Add internal QQuickPageLayout helper

Does the header/content/footer layout for Page, and will
be shared with the upcoming Dialog.

Change-Id: Ic550a87b5f4bb4eb44e2d08a4c977183f3b5bbff
Reviewed-by: Mitch Curtis <mitch.curtis@qt.io>

4 files changed, 289 insertions, 117 deletions

diff --git a/src/quicktemplates2/qquickpage.cpp b/src/quicktemplates2/qquickpage.cpp
index 56a9f86e..9c0c22ec 100644
--- a/src/quicktemplates2/qquickpage.cpp
+++ b/src/quicktemplates2/qquickpage.cpp
@@ -36,11 +36,7 @@
 
 #include "qquickpage_p.h"
 #include "qquickcontrol_p_p.h"
-#include "qquicktoolbar_p.h"
-#include "qquicktabbar_p.h"
-#include "qquickdialogbuttonbox_p.h"
-
-#include <QtQuick/private/qquickitemchangelistener_p.h>
+#include "qquickpagelayout_p_p.h"
 
 QT_BEGIN_NAMESPACE
 
@@ -86,81 +82,23 @@ QT_BEGIN_NAMESPACE
     \sa ApplicationWindow, {Container Controls}
 */
 
-class QQuickPagePrivate : public QQuickControlPrivate, public QQuickItemChangeListener
+class QQuickPagePrivate : public QQuickControlPrivate
 {
     Q_DECLARE_PUBLIC(QQuickPage)
 
 public:
-    QQuickPagePrivate();
-
-    void relayout();
-
-    void itemGeometryChanged(QQuickItem *item, const QRectF &newRect, const QRectF &oldRect) override;
-    void itemVisibilityChanged(QQuickItem *item) override;
-    void itemImplicitWidthChanged(QQuickItem *item) override;
-    void itemImplicitHeightChanged(QQuickItem *item) override;
-
     QString title;
-    QQuickItem *header;
-    QQuickItem *footer;
+    QScopedPointer<QQuickPageLayout> layout;
 };
 
-QQuickPagePrivate::QQuickPagePrivate() : header(nullptr), footer(nullptr)
-{
-}
-
-void QQuickPagePrivate::relayout()
-{
-    Q_Q(QQuickPage);
-    QQuickItem *content = q->contentItem();
-    const qreal hh = header ? header->height() : 0;
-    const qreal fh = footer ? footer->height() : 0;
-
-    content->setY(hh + q->topPadding());
-    content->setX(q->leftPadding());
-    content->setWidth(q->availableWidth());
-    content->setHeight(q->availableHeight() - hh - fh);
-
-    if (header)
-        header->setWidth(q->width());
-
-    if (footer) {
-        footer->setY(q->height() - fh);
-        footer->setWidth(q->width());
-    }
-}
-
-void QQuickPagePrivate::itemGeometryChanged(QQuickItem *item, const QRectF &newRect, const QRectF &oldRect)
-{
-    Q_UNUSED(item)
-    Q_UNUSED(newRect)
-    Q_UNUSED(oldRect)
-    relayout();
-}
-
-void QQuickPagePrivate::itemVisibilityChanged(QQuickItem *item)
-{
-    Q_UNUSED(item);
-    relayout();
-}
-
-void QQuickPagePrivate::itemImplicitWidthChanged(QQuickItem *item)
-{
-    Q_UNUSED(item);
-    relayout();
-}
-
-void QQuickPagePrivate::itemImplicitHeightChanged(QQuickItem *item)
-{
-    Q_UNUSED(item);
-    relayout();
-}
 
 QQuickPage::QQuickPage(QQuickItem *parent) :
     QQuickControl(*(new QQuickPagePrivate), parent)
 {
+    Q_D(QQuickPage);
     setFlag(ItemIsFocusScope);
     setAcceptedMouseButtons(Qt::AllButtons);
+    d->layout.reset(new QQuickPageLayout(this));
 }
 
 /*!
@@ -199,37 +137,16 @@ void QQuickPage::setTitle(const QString &title)
 QQuickItem *QQuickPage::header() const
 {
     Q_D(const QQuickPage);
-    return d->header;
+    return d->layout->header();
 }
 
 void QQuickPage::setHeader(QQuickItem *header)
 {
     Q_D(QQuickPage);
-    if (d->header == header)
+    if (!d->layout->setHeader(header))
         return;
-
-    if (d->header) {
-        QQuickItemPrivate::get(d->header)->removeItemChangeListener(d, QQuickItemPrivate::Geometry | QQuickItemPrivate::Visibility |
-                                                                    QQuickItemPrivate::ImplicitWidth | QQuickItemPrivate::ImplicitHeight);
-        d->header->setParentItem(nullptr);
-    }
-    d->header = header;
-    if (header) {
-        header->setParentItem(this);
-        QQuickItemPrivate *p = QQuickItemPrivate::get(header);
-        p->addItemChangeListener(d, QQuickItemPrivate::Geometry | QQuickItemPrivate::Visibility |
-                                 QQuickItemPrivate::ImplicitWidth | QQuickItemPrivate::ImplicitHeight);
-        if (qFuzzyIsNull(header->z()))
-            header->setZ(1);
-        if (QQuickToolBar *toolBar = qobject_cast<QQuickToolBar *>(header))
-            toolBar->setPosition(QQuickToolBar::Header);
-        else if (QQuickTabBar *tabBar = qobject_cast<QQuickTabBar *>(header))
-            tabBar->setPosition(QQuickTabBar::Header);
-        else if (QQuickDialogButtonBox *buttonBox = qobject_cast<QQuickDialogButtonBox *>(header))
-            buttonBox->setPosition(QQuickDialogButtonBox::Header);
-    }
     if (isComponentComplete())
-        d->relayout();
+        d->layout->update();
     emit headerChanged();
 }
 
@@ -248,37 +165,16 @@ void QQuickPage::setHeader(QQuickItem *header)
 QQuickItem *QQuickPage::footer() const
 {
     Q_D(const QQuickPage);
-    return d->footer;
+    return d->layout->footer();
 }
 
 void QQuickPage::setFooter(QQuickItem *footer)
 {
     Q_D(QQuickPage);
-    if (d->footer == footer)
+    if (!d->layout->setFooter(footer))
         return;
-
-    if (d->footer) {
-        QQuickItemPrivate::get(d->footer)->removeItemChangeListener(d, QQuickItemPrivate::Geometry | QQuickItemPrivate::Visibility |
-                                                                    QQuickItemPrivate::ImplicitWidth | QQuickItemPrivate::ImplicitHeight);
-        d->footer->setParentItem(nullptr);
-    }
-    d->footer = footer;
-    if (footer) {
-        footer->setParentItem(this);
-        QQuickItemPrivate *p = QQuickItemPrivate::get(footer);
-        p->addItemChangeListener(d, QQuickItemPrivate::Geometry | QQuickItemPrivate::Visibility |
-                                 QQuickItemPrivate::ImplicitWidth | QQuickItemPrivate::ImplicitHeight);
-        if (qFuzzyIsNull(footer->z()))
-            footer->setZ(1);
-        if (QQuickToolBar *toolBar = qobject_cast<QQuickToolBar *>(footer))
-            toolBar->setPosition(QQuickToolBar::Footer);
-        else if (QQuickTabBar *tabBar = qobject_cast<QQuickTabBar *>(footer))
-            tabBar->setPosition(QQuickTabBar::Footer);
-        else if (QQuickDialogButtonBox *buttonBox = qobject_cast<QQuickDialogButtonBox *>(footer))
-            buttonBox->setPosition(QQuickDialogButtonBox::Header);
-    }
     if (isComponentComplete())
-        d->relayout();
+        d->layout->update();
     emit footerChanged();
 }
 
@@ -331,14 +227,14 @@ void QQuickPage::geometryChanged(const QRectF &newGeometry, const QRectF &oldGeo
 {
     Q_D(QQuickPage);
     QQuickControl::geometryChanged(newGeometry, oldGeometry);
-    d->relayout();
+    d->layout->update();
 }
 
 void QQuickPage::paddingChange(const QMarginsF &newPadding, const QMarginsF &oldPadding)
 {
     Q_D(QQuickPage);
     QQuickControl::paddingChange(newPadding, oldPadding);
-    d->relayout();
+    d->layout->update();
 }
 
 #ifndef QT_NO_ACCESSIBILITY
diff --git a/src/quicktemplates2/qquickpagelayout.cpp b/src/quicktemplates2/qquickpagelayout.cpp
new file mode 100644
index 00000000..552cf3f7
--- /dev/null
+++ b/src/quicktemplates2/qquickpagelayout.cpp
@@ -0,0 +1,188 @@
+/****************************************************************************
+**
+** Copyright (C) 2016 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.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qquickpagelayout_p_p.h"
+#include "qquickcontrol_p.h"
+#include "qquicktoolbar_p.h"
+#include "qquicktabbar_p.h"
+#include "qquickdialogbuttonbox_p.h"
+
+#include <QtQuick/private/qquickitem_p.h>
+
+QT_BEGIN_NAMESPACE
+
+static const QQuickItemPrivate::ChangeTypes ItemChanges = QQuickItemPrivate::Geometry | QQuickItemPrivate::Visibility | QQuickItemPrivate::Destroyed
+                                                        | QQuickItemPrivate::ImplicitWidth | QQuickItemPrivate::ImplicitHeight;
+
+namespace {
+    enum Position {
+        Header,
+        Footer
+    };
+
+    Q_STATIC_ASSERT(int(Header) == int(QQuickTabBar::Header));
+    Q_STATIC_ASSERT(int(Footer) == int(QQuickTabBar::Footer));
+
+    Q_STATIC_ASSERT(int(Header) == int(QQuickToolBar::Header));
+    Q_STATIC_ASSERT(int(Footer) == int(QQuickToolBar::Footer));
+
+    Q_STATIC_ASSERT(int(Header) == int(QQuickDialogButtonBox::Header));
+    Q_STATIC_ASSERT(int(Footer) == int(QQuickDialogButtonBox::Footer));
+}
+
+static void setPosition(QQuickItem *item, Position position)
+{
+    if (QQuickToolBar *toolBar = qobject_cast<QQuickToolBar *>(item))
+        toolBar->setPosition(static_cast<QQuickToolBar::Position>(position));
+    else if (QQuickTabBar *tabBar = qobject_cast<QQuickTabBar *>(item))
+        tabBar->setPosition(static_cast<QQuickTabBar::Position>(position));
+    else if (QQuickDialogButtonBox *buttonBox = qobject_cast<QQuickDialogButtonBox *>(item))
+        buttonBox->setPosition(static_cast<QQuickDialogButtonBox::Position>(position));
+}
+
+QQuickPageLayout::QQuickPageLayout(QQuickControl *control)
+    : m_header(nullptr), m_footer(nullptr), m_control(control)
+{
+}
+
+QQuickPageLayout::~QQuickPageLayout()
+{
+    if (m_header)
+        QQuickItemPrivate::get(m_header)->removeItemChangeListener(this, ItemChanges);
+    if (m_footer)
+        QQuickItemPrivate::get(m_footer)->removeItemChangeListener(this, ItemChanges);
+}
+
+QQuickItem *QQuickPageLayout::header() const
+{
+    return m_header;
+}
+
+bool QQuickPageLayout::setHeader(QQuickItem *header)
+{
+    if (m_header == header)
+        return false;
+
+    if (m_header) {
+        QQuickItemPrivate::get(m_header)->removeItemChangeListener(this, ItemChanges);
+        m_header->setParentItem(nullptr);
+    }
+    m_header = header;
+    if (header) {
+        header->setParentItem(m_control);
+        QQuickItemPrivate::get(header)->addItemChangeListener(this, ItemChanges);
+        if (qFuzzyIsNull(header->z()))
+            header->setZ(1);
+        setPosition(header, Header);
+    }
+    return true;
+}
+
+QQuickItem *QQuickPageLayout::footer() const
+{
+    return m_footer;
+}
+
+bool QQuickPageLayout::setFooter(QQuickItem *footer)
+{
+    if (m_footer == footer)
+        return false;
+
+    if (m_footer) {
+        QQuickItemPrivate::get(m_footer)->removeItemChangeListener(this, ItemChanges);
+        m_footer->setParentItem(nullptr);
+    }
+    m_footer = footer;
+    if (footer) {
+        footer->setParentItem(m_control);
+        QQuickItemPrivate::get(footer)->addItemChangeListener(this, ItemChanges);
+        if (qFuzzyIsNull(footer->z()))
+            footer->setZ(1);
+        setPosition(footer, Footer);
+    }
+    return true;
+}
+
+void QQuickPageLayout::update()
+{
+    QQuickItem *content = m_control->contentItem();
+
+    const qreal hh = m_header ? m_header->height() : 0;
+    const qreal fh = m_footer ? m_footer->height() : 0;
+
+    content->setY(hh + m_control->topPadding());
+    content->setX(m_control->leftPadding());
+    content->setWidth(m_control->availableWidth());
+    content->setHeight(m_control->availableHeight() - hh - fh);
+
+    if (m_header)
+        m_header->setWidth(m_control->width());
+
+    if (m_footer) {
+        m_footer->setY(m_control->height() - fh);
+        m_footer->setWidth(m_control->width());
+    }
+}
+
+void QQuickPageLayout::itemVisibilityChanged(QQuickItem *)
+{
+    update();
+}
+
+void QQuickPageLayout::itemImplicitWidthChanged(QQuickItem *)
+{
+    update();
+}
+
+void QQuickPageLayout::itemImplicitHeightChanged(QQuickItem *)
+{
+    update();
+}
+
+void QQuickPageLayout::itemGeometryChanged(QQuickItem *, const QRectF &, const QRectF &)
+{
+    update();
+}
+
+void QQuickPageLayout::itemDestroyed(QQuickItem *item)
+{
+    if (item == m_header)
+        m_header = nullptr;
+    else if (item == m_footer)
+        m_footer = nullptr;
+}
+
+QT_END_NAMESPACE
diff --git a/src/quicktemplates2/qquickpagelayout_p_p.h b/src/quicktemplates2/qquickpagelayout_p_p.h
new file mode 100644
index 00000000..baaf53e7
--- /dev/null
+++ b/src/quicktemplates2/qquickpagelayout_p_p.h
@@ -0,0 +1,86 @@
+/****************************************************************************
+**
+** Copyright (C) 2016 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 QQUICKPAGELAYOUT_P_P_H
+#define QQUICKPAGELAYOUT_P_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 <QtQuick/private/qquickitemchangelistener_p.h>
+
+QT_BEGIN_NAMESPACE
+
+class QQuickControl;
+
+class QQuickPageLayout : public QQuickItemChangeListener
+{
+public:
+    explicit QQuickPageLayout(QQuickControl *control);
+    ~QQuickPageLayout();
+
+    QQuickItem *header() const;
+    bool setHeader(QQuickItem *header);
+
+    QQuickItem *footer() const;
+    bool setFooter(QQuickItem *footer);
+
+    void update();
+
+protected:
+    void itemVisibilityChanged(QQuickItem *item) override;
+    void itemImplicitWidthChanged(QQuickItem *item) override;
+    void itemImplicitHeightChanged(QQuickItem *item) override;
+    void itemGeometryChanged(QQuickItem *item, const QRectF &newRect, const QRectF &oldRect) override;
+    void itemDestroyed(QQuickItem *item) override;
+
+private:
+    QQuickItem *m_header;
+    QQuickItem *m_footer;
+    QQuickControl *m_control;
+};
+
+QT_END_NAMESPACE
+
+#endif // QQUICKPAGELAYOUT_P_P_H
diff --git a/src/quicktemplates2/quicktemplates2.pri b/src/quicktemplates2/quicktemplates2.pri
index df036ed9..4f3f6af0 100644
--- a/src/quicktemplates2/quicktemplates2.pri
+++ b/src/quicktemplates2/quicktemplates2.pri
@@ -31,6 +31,7 @@ HEADERS += \
     $$PWD/qquickoverlay_p.h \
     $$PWD/qquickpage_p.h \
     $$PWD/qquickpageindicator_p.h \
+    $$PWD/qquickpagelayout_p_p.h \
     $$PWD/qquickpane_p.h \
     $$PWD/qquickpane_p_p.h \
     $$PWD/qquickpopup_p.h \
@@ -85,6 +86,7 @@ SOURCES += \
     $$PWD/qquickoverlay.cpp \
     $$PWD/qquickpage.cpp \
     $$PWD/qquickpageindicator.cpp \
+    $$PWD/qquickpagelayout.cpp \
     $$PWD/qquickpane.cpp \
     $$PWD/qquickpopup.cpp \
     $$PWD/qquickpresshandler.cpp \