Add test for output rendering

For now this is mostly an example - but it seems useful to have the
ability to test rendering output.

.circleci/config.yml

@@ -23,17 +23,19 @@ jobs:
             pyenv global system
             mkdir build
             cd build
-            cmake -DCMAKE_BUILD_TYPE=Debug -DUSE_GCOV=ON -DPYTHON_EXECUTABLE=/usr/bin/python3 ..
+            cmake -DCMAKE_BUILD_TYPE=Debug -DUSE_GCOV=ON -DPYTHON_EXECUTABLE=/usr/bin/python3 -DENABLE_TESTS=ON ..
             cmake --build . --target bindings -- VERBOSE=1
             cmake --build . -- VERBOSE=1
       - run:
           name: test
           command: |
             cd build
-            ctest -VV
+            xvfb-run -a -e /dev/stdout ctest -VV
       - run:
           name: Generate coverage report with lcov
           command: lcov --directory . --capture --output-file coverage.info
       - run:
           name: Upload coverage report to codecov
           command: bash <(curl -s https://codecov.io/bash) -f coverage.info 
+      - store_test_results:
+          path: build/test_shellwidget_output/

src/gui/shellwidget/test/CMakeLists.txt

@@ -14,6 +14,9 @@ function(add_xtest SOURCE_NAME)
 	add_test(NAME ${SOURCE_NAME} COMMAND ${SOURCE_NAME} ${CTEST_EXE_ARGS})
 endfunction()
 
+file(TO_CMAKE_PATH ${CMAKE_CURRENT_SOURCE_DIR} TEST_SOURCE_DIR)
+add_definitions(-DTEST_SOURCE_DIR="${TEST_SOURCE_DIR}")
+
 add_xtest(test_cell)
 add_xtest(test_shellcontents)
 add_xtest(test_shellwidget)

src/gui/shellwidget/test/test_shellwidget.cpp

@@ -1,4 +1,5 @@
 #include <QtTest/QtTest>
+#include <QPainter>
 #include "shellwidget.h"
 
 #if defined(Q_OS_WIN) && defined(USE_STATIC_QT)
@@ -14,8 +15,33 @@ private slots:
 	void clearRegion();
 	void fontDescriptionFromQFont();
 	void fontDescriptionToQFont();
+	void render();
+private:
+	QString outputFolderPath();
+	QString outputFilePath(const QString &name);
+	QString originalFilePath(const QString &name);
+	void saveWidgetOutput(ShellWidget &w, QString name);
+	void diffWidgetOutput(QString name);
 };
 
+QString Test::outputFolderPath()
+{
+	auto folderName = "test_shellwidget_output";
+	QDir().mkpath(folderName);
+	return folderName;
+}
+
+/// Render Output file path to save a file
+QString Test::outputFilePath(const QString &name)
+{
+	return QDir(outputFolderPath()).filePath(name);
+}
+
+/// Previous output from rendering, from the source test folder
+QString Test::originalFilePath(const QString &name)
+{
+	return QDir(QDir(TEST_SOURCE_DIR).filePath("renderoutput")).filePath(name);
+}
 
 void Test::clearRegion()
 {
@@ -126,5 +152,86 @@ void Test::fontDescriptionToQFont()
 	QCOMPARE(varInvalidHeight, QVariant{ QString{ "Invalid font height" } });
 }
 
+void Test::saveWidgetOutput(ShellWidget &w, QString name)
+{
+	QImage img(w.size(), QImage::Format_ARGB32);
+	QPainter painter(&img);
+	w.render(&painter);
+	QCOMPARE(img.save(outputFilePath(name)), true);
+}
+
+void Test::diffWidgetOutput(QString name)
+{
+	auto p1 = outputFilePath(name);
+	auto output = QImage(p1);
+	qDebug() << "Loading" << p1 << output;
+	auto p2 = originalFilePath(name);
+	auto expected = QImage(p2);
+	qDebug() << "Loading" << p2 << expected;
+
+	QCOMPARE(output.isNull(), false);
+	QCOMPARE(expected.isNull(), false);
+
+	QImage diff(output.size(), QImage::Format_RGB32);
+	diff.fill(Qt::white);
+
+	bool failed = false;
+
+	for(int y=0; y<output.height(); y++){
+		for(int x=0; x<output.width(); x++){
+			auto outputColor = output.pixel(x, y);
+			auto expectedColor = expected.pixel(x, y);
+
+			if (outputColor != expectedColor) {
+				//qWarning() << "Pixel color mismatch at position " << x << y;
+				//qWarning() << "  output:" << outputColor << "expected:" << expectedColor;
+				diff.setPixel(x, y, Qt::red);
+				failed = true;
+			}
+		}
+	}
+
+	auto outpath = outputFilePath("diff_" + name);
+	qDebug() << "Saving diff" << outpath;
+
+
+	if (QGuiApplication::platformName() != "xcb") {
+		auto msg = QString("Skipping render test in non X11: %1")
+			.arg(QGuiApplication::platformName());
+		QSKIP(qPrintable(msg));
+	}
+
+	QCOMPARE(diff.save(outpath), true);
+
+	QCOMPARE(output.width(), expected.width());
+	QCOMPARE(output.height(), expected.height());
+
+	if (failed) {
+		qWarning() << "Failing diff, check the output diff image" << outpath;
+		QCOMPARE(failed, false);
+	}
+}
+
+/// This is mostly an example it renders a shell widget and saves it as an image.
+/// For more complicated tests we may want to parametrize these.
+void Test::render()
+{
+	ShellWidget w;
+	w.setShellFont(QFont("Monospace", 11, QFont::Weight::Normal, false));
+	w.resizeShell(20, 20);
+	w.show();
+
+	w.put("hello", 2, 2, HighlightAttribute());
+	w.put("fffffff", 3, 3, HighlightAttribute(Qt::red, Qt::black, Qt::white, false, false, false, false, false, false));
+	w.put("italic text", 4, 3, HighlightAttribute(Qt::white, Qt::black, Qt::white, false, true, false, false, false, false));
+	w.put("bold text", 5, 3, HighlightAttribute(Qt::white, Qt::black, Qt::white, false, false, true, false, false, false));
+	w.put("underline text", 6, 3, HighlightAttribute(Qt::white, Qt::black, Qt::white, false, false, false, true, false, false));
+	w.put("undercurl text", 7, 3, HighlightAttribute(Qt::white, Qt::black, Qt::red, false, false, false, false, true, false));
+
+	auto name = "shellwidget_render_works.png";
+	saveWidgetOutput(w, name);
+	diffWidgetOutput(name);
+}
+
 QTEST_MAIN(Test)
 #include "test_shellwidget.moc"