rename ravenlog to krowlog

There is a database named RavenDB.
KrowLog starts with a K, which is a) distinctive and b) has an association to KDE.

src/ui/bigtext/highlight_regex.py

@@ -0,0 +1,64 @@
+from typing import Optional
+
+from src.ui.bigtext.highlight import Highlight
+from src.ui.bigtext.highlighted_range import HighlightedRange
+from src.ui.bigtext.line import Line
+from PySide6.QtGui import QBrush, QColor
+
+from typing import List
+import re
+
+
+class HighlightRegex(Highlight):
+
+    def __init__(self, query: str, ignore_case: bool, is_regex: bool, hit_background_color: str = "None",
+                 line_background_color: str = "None"):
+        self.query = query
+        self.ignore_case = ignore_case
+        self.is_regex = is_regex
+        self.regex = self._get_regex()
+        self.hit_background_color = hit_background_color
+        self.line_background_color = line_background_color
+        self._brush_hit = self.brush(self.hit_background_color)
+        self._brush_line = self.brush(self.line_background_color)
+
+    def _get_regex(self):
+        flags = re.IGNORECASE if self.ignore_case else 0
+        if self.is_regex:
+            return re.compile(self.query, flags=flags)
+        else:
+            return re.compile(re.escape(self.query), flags=flags)
+
+    def compute_highlight(self, line: Line) -> Optional[List[HighlightedRange]]:
+        result = []
+        # print("execute regex: %s in %s" % (self.regex, line.line()))
+        match_iter = re.finditer(self.regex, line.line())
+        for match in match_iter:
+            # print("%s" % match)
+            start_char = match.start(0)
+            end_char = match.end(0)
+
+            start_column = line.char_to_column(start_char)
+            end_column = line.char_to_column(end_char)
+
+            result.append(HighlightedRange(
+                start_column,
+                end_column - start_column,
+                highlight_full_line=True,
+                brush=self._brush_hit,
+                brush_full_line=self._brush_line
+            ))
+
+        return result
+
+    def hit_background_brush(self):
+        return self.brush(self.hit_background_color)
+
+    @staticmethod
+    def brush(color: str) -> QBrush:
+        if re.match("[0-9a-f]{6}", color, flags=re.IGNORECASE):
+            red = int(color[0:2], 16)
+            green = int(color[2:4], 16)
+            blue = int(color[4:6], 16)
+            return QBrush(QColor(red, green, blue))
+        return QBrush()