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>

3 files changed, 271 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);
 }
 
diff --git a/tests/auto/gui/text/qtextdocumentfragment/tst_qtextdocumentfragment.cpp b/tests/auto/gui/text/qtextdocumentfragment/tst_qtextdocumentfragment.cpp
index c5243d1535..b6917f1208 100644
--- a/tests/auto/gui/text/qtextdocumentfragment/tst_qtextdocumentfragment.cpp
+++ b/tests/auto/gui/text/qtextdocumentfragment/tst_qtextdocumentfragment.cpp
@@ -181,6 +181,11 @@ private slots:
     void html_tableCellBackground();
     void css_bodyBackground();
     void css_tableCellBackground();
+    void css_tableCellBorder();
+    void css_tableCellBorderShorthand();
+    void css_tableCellAllBordersShorthand();
+    void css_tableCellOverrideOneBorder();
+    void css_tableBorderCollapse();
     void css_fontWeight();
     void css_float();
     void css_textIndent();
@@ -1753,6 +1758,135 @@ void tst_QTextDocumentFragment::css_tableCellBackground()
     QCOMPARE(cell.format().background().style(), Qt::TexturePattern);
 }
 
+void tst_QTextDocumentFragment::css_tableCellBorder()
+{
+    const char html[] = "<body><table><tr><td style=\"border-width:8px;border-color:green;border-style:groove;border-left-style:dashed;border-left-color:red;border-left-width:4px\">Foo</td></tr></table></body>";
+    doc->setHtml(html);
+
+    cursor.movePosition(QTextCursor::Start);
+    cursor.movePosition(QTextCursor::NextBlock);
+    QTextTable *table = cursor.currentTable();
+    QVERIFY(table);
+
+    QTextTableCell cell = table->cellAt(0, 0);
+    QTextTableCellFormat cellFormat = cell.format().toTableCellFormat();
+    QCOMPARE(cellFormat.leftBorder(), qreal(4));
+    QCOMPARE(cellFormat.leftBorderBrush(), QBrush(QColor("red")));
+    QCOMPARE(cellFormat.leftBorderStyle(), QTextFrameFormat::BorderStyle_Dashed);
+
+    QCOMPARE(cellFormat.rightBorder(), qreal(8));
+    QCOMPARE(cellFormat.rightBorderBrush(), QBrush(QColor("green")));
+    QCOMPARE(cellFormat.rightBorderStyle(), QTextFrameFormat::BorderStyle_Groove);
+
+    QCOMPARE(cellFormat.bottomBorder(), qreal(8));
+    QCOMPARE(cellFormat.bottomBorderBrush(), QBrush(QColor("green")));
+    QCOMPARE(cellFormat.bottomBorderStyle(), QTextFrameFormat::BorderStyle_Groove);
+
+    QCOMPARE(cellFormat.topBorder(), qreal(8));
+    QCOMPARE(cellFormat.topBorderBrush(), QBrush(QColor("green")));
+    QCOMPARE(cellFormat.topBorderStyle(), QTextFrameFormat::BorderStyle_Groove);
+}
+
+void tst_QTextDocumentFragment::css_tableCellBorderShorthand()
+{
+    const char html[] = "<body><table><tr><td style=\"border-left:1px solid green;border-right:2px dashed red;border-bottom:3px dotted yellow;border-top:4px dot-dash blue\">Foo</td></tr></table></body>";
+    doc->setHtml(html);
+
+    cursor.movePosition(QTextCursor::Start);
+    cursor.movePosition(QTextCursor::NextBlock);
+    QTextTable *table = cursor.currentTable();
+    QVERIFY(table);
+
+    QTextTableCell cell = table->cellAt(0, 0);
+    QTextTableCellFormat cellFormat = cell.format().toTableCellFormat();
+    QCOMPARE(cellFormat.leftBorder(), qreal(1));
+    QCOMPARE(cellFormat.leftBorderBrush(), QBrush(QColor("green")));
+    QCOMPARE(cellFormat.leftBorderStyle(), QTextFrameFormat::BorderStyle_Solid);
+
+    QCOMPARE(cellFormat.rightBorder(), qreal(2));
+    QCOMPARE(cellFormat.rightBorderBrush(), QBrush(QColor("red")));
+    QCOMPARE(cellFormat.rightBorderStyle(), QTextFrameFormat::BorderStyle_Dashed);
+
+    QCOMPARE(cellFormat.bottomBorder(), qreal(3));
+    QCOMPARE(cellFormat.bottomBorderBrush(), QBrush(QColor("yellow")));
+    QCOMPARE(cellFormat.bottomBorderStyle(), QTextFrameFormat::BorderStyle_Dotted);
+
+    QCOMPARE(cellFormat.topBorder(), qreal(4));
+    QCOMPARE(cellFormat.topBorderBrush(), QBrush(QColor("blue")));
+    QCOMPARE(cellFormat.topBorderStyle(), QTextFrameFormat::BorderStyle_DotDash);
+}
+
+void tst_QTextDocumentFragment::css_tableCellAllBordersShorthand()
+{
+    const char html[] = "<body><table><tr><td style=\"border:2px dashed green\">Foo</td></tr></table></body>";
+    doc->setHtml(html);
+
+    cursor.movePosition(QTextCursor::Start);
+    cursor.movePosition(QTextCursor::NextBlock);
+    QTextTable *table = cursor.currentTable();
+    QVERIFY(table);
+
+    QTextTableCell cell = table->cellAt(0, 0);
+    QTextTableCellFormat cellFormat = cell.format().toTableCellFormat();
+    QCOMPARE(cellFormat.leftBorder(), qreal(2));
+    QCOMPARE(cellFormat.leftBorderBrush(), QBrush(QColor("green")));
+    QCOMPARE(cellFormat.leftBorderStyle(), QTextFrameFormat::BorderStyle_Dashed);
+
+    QCOMPARE(cellFormat.rightBorder(), qreal(2));
+    QCOMPARE(cellFormat.rightBorderBrush(), QBrush(QColor("green")));
+    QCOMPARE(cellFormat.rightBorderStyle(), QTextFrameFormat::BorderStyle_Dashed);
+
+    QCOMPARE(cellFormat.bottomBorder(), qreal(2));
+    QCOMPARE(cellFormat.bottomBorderBrush(), QBrush(QColor("green")));
+    QCOMPARE(cellFormat.bottomBorderStyle(), QTextFrameFormat::BorderStyle_Dashed);
+
+    QCOMPARE(cellFormat.topBorder(), qreal(2));
+    QCOMPARE(cellFormat.topBorderBrush(), QBrush(QColor("green")));
+    QCOMPARE(cellFormat.topBorderStyle(), QTextFrameFormat::BorderStyle_Dashed);
+}
+
+void tst_QTextDocumentFragment::css_tableCellOverrideOneBorder()
+{
+    const char html[] = "<body><table><tr><td style=\"border:2px dashed green;border-left:4px solid red\">Foo</td></tr></table></body>";
+    doc->setHtml(html);
+
+    cursor.movePosition(QTextCursor::Start);
+    cursor.movePosition(QTextCursor::NextBlock);
+    QTextTable *table = cursor.currentTable();
+    QVERIFY(table);
+
+    QTextTableCell cell = table->cellAt(0, 0);
+    QTextTableCellFormat cellFormat = cell.format().toTableCellFormat();
+    QCOMPARE(cellFormat.leftBorder(), qreal(4));
+    QCOMPARE(cellFormat.leftBorderBrush(), QBrush(QColor("red")));
+    QCOMPARE(cellFormat.leftBorderStyle(), QTextFrameFormat::BorderStyle_Solid);
+
+    QCOMPARE(cellFormat.rightBorder(), qreal(2));
+    QCOMPARE(cellFormat.rightBorderBrush(), QBrush(QColor("green")));
+    QCOMPARE(cellFormat.rightBorderStyle(), QTextFrameFormat::BorderStyle_Dashed);
+
+    QCOMPARE(cellFormat.bottomBorder(), qreal(2));
+    QCOMPARE(cellFormat.bottomBorderBrush(), QBrush(QColor("green")));
+    QCOMPARE(cellFormat.bottomBorderStyle(), QTextFrameFormat::BorderStyle_Dashed);
+
+    QCOMPARE(cellFormat.topBorder(), qreal(2));
+    QCOMPARE(cellFormat.topBorderBrush(), QBrush(QColor("green")));
+    QCOMPARE(cellFormat.topBorderStyle(), QTextFrameFormat::BorderStyle_Dashed);
+}
+
+void tst_QTextDocumentFragment::css_tableBorderCollapse()
+{
+    const char html[] = "<body><table style=\"border-collapse:collapse\"><tr><td>Foo</td></tr></table></body>";
+    doc->setHtml(html);
+
+    cursor.movePosition(QTextCursor::Start);
+    cursor.movePosition(QTextCursor::NextBlock);
+    QTextTable *table = cursor.currentTable();
+    QVERIFY(table);
+
+    QCOMPARE(table->format().borderCollapse(), true);
+}
+
 void tst_QTextDocumentFragment::css_cellPaddings()
 {
     const char html[] = "<body><table><tr><td style=\"padding-left:1\">Foo</td>"
diff --git a/tests/auto/gui/text/qtexttable/tst_qtexttable.cpp b/tests/auto/gui/text/qtexttable/tst_qtexttable.cpp
index f21b969aa7..7b2ff4cc10 100644
--- a/tests/auto/gui/text/qtexttable/tst_qtexttable.cpp
+++ b/tests/auto/gui/text/qtexttable/tst_qtexttable.cpp
@@ -50,6 +50,8 @@ typedef QList<int> IntList;
 
 QT_FORWARD_DECLARE_CLASS(QTextDocument)
 
+Q_DECLARE_METATYPE(QTextFrameFormat::BorderStyle);
+
 class tst_QTextTable : public QObject
 {
     Q_OBJECT
@@ -95,6 +97,8 @@ private slots:
 #if !defined(QT_NO_PRINTER) && defined(QT_BUILD_INTERNAL)
     void QTBUG31330_renderBackground();
 #endif
+    void checkBorderAttributes_data();
+    void checkBorderAttributes();
 
 private:
     QTextTable *create2x2Table();
@@ -1170,5 +1174,109 @@ void tst_QTextTable::QTBUG31330_renderBackground()
 }
 #endif
 
+void tst_QTextTable::checkBorderAttributes_data()
+{
+    QTest::addColumn<QString>("html");
+    QTest::addColumn<qreal>("topBorderWidth");
+    QTest::addColumn<qreal>("bottomBorderWidth");
+    QTest::addColumn<qreal>("leftBorderWidth");
+    QTest::addColumn<qreal>("rightBorderWidth");
+    QTest::addColumn<QTextFrameFormat::BorderStyle>("topBorderStyle");
+    QTest::addColumn<QTextFrameFormat::BorderStyle>("bottomBorderStyle");
+    QTest::addColumn<QTextFrameFormat::BorderStyle>("leftBorderStyle");
+    QTest::addColumn<QTextFrameFormat::BorderStyle>("rightBorderStyle");
+    QTest::addColumn<QBrush>("topBorderBrush");
+    QTest::addColumn<QBrush>("bottomBorderBrush");
+    QTest::addColumn<QBrush>("leftBorderBrush");
+    QTest::addColumn<QBrush>("rightBorderBrush");
+
+    const QString tableHtmlStart = QStringLiteral("<html><head><style>");
+    const QString tableHtmlEnd = QStringLiteral("</style></head><body>"
+                                                "<table border=\"1\"><tr><td>One</td><td>Two</td></tr>"
+                                                "<tr><td>Three</td><td>Four</td></tr></table></body></html>");
+    QTest::newRow("1px-solid-colors")
+        << QString("%1"
+                   "td {"
+                   "border-top: 1px solid red;"
+                   "border-bottom: 1px solid blue;"
+                   "border-left: 1px solid green;"
+                   "border-right: 1px solid yellow;"
+                   "}"
+                   "%2").arg(tableHtmlStart).arg(tableHtmlEnd)
+        << 1.0 << 1.0 << 1.0 << 1.0
+        << QTextFrameFormat::BorderStyle_Solid << QTextFrameFormat::BorderStyle_Solid
+        << QTextFrameFormat::BorderStyle_Solid << QTextFrameFormat::BorderStyle_Solid
+        << QBrush(Qt::red) << QBrush(Qt::blue) << QBrush(Qt::darkGreen) << QBrush(Qt::yellow);
+    QTest::newRow("MixedWidth-solid-colors")
+        << QString("%1"
+                   "td {"
+                   "border-top: 1px solid red;"
+                   "border-bottom: 2px solid blue;"
+                   "border-left: 3px solid green;"
+                   "border-right: 4px solid yellow;"
+                   "}"
+                   "%2").arg(tableHtmlStart).arg(tableHtmlEnd)
+        << 1.0 << 2.0 << 3.0 << 4.0
+        << QTextFrameFormat::BorderStyle_Solid << QTextFrameFormat::BorderStyle_Solid
+        << QTextFrameFormat::BorderStyle_Solid << QTextFrameFormat::BorderStyle_Solid
+        << QBrush(Qt::red) << QBrush(Qt::blue) << QBrush(Qt::darkGreen) << QBrush(Qt::yellow);
+    QTest::newRow("MixedWidth-MixedStyle-colors")
+        << QString("%1"
+                   "td {"
+                   "border-top: 1px solid red;"
+                   "border-bottom: 2px dotted blue;"
+                   "border-left: 3px dashed green;"
+                   "border-right: 4px inset yellow;"
+                   "}"
+                   "%2").arg(tableHtmlStart).arg(tableHtmlEnd)
+        << 1.0 << 2.0 << 3.0 << 4.0
+        << QTextFrameFormat::BorderStyle_Solid << QTextFrameFormat::BorderStyle_Dotted
+        << QTextFrameFormat::BorderStyle_Dashed << QTextFrameFormat::BorderStyle_Inset
+        << QBrush(Qt::red) << QBrush(Qt::blue) << QBrush(Qt::darkGreen) << QBrush(Qt::yellow);
+}
+
+void tst_QTextTable::checkBorderAttributes()
+{
+    QFETCH(QString, html);
+    QFETCH(qreal, topBorderWidth);
+    QFETCH(qreal, bottomBorderWidth);
+    QFETCH(qreal, leftBorderWidth);
+    QFETCH(qreal, rightBorderWidth);
+    QFETCH(QTextFrameFormat::BorderStyle, topBorderStyle);
+    QFETCH(QTextFrameFormat::BorderStyle, bottomBorderStyle);
+    QFETCH(QTextFrameFormat::BorderStyle, leftBorderStyle);
+    QFETCH(QTextFrameFormat::BorderStyle, rightBorderStyle);
+    QFETCH(QBrush, topBorderBrush);
+    QFETCH(QBrush, bottomBorderBrush);
+    QFETCH(QBrush, leftBorderBrush);
+    QFETCH(QBrush, rightBorderBrush);
+
+    QTextDocument doc;
+    doc.setHtml(html);
+    QTextCursor cursor(doc.firstBlock());
+    cursor.movePosition(QTextCursor::Right);
+
+    QTextTable *currentTable = cursor.currentTable();
+    QVERIFY(currentTable);
+    for (int row = 0; row < 2; row++) {
+        for (int column = 0; column < 2; column++) {
+            QTextTableCell cell = currentTable->cellAt(row, column);
+            QTextCharFormat cellFormat = cell.format();
+            QCOMPARE(cellFormat.doubleProperty(QTextFormat::TableCellTopBorder), topBorderWidth);
+            QCOMPARE(cellFormat.doubleProperty(QTextFormat::TableCellBottomBorder), bottomBorderWidth);
+            QCOMPARE(cellFormat.doubleProperty(QTextFormat::TableCellLeftBorder), leftBorderWidth);
+            QCOMPARE(cellFormat.doubleProperty(QTextFormat::TableCellRightBorder), rightBorderWidth);
+            QCOMPARE(cellFormat.property(QTextFormat::TableCellTopBorderStyle), topBorderStyle);
+            QCOMPARE(cellFormat.property(QTextFormat::TableCellBottomBorderStyle), bottomBorderStyle);
+            QCOMPARE(cellFormat.property(QTextFormat::TableCellLeftBorderStyle), leftBorderStyle);
+            QCOMPARE(cellFormat.property(QTextFormat::TableCellRightBorderStyle), rightBorderStyle);
+            QCOMPARE(cellFormat.brushProperty(QTextFormat::TableCellTopBorderBrush), topBorderBrush);
+            QCOMPARE(cellFormat.brushProperty(QTextFormat::TableCellBottomBorderBrush), bottomBorderBrush);
+            QCOMPARE(cellFormat.brushProperty(QTextFormat::TableCellLeftBorderBrush), leftBorderBrush);
+            QCOMPARE(cellFormat.brushProperty(QTextFormat::TableCellRightBorderBrush), rightBorderBrush);
+        }
+    }
+}
+
 QTEST_MAIN(tst_QTextTable)
 #include "tst_qtexttable.moc"