A result model

The result model drives the data retrieval and provides the interace
for consumers

1 files changed, 180 insertions, 0 deletions

diff --git a/common/modelresult.h b/common/modelresult.h
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+/*
+ * Copyright (C) 2014 Christian Mollekopf <chrigi_1@fastmail.fm>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) version 3, or any
+ * later version accepted by the membership of KDE e.V. (or its
+ * successor approved by the membership of KDE e.V.), which shall
+ * act as a proxy defined in Section 6 of version 3 of the license.
+ *
+ * This library 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+
+#include <QAbstractItemModel>
+#include <QModelIndex>
+#include <QDebug>
+#include "query.h"
+#include "clientapi.h"
+
+#include "resultprovider.h"
+
+template<class T>
+class ModelResult : public QAbstractItemModel
+{
+public:
+
+    enum Roles {
+        DomainObjectRole = Qt::UserRole + 1
+    };
+
+    ModelResult(const Akonadi2::Query &query, const QList<QByteArray> &propertyColumns)
+        :QAbstractItemModel(),
+        mPropertyColumns(propertyColumns)
+    {
+    }
+
+    static qint64 getIdentifier(const QModelIndex &idx)
+    {
+        if (!idx.isValid()) {
+            return 0;
+        }
+        return idx.internalId();
+    }
+
+    int rowCount(const QModelIndex &parent = QModelIndex()) const
+    {
+        return mTree[getIdentifier(parent)].size();
+    }
+
+    int columnCount(const QModelIndex &parent = QModelIndex()) const
+    {
+        return mPropertyColumns.size();
+    }
+
+    virtual QVariant data(const QModelIndex &index, int role = Qt::DisplayRole) const
+    {
+        if (role == DomainObjectRole) {
+            qWarning() << "trying to get entity " << index.internalId();
+            Q_ASSERT(mEntities.contains(index.internalId()));
+            return QVariant::fromValue(mEntities.value(index.internalId()));
+        }
+        qDebug() << "Invalid role";
+        return QVariant();
+    }
+
+    QModelIndex index(int row, int column, const QModelIndex & parent = QModelIndex()) const
+    {
+        auto id = getIdentifier(parent);
+        auto childId = mTree.value(id).at(row);
+        return createIndex(row, column, childId);
+    }
+
+    QModelIndex parent(const QModelIndex &index) const
+    {
+        auto id = getIdentifier(index);
+        auto parentId = mParents.value(id);
+        auto grandParentId = mParents.value(parentId, 0);
+        auto row = mTree.value(grandParentId).indexOf(parentId);
+        return createIndex(row, 0, parentId);
+    }
+
+    bool canFetchMore(const QModelIndex &parent) const
+    {
+        return mEntityChildrenFetched.value(parent.internalId());
+    }
+
+    void fetchMore(const QModelIndex &parent)
+    {
+        fetchEntities(parent);
+    }
+
+    void fetchEntities(const QModelIndex &parent)
+    {
+        qDebug() << "Fetching entities";
+        const auto id = getIdentifier(parent);
+        // beginResetModel();
+        // mEntities.remove(id);
+        mEntityChildrenFetched[id] = true;
+        auto query = mQuery;
+        if (!parent.isValid()) {
+            qDebug() << "no parent";
+            query.propertyFilter.insert("parent", QByteArray());
+        } else {
+            qDebug() << "parent is valid";
+            auto object = parent.data(DomainObjectRole).template value<typename T::Ptr>();
+            Q_ASSERT(object);
+            query.propertyFilter.insert("parent", object->identifier());
+        }
+        auto emitter = Akonadi2::Store::load<T>(query);
+        emitter->onAdded([this, id, parent](const typename T::Ptr &value) {
+            auto childId = qHash(value->identifier());
+            qDebug() << "Added entity " << childId;
+            const auto keys = mTree[id];
+            int index = 0;
+            for (; index < keys.size(); index++) {
+                if (childId < keys.at(index)) {
+                    break;
+                }
+            }
+            beginInsertRows(parent, index, index);
+            mEntities.insert(childId, value);
+            mTree[id].insert(index, childId);
+            mParents.insert(childId, id);
+            endInsertRows();
+        });
+        emitter->onModified([this, id, parent](const typename T::Ptr &value) {
+            auto childId = qHash(value->identifier());
+            qDebug() << "Modified entity" << childId;
+            auto i = mTree[id].indexOf(childId);
+            mEntities.remove(childId);
+            mEntities.insert(childId, value);
+            //TODO check for change of parents
+            auto idx = index(i, 0, parent);
+            emit dataChanged(idx, idx);
+        });
+        emitter->onRemoved([this, id, parent](const typename T::Ptr &value) {
+            auto childId = qHash(value->identifier());
+            qDebug() << "Removed entity" << childId;
+            auto index = mTree[id].indexOf(qHash(value->identifier()));
+            beginRemoveRows(parent, index, index);
+            mEntities.remove(childId);
+            mTree[id].removeAll(childId);
+            mParents.remove(childId);
+            //TODO remove children
+            endRemoveRows();
+        });
+        emitter->onInitialResultSetComplete([this]() {
+        });
+        emitter->onComplete([this, id]() {
+            mEmitter[id].clear();
+        });
+        emitter->onClear([this]() {
+            // beginResetModel();
+            // mEntities.clear();
+            // endResetModel();
+        });
+        mEmitter.insert(id, emitter);
+        // endResetModel();
+    }
+
+private:
+    QMap<qint64 /* parent entity id */, QSharedPointer<Akonadi2::ResultEmitter<typename T::Ptr> >> mEmitter;
+    //TODO we should be able to directly use T as index, with an appropriate hash function, and thus have a QMap<T, T> and QList<T>
+    QMap<qint64 /* entity id */, typename T::Ptr> mEntities;
+    QMap<qint64 /* parent entity id */, QList<qint64> /* child entity id*/> mTree;
+    QMap<qint64 /* child entity id */, qint64 /* parent entity id*/> mParents;
+    QMap<qint64 /* entity id */, bool> mEntityChildrenFetched;
+    QList<QByteArray> mPropertyColumns;
+    Akonadi2::Query mQuery;
+};
+