WIP first version of markdown highlighter

qtribu/gui/markdown_highlighter.py

@@ -0,0 +1,160 @@
+import re
+
+from qgis.PyQt.QtGui import (
+    QBrush,
+    QColor,
+    QFont,
+    QFontMetricsF,
+    QPalette,
+    QSyntaxHighlighter,
+    QTextCharFormat,
+    QTextCursor,
+    QTextLayout,
+)
+
+
+class MarkdownHighlighter(QSyntaxHighlighter):
+
+    MARKDOWN_KEYS_REGEX = {
+        "Bold": re.compile("(?P<delim>\*\*)(?P<text>.+)(?P=delim)"),
+        "uBold": re.compile("(?P<delim>__)(?P<text>[^_]{2,})(?P=delim)"),
+        "Italic": re.compile("(?P<delim>\*)(?P<text>[^*]{2,})(?P=delim)"),
+        "uItalic": re.compile("(?P<delim>_)(?P<text>[^_]+)(?P=delim)"),
+        "Link": re.compile("(?u)(^|(?P<pre>[^!]))\[.*?\]:?[ \t]*\(?[^)]+\)?"),
+        "Image": re.compile("(?u)!\[.*?\]\(.+?\)"),
+        "HeaderAtx": re.compile("(?u)^\#{1,6}(.*?)\#*(\n|$)"),
+        "Header": re.compile("^(.+)[ \t]*\n(=+|-+)[ \t]*\n+"),
+        "CodeBlock": re.compile("^([ ]{4,}|\t).*"),
+        "UnorderedList": re.compile("(?u)^\s*(\* |\+ |- )+\s*"),
+        "UnorderedListStar": re.compile("^\s*(\* )+\s*"),
+        "OrderedList": re.compile("(?u)^\s*(\d+\. )\s*"),
+        "BlockQuote": re.compile("(?u)^\s*>+\s*"),
+        "BlockQuoteCount": re.compile("^[ \t]*>[ \t]?"),
+        "CodeSpan": re.compile("(?P<delim>`+).+?(?P=delim)"),
+        "HR": re.compile("(?u)^(\s*(\*|-)\s*){3,}$"),
+        "eHR": re.compile("(?u)^(\s*(\*|=)\s*){3,}$"),
+        "Html": re.compile("<.+?>"),
+    }
+
+    def __init__(self, parent):
+        super().__init__(parent)
+        self.parent = parent
+        parent.setTabStopDistance(
+            QFontMetricsF(parent.font()).horizontalAdvance(" ") * 4
+        )
+
+        self.defaultTheme = {
+            "background-color": "#d7d7d7",
+            "color": "#191970",
+            "bold": {"color": "#859900", "font-weight": "bold", "font-style": "normal"},
+            "emphasis": {
+                "color": "#b58900",
+                "font-weight": "bold",
+                "font-style": "italic",
+            },
+            "link": {
+                "color": "#cb4b16",
+                "font-weight": "normal",
+                "font-style": "normal",
+            },
+            "image": {
+                "color": "#cb4b16",
+                "font-weight": "normal",
+                "font-style": "normal",
+            },
+            "header": {
+                "color": "#2aa198",
+                "font-weight": "bold",
+                "font-style": "normal",
+            },
+            "unorderedlist": {
+                "color": "#dc322f",
+                "font-weight": "normal",
+                "font-style": "normal",
+            },
+            "orderedlist": {
+                "color": "#dc322f",
+                "font-weight": "normal",
+                "font-style": "normal",
+            },
+            "blockquote": {
+                "color": "#dc322f",
+                "font-weight": "normal",
+                "font-style": "normal",
+            },
+            "codespan": {
+                "color": "#dc322f",
+                "font-weight": "normal",
+                "font-style": "normal",
+            },
+            "codeblock": {
+                "color": "#ff9900",
+                "font-weight": "normal",
+                "font-style": "normal",
+            },
+            "line": {
+                "color": "#2aa198",
+                "font-weight": "normal",
+                "font-style": "normal",
+            },
+            "html": {
+                "color": "#c000c0",
+                "font-weight": "normal",
+                "font-style": "normal",
+            },
+        }
+        self.setTheme(self.defaultTheme)
+
+    def setTheme(self, theme):
+        self.theme = theme
+        self.MARKDOWN_KWS_FORMAT = {}
+
+        pal = self.parent.palette()
+        pal.setColor(QPalette.Base, QColor(theme["background-color"]))
+        self.parent.setPalette(pal)
+        self.parent.setTextColor(QColor(theme["color"]))
+
+        text_char_format = QTextCharFormat()
+        text_char_format.setForeground(QBrush(QColor(theme["header"]["color"])))
+        text_char_format.setFontWeight(
+            QFont.Bold if theme["header"]["font-weight"] == "bold" else QFont.Normal
+        )
+        text_char_format.setFontItalic(
+            True if theme["header"]["font-style"] == "italic" else False
+        )
+        self.MARKDOWN_KWS_FORMAT["HeaderAtx"] = text_char_format
+
+        self.rehighlight()
+
+    def highlightBlock(self, text):
+        text = str(text)
+        self.highlightMarkdown(text, 0)
+
+    def highlightMarkdown(self, text, strt):
+        cursor = QTextCursor(self.document())
+        bf = cursor.blockFormat()
+        self.setFormat(0, len(text), QColor(self.theme["color"]))
+
+        if self.highlightAtxHeader(text, cursor, bf, strt):
+            return
+
+    def highlightEmptyLine(self, text, cursor, bf, strt):
+        textAscii = str(text.replace("\u2029", "\n"))
+        if textAscii.strip():
+            return False
+        else:
+            return True
+
+    def highlightAtxHeader(self, text, cursor, bf, strt):
+        found = False
+        for mo in re.finditer(self.MARKDOWN_KEYS_REGEX["HeaderAtx"], text):
+            # bf.setBackground(QBrush(QColor(7,54,65)))
+            # cursor.movePosition(QTextCursor.End)
+            # cursor.mergeBlockFormat(bf)
+            self.setFormat(
+                mo.start() + strt,
+                mo.end() - mo.start(),
+                self.MARKDOWN_KWS_FORMAT["HeaderAtx"],
+            )
+            found = True
+        return found