Add support for configurable fonts

A style's default font is specified in qtquickcontrols2.conf in
a "Font" group under the style's section. QSettings supports the
following two alternative syntaxes:

    [Default]
    Font\Family=Open Sans
    Font\PixelSize=20

or

    [Default\Font]
    Family=Open Sans
    PixelSize=20

[ChangeLog][Controls] Added support for specifying the default
font for different styles in qtquickcontrols2.conf.

Change-Id: I54e1efb79a2913eab35174dbf09b6956fe740e28
Reviewed-by: Mitch Curtis <mitch.curtis@qt.io>

16 files changed, 288 insertions, 24 deletions

diff --git a/src/imports/controls/doc/src/qtquickcontrols2-configuration.qdoc b/src/imports/controls/doc/src/qtquickcontrols2-configuration.qdoc
index 36bce98d..1e0a1e42 100644
--- a/src/imports/controls/doc/src/qtquickcontrols2-configuration.qdoc
+++ b/src/imports/controls/doc/src/qtquickcontrols2-configuration.qdoc
@@ -63,6 +63,53 @@
 
     \include qquickuniversalstyle.qdocinc conf
 
+    The default \l {Control::font}{font} can be specified in a \c Font sub-group
+    in each style's section in the configuration file. The \c Font sub-group can
+    be defined in two alternative ways:
+
+    \code
+    [Default]
+    Font\Family=Open Sans
+    Font\PixelSize=20
+
+    [Material\Font]
+    Family=Open Sans
+    PixelSize=20
+    \endcode
+
+    Supported font attributes:
+    \table
+        \header
+            \li Variable
+            \li Description
+        \row
+            \li \c Family
+            \li The \l {QFont::family}{font family}.
+        \row
+            \li \c PointSize
+            \li The \l {QFont::pointSizeF}{point size}.
+        \row
+            \li \c PixelSize
+            \li The \l {QFont::pixelSize}{pixel size}.
+        \row
+            \li \c StyleHint
+            \li The \l {QFont::styleHint}{style hint}.
+                Available values: \c SansSerif, \c Helvetica, \c Serif, \c Times, \c TypeWriter, \c Courier,
+                                  \c OldEnglish, \c Decorative, \c Monospace, \c Fantasy, \c Cursive.
+        \row
+            \li \c Weight
+            \li The \l {QFont::}{weight}. Qt uses a weighting scale from \c 0 to \c 99 similar to,
+                but not the same as, the scales used in Windows or CSS. A weight of \c 0 will be thin,
+                whilst \c 99 will be extremely black.
+                Available pre-defined weights: \c Thin (0), \c ExtraLight (12), \c Light (25), \c Normal (50),
+                                               \c Medium (57), \c DemiBold (63), \c Bold (75), \c ExtraBold (81),
+                                               \c Black (87).
+        \row
+            \li \c Style
+            \li The \l {QFont::}{style}.
+                Available values: \c StyleNormal, \c StyleItalic, \c StyleOblique.
+    \endtable
+
     In order to make it possible for Qt Quick Controls 2 to find the configuration file,
     it must be built into application's resources using the \l {The Qt Resource System}.
     Here's an example \c .qrc file:
diff --git a/src/imports/controls/fusion/qquickfusiontheme.cpp b/src/imports/controls/fusion/qquickfusiontheme.cpp
index 54536101..1c5025a4 100644
--- a/src/imports/controls/fusion/qquickfusiontheme.cpp
+++ b/src/imports/controls/fusion/qquickfusiontheme.cpp
@@ -38,8 +38,8 @@
 
 QT_BEGIN_NAMESPACE
 
-QQuickFusionTheme::QQuickFusionTheme(QPlatformTheme *theme)
-    : QQuickProxyTheme(theme)
+QQuickFusionTheme::QQuickFusionTheme()
+    : QQuickTheme(QStringLiteral("Fusion"))
 {
 }
 
diff --git a/src/imports/controls/fusion/qquickfusiontheme_p.h b/src/imports/controls/fusion/qquickfusiontheme_p.h
index c5949848..19cb8617 100644
--- a/src/imports/controls/fusion/qquickfusiontheme_p.h
+++ b/src/imports/controls/fusion/qquickfusiontheme_p.h
@@ -50,14 +50,14 @@
 
 #include <QtCore/qvariant.h>
 #include <QtGui/qpalette.h>
-#include <QtQuickControls2/private/qquickproxytheme_p.h>
+#include <QtQuickControls2/private/qquicktheme_p.h>
 
 QT_BEGIN_NAMESPACE
 
-class QQuickFusionTheme :  public QQuickProxyTheme
+class QQuickFusionTheme :  public QQuickTheme
 {
 public:
-    explicit QQuickFusionTheme(QPlatformTheme *theme = nullptr);
+    explicit QQuickFusionTheme();
 
     const QPalette *palette(Palette type = SystemPalette) const override;
 };
diff --git a/src/imports/controls/material/qquickmaterialtheme.cpp b/src/imports/controls/material/qquickmaterialtheme.cpp
index f75fa8a5..7ef2f0e7 100644
--- a/src/imports/controls/material/qquickmaterialtheme.cpp
+++ b/src/imports/controls/material/qquickmaterialtheme.cpp
@@ -42,8 +42,8 @@
 
 QT_BEGIN_NAMESPACE
 
-QQuickMaterialTheme::QQuickMaterialTheme(QPlatformTheme *theme)
-    : QQuickProxyTheme(theme)
+QQuickMaterialTheme::QQuickMaterialTheme()
+    : QQuickTheme(QStringLiteral("Material"))
 {
     QFont font;
     font.setFamily(QLatin1String("Roboto"));
@@ -65,22 +65,29 @@ QQuickMaterialTheme::QQuickMaterialTheme(QPlatformTheme *theme)
     }
 
     systemFont.setPixelSize(14);
+    systemFont = resolveFont(systemFont);
 
     buttonFont.setPixelSize(14);
     buttonFont.setCapitalization(QFont::AllUppercase);
     buttonFont.setWeight(QFont::Medium);
+    buttonFont = resolveFont(buttonFont);
 
     toolTipFont.setPixelSize(14);
     toolTipFont.setWeight(QFont::Medium);
+    toolTipFont = resolveFont(toolTipFont);
 
     itemViewFont.setPixelSize(14);
     itemViewFont.setWeight(QFont::Medium);
+    itemViewFont = resolveFont(itemViewFont);
 
     listViewFont.setPixelSize(16);
+    listViewFont = resolveFont(listViewFont);
 
     menuItemFont.setPixelSize(16);
+    menuItemFont = resolveFont(menuItemFont);
 
     editorFont.setPixelSize(16);
+    editorFont = resolveFont(editorFont);
 }
 
 const QFont *QQuickMaterialTheme::font(QPlatformTheme::Font type) const
diff --git a/src/imports/controls/material/qquickmaterialtheme_p.h b/src/imports/controls/material/qquickmaterialtheme_p.h
index f31ab58f..0e791386 100644
--- a/src/imports/controls/material/qquickmaterialtheme_p.h
+++ b/src/imports/controls/material/qquickmaterialtheme_p.h
@@ -50,14 +50,14 @@
 
 #include <QtCore/qvariant.h>
 #include <QtGui/qfont.h>
-#include <QtQuickControls2/private/qquickproxytheme_p.h>
+#include <QtQuickControls2/private/qquicktheme_p.h>
 
 QT_BEGIN_NAMESPACE
 
-class QQuickMaterialTheme : public QQuickProxyTheme
+class QQuickMaterialTheme : public QQuickTheme
 {
 public:
-    explicit QQuickMaterialTheme(QPlatformTheme *theme = nullptr);
+    explicit QQuickMaterialTheme();
 
     const QFont *font(Font type = SystemFont) const override;
 
diff --git a/src/imports/controls/qquickdefaulttheme.cpp b/src/imports/controls/qquickdefaulttheme.cpp
index 69bc49c5..f9cdcddc 100644
--- a/src/imports/controls/qquickdefaulttheme.cpp
+++ b/src/imports/controls/qquickdefaulttheme.cpp
@@ -39,7 +39,7 @@
 QT_BEGIN_NAMESPACE
 
 QQuickDefaultTheme::QQuickDefaultTheme()
-    : QQuickProxyTheme()
+    : QQuickTheme(QStringLiteral("Default"))
 {
 }
 
diff --git a/src/imports/controls/qquickdefaulttheme_p.h b/src/imports/controls/qquickdefaulttheme_p.h
index f3337dd9..e0811dcb 100644
--- a/src/imports/controls/qquickdefaulttheme_p.h
+++ b/src/imports/controls/qquickdefaulttheme_p.h
@@ -48,11 +48,11 @@
 // We mean it.
 //
 
-#include <QtQuickControls2/private/qquickproxytheme_p.h>
+#include <QtQuickControls2/private/qquicktheme_p.h>
 
 QT_BEGIN_NAMESPACE
 
-class QQuickDefaultTheme : public QQuickProxyTheme
+class QQuickDefaultTheme : public QQuickTheme
 {
 public:
     explicit QQuickDefaultTheme();
diff --git a/src/imports/controls/universal/qquickuniversaltheme.cpp b/src/imports/controls/universal/qquickuniversaltheme.cpp
index a7bcbb8c..549840b6 100644
--- a/src/imports/controls/universal/qquickuniversaltheme.cpp
+++ b/src/imports/controls/universal/qquickuniversaltheme.cpp
@@ -41,8 +41,8 @@
 
 QT_BEGIN_NAMESPACE
 
-QQuickUniversalTheme::QQuickUniversalTheme(QPlatformTheme *theme)
-    : QQuickProxyTheme(theme)
+QQuickUniversalTheme::QQuickUniversalTheme()
+    : QQuickTheme(QStringLiteral("Universal"))
 {
     const QFont font(QLatin1String("Segoe UI"));
     if (QFontInfo(font).family() == QLatin1String("Segoe UI")) {
@@ -53,12 +53,15 @@ QQuickUniversalTheme::QQuickUniversalTheme(QPlatformTheme *theme)
     }
 
     systemFont.setPixelSize(15);
+    systemFont = resolveFont(systemFont);
 
     groupBoxTitleFont.setPixelSize(15);
     groupBoxTitleFont.setWeight(QFont::DemiBold);
+    groupBoxTitleFont = resolveFont(groupBoxTitleFont);
 
     tabButtonFont.setPixelSize(24);
     tabButtonFont.setWeight(QFont::Light);
+    tabButtonFont = resolveFont(tabButtonFont);
 }
 
 const QFont *QQuickUniversalTheme::font(QPlatformTheme::Font type) const
diff --git a/src/imports/controls/universal/qquickuniversaltheme_p.h b/src/imports/controls/universal/qquickuniversaltheme_p.h
index 7e18a483..f15dee3e 100644
--- a/src/imports/controls/universal/qquickuniversaltheme_p.h
+++ b/src/imports/controls/universal/qquickuniversaltheme_p.h
@@ -49,14 +49,14 @@
 //
 
 #include <QtGui/qfont.h>
-#include <QtQuickControls2/private/qquickproxytheme_p.h>
+#include <QtQuickControls2/private/qquicktheme_p.h>
 
 QT_BEGIN_NAMESPACE
 
-class QQuickUniversalTheme : public QQuickProxyTheme
+class QQuickUniversalTheme : public QQuickTheme
 {
 public:
-    explicit QQuickUniversalTheme(QPlatformTheme *theme = nullptr);
+    explicit QQuickUniversalTheme();
 
     const QFont *font(Font type = SystemFont) const override;
 
diff --git a/src/quickcontrols2/qquicktheme.cpp b/src/quickcontrols2/qquicktheme.cpp
new file mode 100644
index 00000000..54653e6b
--- /dev/null
+++ b/src/quickcontrols2/qquicktheme.cpp
@@ -0,0 +1,112 @@
+/****************************************************************************
+**
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: http://www.qt.io/licensing/
+**
+** This file is part of the Qt Quick Controls 2 module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL3$
+** 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 http://www.qt.io/terms-conditions. For further
+** information use the contact form at http://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPLv3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or later as published by the Free
+** Software Foundation and appearing in the file LICENSE.GPL included in
+** the packaging of this file. Please review the following information to
+** ensure the GNU General Public License version 2.0 requirements will be
+** met: http://www.gnu.org/licenses/gpl-2.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qquicktheme_p.h"
+#include "qquickstyle_p.h"
+
+#include <QtCore/qmetaobject.h>
+#include <QtCore/qsettings.h>
+
+#include <functional>
+
+QT_BEGIN_NAMESPACE
+
+#if QT_CONFIG(settings)
+static void readValue(const QSharedPointer<QSettings> &settings, const QString &name, std::function<void(const QVariant &)> setValue)
+{
+    const QVariant var = settings->value(name);
+    if (var.isValid())
+        setValue(var);
+}
+
+template <typename Enum>
+static Enum toEnumValue(const QVariant &var)
+{
+    // ### TODO: expose QFont enums to the meta object system using Q_ENUM
+    //QMetaEnum enumeration = QMetaEnum::fromType<Enum>();
+    //bool ok = false;
+    //int value = enumeration.keyToValue(var.toByteArray(), &ok);
+    //if (!ok)
+    //    value = var.toInt();
+    //return static_cast<Enum>(value);
+
+    return static_cast<Enum>(var.toInt());
+}
+
+QFont *readFont(const QSharedPointer<QSettings> &settings)
+{
+    const QVariant var = settings->value(QStringLiteral("Font"));
+    if (var.isValid())
+        return new QFont(var.value<QFont>());
+
+    QFont f;
+    settings->beginGroup(QStringLiteral("Font"));
+    readValue(settings, QStringLiteral("Family"), [&f](const QVariant &var) { f.setFamily(var.toString()); });
+    readValue(settings, QStringLiteral("PointSize"), [&f](const QVariant &var) { f.setPointSizeF(var.toReal()); });
+    readValue(settings, QStringLiteral("PixelSize"), [&f](const QVariant &var) { f.setPixelSize(var.toInt()); });
+    readValue(settings, QStringLiteral("StyleHint"), [&f](const QVariant &var) { f.setStyleHint(toEnumValue<QFont::StyleHint>(var.toInt())); });
+    readValue(settings, QStringLiteral("Weight"), [&f](const QVariant &var) { f.setWeight(toEnumValue<QFont::Weight>(var)); });
+    readValue(settings, QStringLiteral("Style"), [&f](const QVariant &var) { f.setStyle(toEnumValue<QFont::Style>(var.toInt())); });
+    settings->endGroup();
+    return new QFont(f);
+}
+#endif // QT_CONFIG(settings)
+
+QQuickTheme::QQuickTheme(const QString &style)
+    : QQuickProxyTheme()
+{
+#if QT_CONFIG(settings)
+    QSharedPointer<QSettings> settings = QQuickStylePrivate::settings(style);
+    if (settings)
+        m_styleFont.reset(readFont(settings));
+#endif
+}
+
+const QFont *QQuickTheme::font(Font type) const
+{
+    Q_UNUSED(type);
+    return m_styleFont.data();
+}
+
+QFont QQuickTheme::resolveFont(const QFont &font) const
+{
+    if (!m_styleFont)
+        return font;
+
+    return m_styleFont->resolve(font);
+}
+
+QT_END_NAMESPACE
diff --git a/src/quickcontrols2/qquicktheme_p.h b/src/quickcontrols2/qquicktheme_p.h
new file mode 100644
index 00000000..7ddd1d1d
--- /dev/null
+++ b/src/quickcontrols2/qquicktheme_p.h
@@ -0,0 +1,73 @@
+/****************************************************************************
+**
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: http://www.qt.io/licensing/
+**
+** This file is part of the Qt Quick Controls 2 module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL3$
+** 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 http://www.qt.io/terms-conditions. For further
+** information use the contact form at http://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPLv3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or later as published by the Free
+** Software Foundation and appearing in the file LICENSE.GPL included in
+** the packaging of this file. Please review the following information to
+** ensure the GNU General Public License version 2.0 requirements will be
+** met: http://www.gnu.org/licenses/gpl-2.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QQUICKTHEME_P_H
+#define QQUICKTHEME_P_H
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
+#include <QtQuickControls2/private/qquickproxytheme_p.h>
+#include <QtCore/qscopedpointer.h>
+#include <QtGui/qfont.h>
+
+QT_BEGIN_NAMESPACE
+
+class Q_QUICKCONTROLS2_PRIVATE_EXPORT QQuickTheme :  public QQuickProxyTheme
+{
+public:
+    QQuickTheme(const QString &name);
+
+    const QFont *font(Font type = SystemFont) const override;
+
+protected:
+    QFont resolveFont(const QFont &font) const;
+
+private:
+    QScopedPointer<QFont> m_styleFont;
+};
+
+QT_END_NAMESPACE
+
+#endif // QQUICKTHEME_P_H
diff --git a/src/quickcontrols2/quickcontrols2.pri b/src/quickcontrols2/quickcontrols2.pri
index bf96607b..31b8e66f 100644
--- a/src/quickcontrols2/quickcontrols2.pri
+++ b/src/quickcontrols2/quickcontrols2.pri
@@ -14,7 +14,8 @@ HEADERS += \
     $$PWD/qquickstyle_p.h \
     $$PWD/qquickstyleplugin_p.h \
     $$PWD/qquickstyleselector_p.h \
-    $$PWD/qquickstyleselector_p_p.h
+    $$PWD/qquickstyleselector_p_p.h \
+    $$PWD/qquicktheme_p.h
 
 SOURCES += \
     $$PWD/qquickanimatednode.cpp \
@@ -28,7 +29,8 @@ SOURCES += \
     $$PWD/qquickproxytheme.cpp \
     $$PWD/qquickstyle.cpp \
     $$PWD/qquickstyleplugin.cpp \
-    $$PWD/qquickstyleselector.cpp
+    $$PWD/qquickstyleselector.cpp \
+    $$PWD/qquicktheme.cpp
 
 qtConfig(quick-listview):qtConfig(quick-pathview) {
     HEADERS += \
diff --git a/tests/auto/qquickmaterialstyleconf/qtquickcontrols2.conf b/tests/auto/qquickmaterialstyleconf/qtquickcontrols2.conf
index 78634834..30cee878 100644
--- a/tests/auto/qquickmaterialstyleconf/qtquickcontrols2.conf
+++ b/tests/auto/qquickmaterialstyleconf/qtquickcontrols2.conf
@@ -4,3 +4,7 @@ Style=Material
 [Material]
 Background=#444444
 Foreground=Red
+Font\PixelSize=22
+
+[Material\Font]
+Family=Courier
diff --git a/tests/auto/qquickmaterialstyleconf/tst_qquickmaterialstyleconf.cpp b/tests/auto/qquickmaterialstyleconf/tst_qquickmaterialstyleconf.cpp
index cc81afea..17d1ea6d 100644
--- a/tests/auto/qquickmaterialstyleconf/tst_qquickmaterialstyleconf.cpp
+++ b/tests/auto/qquickmaterialstyleconf/tst_qquickmaterialstyleconf.cpp
@@ -55,16 +55,22 @@ void tst_qquickmaterialstyleconf::conf()
 {
     QQuickApplicationHelper helper(this, QLatin1String("applicationwindow.qml"));
 
+    QFont customFont;
+    customFont.setFamily("Courier");
+    customFont.setPixelSize(22);
+
     QQuickApplicationWindow *window = helper.appWindow;
     window->show();
     QVERIFY(QTest::qWaitForWindowExposed(window));
-    // We specified a custom background color, so the window should have it.
+    // We specified a custom background color and font, so the window should have them.
     QCOMPARE(window->property("color").value<QColor>(), QColor("#444444"));
+    QCOMPARE(window->property("font").value<QFont>(), customFont);
 
-    // We specified a custom foreground color, so the label should have it.
+    // We specified a custom foreground color and font, so the label should have them.
     QQuickItem *label = window->property("label").value<QQuickItem*>();
     QVERIFY(label);
     QCOMPARE(label->property("color").value<QColor>(), QColor("#F44336"));
+    QCOMPARE(label->property("font").value<QFont>(), customFont);
 }
 
 QTEST_MAIN(tst_qquickmaterialstyleconf)
diff --git a/tests/auto/qquickuniversalstyleconf/qtquickcontrols2.conf b/tests/auto/qquickuniversalstyleconf/qtquickcontrols2.conf
index 836372c9..0ec13258 100644
--- a/tests/auto/qquickuniversalstyleconf/qtquickcontrols2.conf
+++ b/tests/auto/qquickuniversalstyleconf/qtquickcontrols2.conf
@@ -4,3 +4,7 @@ Style=Universal
 [Universal]
 Background=#444444
 Foreground=Red
+Font\PixelSize=22
+
+[Universal\Font]
+Family=Courier
diff --git a/tests/auto/qquickuniversalstyleconf/tst_qquickuniversalstyleconf.cpp b/tests/auto/qquickuniversalstyleconf/tst_qquickuniversalstyleconf.cpp
index c6b28be3..51cc5883 100644
--- a/tests/auto/qquickuniversalstyleconf/tst_qquickuniversalstyleconf.cpp
+++ b/tests/auto/qquickuniversalstyleconf/tst_qquickuniversalstyleconf.cpp
@@ -55,16 +55,22 @@ void tst_qquickuniversalstyleconf::conf()
 {
     QQuickApplicationHelper helper(this, QLatin1String("applicationwindow.qml"));
 
+    QFont customFont;
+    customFont.setFamily("Courier");
+    customFont.setPixelSize(22);
+
     QQuickApplicationWindow *window = helper.appWindow;
     window->show();
     QVERIFY(QTest::qWaitForWindowExposed(window));
-    // We specified a custom background color, so the window should have it.
+    // We specified a custom background color and font, so the window should have them.
     QCOMPARE(window->property("color").value<QColor>(), QColor("#444444"));
+    QCOMPARE(window->property("font").value<QFont>(), customFont);
 
-    // We specified a custom foreground color, so the label should have it.
+    // We specified a custom foreground color and font, so the label should have them.
     QQuickItem *label = window->property("label").value<QQuickItem*>();
     QVERIFY(label);
     QCOMPARE(label->property("color").value<QColor>(), QColor("#E51400"));
+    QCOMPARE(label->property("font").value<QFont>(), customFont);
 }
 
 QTEST_MAIN(tst_qquickuniversalstyleconf)