Use CSS classes on html list items for checkbox support

If we replace the bullet character with a UC checkbox character, it
looks ok in a browser, and the HTML parser can recover the BlockMarker
attribute from the css class.

[ChangeLog][QtGui][Text] Checkbox list items can now be read and written
in both HTML and Markdown, including conversions.

Task-number: QTBUG-103714
Change-Id: Ic6b74512075cd4ac16d6f80fdf55b221447491a9
Reviewed-by: Qt CI Bot <[email protected]>
Reviewed-by: Allan Sandfeld Jensen <[email protected]>

2 files changed, 23 insertions, 1 deletions

diff --git a/src/gui/text/qtextdocument.cpp b/src/gui/text/qtextdocument.cpp
index 71511257f51..463026ed238 100644
--- a/src/gui/text/qtextdocument.cpp
+++ b/src/gui/text/qtextdocument.cpp
@@ -2372,6 +2372,8 @@ QString QTextHtmlExporter::toHtml(ExportMode mode)
     html += "<style type=\"text/css\">\n"_L1;
     html += "p, li { white-space: pre-wrap; }\n"_L1;
     html += "hr { height: 1px; border-width: 0; }\n"_L1;
+    html += "li.unchecked::marker { content: \"\\2610\"; }\n"_L1;
+    html += "li.checked::marker { content: \"\\2612\"; }\n"_L1;
     html += "</style>"_L1;
     html += "</head><body"_L1;
 
@@ -3038,7 +3040,7 @@ void QTextHtmlExporter::emitBlock(const QTextBlock &block)
 
             html += " style=\""_L1;
             html += styleString;
-            html += "\">"_L1;
+            html += "\">\n"_L1;
         }
 
         html += "<li"_L1;
@@ -3051,6 +3053,18 @@ void QTextHtmlExporter::emitBlock(const QTextBlock &block)
 
             defaultCharFormat.merge(block.charFormat());
         }
+        if (block.blockFormat().hasProperty(QTextFormat::BlockMarker)) {
+            switch (block.blockFormat().marker()) {
+            case QTextBlockFormat::MarkerType::Checked:
+                html += " class=\"checked\""_L1;
+                break;
+            case QTextBlockFormat::MarkerType::Unchecked:
+                html += " class=\"unchecked\""_L1;
+                break;
+            case QTextBlockFormat::MarkerType::NoMarker:
+                break;
+            }
+        }
     }
 
     const QTextBlockFormat blockFormat = block.blockFormat();
diff --git a/src/gui/text/qtexthtmlparser.cpp b/src/gui/text/qtexthtmlparser.cpp
index a10b8808862..ded2dd185a5 100644
--- a/src/gui/text/qtexthtmlparser.cpp
+++ b/src/gui/text/qtexthtmlparser.cpp
@@ -1636,6 +1636,14 @@ void QTextHtmlParser::applyAttributes(const QStringList &attributes)
                     }
                 }
                 break;
+            case Html_li:
+                if (key == "class"_L1) {
+                    if (value == "unchecked"_L1)
+                        node->blockFormat.setMarker(QTextBlockFormat::MarkerType::Unchecked);
+                    else if (value == "checked"_L1)
+                        node->blockFormat.setMarker(QTextBlockFormat::MarkerType::Checked);
+                }
+                break;
             case Html_a:
                 if (key == "href"_L1)
                     node->charFormat.setAnchorHref(value);