From 914e25bf01e6264dd80b6f27e50b45a578a7fe89 Mon Sep 17 00:00:00 2001
From: Eirik Aavitsland <eirik.aavitsland@qt.io>
Date: Mon, 13 Feb 2017 12:38:10 +0100
Subject: Add support for pattern brushes to svg generator

Pattern brushes was not implemented in the svg generator. Shapes
drawn with such brushes would not be included in the svg file.

[ChangeLog][][QSvgGenerator] Add support for pattern brushes

Task-number: QTBUG-58148
Change-Id: Ib275661c596631fea64cb250c9743a529cd7b834
Reviewed-by: Joerg Bornemann <joerg.bornemann@qt.io>
---
 src/svg/qsvggenerator.cpp                      | 64 +++++++++++++++++++++++++-
 tests/auto/qsvggenerator/tst_qsvggenerator.cpp | 42 +++++++++++++++++
 2 files changed, 105 insertions(+), 1 deletion(-)

diff --git a/src/svg/qsvggenerator.cpp b/src/svg/qsvggenerator.cpp
index 6af4370..de6e8d4 100644
--- a/src/svg/qsvggenerator.cpp
+++ b/src/svg/qsvggenerator.cpp
@@ -52,6 +52,7 @@
 #include "qtextstream.h"
 #include "qbuffer.h"
 #include "qmath.h"
+#include "qbitmap.h"
 
 #include "qdebug.h"
 
@@ -128,6 +129,9 @@ public:
     QString currentGradientName;
     int numGradients;
 
+    QStringList savedPatternBrushes;
+    QStringList savedPatternMasks;
+
     struct _attributes {
         QString document_title;
         QString document_description;
@@ -145,12 +149,13 @@ static inline QPaintEngine::PaintEngineFeatures svgEngineFeatures()
 {
     return QPaintEngine::PaintEngineFeatures(
         QPaintEngine::AllFeatures
-        & ~QPaintEngine::PatternBrush
         & ~QPaintEngine::PerspectiveTransform
         & ~QPaintEngine::ConicalGradientFill
         & ~QPaintEngine::PorterDuff);
 }
 
+Q_GUI_EXPORT QImage qt_imageForBrush(int brushStyle, bool invert);
+
 class QSvgPaintEngine : public QPaintEngine
 {
     Q_DECLARE_PRIVATE(QSvgPaintEngine)
@@ -212,6 +217,41 @@ public:
         Q_ASSERT(!isActive());
         d_func()->resolution = resolution;
     }
+
+    QString savePatternMask(Qt::BrushStyle style)
+    {
+        QString maskId = QString(QStringLiteral("patternmask%1")).arg(style);
+        if (!d_func()->savedPatternMasks.contains(maskId)) {
+            QImage img = qt_imageForBrush(style, true);
+            QRegion reg(QBitmap::fromData(img.size(), img.constBits()));
+            QString rct(QStringLiteral("<rect x=\"%1\" y=\"%2\" width=\"%3\" height=\"%4\" />"));
+            QTextStream str(&d_func()->defs, QIODevice::Append);
+            str << "<mask id=\"" << maskId << "\" x=\"0\" y=\"0\" width=\"8\" height=\"8\" "
+                << "stroke=\"none\" fill=\"#ffffff\" patternUnits=\"userSpaceOnUse\" >" << endl;
+            for (QRect r : reg.rects()) {
+                str << rct.arg(r.x()).arg(r.y()).arg(r.width()).arg(r.height()) << endl;
+            }
+            str << QStringLiteral("</mask>") << endl << endl;
+            d_func()->savedPatternMasks.append(maskId);
+        }
+        return maskId;
+    }
+
+    QString savePatternBrush(const QString &color, const QBrush &brush)
+    {
+        QString patternId = QString(QStringLiteral("fillpattern%1_")).arg(brush.style()) + color.midRef(1);
+        if (!d_func()->savedPatternBrushes.contains(patternId)) {
+            QString maskId = savePatternMask(brush.style());
+            QString geo(QStringLiteral("x=\"0\" y=\"0\" width=\"8\" height=\"8\""));
+            QTextStream str(&d_func()->defs, QIODevice::Append);
+            str << QString(QStringLiteral("<pattern id=\"%1\" %2 patternUnits=\"userSpaceOnUse\" >")).arg(patternId, geo) << endl;
+            str << QString(QStringLiteral("<rect %1 stroke=\"none\" fill=\"%2\" mask=\"url(#%3);\" />")).arg(geo, color, maskId) << endl;
+            str << QStringLiteral("</pattern>") << endl << endl;
+            d_func()->savedPatternBrushes.append(patternId);
+        }
+        return patternId;
+    }
+
     void saveLinearGradientBrush(const QGradient *g)
     {
         QTextStream str(&d_func()->defs, QIODevice::Append);
@@ -421,6 +461,28 @@ public:
             d_func()->attributes.fillOpacity = colorOpacity;
         }
             break;
+        case Qt::Dense1Pattern:
+        case Qt::Dense2Pattern:
+        case Qt::Dense3Pattern:
+        case Qt::Dense4Pattern:
+        case Qt::Dense5Pattern:
+        case Qt::Dense6Pattern:
+        case Qt::Dense7Pattern:
+        case Qt::HorPattern:
+        case Qt::VerPattern:
+        case Qt::CrossPattern:
+        case Qt::BDiagPattern:
+        case Qt::FDiagPattern:
+        case Qt::DiagCrossPattern: {
+            QString color, colorOpacity;
+            translate_color(sbrush.color(), &color, &colorOpacity);
+            QString patternId = savePatternBrush(color, sbrush);
+            QString patternRef = QString(QStringLiteral("url(#%1)")).arg(patternId);
+            stream() << "fill=\"" << patternRef << "\" fill-opacity=\"" << colorOpacity << "\" ";
+            d_func()->attributes.fill = patternRef;
+            d_func()->attributes.fillOpacity = colorOpacity;
+            break;
+        }
         case Qt::LinearGradientPattern:
             saveLinearGradientBrush(sbrush.gradient());
             d_func()->attributes.fill = QString::fromLatin1("url(#%1)").arg(d_func()->currentGradientName);
diff --git a/tests/auto/qsvggenerator/tst_qsvggenerator.cpp b/tests/auto/qsvggenerator/tst_qsvggenerator.cpp
index 4795b55..b55b687 100644
--- a/tests/auto/qsvggenerator/tst_qsvggenerator.cpp
+++ b/tests/auto/qsvggenerator/tst_qsvggenerator.cpp
@@ -58,6 +58,7 @@ private slots:
     void fractionalFontSize();
     void titleAndDescription();
     void gradientInterpolation();
+    void patternBrush();
 };
 
 tst_QSvgGenerator::tst_QSvgGenerator()
@@ -423,5 +424,46 @@ void tst_QSvgGenerator::gradientInterpolation()
     QVERIFY(sqrImageDiff(image, refImage) < 2); // pixel error < 1.41 (L2-norm)
 }
 
+void tst_QSvgGenerator::patternBrush()
+{
+    { // Pattern brush should create mask and pattern used as fill
+        QSvgGenerator generator;
+        QByteArray byteArray;
+        QBuffer buffer(&byteArray);
+        generator.setOutputDevice(&buffer);
+        QPainter painter(&generator);
+        painter.setBrush(Qt::CrossPattern);
+        painter.drawRect(0, 0, 100, 100);
+        painter.end();
+
+        QVERIFY(byteArray.contains("<mask id=\"patternmask"));
+        QVERIFY(byteArray.contains("<pattern id=\"fillpattern"));
+        QVERIFY(byteArray.contains("<g fill=\"url(#fillpattern"));
+    }
+
+    { // Masks and patterns should be reused, not regenerated
+        QSvgGenerator generator;
+        QByteArray byteArray;
+        QBuffer buffer(&byteArray);
+        generator.setOutputDevice(&buffer);
+        QPainter painter(&generator);
+        painter.setBrush(QBrush(Qt::red, Qt::Dense3Pattern));
+        painter.drawRect(0, 0, 100, 100);
+        painter.drawEllipse(200, 50, 50, 50);
+        painter.setBrush(QBrush(Qt::green, Qt::Dense3Pattern));
+        painter.drawRoundedRect(0, 200, 100, 100, 10, 10);
+        painter.setBrush(QBrush(Qt::blue, Qt::Dense4Pattern));
+        painter.drawRect(200, 200, 100, 100);
+        painter.setBrush(QBrush(Qt::red, Qt::Dense3Pattern));
+        painter.drawRoundedRect(120, 120, 60, 60, 5, 5);
+        painter.end();
+
+        QCOMPARE(byteArray.count("<mask id=\"patternmask"), 2);
+        QCOMPARE(byteArray.count("<pattern id=\"fillpattern"), 3);
+        QVERIFY(byteArray.count("<g fill=\"url(#fillpattern") >= 4);
+    }
+
+}
+
 QTEST_MAIN(tst_QSvgGenerator)
 #include "tst_qsvggenerator.moc"
-- 
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