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Diffstat (limited to 'src/quickcontrols2/qquicktumblerview.cpp')
| -rw-r--r-- | src/quickcontrols2/qquicktumblerview.cpp | 273 |
1 files changed, 273 insertions, 0 deletions
diff --git a/src/quickcontrols2/qquicktumblerview.cpp b/src/quickcontrols2/qquicktumblerview.cpp new file mode 100644 index 00000000..540a8dd1 --- /dev/null +++ b/src/quickcontrols2/qquicktumblerview.cpp @@ -0,0 +1,273 @@ +/**************************************************************************** +** +** Copyright (C) 2016 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 "qquicktumblerview_p.h" + +#include <QtQml/private/qqmldelegatemodel_p.h> +#include <QtQuick/private/qquickitem_p.h> +#include <QtQuick/private/qquicklistview_p.h> +#include <QtQuick/private/qquickpathview_p.h> + +#include <QtQuickTemplates2/private/qquicktumbler_p.h> +#include <QtQuickTemplates2/private/qquicktumbler_p_p.h> + +QT_BEGIN_NAMESPACE + +QQuickTumblerView::QQuickTumblerView(QQuickItem *parent) : + QQuickItem(parent), + m_tumbler(nullptr), + m_delegate(nullptr), + m_pathView(nullptr), + m_listView(nullptr), + m_path(nullptr) +{ + // We don't call createView() here because we don't know what the wrap flag is set to + // yet, and we don't want to create a view that might never get used. +} + +QVariant QQuickTumblerView::model() const +{ + return m_model; +} + +void QQuickTumblerView::setModel(const QVariant &model) +{ + if (model == m_model) + return; + + m_model = model; + + if (m_pathView) { + m_pathView->setModel(m_model); + } else if (m_listView) { + // QQuickItemView::setModel() resets the current index, + // but if we're still creating the Tumbler, it should be maintained. + const int oldCurrentIndex = m_listView->currentIndex(); + m_listView->setModel(m_model); + if (!isComponentComplete()) + m_listView->setCurrentIndex(oldCurrentIndex); + } + + emit modelChanged(); +} + +QQmlComponent *QQuickTumblerView::delegate() const +{ + return m_delegate; +} + +void QQuickTumblerView::setDelegate(QQmlComponent *delegate) +{ + if (delegate == m_delegate) + return; + + m_delegate = delegate; + + if (m_pathView) + m_pathView->setDelegate(m_delegate); + else if (m_listView) + m_listView->setDelegate(m_delegate); + + emit delegateChanged(); +} + +QQuickPath *QQuickTumblerView::path() const +{ + return m_path; +} + +void QQuickTumblerView::setPath(QQuickPath *path) +{ + if (path == m_path) + return; + + m_path = path; + emit pathChanged(); +} + +void QQuickTumblerView::createView() +{ + Q_ASSERT(m_tumbler); + + // We create a view regardless of whether or not we know + // the count yet, because we rely on the view to tell us the count. + if (m_tumbler->wrap()) { + if (m_listView) { + delete m_listView; + m_listView = nullptr; + } + + if (!m_pathView) { + m_pathView = new QQuickPathView; + QQmlEngine::setContextForObject(m_pathView, qmlContext(this)); + QQml_setParent_noEvent(m_pathView, this); + m_pathView->setParentItem(this); + m_pathView->setPath(m_path); + m_pathView->setDelegate(m_delegate); + m_pathView->setPreferredHighlightBegin(0.5); + m_pathView->setPreferredHighlightEnd(0.5); + m_pathView->setClip(true); + + // Give the view a size. + updateView(); + // Ensure that the model is set eventually. + polish(); + } + } else { + if (m_pathView) { + delete m_pathView; + m_pathView = nullptr; + } + + if (!m_listView) { + m_listView = new QQuickListView; + QQmlEngine::setContextForObject(m_listView, qmlContext(this)); + QQml_setParent_noEvent(m_listView, this); + m_listView->setParentItem(this); + m_listView->setSnapMode(QQuickListView::SnapToItem); + m_listView->setHighlightRangeMode(QQuickListView::StrictlyEnforceRange); + m_listView->setClip(true); + m_listView->setDelegate(m_delegate); + + // Give the view a size. + updateView(); + // Ensure that the model is set eventually. + polish(); + } + } +} + +// Called whever the size or visibleItemCount changes. +void QQuickTumblerView::updateView() +{ + QQuickItem *theView = view(); + if (!theView) + return; + + theView->setSize(QSizeF(width(), height())); + + // Can be called in geometryChanged when it might not have a parent item yet. + if (!m_tumbler) + return; + + // Set view-specific properties that have a dependency on the size, etc. + if (m_pathView) { + m_pathView->setPathItemCount(m_tumbler->visibleItemCount() + 1); + m_pathView->setDragMargin(width() / 2); + } else { + m_listView->setPreferredHighlightBegin(height() / 2 - (height() / m_tumbler->visibleItemCount() / 2)); + m_listView->setPreferredHighlightEnd(height() / 2 + (height() / m_tumbler->visibleItemCount() / 2)); + } +} + +void QQuickTumblerView::geometryChanged(const QRectF &newGeometry, const QRectF &oldGeometry) +{ + QQuickItem::geometryChanged(newGeometry, oldGeometry); + updateView(); +} + +void QQuickTumblerView::componentComplete() +{ + QQuickItem::componentComplete(); + updateView(); +} + +void QQuickTumblerView::itemChange(QQuickItem::ItemChange change, const QQuickItem::ItemChangeData &data) +{ + QQuickItem::itemChange(change, data); + + if (change == QQuickItem::ItemParentHasChanged && data.item) { + if (m_tumbler) + m_tumbler->disconnect(this); + + m_tumbler = qobject_cast<QQuickTumbler*>(parentItem()); + + if (m_tumbler) { + // We assume that the parentChanged() signal of the tumbler will be emitted before its wrap property is set... + connect(m_tumbler, &QQuickTumbler::wrapChanged, this, &QQuickTumblerView::createView); + connect(m_tumbler, &QQuickTumbler::visibleItemCountChanged, this, &QQuickTumblerView::updateView); + } + } +} + +void QQuickTumblerView::updatePolish() +{ + // There are certain cases where model count changes can potentially cause problems. + // An example of this is a ListModel that appends items in a for loop in Component.onCompleted. + // If we didn't delay assignment of the model, the PathView/ListView would be deleted in + // response to it emitting countChanged(), causing a crash. To avoid this issue, + // and to avoid the overhead of count affecting the wrap property, which in turn may + // unnecessarily create delegates that are never seen, we delay setting the model. This ensures that + // Component.onCompleted would have been finished, for example. + if (m_pathView && !m_pathView->model().isValid() && m_model.isValid()) { + // QQuickPathView::setPathItemCount() resets the offset animation, + // so we just skip the animation while constructing the view. + const int oldHighlightMoveDuration = m_pathView->highlightMoveDuration(); + m_pathView->setHighlightMoveDuration(0); + + // Setting model can change the count, which can affect the wrap, which can cause + // the current view to be deleted before setModel() is finished, which causes a crash. + // Since QQuickTumbler can't know about QQuickTumblerView, we use its private API to + // inform it that it should delay setting wrap. + QQuickTumblerPrivate *tumblerPrivate = QQuickTumblerPrivate::get(m_tumbler); + tumblerPrivate->lockWrap(); + m_pathView->setModel(m_model); + tumblerPrivate->unlockWrap(); + + // The count-depends-on-wrap behavior could cause wrap to change after + // the call above, so we must check that we're still using a PathView. + if (m_pathView) + m_pathView->setHighlightMoveDuration(oldHighlightMoveDuration); + } else if (m_listView && !m_listView->model().isValid() && m_model.isValid()) { + // Usually we'd do this in QQuickTumbler::setWrap(), but that will be too early for polishes. + const int currentIndex = m_tumbler->currentIndex(); + m_listView->setModel(m_model); + m_listView->setCurrentIndex(currentIndex); + } +} + +QQuickItem *QQuickTumblerView::view() +{ + if (!m_tumbler) + return nullptr; + + if (m_tumbler->wrap()) + return m_pathView; + + return m_listView; +} + +QT_END_NAMESPACE |