filemanager/model/positioner.cpp
2021-03-29 16:51:34 +08:00

951 lines
25 KiB
C++

/***************************************************************************
* Copyright (C) 2014 by Eike Hein <hein@kde.org> *
* *
* This program is free software; you can redistribute it and/or modify *
* it under the terms of the GNU General Public License as published by *
* the Free Software Foundation; either version 2 of the License, or *
* (at your option) any later version. *
* *
* This program is distributed in the hope that it will be useful, *
* but WITHOUT ANY WARRANTY; without even the implied warranty of *
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
* GNU General Public License for more details. *
* *
* You should have received a copy of the GNU General Public License *
* along with this program; if not, write to the *
* Free Software Foundation, Inc., *
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA . *
***************************************************************************/
#include "positioner.h"
#include "foldermodel.h"
#include <QDebug>
#include <QTimer>
#include <cstdlib>
Positioner::Positioner(QObject *parent)
: QAbstractItemModel(parent)
, m_enabled(false)
, m_folderModel(nullptr)
, m_perStripe(0)
, m_ignoreNextTransaction(false)
, m_deferApplyPositions(false)
, m_updatePositionsTimer(new QTimer(this))
{
m_updatePositionsTimer->setSingleShot(true);
m_updatePositionsTimer->setInterval(0);
connect(m_updatePositionsTimer, &QTimer::timeout, this, &Positioner::updatePositions);
}
Positioner::~Positioner()
{
}
bool Positioner::enabled() const
{
return m_enabled;
}
void Positioner::setEnabled(bool enabled)
{
if (m_enabled != enabled) {
m_enabled = enabled;
beginResetModel();
if (enabled && m_folderModel) {
initMaps();
}
endResetModel();
emit enabledChanged();
if (!enabled) {
m_updatePositionsTimer->start();
}
}
}
FolderModel *Positioner::folderModel() const
{
return m_folderModel;
}
void Positioner::setFolderModel(QObject *folderModel)
{
if (m_folderModel != folderModel) {
beginResetModel();
if (m_folderModel) {
disconnectSignals(m_folderModel);
}
m_folderModel = qobject_cast<FolderModel *>(folderModel);
if (m_folderModel) {
connectSignals(m_folderModel);
if (m_enabled) {
initMaps();
}
}
endResetModel();
emit folderModelChanged();
}
}
int Positioner::perStripe() const
{
return m_perStripe;
}
void Positioner::setPerStripe(int perStripe)
{
if (m_perStripe != perStripe) {
m_perStripe = perStripe;
emit perStripeChanged();
if (m_enabled && perStripe > 0 && !m_proxyToSource.isEmpty()) {
applyPositions();
}
}
}
QStringList Positioner::positions() const
{
return m_positions;
}
void Positioner::setPositions(const QStringList &positions)
{
if (m_positions != positions) {
m_positions = positions;
emit positionsChanged();
// Defer applying positions until listing completes.
if (m_folderModel->status() == FolderModel::Listing) {
m_deferApplyPositions = true;
} else {
applyPositions();
}
}
}
int Positioner::map(int row) const
{
if (m_enabled && m_folderModel) {
return m_proxyToSource.value(row, -1);
}
return row;
}
int Positioner::nearestItem(int currentIndex, Qt::ArrowType direction)
{
if (!m_enabled || currentIndex >= rowCount()) {
return -1;
}
if (currentIndex < 0) {
return firstRow();
}
int hDirection = 0;
int vDirection = 0;
switch (direction) {
case Qt::LeftArrow:
hDirection = -1;
break;
case Qt::RightArrow:
hDirection = 1;
break;
case Qt::UpArrow:
vDirection = -1;
break;
case Qt::DownArrow:
vDirection = 1;
break;
default:
return -1;
}
QList<int> rows(m_proxyToSource.keys());
std::sort(rows.begin(), rows.end());
int nearestItem = -1;
const QPoint currentPos(currentIndex % m_perStripe, currentIndex / m_perStripe);
int lastDistance = -1;
int distance = 0;
foreach (int row, rows) {
const QPoint pos(row % m_perStripe, row / m_perStripe);
if (row == currentIndex) {
continue;
}
if (hDirection == 0) {
if (vDirection * pos.y() > vDirection * currentPos.y()) {
distance = (pos - currentPos).manhattanLength();
if (nearestItem == -1 || distance < lastDistance || (distance == lastDistance && pos.x() == currentPos.x())) {
nearestItem = row;
lastDistance = distance;
}
}
} else if (vDirection == 0) {
if (hDirection * pos.x() > hDirection * currentPos.x()) {
distance = (pos - currentPos).manhattanLength();
if (nearestItem == -1 || distance < lastDistance || (distance == lastDistance && pos.y() == currentPos.y())) {
nearestItem = row;
lastDistance = distance;
}
}
}
}
return nearestItem;
}
bool Positioner::isBlank(int row) const
{
if (!m_enabled && m_folderModel) {
return m_folderModel->isBlank(row);
}
if (m_proxyToSource.contains(row) && m_folderModel && !m_folderModel->isBlank(m_proxyToSource.value(row))) {
return false;
}
return true;
}
int Positioner::indexForUrl(const QUrl &url) const
{
if (!m_folderModel) {
return -1;
}
const QString &name = url.fileName();
int sourceIndex = -1;
// TODO Optimize.
for (int i = 0; i < m_folderModel->rowCount(); ++i) {
if (m_folderModel->data(m_folderModel->index(i, 0), FolderModel::FileNameRole).toString() == name) {
sourceIndex = i;
break;
}
}
return m_sourceToProxy.value(sourceIndex, -1);
}
void Positioner::setRangeSelected(int anchor, int to)
{
if (!m_folderModel) {
return;
}
if (m_enabled) {
QVariantList indices;
for (int i = qMin(anchor, to); i <= qMax(anchor, to); ++i) {
if (m_proxyToSource.contains(i)) {
indices.append(m_proxyToSource.value(i));
}
}
if (!indices.isEmpty()) {
m_folderModel->updateSelection(indices, false);
}
} else {
m_folderModel->setRangeSelected(anchor, to);
}
}
QHash<int, QByteArray> Positioner::roleNames() const
{
return FolderModel::staticRoleNames();
}
QModelIndex Positioner::index(int row, int column, const QModelIndex &parent) const
{
if (parent.isValid()) {
return QModelIndex();
}
return createIndex(row, column);
}
QModelIndex Positioner::parent(const QModelIndex &index) const
{
if (m_folderModel) {
m_folderModel->parent(index);
}
return QModelIndex();
}
QVariant Positioner::data(const QModelIndex &index, int role) const
{
if (!index.isValid()) {
return QVariant();
}
if (m_folderModel) {
if (m_enabled) {
if (m_proxyToSource.contains(index.row())) {
return m_folderModel->data(m_folderModel->index(m_proxyToSource.value(index.row()), 0), role);
} else if (role == FolderModel::BlankRole) {
return true;
}
} else {
return m_folderModel->data(m_folderModel->index(index.row(), 0), role);
}
}
return QVariant();
}
int Positioner::rowCount(const QModelIndex &parent) const
{
if (m_folderModel) {
if (m_enabled) {
if (parent.isValid()) {
return 0;
} else {
return lastRow() + 1;
}
} else {
return m_folderModel->rowCount(parent);
}
}
return 0;
}
int Positioner::columnCount(const QModelIndex &parent) const
{
Q_UNUSED(parent)
if (m_folderModel) {
return 1;
}
return 0;
}
void Positioner::reset()
{
beginResetModel();
initMaps();
endResetModel();
m_positions = QStringList();
emit positionsChanged();
}
void Positioner::move(const QVariantList &moves)
{
// Don't allow moves while listing.
if (m_folderModel->status() == FolderModel::Listing) {
m_deferMovePositions = moves;
return;
}
QVector<int> fromIndices;
QVector<int> toIndices;
QVector<int> sourceRows;
for (int i = 0; i < moves.count(); ++i) {
const int isFrom = (i % 2 == 0);
const int v = moves[i].toInt();
if (isFrom) {
if (m_proxyToSource.contains(v)) {
sourceRows.append(m_proxyToSource.value(v));
} else {
sourceRows.append(-1);
}
}
(isFrom ? fromIndices : toIndices).append(v);
}
const int oldCount = rowCount();
for (int i = 0; i < fromIndices.count(); ++i) {
const int from = fromIndices[i];
int to = toIndices[i];
const int sourceRow = sourceRows[i];
if (sourceRow == -1 || from == to) {
continue;
}
if (to == -1) {
to = firstFreeRow();
if (to == -1) {
to = lastRow() + 1;
}
}
if (!fromIndices.contains(to) && !isBlank(to)) {
/* find the next blank space
* we won't be happy if we're moving two icons to the same place
*/
while ((!isBlank(to) && from != to) || toIndices.contains(to)) {
to++;
}
}
toIndices[i] = to;
if (!toIndices.contains(from)) {
m_proxyToSource.remove(from);
}
updateMaps(to, sourceRow);
const QModelIndex &fromIdx = index(from, 0);
emit dataChanged(fromIdx, fromIdx);
if (to < oldCount) {
const QModelIndex &toIdx = index(to, 0);
emit dataChanged(toIdx, toIdx);
}
}
const int newCount = rowCount();
if (newCount > oldCount) {
if (m_beginInsertRowsCalled) {
endInsertRows();
m_beginInsertRowsCalled = false;
}
beginInsertRows(QModelIndex(), oldCount, newCount - 1);
endInsertRows();
}
if (newCount < oldCount) {
beginRemoveRows(QModelIndex(), newCount, oldCount - 1);
endRemoveRows();
}
m_updatePositionsTimer->start();
}
void Positioner::updatePositions()
{
QStringList positions;
if (m_enabled && !m_proxyToSource.isEmpty() && m_perStripe > 0) {
positions.append(QString::number((1 + ((rowCount() - 1) / m_perStripe))));
positions.append(QString::number(m_perStripe));
QHashIterator<int, int> it(m_proxyToSource);
while (it.hasNext()) {
it.next();
const QString &name = m_folderModel->data(m_folderModel->index(it.value(), 0), FolderModel::UrlRole).toString();
if (name.isEmpty()) {
qDebug() << this << it.value() << "Source model doesn't know this index!";
return;
}
positions.append(name);
positions.append(QString::number(qMax(0, it.key() / m_perStripe)));
positions.append(QString::number(qMax(0, it.key() % m_perStripe)));
}
}
if (positions != m_positions) {
m_positions = positions;
emit positionsChanged();
}
}
void Positioner::sourceStatusChanged()
{
if (m_deferApplyPositions && m_folderModel->status() != FolderModel::Listing) {
applyPositions();
}
if (m_deferMovePositions.count() && m_folderModel->status() != FolderModel::Listing) {
move(m_deferMovePositions);
m_deferMovePositions.clear();
}
}
void Positioner::sourceDataChanged(const QModelIndex &topLeft, const QModelIndex &bottomRight, const QVector<int> &roles)
{
if (m_enabled) {
int start = topLeft.row();
int end = bottomRight.row();
for (int i = start; i <= end; ++i) {
if (m_sourceToProxy.contains(i)) {
const QModelIndex &idx = index(m_sourceToProxy.value(i), 0);
emit dataChanged(idx, idx);
}
}
} else {
emit dataChanged(topLeft, bottomRight, roles);
}
}
void Positioner::sourceModelAboutToBeReset()
{
emit beginResetModel();
}
void Positioner::sourceModelReset()
{
if (m_enabled) {
initMaps();
}
emit endResetModel();
}
void Positioner::sourceRowsAboutToBeInserted(const QModelIndex &parent, int start, int end)
{
if (m_enabled) {
// Don't insert yet if we're waiting for listing to complete to apply
// initial positions;
if (m_deferApplyPositions) {
return;
} else if (m_proxyToSource.isEmpty()) {
beginInsertRows(parent, start, end);
m_beginInsertRowsCalled = true;
initMaps(end + 1);
return;
}
// When new rows are inserted, they might go in the beginning or in the middle.
// In this case we must update first the existing proxy->source and source->proxy
// mapping, otherwise the proxy items will point to the wrong source item.
int count = end - start + 1;
m_sourceToProxy.clear();
for (auto it = m_proxyToSource.begin(); it != m_proxyToSource.end(); ++it) {
int sourceIdx = *it;
if (sourceIdx >= start) {
*it += count;
}
m_sourceToProxy[*it] = it.key();
}
int free = -1;
int rest = -1;
for (int i = start; i <= end; ++i) {
free = firstFreeRow();
if (free != -1) {
updateMaps(free, i);
m_pendingChanges << createIndex(free, 0);
} else {
rest = i;
break;
}
}
if (rest != -1) {
int firstNew = lastRow() + 1;
int remainder = (end - rest);
beginInsertRows(parent, firstNew, firstNew + remainder);
m_beginInsertRowsCalled = true;
for (int i = 0; i <= remainder; ++i) {
updateMaps(firstNew + i, rest + i);
}
} else {
m_ignoreNextTransaction = true;
}
} else {
emit beginInsertRows(parent, start, end);
beginInsertRows(parent, start, end);
m_beginInsertRowsCalled = true;
}
}
void Positioner::sourceRowsAboutToBeMoved(const QModelIndex &sourceParent,
int sourceStart,
int sourceEnd,
const QModelIndex &destinationParent,
int destinationRow)
{
emit beginMoveRows(sourceParent, sourceStart, sourceEnd, destinationParent, destinationRow);
}
void Positioner::sourceRowsAboutToBeRemoved(const QModelIndex &parent, int first, int last)
{
if (m_enabled) {
int oldLast = lastRow();
for (int i = first; i <= last; ++i) {
int proxyRow = m_sourceToProxy.take(i);
m_proxyToSource.remove(proxyRow);
m_pendingChanges << createIndex(proxyRow, 0);
}
QHash<int, int> newProxyToSource;
QHash<int, int> newSourceToProxy;
QHashIterator<int, int> it(m_sourceToProxy);
int delta = std::abs(first - last) + 1;
while (it.hasNext()) {
it.next();
if (it.key() > last) {
newProxyToSource.insert(it.value(), it.key() - delta);
newSourceToProxy.insert(it.key() - delta, it.value());
} else {
newProxyToSource.insert(it.value(), it.key());
newSourceToProxy.insert(it.key(), it.value());
}
}
m_proxyToSource = newProxyToSource;
m_sourceToProxy = newSourceToProxy;
int newLast = lastRow();
if (oldLast > newLast) {
int diff = oldLast - newLast;
beginRemoveRows(QModelIndex(), ((oldLast - diff) + 1), oldLast);
} else {
m_ignoreNextTransaction = true;
}
} else {
emit beginRemoveRows(parent, first, last);
}
}
void Positioner::sourceLayoutAboutToBeChanged(const QList<QPersistentModelIndex> &parents, QAbstractItemModel::LayoutChangeHint hint)
{
Q_UNUSED(parents)
emit layoutAboutToBeChanged(QList<QPersistentModelIndex>(), hint);
}
void Positioner::sourceRowsInserted(const QModelIndex &parent, int first, int last)
{
Q_UNUSED(parent)
Q_UNUSED(first)
Q_UNUSED(last)
if (!m_ignoreNextTransaction) {
if (m_beginInsertRowsCalled) {
endInsertRows();
m_beginInsertRowsCalled = false;
}
} else {
m_ignoreNextTransaction = false;
}
flushPendingChanges();
// Don't generate new positions data if we're waiting for listing to
// complete to apply initial positions.
if (!m_deferApplyPositions) {
m_updatePositionsTimer->start();
}
}
void Positioner::sourceRowsMoved(const QModelIndex &sourceParent, int sourceStart, int sourceEnd, const QModelIndex &destinationParent, int destinationRow)
{
Q_UNUSED(sourceParent)
Q_UNUSED(sourceStart)
Q_UNUSED(sourceEnd)
Q_UNUSED(destinationParent)
Q_UNUSED(destinationRow)
emit endMoveRows();
}
void Positioner::sourceRowsRemoved(const QModelIndex &parent, int first, int last)
{
Q_UNUSED(parent)
Q_UNUSED(first)
Q_UNUSED(last)
if (!m_ignoreNextTransaction) {
emit endRemoveRows();
} else {
m_ignoreNextTransaction = false;
}
flushPendingChanges();
m_updatePositionsTimer->start();
}
void Positioner::sourceLayoutChanged(const QList<QPersistentModelIndex> &parents, QAbstractItemModel::LayoutChangeHint hint)
{
Q_UNUSED(parents)
if (m_enabled) {
initMaps();
}
emit layoutChanged(QList<QPersistentModelIndex>(), hint);
}
void Positioner::initMaps(int size)
{
m_proxyToSource.clear();
m_sourceToProxy.clear();
if (size == -1) {
size = m_folderModel->rowCount();
}
if (!size) {
return;
}
for (int i = 0; i < size; ++i) {
updateMaps(i, i);
}
}
void Positioner::updateMaps(int proxyIndex, int sourceIndex)
{
m_proxyToSource.insert(proxyIndex, sourceIndex);
m_sourceToProxy.insert(sourceIndex, proxyIndex);
}
int Positioner::firstRow() const
{
if (!m_proxyToSource.isEmpty()) {
QList<int> keys(m_proxyToSource.keys());
std::sort(keys.begin(), keys.end());
return keys.first();
}
return -1;
}
int Positioner::lastRow() const
{
if (!m_proxyToSource.isEmpty()) {
QList<int> keys(m_proxyToSource.keys());
std::sort(keys.begin(), keys.end());
return keys.last();
}
return 0;
}
int Positioner::firstFreeRow() const
{
if (!m_proxyToSource.isEmpty()) {
int last = lastRow();
for (int i = 0; i <= last; ++i) {
if (!m_proxyToSource.contains(i)) {
return i;
}
}
}
return -1;
}
void Positioner::applyPositions()
{
// We were called while the source model is listing. Defer applying positions
// until listing completes.
if (m_folderModel->status() == FolderModel::Listing) {
m_deferApplyPositions = true;
return;
}
if (m_positions.size() < 5) {
// We were waiting for listing to complete before proxying source rows,
// but we don't have positions to apply. Reset to populate.
if (m_deferApplyPositions) {
m_deferApplyPositions = false;
reset();
}
return;
}
beginResetModel();
m_proxyToSource.clear();
m_sourceToProxy.clear();
const QStringList &positions = m_positions.mid(2);
if (positions.count() % 3 != 0) {
return;
}
QHash<QString, int> sourceIndices;
for (int i = 0; i < m_folderModel->rowCount(); ++i) {
sourceIndices.insert(m_folderModel->data(m_folderModel->index(i, 0), FolderModel::UrlRole).toString(), i);
}
QString name;
int stripe = -1;
int pos = -1;
int sourceIndex = -1;
int index = -1;
bool ok = false;
int offset = 0;
// Restore positions for items that still fit.
for (int i = 0; i < positions.count() / 3; ++i) {
offset = i * 3;
pos = positions.at(offset + 2).toInt(&ok);
if (!ok) {
return;
}
if (pos <= m_perStripe) {
name = positions.at(offset);
stripe = positions.at(offset + 1).toInt(&ok);
if (!ok) {
return;
}
if (!sourceIndices.contains(name)) {
continue;
} else {
sourceIndex = sourceIndices.value(name);
}
index = (stripe * m_perStripe) + pos;
if (m_proxyToSource.contains(index)) {
continue;
}
updateMaps(index, sourceIndex);
sourceIndices.remove(name);
}
}
// Find new positions for items that didn't fit.
for (int i = 0; i < positions.count() / 3; ++i) {
offset = i * 3;
pos = positions.at(offset + 2).toInt(&ok);
if (!ok) {
return;
}
if (pos > m_perStripe) {
name = positions.at(offset);
if (!sourceIndices.contains(name)) {
continue;
} else {
sourceIndex = sourceIndices.take(name);
}
index = firstFreeRow();
if (index == -1) {
index = lastRow() + 1;
}
updateMaps(index, sourceIndex);
}
}
QHashIterator<QString, int> it(sourceIndices);
// Find positions for new source items we don't have records for.
while (it.hasNext()) {
it.next();
index = firstFreeRow();
if (index == -1) {
index = lastRow() + 1;
}
updateMaps(index, it.value());
}
endResetModel();
m_deferApplyPositions = false;
m_updatePositionsTimer->start();
}
void Positioner::flushPendingChanges()
{
if (m_pendingChanges.isEmpty()) {
return;
}
int last = lastRow();
foreach (const QModelIndex &idx, m_pendingChanges) {
if (idx.row() <= last) {
emit dataChanged(idx, idx);
}
}
m_pendingChanges.clear();
}
void Positioner::connectSignals(FolderModel *model)
{
connect(model, &QAbstractItemModel::dataChanged, this, &Positioner::sourceDataChanged, Qt::UniqueConnection);
connect(model, &QAbstractItemModel::rowsAboutToBeInserted, this, &Positioner::sourceRowsAboutToBeInserted, Qt::UniqueConnection);
connect(model, &QAbstractItemModel::rowsAboutToBeMoved, this, &Positioner::sourceRowsAboutToBeMoved, Qt::UniqueConnection);
connect(model, &QAbstractItemModel::rowsAboutToBeRemoved, this, &Positioner::sourceRowsAboutToBeRemoved, Qt::UniqueConnection);
connect(model, &QAbstractItemModel::layoutAboutToBeChanged, this, &Positioner::sourceLayoutAboutToBeChanged, Qt::UniqueConnection);
connect(model, &QAbstractItemModel::rowsInserted, this, &Positioner::sourceRowsInserted, Qt::UniqueConnection);
connect(model, &QAbstractItemModel::rowsMoved, this, &Positioner::sourceRowsMoved, Qt::UniqueConnection);
connect(model, &QAbstractItemModel::rowsRemoved, this, &Positioner::sourceRowsRemoved, Qt::UniqueConnection);
connect(model, &QAbstractItemModel::layoutChanged, this, &Positioner::sourceLayoutChanged, Qt::UniqueConnection);
connect(m_folderModel, &FolderModel::urlChanged, this, &Positioner::reset, Qt::UniqueConnection);
connect(m_folderModel, &FolderModel::statusChanged, this, &Positioner::sourceStatusChanged, Qt::UniqueConnection);
}
void Positioner::disconnectSignals(FolderModel *model)
{
disconnect(model, &QAbstractItemModel::dataChanged, this, &Positioner::sourceDataChanged);
disconnect(model, &QAbstractItemModel::rowsAboutToBeInserted, this, &Positioner::sourceRowsAboutToBeInserted);
disconnect(model, &QAbstractItemModel::rowsAboutToBeMoved, this, &Positioner::sourceRowsAboutToBeMoved);
disconnect(model, &QAbstractItemModel::rowsAboutToBeRemoved, this, &Positioner::sourceRowsAboutToBeRemoved);
disconnect(model, &QAbstractItemModel::layoutAboutToBeChanged, this, &Positioner::sourceLayoutAboutToBeChanged);
disconnect(model, &QAbstractItemModel::rowsInserted, this, &Positioner::sourceRowsInserted);
disconnect(model, &QAbstractItemModel::rowsMoved, this, &Positioner::sourceRowsMoved);
disconnect(model, &QAbstractItemModel::rowsRemoved, this, &Positioner::sourceRowsRemoved);
disconnect(model, &QAbstractItemModel::layoutChanged, this, &Positioner::sourceLayoutChanged);
disconnect(m_folderModel, &FolderModel::urlChanged, this, &Positioner::reset);
disconnect(m_folderModel, &FolderModel::statusChanged, this, &Positioner::sourceStatusChanged);
}