
     def destruct(self):
-        self.observer.stop()
-        # self.observer.join(1)
+        self.stop.set()
 
 
 class BigText(QWidget):
@@ -503,7 +479,7 @@ class InnerBigText(QWidget):
             # # print("%s + %s = %s" % (line.byte_offset(), char_in_line, current_byte))
         else:
             current_byte = self.model.byte_count()
-        return current_byte
+            return SelectionPos(current_byte, True, 1)
 
     def elided_text(self, text: str, width: int):
         w = width + self.font_metric.horizontalAdvance("…")
@@ -581,7 +557,6 @@ class InnerBigText(QWidget):
 
     def _toggle_follow(self):
         self._follow = not self._follow
-        print(f"follow={self._follow}")
         self.update()
 
     def _update_highlight_selected_text(self):

src/ui/bigtext/line.py

@@ -15,7 +15,7 @@ class Line:
         self._cache_char_to_column()
 
     def get_width_in_px(self, font_metric: QFontMetrics):
-        return font_metric.horizontalAdvance(self._line)
+        return font_metric.horizontalAdvance(self.line_prepared_for_display())
 
     def byte_offset(self) -> int:
         return self._byte_offset
@@ -43,7 +43,8 @@ class Line:
         return len(prefix_chars)
 
     def line_prepared_for_display(self) -> str:
-        line = self._line_tabs_replaced()
+        # line = self._line_tabs_replaced()
+        line = self._line
         line = self._replace_control_chars_with_pictures(line)
         return line
 
@@ -108,7 +109,7 @@ class Line:
             if not result in self._column_to_char_cache:
                 self._column_to_char_cache[result] = i
             current_char = self._line[i]
-            if current_char == "\t":
+            if False and current_char == "\t":
                 result = result + constants.tab_width - result % constants.tab_width
             else:
                 result = result + 1

src/ui/bigtext/selectionPos.py

@@ -0,0 +1,11 @@
+class SelectionPos:
+    def __init__(self, index: int, is_in_left_half: bool, num_bytes_of_char: int):
+        self.index = index
+        self.is_in_left_half = is_in_left_half
+        self.num_bytes_of_char = num_bytes_of_char
+
+    def __repr__(self):
+        return f"{self.index}{'🞀' if self.is_in_left_half else '🞂'}({self.num_bytes_of_char})"
+
+    def pos(self):
+        return self.index + (0 if self.is_in_left_half else self.num_bytes_of_char)

src/ui/bigtext/testline.py

@@ -78,20 +78,6 @@ class MyTestCase(unittest.TestCase):
         self.assertEqual(2, line.char_to_column(4))  # z̈
         self.assertEqual(2, line.char_to_column(5))  # z̈
 
-    def test_line_tabs_replaced(self):
-        byte_offset = 123
-        text = "\ta\tb"  # will be rendered as: ....abc  where . represents a whitespace column
-        expected = "    a   b"
-        line = Line(byte_offset=byte_offset, byte_end=byte_offset + len(text.encode("utf8")), line=text)
-        self.assertEqual(expected, line.line_prepared_for_display())
-
-    def test_line_tabs_replaced_performance(self):
-        byte_offset = 123
-        text = "a\t" * 10000
-        expected = "a   " * 10000
-        line = Line(byte_offset=byte_offset, byte_end=byte_offset + len(text.encode("utf8")), line=text)
-        self.assertEqual(expected, line.line_prepared_for_display())
-
     def test_byte_index_to_char_index(self):
         byte_offset = 123
         text = "x\u0308y\u0308z\u0308\t\u0308a"

testbed/example.log

@@ -177,3 +177,7 @@ ä---------ä----------ä---------ä----------ä---------ä----------ä--
 17
 18
 19
+
+
+アンドレアス
+アンドレアス

version.py

@@ -0,0 +1,28 @@
+VSVersionInfo(
+  ffi=FixedFileInfo(
+    filevers=(0, 2, 1, 0),
+    prodvers=(0, 2, 1, 0),
+    mask=0x3f,
+    flags=0x0,
+    OS=0x40004,
+    fileType=0x1,
+    subtype=0x0,
+    date=(0, 0)
+    ),
+  kids=[
+    StringFileInfo(
+      [
+      StringTable(
+        u'040904B0',
+        [StringStruct(u'CompanyName', u''),
+        StringStruct(u'FileDescription', u'KrowLog is a viewer for log files of arbitrary size.'),
+        StringStruct(u'FileVersion', u'0.2.1' ),
+        StringStruct(u'InternalName', u'krowlog'),
+        StringStruct(u'LegalCopyright', u'\xa9 Andreas Huber'),
+        StringStruct(u'OriginalFilename', u'krowlog.exe'),
+        StringStruct(u'ProductName', u'KrowLog'),
+        StringStruct(u'ProductVersion', u'0.2.1-dev')])
+      ]), 
+    VarFileInfo([VarStruct(u'Translation', [1033, 1200])])
+  ]
+)

version.txt

@@ -1 +0,0 @@
-0.2.1-36-g9902be0