Add SplitView

SplitView is an important tool for desktop applications that do not
want to use a dock widget-style approach for their user interface.
It allows users to have some degree of control over the sizing of
elements in the UI, as well as the ability to conveniently serialize
those sizes so that they're remembered across sessions.

The main differences between this and the SplitView in
Qt Quick Controls 1 are:

- Has its own SplitView attached properties, rather than relying on
  the Layout attached properties (which required an additional import).
- Uses the attached preferredWidth and preferredHeight properties
  as well as Item's implicitWidth/implicitHeight properties
  for the preferred size of items, rather than using the width and
  height properties.
- Inherits from Container, so supports most of its API (though some
  parts of the API, like the currentIndex-related stuff, make no
  sense for SplitView).
- Uses attached SplitHandle properties for the handle delegate to
  visualize hovered/pressed effects.
- Offers convenience API for serializing the user's preferred sizes.

[ChangeLog][Controls][SplitView] Introduced SplitView, a control that
lays out items horizontally or vertically with a draggable splitter
between each item.

Task-number: QTBUG-56318
Change-Id: I3da91643ab312eb9ef5b0567da4e758f17747192
Reviewed-by: Richard Moe Gustavsen <richard.gustavsen@qt.io>

1 files changed, 218 insertions, 0 deletions

diff --git a/src/quicktemplates2/qquicksplitview_p.h b/src/quicktemplates2/qquicksplitview_p.h
new file mode 100644
index 00000000..99001615
--- /dev/null
+++ b/src/quicktemplates2/qquicksplitview_p.h
@@ -0,0 +1,218 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 The Qt Company Ltd.
+** Contact: http://www.qt.io/licensing/
+**
+** This file is part of the Qt Quick Templates 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 QQUICKSPLITVIEW_P_H
+#define QQUICKSPLITVIEW_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 <QtQuickTemplates2/private/qquickcontainer_p.h>
+#include <QtQml/qqmllist.h>
+
+QT_BEGIN_NAMESPACE
+
+class QQuickSplitViewPrivate;
+class QQuickSplitViewAttached;
+class QQuickSplitViewAttachedPrivate;
+class QQuickSplitHandleAttached;
+class QQuickSplitHandleAttachedPrivate;
+
+class Q_QUICKTEMPLATES2_PRIVATE_EXPORT QQuickSplitView : public QQuickContainer
+{
+    Q_OBJECT
+    Q_PROPERTY(Qt::Orientation orientation READ orientation WRITE setOrientation NOTIFY orientationChanged FINAL)
+    Q_PROPERTY(bool resizing READ isResizing NOTIFY resizingChanged)
+    Q_PROPERTY(QQmlComponent *handle READ handle WRITE setHandle NOTIFY handleChanged FINAL)
+
+public:
+    explicit QQuickSplitView(QQuickItem *parent = nullptr);
+    ~QQuickSplitView() override;
+
+    Qt::Orientation orientation() const;
+    void setOrientation(Qt::Orientation orientation);
+
+    bool isResizing() const;
+
+    QQmlComponent *handle();
+    void setHandle(QQmlComponent *handle);
+
+    bool isContent(QQuickItem *item) const override;
+
+    static QQuickSplitViewAttached *qmlAttachedProperties(QObject *object);
+
+    // Based on the same code in QMainWindow.
+    enum VersionMarkers {
+        VersionMarker = 0xff
+    };
+    Q_INVOKABLE QVariant saveState();
+    Q_INVOKABLE bool restoreState(const QVariant &state);
+
+Q_SIGNALS:
+    void orientationChanged();
+    void resizingChanged();
+    void handleChanged();
+
+protected:
+    QQuickSplitView(QQuickSplitViewPrivate &dd, QQuickItem *parent);
+
+    void componentComplete() override;
+    void hoverMoveEvent(QHoverEvent *event) override;
+    void geometryChanged(const QRectF &newGeometry, const QRectF &oldGeometry) override;
+
+    void itemAdded(int index, QQuickItem *item) override;
+    void itemMoved(int index, QQuickItem *item) override;
+    void itemRemoved(int index, QQuickItem *item) override;
+
+#if QT_CONFIG(accessibility)
+    QAccessible::Role accessibleRole() const override;
+#endif
+
+private:
+    Q_DISABLE_COPY(QQuickSplitView)
+    Q_DECLARE_PRIVATE(QQuickSplitView)
+};
+
+class Q_QUICKTEMPLATES2_PRIVATE_EXPORT QQuickSplitViewAttached : public QObject
+{
+    Q_OBJECT
+    Q_PROPERTY(QQuickSplitView *view READ view NOTIFY viewChanged FINAL)
+    Q_PROPERTY(qreal minimumWidth READ minimumWidth WRITE setMinimumWidth
+        RESET resetMinimumWidth NOTIFY minimumWidthChanged FINAL)
+    Q_PROPERTY(qreal minimumHeight READ minimumHeight WRITE setMinimumHeight
+        RESET resetMinimumHeight NOTIFY minimumHeightChanged FINAL)
+    Q_PROPERTY(qreal preferredWidth READ preferredWidth WRITE setPreferredWidth
+        RESET resetPreferredWidth NOTIFY preferredWidthChanged FINAL)
+    Q_PROPERTY(qreal preferredHeight READ preferredHeight WRITE setPreferredHeight
+        RESET resetPreferredHeight NOTIFY preferredHeightChanged FINAL)
+    Q_PROPERTY(qreal maximumWidth READ maximumWidth WRITE setMaximumWidth
+        RESET resetMaximumWidth NOTIFY maximumWidthChanged FINAL)
+    Q_PROPERTY(qreal maximumHeight READ maximumHeight WRITE setMaximumHeight
+        RESET resetMaximumHeight NOTIFY maximumHeightChanged FINAL)
+    Q_PROPERTY(bool fillHeight READ fillHeight WRITE setFillHeight NOTIFY fillHeightChanged FINAL)
+    Q_PROPERTY(bool fillWidth READ fillWidth WRITE setFillWidth NOTIFY fillWidthChanged FINAL)
+
+public:
+    explicit QQuickSplitViewAttached(QObject *parent = nullptr);
+
+    QQuickSplitView *view() const;
+
+    qreal minimumWidth() const;
+    void setMinimumWidth(qreal width);
+    void resetMinimumWidth();
+
+    qreal minimumHeight() const;
+    void setMinimumHeight(qreal height);
+    void resetMinimumHeight();
+
+    qreal preferredWidth() const;
+    void setPreferredWidth(qreal width);
+    void resetPreferredWidth();
+
+    qreal preferredHeight() const;
+    void setPreferredHeight(qreal height);
+    void resetPreferredHeight();
+
+    qreal maximumWidth() const;
+    void setMaximumWidth(qreal width);
+    void resetMaximumWidth();
+
+    qreal maximumHeight() const;
+    void setMaximumHeight(qreal height);
+    void resetMaximumHeight();
+
+    bool fillWidth() const;
+    void setFillWidth(bool fill);
+
+    bool fillHeight() const;
+    void setFillHeight(bool fill);
+
+Q_SIGNALS:
+    void viewChanged();
+    void minimumWidthChanged();
+    void minimumHeightChanged();
+    void preferredWidthChanged();
+    void preferredHeightChanged();
+    void maximumWidthChanged();
+    void maximumHeightChanged();
+    void fillWidthChanged();
+    void fillHeightChanged();
+
+private:
+    Q_DISABLE_COPY(QQuickSplitViewAttached)
+    Q_DECLARE_PRIVATE(QQuickSplitViewAttached)
+};
+
+class Q_QUICKTEMPLATES2_PRIVATE_EXPORT QQuickSplitHandleAttached : public QObject
+{
+    Q_OBJECT
+    Q_PROPERTY(bool hovered READ isHovered NOTIFY hoveredChanged FINAL)
+    Q_PROPERTY(bool pressed READ isPressed NOTIFY pressedChanged FINAL)
+
+public:
+    explicit QQuickSplitHandleAttached(QObject *parent = nullptr);
+
+    bool isHovered() const;
+    bool isPressed() const;
+
+    static QQuickSplitHandleAttached *qmlAttachedProperties(QObject *object);
+
+Q_SIGNALS:
+    void hoveredChanged();
+    void pressedChanged();
+
+private:
+    Q_DISABLE_COPY(QQuickSplitHandleAttached)
+    Q_DECLARE_PRIVATE(QQuickSplitHandleAttached)
+};
+
+QT_END_NAMESPACE
+
+QML_DECLARE_TYPE(QQuickSplitView)
+QML_DECLARE_TYPEINFO(QQuickSplitView, QML_HAS_ATTACHED_PROPERTIES)
+
+QML_DECLARE_TYPE(QQuickSplitHandleAttached)
+QML_DECLARE_TYPEINFO(QQuickSplitHandleAttached, QML_HAS_ATTACHED_PROPERTIES)
+
+#endif // QQUICKSPLITVIEW_P_H