QTextDocument: add css-styling of table cell borders to HTML import/export

Supported style attributes:

<table>
style: supports "border-collapse: collapse" and "border-color".
border: width of the outer border
bordercolor: basic color for all borders

<tr>
style: not supported

<td>/</th>
style: supports the "border", "border-[top|left|bottom|right]]"
       shorthand styles and the "border-width", "border-color"
       and "border-style" (and the top/left/bottom/right variants)
       attributes

<table border=1 style="border-collapse: collapse"> will render
a simple 1px table grid.

Notes:

The QTextDocument table model is much simpler than the HTML table model.
It basically only has <table> and <td> support. So the HTML parser is
forced to map markup and styling to the QTextDocument model which
is not without loss.

In other words: While QTextDocument -> HTML -> QTextDocument should
preserve the QTextDocument structure, HTML -> QTextDocument -> HTML
does not preserve the HTML DOM at all.

So for now the HTML importer and writer only support border styles on
the <td> and <th> nodes. In future updates, the HTML parser might be
enhanced to map <tr> and <table> CSS styles to the cells.

Change-Id: If9e7312fa6cbf270cf8f7b3c72ba1fa094107517
Reviewed-by: Shawn Rutledge <shawn.rutledge@qt.io>

1 files changed, 29 insertions, 0 deletions

diff --git a/tests/auto/gui/text/qtextdocument/tst_qtextdocument.cpp b/tests/auto/gui/text/qtextdocument/tst_qtextdocument.cpp
index 58810f73c1..52e56feb5a 100644
--- a/tests/auto/gui/text/qtextdocument/tst_qtextdocument.cpp
+++ b/tests/auto/gui/text/qtextdocument/tst_qtextdocument.cpp
@@ -50,6 +50,7 @@
 #include <QDomDocument>
 #include "common.h"
 
+// #define DEBUG_WRITE_OUTPUT
 
 QT_FORWARD_DECLARE_CLASS(QTextDocument)
 
@@ -196,6 +197,7 @@ private:
     void backgroundImage_checkExpectedHtml(const QTextDocument &doc);
     void buildRegExpData();
     static QString cssFontSizeString(const QFont &font);
+    void writeActualAndExpected(const char* testTag, const QString &actual, const QString &expected);
 
     QTextDocument *doc;
     QTextCursor cursor;
@@ -224,6 +226,27 @@ QString tst_QTextDocument::cssFontSizeString(const QFont &font)
             : QString::number(font.pixelSize()) + QStringLiteral("px");
 }
 
+void tst_QTextDocument::writeActualAndExpected(const char *testTag, const QString &actual, const QString &expected)
+{
+#ifdef DEBUG_WRITE_OUTPUT
+    {
+        QFile out(QDir::temp().absoluteFilePath(QLatin1String(testTag) + QLatin1String("-actual.html")));
+        out.open(QFile::WriteOnly);
+        out.write(actual.toUtf8());
+        out.close();
+    } {
+        QFile out(QDir::temp().absoluteFilePath(QLatin1String(testTag) + QLatin1String("-expected.html")));
+        out.open(QFile::WriteOnly);
+        out.write(expected.toUtf8());
+        out.close();
+    }
+#else
+    Q_UNUSED(testTag)
+    Q_UNUSED(actual)
+    Q_UNUSED(expected)
+#endif
+}
+
 // Testing get/set functions
 void tst_QTextDocument::getSetCheck()
 {
@@ -1765,6 +1788,8 @@ void tst_QTextDocument::toHtml()
 
     QString output = doc->toHtml();
 
+    writeActualAndExpected(QTest::currentDataTag(), output, expectedOutput);
+
     QCOMPARE(output, expectedOutput);
 
     QDomDocument document;
@@ -1962,6 +1987,8 @@ void tst_QTextDocument::toHtmlRootFrameProperties()
     expectedOutput.replace("DEFAULTBLOCKSTYLE", "style=\" margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px;\"");
     expectedOutput.append(htmlTail);
 
+    writeActualAndExpected(QTest::currentTestFunction(), doc.toHtml(), expectedOutput);
+
     QCOMPARE(doc.toHtml(), expectedOutput);
 }
 
@@ -2734,6 +2761,8 @@ void tst_QTextDocument::backgroundImage_checkExpectedHtml(const QTextDocument &d
                     .arg(defaultFont.weight() * 8)
                     .arg((defaultFont.italic() ? "italic" : "normal"));
 
+    writeActualAndExpected(QTest::currentTestFunction(), doc.toHtml(), expectedHtml);
+
     QCOMPARE(doc.toHtml(), expectedHtml);
 }