changed my mind, gonna implement the feed on qt instead of qml, first tries, nothing working yet

ui/utils/feedview.cpp

@@ -0,0 +1,125 @@
+/*
+ * Squawk messenger. 
+ * Copyright (C) 2019  Yury Gubich <blue@macaw.me>
+ * 
+ * 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 "feedview.h"
+
+#include <QPaintEvent>
+#include <QPainter>
+#include <QDebug>
+
+FeedView::FeedView(QWidget* parent):
+    QAbstractItemView(parent),
+    hints()
+{
+
+}
+
+FeedView::~FeedView()
+{
+}
+
+QModelIndex FeedView::indexAt(const QPoint& point) const
+{
+    return QModelIndex();
+}
+
+void FeedView::scrollTo(const QModelIndex& index, QAbstractItemView::ScrollHint hint)
+{
+}
+
+QRect FeedView::visualRect(const QModelIndex& index) const
+{
+    if (!index.isValid() || index.row() >= hints.size()) {
+        return QRect();
+    } else {
+        const Hint& hint = hints.at(index.row());
+        const QWidget* vp = viewport();
+        return QRect(0, vp->height() - hint.height - hint.offset, vp->width(), hint.height);
+    }
+}
+
+int FeedView::horizontalOffset() const
+{
+    return 0;
+}
+
+bool FeedView::isIndexHidden(const QModelIndex& index) const
+{
+    return true;
+}
+
+QModelIndex FeedView::moveCursor(QAbstractItemView::CursorAction cursorAction, Qt::KeyboardModifiers modifiers)
+{
+    return QModelIndex();
+}
+
+void FeedView::setSelection(const QRect& rect, QItemSelectionModel::SelectionFlags command)
+{
+}
+
+int FeedView::verticalOffset() const
+{
+    return 0;
+}
+
+QRegion FeedView::visualRegionForSelection(const QItemSelection& selection) const
+{
+    return QRegion();
+}
+
+void FeedView::rowsInserted(const QModelIndex& parent, int start, int end)
+{
+    scheduleDelayedItemsLayout();
+    QAbstractItemView::rowsInserted(parent, start, end);
+}
+
+void FeedView::updateGeometries()
+{
+    qDebug() << "updateGeometries";
+    QAbstractItemView::updateGeometries();
+    const QAbstractItemModel* m = model();
+    QStyleOptionViewItem option = viewOptions();
+    uint32_t previousOffset = 0;
+    
+    hints.clear();
+    for (int i = 0, size = m->rowCount(); i < size; ++i) {
+        QModelIndex index = m->index(i, 0, QModelIndex());
+        int height = itemDelegate(index)->sizeHint(option, index).height();
+        hints.emplace_back(Hint({
+            false,
+            previousOffset,
+            static_cast<uint32_t>(height)
+        }));
+        previousOffset += height;
+    }
+}
+
+void FeedView::paintEvent(QPaintEvent* event)
+{
+    qDebug() << "paint";
+    const QAbstractItemModel* m = model();
+    QRect zone = event->rect().translated(horizontalOffset(), -verticalOffset());
+    QPainter painter(viewport());
+    QStyleOptionViewItem option = viewOptions();
+    
+    for (int i = 0, size = m->rowCount(); i < size; ++i) {
+        QModelIndex index = m->index(i, 0, QModelIndex());
+        option.rect = visualRect(index);
+        itemDelegate(index)->paint(&painter, option, index);
+    }
+}

ui/utils/feedview.h

@@ -0,0 +1,65 @@
+/*
+ * Squawk messenger. 
+ * Copyright (C) 2019  Yury Gubich <blue@macaw.me>
+ * 
+ * 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/>.
+ */
+
+#ifndef FEEDVIEW_H
+#define FEEDVIEW_H
+
+#include <QAbstractItemView>
+
+#include <deque>
+
+#include <ui/models/messagefeed.h>
+
+/**
+ * @todo write docs
+ */
+class FeedView : public QAbstractItemView
+{
+    Q_OBJECT
+public:
+    FeedView(QWidget* parent = nullptr);
+    ~FeedView();
+    
+    QModelIndex indexAt(const QPoint & point) const override;
+    void scrollTo(const QModelIndex & index, QAbstractItemView::ScrollHint hint) override;
+    QRect visualRect(const QModelIndex & index) const override;
+    bool isIndexHidden(const QModelIndex & index) const override;
+    QModelIndex moveCursor(QAbstractItemView::CursorAction cursorAction, Qt::KeyboardModifiers modifiers) override;
+    void setSelection(const QRect & rect, QItemSelectionModel::SelectionFlags command) override;
+    QRegion visualRegionForSelection(const QItemSelection & selection) const override;
+    
+protected slots:
+    void rowsInserted(const QModelIndex & parent, int start, int end) override;
+    
+protected:
+    int verticalOffset() const override;
+    int horizontalOffset() const override;
+    void paintEvent(QPaintEvent * event) override;
+    void updateGeometries() override;
+    
+private:
+    struct Hint {
+        bool dirty;
+        uint32_t offset;
+        uint32_t height;
+    };
+    std::deque<Hint> hints;
+    
+};
+
+#endif //FEEDVIEW_H