preserve HTML heading level in QTextBlockFormat; demonstrate in example

When reading an HTML file with <H1> for example, we still set the font
size as before (that's how it always was done),
but now it remembers that it came from an H1 tag, so it writes
<h1 ...><span font-size:xx-large ...> ...  rather than
<p ...><span ...> ...  This will help with the upcoming Markdown
format, where heading level is saved but the font is not.

Now the style combobox in examples/widgets/richtext/textedit can set
list item type, heading type or "standard" formatting, and also shows the
current formatting of the line that has the cursor.  It was always a
shortcoming in this example that it only allowed setting the current line's
block format but had no feedback to show the current format.

Change-Id: I0a7849b74f23fea84d3375c487c3a6b9f43240c1
Reviewed-by: Lars Knoll <lars.knoll@qt.io>

1 files changed, 12 insertions, 3 deletions

diff --git a/src/gui/text/qtextdocument.cpp b/src/gui/text/qtextdocument.cpp
index d95932f4db..e58cd02af5 100644
--- a/src/gui/text/qtextdocument.cpp
+++ b/src/gui/text/qtextdocument.cpp
@@ -2906,7 +2906,11 @@ void QTextHtmlExporter::emitBlock(const QTextBlock &block)
             html += QLatin1Char('>');
         html += QLatin1String("<pre");
     } else if (!list) {
-        html += QLatin1String("<p");
+        int headingLevel = blockFormat.headingLevel();
+        if (headingLevel > 0 && headingLevel <= 6)
+            html += QLatin1String("<h") + QString::number(headingLevel);
+        else
+            html += QLatin1String("<p");
     }
 
     emitBlockAttributes(block);
@@ -2929,8 +2933,13 @@ void QTextHtmlExporter::emitBlock(const QTextBlock &block)
         html += QLatin1String("</pre>");
     else if (list)
         html += QLatin1String("</li>");
-    else
-        html += QLatin1String("</p>");
+    else {
+        int headingLevel = blockFormat.headingLevel();
+        if (headingLevel > 0 && headingLevel <= 6)
+            html += QLatin1String("</h") + QString::number(headingLevel) + QLatin1Char('>');
+        else
+            html += QLatin1String("</p>");
+    }
 
     if (list) {
         if (list->itemNumber(block) == list->count() - 1) { // last item? close list