Use defaultSize according to svg standard in svg plugin

The viewBox attribute defines the svg internal coordinate system. If no
width/height is set, the viewBox size is the right choice for defaultSize.
Otherwise the standard prescribes that the specified height/width must be
used.

The old behavior ignored the width and height attributes, and this caused a
lot of problems in qml. If the viewBox was very small the result was a low
resolution image. If the viewBox was very large, loading took ages and the
result used much more memory than needed. Both situations could be avoided
by setting sourceSize. But when using the same image several times, the
sourceSize must be set every time to the same value, otherwise the image
cache would not work. It is cheaper to have the same high-quality source
image in the cache, and scale it down when required.

With the new behavior it is possible to control the default image size
directly in the svg file at one place while it is still possible to set
different sourceSizes if needed.

Task-number: QTBUG-44863
Change-Id: I9c2fc7c122a29ebcf288b7cbd12427e081d404d5
Reviewed-by: André Klitzing <aklitzing@gmail.com>
Reviewed-by: Edward Welbourne <edward.welbourne@qt.io>

16 files changed, 193 insertions, 0 deletions

diff --git a/tests/auto/qsvgplugin/.gitignore b/tests/auto/qsvgplugin/.gitignore
new file mode 100644
index 0000000..c41c448
--- /dev/null
+++ b/tests/auto/qsvgplugin/.gitignore
@@ -0,0 +1 @@
+tst_qsvgplugin
diff --git a/tests/auto/qsvgplugin/qsvgplugin.pro b/tests/auto/qsvgplugin/qsvgplugin.pro
new file mode 100644
index 0000000..3fec52e
--- /dev/null
+++ b/tests/auto/qsvgplugin/qsvgplugin.pro
@@ -0,0 +1,8 @@
+TARGET = tst_qsvgplugin
+CONFIG += testcase
+QT += svg testlib widgets gui-private
+
+SOURCES += tst_qsvgplugin.cpp
+RESOURCES += resources.qrc
+
+DEFINES += SRCDIR=\\\"$$PWD/\\\"
diff --git a/tests/auto/qsvgplugin/resources.qrc b/tests/auto/qsvgplugin/resources.qrc
new file mode 100644
index 0000000..fcb311a
--- /dev/null
+++ b/tests/auto/qsvgplugin/resources.qrc
@@ -0,0 +1,16 @@
+<!DOCTYPE RCC><RCC version="1.0">
+<qresource>
+   <file>square.svg</file>
+   <file>square_size.svg</file>
+   <file>square_size_viewbox.svg</file>
+   <file>square_viewbox.svg</file>
+   <file>tall.svg</file>
+   <file>tall_size.svg</file>
+   <file>tall_size_viewbox.svg</file>
+   <file>tall_viewbox.svg</file>
+   <file>wide.svg</file>
+   <file>wide_size.svg</file>
+   <file>wide_size_viewbox.svg</file>
+   <file>wide_viewbox.svg</file>
+</qresource>
+</RCC>
diff --git a/tests/auto/qsvgplugin/square.svg b/tests/auto/qsvgplugin/square.svg
new file mode 100644
index 0000000..f35fb87
--- /dev/null
+++ b/tests/auto/qsvgplugin/square.svg
@@ -0,0 +1,5 @@
+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.0//EN" "http://www.w3.org/TR/2001/REC-SVG-20010904/DTD/svg10.dtd">
+<svg version="1.0" xmlns="http://www.w3.org/2000/svg">
+  <circle cx="50" cy="50" r="25" fill="#00ff00" />
+</svg>
diff --git a/tests/auto/qsvgplugin/square_size.svg b/tests/auto/qsvgplugin/square_size.svg
new file mode 100644
index 0000000..f4aeb67
--- /dev/null
+++ b/tests/auto/qsvgplugin/square_size.svg
@@ -0,0 +1,5 @@
+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.0//EN" "http://www.w3.org/TR/2001/REC-SVG-20010904/DTD/svg10.dtd">
+<svg version="1.0" xmlns="http://www.w3.org/2000/svg" width="200px" height="200px">
+  <circle cx="50" cy="50" r="25" fill="#00ff00" />
+</svg>
diff --git a/tests/auto/qsvgplugin/square_size_viewbox.svg b/tests/auto/qsvgplugin/square_size_viewbox.svg
new file mode 100644
index 0000000..cf39bd7
--- /dev/null
+++ b/tests/auto/qsvgplugin/square_size_viewbox.svg
@@ -0,0 +1,5 @@
+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.0//EN" "http://www.w3.org/TR/2001/REC-SVG-20010904/DTD/svg10.dtd">
+<svg version="1.0" xmlns="http://www.w3.org/2000/svg" width="200px" height="200px" viewBox="0 0 100 100">
+  <circle cx="50" cy="50" r="25" fill="#00ff00" />
+</svg>
diff --git a/tests/auto/qsvgplugin/square_viewbox.svg b/tests/auto/qsvgplugin/square_viewbox.svg
new file mode 100644
index 0000000..5811505
--- /dev/null
+++ b/tests/auto/qsvgplugin/square_viewbox.svg
@@ -0,0 +1,5 @@
+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.0//EN" "http://www.w3.org/TR/2001/REC-SVG-20010904/DTD/svg10.dtd">
+<svg version="1.0" xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100">
+  <circle cx="50" cy="50" r="25" fill="#00ff00" />
+</svg>
diff --git a/tests/auto/qsvgplugin/tall.svg b/tests/auto/qsvgplugin/tall.svg
new file mode 100644
index 0000000..b243b62
--- /dev/null
+++ b/tests/auto/qsvgplugin/tall.svg
@@ -0,0 +1,5 @@
+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.0//EN" "http://www.w3.org/TR/2001/REC-SVG-20010904/DTD/svg10.dtd">
+<svg version="1.0" xmlns="http://www.w3.org/2000/svg">
+  <ellipse cx="25" cy="50" rx="12.5" ry="25" fill="#00ff00" />
+</svg>
diff --git a/tests/auto/qsvgplugin/tall_size.svg b/tests/auto/qsvgplugin/tall_size.svg
new file mode 100644
index 0000000..6121451
--- /dev/null
+++ b/tests/auto/qsvgplugin/tall_size.svg
@@ -0,0 +1,5 @@
+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.0//EN" "http://www.w3.org/TR/2001/REC-SVG-20010904/DTD/svg10.dtd">
+<svg version="1.0" xmlns="http://www.w3.org/2000/svg" width="100px" height="200px">
+  <ellipse cx="25" cy="50" rx="12.5" ry="25" fill="#00ff00" />
+</svg>
diff --git a/tests/auto/qsvgplugin/tall_size_viewbox.svg b/tests/auto/qsvgplugin/tall_size_viewbox.svg
new file mode 100644
index 0000000..9d82492
--- /dev/null
+++ b/tests/auto/qsvgplugin/tall_size_viewbox.svg
@@ -0,0 +1,5 @@
+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.0//EN" "http://www.w3.org/TR/2001/REC-SVG-20010904/DTD/svg10.dtd">
+<svg version="1.0" xmlns="http://www.w3.org/2000/svg" width="100px" height="200px" viewBox="0 0 50 100">
+  <ellipse cx="25" cy="50" rx="12.5" ry="25" fill="#00ff00" />
+</svg>
diff --git a/tests/auto/qsvgplugin/tall_viewbox.svg b/tests/auto/qsvgplugin/tall_viewbox.svg
new file mode 100644
index 0000000..8ed61a9
--- /dev/null
+++ b/tests/auto/qsvgplugin/tall_viewbox.svg
@@ -0,0 +1,5 @@
+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.0//EN" "http://www.w3.org/TR/2001/REC-SVG-20010904/DTD/svg10.dtd">
+<svg version="1.0" xmlns="http://www.w3.org/2000/svg" viewBox="0 0 50 100">
+  <ellipse cx="25" cy="50" rx="12.5" ry="25" fill="#00ff00" />
+</svg>
diff --git a/tests/auto/qsvgplugin/tst_qsvgplugin.cpp b/tests/auto/qsvgplugin/tst_qsvgplugin.cpp
new file mode 100644
index 0000000..4ec1737
--- /dev/null
+++ b/tests/auto/qsvgplugin/tst_qsvgplugin.cpp
@@ -0,0 +1,108 @@
+/****************************************************************************
+**
+** Copyright (C) 2016 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 <QtTest/QtTest>
+
+#include "../../../src/plugins/imageformats/svg/qsvgiohandler.cpp"
+#include <QImage>
+#include <QStringList>
+#include <QVector>
+
+#ifndef SRCDIR
+#define SRCDIR
+#endif
+
+
+class tst_QSvgPlugin : public QObject
+{
+Q_OBJECT
+
+public:
+    tst_QSvgPlugin();
+    virtual ~tst_QSvgPlugin();
+
+private slots:
+    void checkSize_data();
+    void checkSize();
+};
+
+
+
+tst_QSvgPlugin::tst_QSvgPlugin()
+{
+}
+
+tst_QSvgPlugin::~tst_QSvgPlugin()
+{
+}
+
+void tst_QSvgPlugin::checkSize_data()
+{
+    QTest::addColumn<QString>("filename");
+    QTest::addColumn<int>("imageHeight");
+    QTest::addColumn<int>("imageWidth");
+
+    QTest::newRow("square")              << SRCDIR "square.svg"              <<  50 <<  50;
+    QTest::newRow("square_size")         << SRCDIR "square_size.svg"         << 200 << 200;
+    QTest::newRow("square_size_viewbox") << SRCDIR "square_size_viewbox.svg" << 200 << 200;
+    QTest::newRow("square_viewbox")      << SRCDIR "square_viewbox.svg"      << 100 << 100;
+    QTest::newRow("tall")                << SRCDIR "tall.svg"                <<  50 <<  25;
+    QTest::newRow("tall_size")           << SRCDIR "tall_size.svg"           << 200 << 100;
+    QTest::newRow("tall_size_viewbox")   << SRCDIR "tall_size_viewbox.svg"   << 200 << 100;
+    QTest::newRow("tall_viewbox")        << SRCDIR "tall_viewbox.svg"        << 100 <<  50;
+    QTest::newRow("wide")                << SRCDIR "wide.svg"                <<  25 <<  50;
+    QTest::newRow("wide_size")           << SRCDIR "wide_size.svg"           << 100 << 200;
+    QTest::newRow("wide_size_viewbox")   << SRCDIR "wide_size_viewbox.svg"   << 100 << 200;
+    QTest::newRow("wide_viewbox")        << SRCDIR "wide_viewbox.svg"        <<  50 << 100;
+}
+
+void tst_QSvgPlugin::checkSize()
+{
+    QFETCH(QString, filename);
+    QFETCH(int, imageHeight);
+    QFETCH(int, imageWidth);
+
+    QFile file(filename);
+    file.open(QIODevice::ReadOnly);
+
+    QSvgIOHandler plugin;
+    plugin.setDevice(&file);
+
+    QImage image;
+    plugin.read(&image);
+
+    file.close();
+
+    QCOMPARE(imageHeight, image.height());
+    QCOMPARE(imageWidth, image.width());
+}
+
+
+QTEST_MAIN(tst_QSvgPlugin)
+#include "tst_qsvgplugin.moc"
diff --git a/tests/auto/qsvgplugin/wide.svg b/tests/auto/qsvgplugin/wide.svg
new file mode 100644
index 0000000..9166606
--- /dev/null
+++ b/tests/auto/qsvgplugin/wide.svg
@@ -0,0 +1,5 @@
+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.0//EN" "http://www.w3.org/TR/2001/REC-SVG-20010904/DTD/svg10.dtd">
+<svg version="1.0" xmlns="http://www.w3.org/2000/svg">
+  <ellipse cx="50" cy="25" rx="25" ry="12.5" fill="#00ff00" />
+</svg>
diff --git a/tests/auto/qsvgplugin/wide_size.svg b/tests/auto/qsvgplugin/wide_size.svg
new file mode 100644
index 0000000..e816154
--- /dev/null
+++ b/tests/auto/qsvgplugin/wide_size.svg
@@ -0,0 +1,5 @@
+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.0//EN" "http://www.w3.org/TR/2001/REC-SVG-20010904/DTD/svg10.dtd">
+<svg version="1.0" xmlns="http://www.w3.org/2000/svg" width="200px" height="100px">
+  <ellipse cx="50" cy="25" rx="25" ry="12.5" fill="#00ff00" />
+</svg>
diff --git a/tests/auto/qsvgplugin/wide_size_viewbox.svg b/tests/auto/qsvgplugin/wide_size_viewbox.svg
new file mode 100644
index 0000000..3d9b044
--- /dev/null
+++ b/tests/auto/qsvgplugin/wide_size_viewbox.svg
@@ -0,0 +1,5 @@
+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.0//EN" "http://www.w3.org/TR/2001/REC-SVG-20010904/DTD/svg10.dtd">
+<svg version="1.0" xmlns="http://www.w3.org/2000/svg" width="200px" height="100px" viewBox="0 0 100 50">
+  <ellipse cx="50" cy="25" rx="25" ry="12.5" fill="#00ff00" />
+</svg>
diff --git a/tests/auto/qsvgplugin/wide_viewbox.svg b/tests/auto/qsvgplugin/wide_viewbox.svg
new file mode 100644
index 0000000..aface45
--- /dev/null
+++ b/tests/auto/qsvgplugin/wide_viewbox.svg
@@ -0,0 +1,5 @@
+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.0//EN" "http://www.w3.org/TR/2001/REC-SVG-20010904/DTD/svg10.dtd">
+<svg version="1.0" xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 50">
+  <ellipse cx="50" cy="25" rx="25" ry="12.5" fill="#00ff00" />
+</svg>