Add baseline test for text rendering

Data-driven test case that renders the HTML files into an 800x600 image
for baseline comparison.

Task-number: QTBUG-99148
Pick-to: 6.3
Change-Id: I9ccc0cd21a1e94ff68d23bb82b84e1da46d6335a
Reviewed-by: Eirik Aavitsland <eirik.aavitsland@qt.io>

tests/baseline/CMakeLists.txt

@@ -4,4 +4,5 @@ endif()
 if(TARGET Qt::Network AND TARGET Qt::Widgets)
     add_subdirectory(widgets)
     add_subdirectory(stylesheet)
+    add_subdirectory(text)
 endif()

tests/baseline/text/CMakeLists.txt

@@ -0,0 +1,16 @@
+list(APPEND test_data "./data")
+
+qt_internal_add_test(tst_baseline_text
+    SOURCES
+        ../shared/baselineprotocol.cpp ../shared/baselineprotocol.h ../shared/lookup3.cpp
+        ../shared/qbaselinetest.cpp ../shared/qbaselinetest.h
+        ../shared/qwidgetbaselinetest.cpp ../shared/qwidgetbaselinetest.h
+        tst_baseline_text.cpp
+    INCLUDE_DIRECTORIES
+        ../shared
+    PUBLIC_LIBRARIES
+        Qt::Gui
+        Qt::Widgets
+        Qt::Network
+    TESTDATA ${test_data}
+)

tests/baseline/text/data/list_items_with_code.html

@@ -0,0 +1,8 @@
+<!-- QTBUG-99148 -->
+<h1>Header</h1>
+<ol>
+    <li><p>Something (<code>this is code</code> something else)</p></li>
+    <li><p>Maybe <code>this is code</code> or not?</p></li>
+    <li><p><code>this is code</code> and it seems to break</p></li>
+    <li><p>This has no code</p></li>
+</ol>

tests/baseline/text/tst_baseline_text.cpp

@@ -0,0 +1,122 @@
+/****************************************************************************
+**
+** Copyright (C) 2021 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the test suite of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:GPL-EXCEPT$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3 as published by the Free Software
+** Foundation with exceptions as appearing in the file LICENSE.GPL3-EXCEPT
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include <qbaselinetest.h>
+#include <qwidgetbaselinetest.h>
+#include <QtWidgets>
+
+class tst_Text : public QWidgetBaselineTest
+{
+    Q_OBJECT
+
+public:
+    tst_Text();
+
+    void loadTestFiles();
+
+private slots:
+    void tst_render_data();
+    void tst_render();
+
+private:
+    QDir htmlDir;
+};
+
+tst_Text::tst_Text()
+{
+    QString baseDir = QFINDTESTDATA("data/empty.html");
+    htmlDir = QDir(QFileInfo(baseDir).path());
+}
+
+void tst_Text::loadTestFiles()
+{
+    QTest::addColumn<QString>("html");
+
+    QStringList htmlFiles;
+    // first add generic test files
+    for (const auto &qssFile : htmlDir.entryList({QStringLiteral("*.html")}, QDir::Files | QDir::Readable))
+        htmlFiles << htmlDir.absoluteFilePath(qssFile);
+
+    // then test-function specific files
+    const QString testFunction = QString(QTest::currentTestFunction()).remove("tst_").toLower();
+    if (htmlDir.cd(testFunction)) {
+        for (const auto &htmlFile : htmlDir.entryList({QStringLiteral("*.html")}, QDir::Files | QDir::Readable))
+            htmlFiles << htmlDir.absoluteFilePath(htmlFile);
+        htmlDir.cdUp();
+    }
+
+    for (const auto &htmlFile : htmlFiles) {
+        QFileInfo fileInfo(htmlFile);
+        QFile file(htmlFile);
+        file.open(QFile::ReadOnly);
+        QString html = QString::fromUtf8(file.readAll());
+        QBaselineTest::newRow(fileInfo.baseName().toUtf8()) << html;
+    }
+}
+
+void tst_Text::tst_render_data()
+{
+    loadTestFiles();
+}
+
+void tst_Text::tst_render()
+{
+    QFETCH(QString, html);
+
+    QTextDocument textDocument;
+    textDocument.setPageSize(QSizeF(800, 600));
+    textDocument.setHtml(html);
+
+    QImage image(800, 600, QImage::Format_ARGB32);
+    image.fill(Qt::white);
+
+    {
+        QPainter painter(&image);
+
+        QAbstractTextDocumentLayout::PaintContext context;
+        context.palette.setColor(QPalette::Text, Qt::black);
+        textDocument.documentLayout()->draw(&painter, context);
+    }
+
+    QBASELINE_TEST(image);
+}
+
+
+#define main _realmain
+QTEST_MAIN(tst_Text)
+#undef main
+
+int main(int argc, char *argv[])
+{
+    qSetGlobalQHashSeed(0);   // Avoid rendering variations caused by QHash randomization
+
+    QBaselineTest::handleCmdLineArgs(&argc, &argv);
+    return _realmain(argc, argv);
+}
+
+#include "tst_baseline_text.moc"