NativeStyle: add ScrollBar

Change-Id: Ied2055866a67798ce60105e7251740a3e66b38db
Reviewed-by: Mitch Curtis <mitch.curtis@qt.io>

3 files changed, 167 insertions, 0 deletions

diff --git a/src/imports/nativestyle/items/items.pri b/src/imports/nativestyle/items/items.pri
index 1bb311fd..bbe6523b 100644
--- a/src/imports/nativestyle/items/items.pri
+++ b/src/imports/nativestyle/items/items.pri
@@ -12,6 +12,7 @@ HEADERS += \
     $$PWD/qquickstyleitemframe.h \
     $$PWD/qquickstyleitemtextarea.h \
     $$PWD/qquickstyleitemcombobox.h \
+    $$PWD/qquickstyleitemscrollbar.h \
 
 SOURCES += \
     $$PWD/qquickstyleitem.cpp \
@@ -25,3 +26,4 @@ SOURCES += \
     $$PWD/qquickstyleitemframe.cpp \
     $$PWD/qquickstyleitemtextarea.cpp \
     $$PWD/qquickstyleitemcombobox.cpp \
+    $$PWD/qquickstyleitemscrollbar.cpp \
diff --git a/src/imports/nativestyle/items/qquickstyleitemscrollbar.cpp b/src/imports/nativestyle/items/qquickstyleitemscrollbar.cpp
new file mode 100644
index 00000000..7a462082
--- /dev/null
+++ b/src/imports/nativestyle/items/qquickstyleitemscrollbar.cpp
@@ -0,0 +1,93 @@
+/****************************************************************************
+**
+** Copyright (C) 2020 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 "qquickstyleitemscrollbar.h"
+
+QFont QQuickStyleItemScrollBar::styleFont(QQuickItem *control)
+{
+    return style()->font(QStyle::CE_ProgressBarLabel, controlSize(control));
+}
+
+void QQuickStyleItemScrollBar::connectToControl()
+{
+    QQuickStyleItem::connectToControl();
+    auto scrollBar = control<QQuickScrollBar>();
+    connect(scrollBar, &QQuickScrollBar::orientationChanged, this, &QQuickStyleItem::markImageDirty);
+    connect(scrollBar, &QQuickScrollBar::pressedChanged, this, &QQuickStyleItem::markImageDirty);
+}
+
+StyleItemGeometry QQuickStyleItemScrollBar::calculateGeometry()
+{
+    QStyleOptionSlider styleOption;
+    initStyleOption(styleOption);
+
+    StyleItemGeometry geometry;
+    geometry.minimumSize = style()->sizeFromContents(QStyle::CT_ScrollBar, &styleOption, QSize(0, 0));
+    geometry.implicitSize = geometry.minimumSize;
+    styleOption.rect = QRect(QPoint(0, 0), geometry.implicitSize);
+    geometry.layoutRect = style()->subElementRect(QStyle::SE_ScrollBarLayoutItem, &styleOption);
+    geometry.ninePatchMargins = style()->ninePatchMargins(QStyle::CC_ScrollBar, &styleOption, geometry.minimumSize);
+
+    return geometry;
+}
+
+void QQuickStyleItemScrollBar::paintEvent(QPainter *painter)
+{
+    QStyleOptionSlider styleOption;
+    initStyleOption(styleOption);
+    style()->drawComplexControl(QStyle::CC_ScrollBar, &styleOption, painter);
+}
+
+void QQuickStyleItemScrollBar::initStyleOption(QStyleOptionSlider &styleOption)
+{
+    initStyleOptionBase(styleOption);
+    auto scrollBar = control<QQuickScrollBar>();
+
+    styleOption.subControls = m_subControl == Groove ? QStyle::SC_ScrollBarGroove : QStyle::SC_ScrollBarSlider;
+    styleOption.activeSubControls = QStyle::SC_None;
+    styleOption.orientation = scrollBar->orientation();
+
+    if (scrollBar->isPressed())
+        styleOption.state |= QStyle::State_Sunken;
+
+    // The following values will let the handle fill 100% of the
+    // groove / imageSize. But when the handle is resized by
+    // QQuickScrollBar, it will end up with the correct size visually.
+    styleOption.pageStep = 1000;
+    styleOption.minimum = 0;
+    styleOption.maximum = 1;
+    styleOption.sliderValue = 0;
+}
diff --git a/src/imports/nativestyle/items/qquickstyleitemscrollbar.h b/src/imports/nativestyle/items/qquickstyleitemscrollbar.h
new file mode 100644
index 00000000..e181d4ec
--- /dev/null
+++ b/src/imports/nativestyle/items/qquickstyleitemscrollbar.h
@@ -0,0 +1,72 @@
+/****************************************************************************
+**
+** Copyright (C) 2020 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 QQUICKSTYLEITEMSCROLLBAR_H
+#define QQUICKSTYLEITEMSCROLLBAR_H
+
+#include "qquickstyleitem.h"
+#include <QtQuickTemplates2/private/qquickscrollbar_p.h>
+
+class QQuickStyleItemScrollBar : public QQuickStyleItem
+{
+    Q_OBJECT
+
+    Q_PROPERTY(SubControl subControl MEMBER m_subControl)
+
+    QML_NAMED_ELEMENT(ScrollBar)
+
+public:
+    enum SubControl {
+        Groove = 1,
+        Handle,
+    };
+    Q_ENUM(SubControl)
+
+    QFont styleFont(QQuickItem *control) override;
+
+protected:
+    void connectToControl() override;
+    void paintEvent(QPainter *painter) override;
+    StyleItemGeometry calculateGeometry() override;
+
+private:
+    void initStyleOption(QStyleOptionSlider &styleOption);
+
+private:
+   SubControl m_subControl = Groove;
+};
+
+#endif // QQUICKSTYLEITEMSCROLLBAR_H