From ef13a517743443384232dd04bdd8731d27e1cca7 Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Wed, 26 Apr 2023 12:35:21 +0530
Subject: [PATCH] Cleanup previous PR

---
 src/calibre/gui2/custom_column_widgets.py |  6 ++
 src/calibre/gui2/markdown_editor.py       | 79 ++++++++++++++++-------
 2 files changed, 62 insertions(+), 23 deletions(-)

diff --git a/src/calibre/gui2/custom_column_widgets.py b/src/calibre/gui2/custom_column_widgets.py
index 98f0957bfa..a5f9d949b9 100644
--- a/src/calibre/gui2/custom_column_widgets.py
+++ b/src/calibre/gui2/custom_column_widgets.py
@@ -481,6 +481,12 @@ class Markdown(Base):
         self._box.setLayout(self._layout)
         self.widgets = [self._box]
 
+    def initialize(self, book_id):
+        path = self.db.abspath(book_id, index_is_id=True)
+        if path:
+            self._tb.set_base_url(QUrl.fromLocalFile(os.path.join(path, 'metadata.html')))
+        return super().initialize(book_id)
+
     def setter(self, val):
         self._tb.markdown = str(val or '').strip()
 
diff --git a/src/calibre/gui2/markdown_editor.py b/src/calibre/gui2/markdown_editor.py
index f709ad2675..e54e1f1b91 100644
--- a/src/calibre/gui2/markdown_editor.py
+++ b/src/calibre/gui2/markdown_editor.py
@@ -1,34 +1,58 @@
 #!/usr/bin/env python
+# License: GPLv3 Copyright: 2023, un_pogaz <un.pogaz@gmail.com>
 
-
-__license__   = 'GPL v3'
-__copyright__ = '2023, un_pogaz <un.pogaz@gmail.com>'
-__docformat__ = 'restructuredtext en'
-
+import os
 from qt.core import (
-    QPlainTextEdit, Qt, QTabWidget, QVBoxLayout, QWidget,
+    QPlainTextEdit, Qt, QTabWidget, QUrl, QVBoxLayout, QWidget, pyqtSignal,
 )
 
+from calibre.gui2 import safe_open_url
 from calibre.gui2.book_details import css
 from calibre.gui2.widgets2 import HTMLDisplay
 from calibre.library.comments import markdown
 
 
+class Preview(HTMLDisplay):
+
+    def __init__(self, parent=None):
+        super().__init__(parent)
+        self.setDefaultStyleSheet(css())
+        self.setTabChangesFocus(True)
+        self.base_url = None
+
+    def loadResource(self, rtype, qurl):
+        if self.base_url is not None and qurl.isRelative():
+            qurl = self.base_url.resolved(qurl)
+        return super().loadResource(rtype, qurl)
+
+
+class MarkdownEdit(QPlainTextEdit):
+
+    smarten_punctuation = pyqtSignal()
+
+    def contextMenuEvent(self, ev):
+        m = self.createStandardContextMenu()
+        m.addSeparator()
+        m.addAction(_('Smarten punctuation'), self.smarten_punctuation.emit)
+        m.exec(ev.globalPos())
+
+
 class Editor(QWidget):  # {{{
 
     def __init__(self, parent=None):
         QWidget.__init__(self, parent)
+        self.base_url = None
         self._layout = QVBoxLayout(self)
         self.setLayout(self._layout)
         self.tabs = QTabWidget(self)
         self.tabs.setTabPosition(QTabWidget.TabPosition.South)
         self._layout.addWidget(self.tabs)
 
-        self.editor = QPlainTextEdit(self.tabs)
+        self.editor = MarkdownEdit(self)
+        self.editor.smarten_punctuation.connect(self.smarten_punctuation)
 
-        self.preview = HTMLDisplay(self.tabs)
-        self.preview.setDefaultStyleSheet(css())
-        self.preview.setTabChangesFocus(True)
+        self.preview = Preview(self)
+        self.preview.anchor_clicked.connect(self.link_clicked)
 
         self.tabs.addTab(self.editor, _('&Markdown source'))
         self.tabs.addTab(self.preview, _('&Preview'))
@@ -36,31 +60,40 @@ class Editor(QWidget):  # {{{
         self.tabs.currentChanged[int].connect(self.change_tab)
         self.layout().setContentsMargins(0, 0, 0, 0)
 
+    def link_clicked(self, qurl):
+        safe_open_url(qurl)
+
+    def set_base_url(self, qurl):
+        self.base_url = qurl
+        self.preview.base_url = self.base_url
+
     def set_minimum_height_for_editor(self, val):
         self.editor.setMinimumHeight(val)
 
     @property
     def markdown(self):
-        self.tabs.setCurrentIndex(0)
         return self.editor.toPlainText().strip()
 
     @markdown.setter
     def markdown(self, v):
         self.editor.setPlainText(str(v or ''))
+        if self.tab == 'preview':
+            self.update_preview()
 
     def change_tab(self, index):
-        if index == 0:  # changing to source
-            pass
         if index == 1:  # changing to preview
-            html = markdown(self.editor.toPlainText().strip())
-            val = f'''\
-            <html>
-                <head></head>
-                <body class="vertical">
-                    <div>{html}</div>
-                </body>
-            <html>'''
-            self.preview.setHtml(val)
+            self.update_preview()
+
+    def update_preview(self):
+        html = markdown(self.editor.toPlainText().strip())
+        val = f'''\
+        <html>
+            <head></head>
+            <body class="vertical">
+                <div>{html}</div>
+            </body>
+        <html>'''
+        self.preview.setHtml(val)
 
     @property
     def tab(self):
@@ -82,7 +115,6 @@ class Editor(QWidget):  # {{{
         newmarkdown = smarten_punctuation(markdown)
         if markdown != newmarkdown:
             self.markdown = newmarkdown
-
 # }}}
 
 
@@ -90,6 +122,7 @@ if __name__ == '__main__':
     from calibre.gui2 import Application
     app = Application([])
     w = Editor()
+    w.set_base_url(QUrl.fromLocalFile(os.getcwd()))
     w.resize(800, 600)
     w.setWindowFlag(Qt.WindowType.Dialog)
     w.show()