File indexing completed on 2024-04-28 04:41:52

 /***************************************************************************
  *   Copyright (C) 2017 by Emmanuel Lepage Vallee                          *
  *   Author : Emmanuel Lepage Vallee <emmanuel.lepage@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 3 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, see <http://www.gnu.org/licenses/>. *
  **************************************************************************/
 #include "listview.h"
 
 // KQuickItemViews
 #include "adapters/abstractitemadapter.h"
 #include "adapters/contextadapter.h"
 class ListViewItem;
 
 // Qt
 #include <QQmlEngine>
 #include <QQmlContext>
 #include <QtCore/QItemSelectionModel>
 
 
 /**
  * Holds the metadata associated with a section.
  *
  * A section is created when a ListViewItem has a property that differs
  * from the previous ListViewItem in the list. It can also cross reference
  * into an external model to provide more flexibility.
  */
 struct ListViewSection final
 {
     explicit ListViewSection(
         ListViewItem* owner,
         const QVariant&    value
     );
     virtual ~ListViewSection();
 
     QQuickItem*      m_pItem    {nullptr};
     QQmlContext*     m_pContent {nullptr};
     int              m_Index    {   0   };
     int              m_RefCount {   1   };
     QVariant         m_Value    {       };
     ListViewSection* m_pPrevious{nullptr};
     ListViewSection* m_pNext    {nullptr};
 
     ListViewPrivate* d_ptr {nullptr};
 
     // Mutator
     QQuickItem* item(QQmlComponent* component);
 
     // Helpers
     void reparentSection(ListViewItem* newParent, ViewBase* view);
 
     // Getter
     ListViewItem *owner() const;
 
     // Setter
     void setOwner(ListViewItem *o);
 
 private:
     ListViewItem *m_pOwner {nullptr};
 };
 
 class ListViewItem : public AbstractItemAdapter
 {
 public:
     explicit ListViewItem(Viewport* r);
     virtual ~ListViewItem();
 
     // Actions
     virtual bool attach () override;
     virtual bool move   () override;
     virtual bool remove () override;
 
     ListViewSection* m_pSection {nullptr};
 
     // Setters
     ListViewSection* setSection(ListViewSection* s, const QVariant& val);
 
     ListViewPrivate* d() const;
 };
 
 class ListViewPrivate : public QObject
 {
     Q_OBJECT
 public:
     explicit ListViewPrivate(ListView* p) : QObject(p), q_ptr(p){}
 
     // When all elements are assumed to have the same height, life is easy
     QVector<qreal>         m_DepthChart {   0   };
     ListViewSections* m_pSections  {nullptr};
 
     // Sections
     QQmlComponent* m_pDelegate   {nullptr};
     QString        m_Property    {       };
     QStringList    m_Roles       {       };
     int            m_CachedRole  {   0   };
     mutable bool   m_IndexLoaded { false };
     ListViewSection* m_pFirstSection {nullptr};
     QSharedPointer<QAbstractItemModel> m_pSectionModel;
 
     // Helpers
     ListViewSection* getSection(ListViewItem* i);
     void reloadSectionIndices() const;
 
     ListView* q_ptr;
 
 public Q_SLOTS:
     void slotCurrentIndexChanged(const QModelIndex& index);
 };
 
 ListView::ListView(QQuickItem* parent) : SingleModelViewBase(new ItemFactory<ListViewItem>(), parent),
     d_ptr(new ListViewPrivate(this))
 {
     connect(this, &SingleModelViewBase::currentIndexChanged,
         d_ptr, &ListViewPrivate::slotCurrentIndexChanged);
 }
 
 ListViewItem::~ListViewItem()
 {
     // If this item is the section owner, assert before crashing
     if (m_pSection && m_pSection->owner() == this) {
         if (m_pSection->m_RefCount == 1)
             delete m_pSection;
         else {
             auto u = static_cast<ListViewItem*>(next(Qt::TopEdge));
             auto d = static_cast<ListViewItem*>(next(Qt::BottomEdge));
             if (u && u->m_pSection == m_pSection) {
                 m_pSection->setOwner(u);
             }
             else if(d && d->m_pSection == m_pSection) {
                 m_pSection->setOwner(d);
                 Q_ASSERT(d == m_pSection->owner());
             }
             else
                 Q_ASSERT(false); //TODO
         }
     }
 
     // Happens on reset
     if (m_pSection && --m_pSection->m_RefCount <= 0)
         delete m_pSection;
 }
 
 ListView::~ListView()
 {
     applyModelChanges(nullptr);
 
     if (d_ptr->m_pSections)
         delete d_ptr->m_pSections;
 
     d_ptr->m_pSections = nullptr;
 }
 
 int ListView::count() const
 {
     return rawModel() ? rawModel()->rowCount() : 0;
 }
 
 int ListView::currentIndex() const
 {
     return selectionModel()->currentIndex().row();
 }
 
 void ListView::setCurrentIndex(int index)
 {
     if (!rawModel())
         return;
 
     SingleModelViewBase::setCurrentIndex(
         rawModel()->index(index, 0),
         QItemSelectionModel::ClearAndSelect
     );
 }
 
 ListViewSections* ListView::section() const
 {
     if (!d_ptr->m_pSections) {
         d_ptr->m_pSections = new ListViewSections(
             const_cast<ListView*>(this)
         );
     }
 
     return d_ptr->m_pSections;
 }
 
 ListViewSection::ListViewSection(ListViewItem* owner, const QVariant& value) :
     m_Value(value), d_ptr(owner->d()), m_pOwner(owner)
 {
     m_pContent = new QQmlContext(owner->view()->rootContext());
     m_pContent->setContextProperty("section", value);
     owner->setBorderDecoration(Qt::TopEdge, 45.0);
 }
 
 QQuickItem* ListViewSection::item(QQmlComponent* component)
 {
     if (m_pItem)
         return m_pItem;
 
     m_pItem = qobject_cast<QQuickItem*>(component->create(
         m_pContent
     ));
 
     m_pItem->setParentItem(owner()->view()->contentItem());
 
     return m_pItem;
 }
 
 ListViewSection* ListViewItem::setSection(ListViewSection* s, const QVariant& val)
 {
     if ((!s) || s->m_Value != val)
         return nullptr;
 
     const auto p = static_cast<ListViewItem*>(next(Qt::TopEdge));
     const auto n = static_cast<ListViewItem*>(next(Qt::BottomEdge));
 
     // Garbage collect or change the old section owner
     if (m_pSection) {
         if (--m_pSection->m_RefCount <= 0)
             delete m_pSection;
         else if (p && n && p->m_pSection && p->m_pSection != m_pSection && n->m_pSection == m_pSection)
             m_pSection->setOwner(n);
         else if (p && p->m_pSection != m_pSection)
             Q_ASSERT(false); // There is a bug somewhere else
     }
 
     m_pSection = s;
     s->m_RefCount++;
 
     if ((!p) || p->m_pSection != s)
         s->setOwner(this);
 
     return s;
 }
 
 static void applyRoles(QQmlContext* ctx, const QModelIndex& self)
 {
     auto m = self.model();
 
     if (Q_UNLIKELY(!m))
         return;
 
     Q_ASSERT(self.model());
     const auto hash = self.model()->roleNames();
 
     // Add all roles to the
     for (auto i = hash.constBegin(); i != hash.constEnd(); ++i)
         ctx->setContextProperty(i.value() , self.data(i.key()));
 
     // Set extra index to improve ListView compatibility
     ctx->setContextProperty(QStringLiteral("index"        ) , self.row()        );
     ctx->setContextProperty(QStringLiteral("rootIndex"    ) , self              );
     ctx->setContextProperty(QStringLiteral("rowCount"     ) , m->rowCount(self) );
 }
 
 /**
  * No lookup is performed, it is based on the previous entry and nothing else.
  *
  * This view only supports list. If it's with a tree, it will break and "don't
  * do this".
  */
 ListViewSection* ListViewPrivate::getSection(ListViewItem* i)
 {
     if (m_pSections->property().isEmpty() || !m_pDelegate)
         return nullptr;
 
     const auto val = q_ptr->rawModel()->data(i->index(), m_pSections->role());
 
     if (i->m_pSection && i->m_pSection->m_Value == val)
         return i->m_pSection;
 
     const auto prev = static_cast<ListViewItem*>(i->next(Qt::TopEdge));
     const auto next = static_cast<ListViewItem*>(i->next(Qt::BottomEdge));
 
     // The section owner isn't currently loaded
     if ((!prev) && i->row() > 0) {
         //Q_ASSERT(false); //TODO when GC is enabled, the assert is to make sure I don't forget
         return nullptr;
     }
 
     Q_ASSERT(!i->m_pSection); //TODO
 
     // Check if the nearby sections are compatible
     for (auto& s : {
         prev ? prev->m_pSection : nullptr, m_pFirstSection, next ? next->m_pSection : nullptr
     }) if (auto ret = i->setSection(s, val))
             return ret;
 
     // Create a section
     i->m_pSection = new ListViewSection(i, val);
     Q_ASSERT(i->m_pSection->m_RefCount == 1);
 
     // Update the double linked list
     if (prev && prev->m_pSection) {
 
         if (prev->m_pSection->m_pNext) {
             prev->m_pSection->m_pNext->m_pPrevious = i->m_pSection;
             i->m_pSection->m_pNext = prev->m_pSection->m_pNext;
         }
 
         prev->m_pSection->m_pNext  = i->m_pSection;
         i->m_pSection->m_pPrevious = prev->m_pSection;
         i->m_pSection->m_Index     = prev->m_pSection->m_Index + 1;
 
         Q_ASSERT(prev->m_pSection != prev->m_pSection->m_pNext);
         Q_ASSERT(i->m_pSection->m_pPrevious !=  i->m_pSection);
     }
 
     m_pFirstSection = m_pFirstSection ?
         m_pFirstSection : i->m_pSection;
 
     Q_ASSERT(m_pFirstSection);
 
     if (m_pSectionModel && !m_IndexLoaded)
         reloadSectionIndices();
 
     if (m_pSectionModel) {
         const auto idx = m_pSectionModel->index(i->m_pSection->m_Index, 0);
         Q_ASSERT((!idx.isValid()) || idx.model() == m_pSectionModel);
 
         //note: If you wish to fork this class, you can create a second context
         // manager and avoid the private API. Given it is available, this isn't
         // done here.
         applyRoles( i->m_pSection->m_pContent, idx);
     }
 
     // Create the item *after* applyRoles to avoid O(N) number of reloads
     q_ptr->rootContext()->engine()->setObjectOwnership(
         i->m_pSection->item(m_pDelegate), QQmlEngine::CppOwnership
     );
 
     return i->m_pSection;
 }
 
 /**
  * Set indices for each sections to the right value.
  */
 void ListViewPrivate::reloadSectionIndices() const
 {
     int idx = 0;
     for (auto i = m_pFirstSection; i; i = i->m_pNext) {
         Q_ASSERT(i != i->m_pNext);
         i->m_Index = idx++;
     }
 
     //FIXME this assumes all sections are always loaded, this isn't correct
 
     m_IndexLoaded = m_pFirstSection != nullptr;
 }
 
 ListViewItem::ListViewItem(Viewport* r) : AbstractItemAdapter(r)
 {
 }
 
 ListViewPrivate* ListViewItem::d() const
 {
     return static_cast<ListView*>(view())->ListView::d_ptr;
 }
 
 bool ListViewItem::attach()
 {
     // This will trigger the lazy-loading of the item
     if (!container())
         return false;
 
     // When the item resizes itself
     QObject::connect(container(), &QQuickItem::heightChanged, container(), [this](){
         updateGeometry();
     });
 
     return move();
 }
 
 void ListViewSection::setOwner(ListViewItem* newParent)
 {
     if (m_pOwner == newParent)
         return;
 
     if (m_pOwner->container()) {
         auto otherAnchors = qvariant_cast<QObject*>(newParent->container()->property("anchors"));
         auto anchors = qvariant_cast<QObject*>(m_pOwner->container()->property("anchors"));
 
         const auto newPrevious = static_cast<ListViewItem*>(m_pOwner->next(Qt::TopEdge));
         Q_ASSERT(newPrevious != m_pOwner);
 
         // Prevent a loop while moving
         if (otherAnchors && otherAnchors->property("top") == m_pOwner->container()->property("bottom")) {
             anchors->setProperty("top", {});
             otherAnchors->setProperty("top", {});
             otherAnchors->setProperty("y", {});
         }
 
         anchors->setProperty("top", newParent->container() ?
             newParent->container()->property("bottom") : QVariant()
         );
 
         // Set the old owner new anchors
         if (newPrevious && newPrevious->container())
             anchors->setProperty("top", newPrevious->container()->property("bottom"));
 
         otherAnchors->setProperty("top", m_pItem->property("bottom"));
     }
     else
         newParent->container()->setY(0);
 
     // Cleanup the previous owner decoration
     if (m_pOwner) {
         m_pOwner->setBorderDecoration(Qt::TopEdge, 0);
     }
 
     m_pOwner = newParent;
 
     // Update the owner decoration size
     m_pOwner->setBorderDecoration(Qt::TopEdge, 45.0);
 }
 
 void ListViewSection::reparentSection(ListViewItem* newParent, ViewBase* view)
 {
     if (!m_pItem)
         return;
 
     if (newParent && newParent->container()) {
         auto anchors = qvariant_cast<QObject*>(m_pItem->property("anchors"));
         anchors->setProperty("top", newParent->container()->property("bottom"));
 
         m_pItem->setParentItem(owner()->view()->contentItem());
     }
     else {
         auto anchors = qvariant_cast<QObject*>(m_pItem->property("anchors"));
         anchors->setProperty("top", {});
         m_pItem->setY(0);
     }
 
     if (!m_pItem->width())
         m_pItem->setWidth(view->contentItem()->width());
 
     // Update the chain //FIXME crashes
     /*if (newParent && newParent->m_pSection && newParent->m_pSection->m_pNext != this) {
         Q_ASSERT(newParent->m_pSection != this);
         Q_ASSERT(newParent->m_pSection->m_pNext != this);
         Q_ASSERT(newParent->m_pSection->m_pNext->m_pPrevious != this);
         m_pNext = newParent->m_pSection->m_pNext;
         newParent->m_pSection->m_pNext = this;
         m_pPrevious = newParent->m_pSection;
         if (m_pNext) {
             m_pNext->m_pPrevious = this;
             Q_ASSERT(m_pNext != this);
         }
         Q_ASSERT(m_pPrevious != this);
     }
     else if (!newParent) {
         m_pPrevious = nullptr;
         m_pNext = d_ptr->m_pFirstSection;
         d_ptr->m_pFirstSection = this;
     }*/
 }
 
 bool ListViewItem::move()
 {
     if (!container())
         return false;
 
     auto prev = static_cast<ListViewItem*>(next(Qt::TopEdge));
 
     const QQuickItem* prevItem = nullptr;
 
     if (d()->m_pSections)
         if (auto sec = d()->getSection(this)) {
             // The item is no longer the first in the section
             if (sec->owner() == this) {
 
                 ListViewItem* newOwner = nullptr;
                 while (prev && prev->m_pSection == sec) {
                     newOwner = prev;
                     prev = static_cast<ListViewItem*>(prev->next(Qt::TopEdge));
                 }
 
                 if (newOwner) {
                     if (newOwner == static_cast<ListViewItem*>(next(Qt::TopEdge)))
                         prev = newOwner;
 
                     sec->setOwner(newOwner);
                 }
                 sec->reparentSection(prev, view());
 
                 if (sec->m_pItem)
                     prevItem = sec->m_pItem;
 
             }
             else if (sec->owner()->row() > row()) { //TODO remove once correctly implemented
                 //HACK to force reparenting when the elements move up
                 sec->setOwner(this);
                 sec->reparentSection(prev, view());
                 prevItem = sec->m_pItem;
             }
         }
 
     // Reset the "real" previous element
     prev = static_cast<ListViewItem*>(next(Qt::TopEdge));
 
     const qreal y = d()->m_DepthChart.first()*row();
 
     if (container()->width() != view()->contentItem()->width())
         container()->setWidth(view()->contentItem()->width());
 
     prevItem = prevItem ? prevItem : prev ? prev->container() : nullptr;
 
     // So other items can be GCed without always resetting to 0x0, note that it
     // might be a good idea to extend Flickable to support a virtual
     // origin point.
     if (!prevItem)
         container()->setY(y);
     else {
         // Row can be 0 if there is a section
         Q_ASSERT(row() || (!prev) || (!prev->container()));
 
         // Prevent loops when swapping 2 items
         auto otherAnchors = qvariant_cast<QObject*>(prevItem->property("anchors"));
         auto anchors = qvariant_cast<QObject*>(container()->property("anchors"));
 
         if (otherAnchors && otherAnchors->property("top") == container()->property("bottom")) {
             anchors->setProperty("top", {});
             otherAnchors->setProperty("top", {});
             otherAnchors->setProperty("y", {});
         }
 
         // Avoid creating too many race conditions
         if (anchors->property("top") != prevItem->property("bottom"))
             anchors->setProperty("top", prevItem->property("bottom"));
 
     }
 
     updateGeometry();
 
     return true;
 }
 
 bool ListViewItem::remove()
 {
     if (m_pSection && --m_pSection->m_RefCount <= 0) {
         delete m_pSection;
     }
     else if (m_pSection && m_pSection->owner() == this) {
         // Reparent the section
         if (auto n = static_cast<ListViewItem*>(next(Qt::BottomEdge))) {
             if (n->m_pSection == m_pSection)
                 m_pSection->setOwner(n);
             /*else
                 Q_ASSERT(false);*/
         }
         /*else
             Q_ASSERT(false);*/
     }
 
     m_pSection = nullptr;
 
     //TODO move back into treeview2
     //TODO check if the item has references, if it does, just release the shared
     // pointer and move on.
     return true;
 }
 
 ListViewSections::ListViewSections(ListView* parent) :
     QObject(parent), d_ptr(parent->d_ptr)
 {
 }
 
 ListViewSection::~ListViewSection()
 {
 
     if (m_pPrevious) {
         Q_ASSERT(m_pPrevious != m_pNext);
         m_pPrevious->m_pNext = m_pNext;
     }
 
     if (m_pNext)
         m_pNext->m_pPrevious = m_pPrevious;
 
     if (this == d_ptr->m_pFirstSection)
         d_ptr->m_pFirstSection = m_pNext;
 
     d_ptr->m_IndexLoaded = false;
 
     if (m_pItem)
         delete m_pItem;
 
     if (m_pContent)
         delete m_pContent;
 }
 
 ListViewSections::~ListViewSections()
 {}
 
 QQmlComponent* ListViewSections::delegate() const
 {
     return d_ptr->m_pDelegate;
 }
 
 void ListViewSections::setDelegate(QQmlComponent* component)
 {
     d_ptr->m_pDelegate = component;
 }
 
 QString ListViewSections::property() const
 {
     return d_ptr->m_Property;
 }
 
 int ListViewSections::role() const
 {
     if (d_ptr->m_Property.isEmpty() || !d_ptr->q_ptr->rawModel())
         return Qt::DisplayRole;
 
     if (d_ptr->m_CachedRole)
         return d_ptr->m_CachedRole;
 
     const auto roles = d_ptr->q_ptr->rawModel()->roleNames();
 
     if (!(d_ptr->m_CachedRole = roles.key(d_ptr->m_Property.toLatin1()))) {
         qWarning() << d_ptr->m_Property << "is not a model property";
         return Qt::DisplayRole;
     }
 
     return d_ptr->m_CachedRole;
 }
 
 void ListViewSections::setProperty(const QString& property)
 {
     d_ptr->m_Property = property;
 }
 
 QStringList ListViewSections::roles() const
 {
     return d_ptr->m_Roles;
 }
 
 void ListViewSections::setRoles(const QStringList& list)
 {
     d_ptr->m_Roles = list;
 }
 
 QSharedPointer<QAbstractItemModel> ListViewSections::model() const
 {
     return d_ptr->m_pSectionModel;
 }
 
 void ListViewSections::setModel(const QSharedPointer<QAbstractItemModel>& m)
 {
     d_ptr->m_pSectionModel = m;
 }
 
 void ListViewPrivate::slotCurrentIndexChanged(const QModelIndex& index)
 {
     emit q_ptr->indexChanged(index.row());
 }
 
 ListViewItem *ListViewSection::owner() const
 {
     return m_pOwner;
 }
 
 void ListView::applyModelChanges(QAbstractItemModel* m)
 {
     // Delete the sections
     while(auto sec = d_ptr->m_pFirstSection)
         delete sec;
 
     d_ptr->m_pFirstSection = nullptr;
 }
 
 #include <listview.moc>