Native style: Add ScrollBar on Windows

Change-Id: I82c8cf3e637550cd458ac77f2cc4f6490dc11802
Reviewed-by: Richard Moe Gustavsen <richard.gustavsen@qt.io>

4 files changed, 87 insertions, 0 deletions

diff --git a/src/imports/controls/windows/CMakeLists.txt b/src/imports/controls/windows/CMakeLists.txt
index f1d01946..edd144bb 100644
--- a/src/imports/controls/windows/CMakeLists.txt
+++ b/src/imports/controls/windows/CMakeLists.txt
@@ -51,6 +51,7 @@ set(qml_files
     "SpinBox.qml"
     "TextArea.qml"
     "TextField.qml"
+    "ScrollBar.qml"
     "ScrollView.qml"
 )
 set_source_files_properties(Button.qml PROPERTIES
diff --git a/src/imports/controls/windows/ScrollBar.qml b/src/imports/controls/windows/ScrollBar.qml
new file mode 100644
index 00000000..d3b09418
--- /dev/null
+++ b/src/imports/controls/windows/ScrollBar.qml
@@ -0,0 +1,84 @@
+/****************************************************************************
+**
+** 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.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+import QtQuick
+import QtQuick.NativeStyle as NativeStyle
+
+NativeStyle.DefaultScrollBar {
+    id: controlRoot
+
+    topPadding: orientation == Qt.Vertical ? 17 : 0
+    bottomPadding: orientation == Qt.Vertical ? 17 : 0
+    leftPadding: orientation == Qt.Horizontal ? 17 : 0
+    rightPadding: orientation == Qt.Horizontal ? 17 : 0
+
+    contentItem: NativeStyle.ScrollBar {
+        control: controlRoot
+        subControl: NativeStyle.ScrollBar.Handle
+    }
+
+    NativeStyle.ScrollBar {
+        // Fade a hovered-looking version of the handle
+        // on top of the default handle when hovering it
+        x: contentItem.x
+        y: contentItem.y
+        z: 1
+        width: contentItem.width
+        height: contentItem.height
+        control: controlRoot
+        subControl: NativeStyle.ScrollBar.Handle
+        overrideState: NativeStyle.StyleItem.AlwaysHovered
+        opacity: controlRoot.hovered || control.pressed ? 1 : 0
+        visible: contentItem instanceof NativeStyle.StyleItem
+        Behavior on opacity { NumberAnimation { duration: contentItem.transitionDuration } }
+    }
+
+    // The groove background should have window color
+    Rectangle {
+        x: background.x
+        y: background.y
+        z: -1
+        width: background.width
+        height: background.height
+        color: controlRoot.palette.window
+    }
+
+    background: NativeStyle.ScrollBar {
+        control: controlRoot
+        subControl: NativeStyle.ScrollBar.Groove
+        overrideState: NativeStyle.ScrollBar.NeverHovered
+    }
+}
diff --git a/src/imports/controls/windows/qmldir b/src/imports/controls/windows/qmldir
index ed9758b3..bc87455d 100644
--- a/src/imports/controls/windows/qmldir
+++ b/src/imports/controls/windows/qmldir
@@ -14,4 +14,5 @@ Frame 6.0 Frame.qml
 TextArea 6.0 TextArea.qml
 ComboBox 6.0 ComboBox.qml
 ProgressBar 6.0 ProgressBar.qml
+ScrollBar 6.0 ScrollBar.qml
 ScrollView 6.0 ScrollView.qml
diff --git a/src/imports/controls/windows/windows.pri b/src/imports/controls/windows/windows.pri
index 4c9e51f7..7f13eab0 100644
--- a/src/imports/controls/windows/windows.pri
+++ b/src/imports/controls/windows/windows.pri
@@ -10,4 +10,5 @@ QML_FILES += \
     $$PWD/SpinBox.qml \
     $$PWD/TextArea.qml \
     $$PWD/TextField.qml \
+    $$PWD/ScrollBar.qml \
     $$PWD/ScrollView.qml \