6 files changed, 1113 insertions, 0 deletions
diff --git a/Swift/QtUI/Trellis/QtDNDTabBar.cpp b/Swift/QtUI/Trellis/QtDNDTabBar.cpp
new file mode 100644
index 0000000..3ae2124
--- /dev/null
+++ b/Swift/QtUI/Trellis/QtDNDTabBar.cpp
@@ -0,0 +1,164 @@
+/*
+ * Copyright (c) 2014-2017 Isode Limited.
+ * All rights reserved.
+ * See the COPYING file for more information.
+ */
+
+#include <Swift/QtUI/Trellis/QtDNDTabBar.h>
+
+#include <cassert>
+
+#include <QDrag>
+#include <QDropEvent>
+#include <QMimeData>
+#include <QMouseEvent>
+#include <QPainter>
+#include <QTabWidget>
+
+namespace Swift {
+
+QtDNDTabBar::QtDNDTabBar(QWidget* parent) : QTabBar(parent) {
+    setAcceptDrops(true);
+
+    // detect the default tab bar height;
+    insertTab(0, "");
+    defaultTabHeight = QTabBar::sizeHint().height();
+    removeTab(0);
+}
+
+QtDNDTabBar::~QtDNDTabBar() {
+
+}
+
+int QtDNDTabBar::getDragIndex() const {
+    return dragIndex;
+}
+
+QString QtDNDTabBar::getDragText() const {
+    return dragText;
+}
+
+QWidget* QtDNDTabBar::getDragWidget() const {
+    return dragWidget;
+}
+
+QSize QtDNDTabBar::sizeHint() const {
+    QSize hint = QTabBar::sizeHint();
+    if (hint.isEmpty()) {
+        hint = QSize(parentWidget()->width(), defaultTabHeight);
+    }
+    return hint;
+}
+
+QSize QtDNDTabBar::tabSizeHint(int index) const {
+    QSize tabSize = QTabBar::tabSizeHint(index);
+#if defined(Q_OS_MAC)
+    // With multiple tabs having the same label in a QTabBar, the size hint computed by
+    // Qt on OS X is too small and it is elided even though there is enough horizontal
+    // space available. We work around this issue by adding the width of a letter to the
+    // size hint.
+    tabSize += QSize(QFontMetrics(font()).width("I"), 0);
+#endif
+    return tabSize;
+}
+
+void QtDNDTabBar::dragEnterEvent(QDragEnterEvent* dragEnterEvent) {
+    QtDNDTabBar* sourceTabBar = dynamic_cast<QtDNDTabBar*>(dragEnterEvent->source());
+    if (sourceTabBar) {
+        dragEnterEvent->acceptProposedAction();
+    }
+}
+
+void QtDNDTabBar::dropEvent(QDropEvent* dropEvent) {
+    auto sourceTabBar = dynamic_cast<QtDNDTabBar*>(dropEvent->source());
+    if (sourceTabBar && dropEvent->mimeData() && dropEvent->mimeData()->data("action") == QByteArray("application/tab-detach")) {
+        int targetTabIndex = tabAt(dropEvent->pos());
+        QRect rect = tabRect(targetTabIndex);
+        if (targetTabIndex >= 0 && (dropEvent->pos().x() - rect.left() - rect.width()/2 > 0)) {
+            targetTabIndex++;
+        }
+
+        QWidget* tab = sourceTabBar->getDragWidget();
+        assert(tab);
+        QTabWidget* targetTabWidget = dynamic_cast<QTabWidget*>(parentWidget());
+
+        QString tabText = sourceTabBar->getDragText();
+
+        /*
+         * When you add a widget to an empty QTabWidget, it's automatically made the current widget.
+         * Making the widget the current widget, widget->show() is called for the widget. Directly reacting
+         * to that event, and adding the widget again to the QTabWidget results in undefined behavior. For
+         * example the tab label is shown but the widget is neither has the old nor in the new QTabWidget as
+         * parent. Blocking signals on the QWidget to be added to a QTabWidget prevents this behavior.
+         */
+        targetTabWidget->setUpdatesEnabled(false);
+        tab->blockSignals(true);
+        targetTabWidget->insertTab(targetTabIndex, tab, tabText);
+        dropEvent->acceptProposedAction();
+        tab->blockSignals(false);
+        targetTabWidget->setUpdatesEnabled(true);
+        onDropSucceeded();
+    }
+}
+
+bool QtDNDTabBar::event(QEvent* event) {
+    QMouseEvent* mouseEvent = dynamic_cast<QMouseEvent*>(event);
+    if (mouseEvent) {
+        QWidget* childAtPoint = window()->childAt(mapTo(window(), mouseEvent->pos()));
+        QtDNDTabBar* underMouse = dynamic_cast<QtDNDTabBar*>(childAtPoint);
+        if (!underMouse && childAtPoint) {
+            underMouse = dynamic_cast<QtDNDTabBar*>(childAtPoint->parent());
+        }
+        if (!underMouse && currentIndex() >= 0) {
+            // detach and drag
+
+            // stop move event
+            QMouseEvent* finishMoveEvent = new QMouseEvent (QEvent::MouseMove, mouseEvent->pos (), Qt::NoButton, Qt::NoButton, Qt::NoModifier);
+            QTabBar::event(finishMoveEvent);
+            delete finishMoveEvent;
+            finishMoveEvent = nullptr;
+
+            // start drag
+            QDrag* drag = new QDrag(this);
+            QMimeData* mimeData = new QMimeData;
+
+            // distinguish tab-reordering drops from other ones
+            mimeData->setData("action", "application/tab-detach") ;
+            drag->setMimeData(mimeData);
+
+            // set drag image
+            QRect rect = tabRect( currentIndex() );
+#if QT_VERSION >= 0x050000
+            QPixmap pixmap = grab(rect);
+#else
+            QPixmap pixmap = QPixmap::grabWidget(this, rect);
+#endif
+            QPixmap targetPixmap (pixmap.size ());
+            QPainter painter (&targetPixmap);
+            painter.setOpacity(0.9);
+            painter.drawPixmap(0,0, pixmap);
+            painter.end ();
+            drag->setPixmap (targetPixmap);
+
+            drag->setHotSpot(QPoint(drag->pixmap().width()/2, drag->pixmap().height()));
+
+            dragIndex = currentIndex();
+            dragText = tabText(dragIndex);
+            dragWidget = dynamic_cast<QTabWidget*>(parent())->widget(dragIndex);
+            assert(dragWidget);
+            dynamic_cast<QTabWidget*>(parent())->removeTab(currentIndex());
+            Qt::DropAction dropAction = drag->exec();
+            if (dropAction == Qt::IgnoreAction) {
+                // aborted drag, put tab back in place
+                // disable event handling during the insert for the tab to prevent infinite recursion (stack overflow)
+                dragWidget->blockSignals(true);
+                dynamic_cast<QTabWidget*>(parent())->insertTab(dragIndex, dragWidget, dragText);
+                dragWidget->blockSignals(false);
+            }
+            return true;
+        }
+    }
+    return QTabBar::event(event);
+}
+
+}
diff --git a/Swift/QtUI/Trellis/QtDNDTabBar.h b/Swift/QtUI/Trellis/QtDNDTabBar.h
new file mode 100644
index 0000000..6de04d5
--- /dev/null
+++ b/Swift/QtUI/Trellis/QtDNDTabBar.h
@@ -0,0 +1,44 @@
+/*
+ * Copyright (c) 2014-2016 Isode Limited.
+ * All rights reserved.
+ * See the COPYING file for more information.
+ */
+
+#pragma once
+
+#include <QTabBar>
+
+#include <Swift/QtUI/QtTabWidget.h>
+
+namespace Swift {
+
+class QtDNDTabBar : public QTabBar {
+    Q_OBJECT
+    public:
+        explicit QtDNDTabBar(QWidget* parent = nullptr);
+        virtual ~QtDNDTabBar();
+
+        int getDragIndex() const;
+        QString getDragText() const;
+        QWidget* getDragWidget() const;
+
+        virtual QSize sizeHint() const;
+
+        friend class QtTabWidget;
+    signals:
+        void onDropSucceeded();
+
+    protected:
+        virtual void dragEnterEvent(QDragEnterEvent* dragEnterEvent);
+        virtual void dropEvent(QDropEvent* dropEvent);
+        virtual bool event(QEvent* event);
+        virtual QSize tabSizeHint(int index) const;
+
+    private:
+        int defaultTabHeight;
+        int dragIndex = -1;
+        QString dragText;
+        QWidget* dragWidget = nullptr;
+};
+
+}
diff --git a/Swift/QtUI/Trellis/QtDynamicGridLayout.cpp b/Swift/QtUI/Trellis/QtDynamicGridLayout.cpp
new file mode 100644
index 0000000..53e2733
--- /dev/null
+++ b/Swift/QtUI/Trellis/QtDynamicGridLayout.cpp
@@ -0,0 +1,561 @@
+/*
+ * Copyright (c) 2014-2019 Isode Limited.
+ * All rights reserved.
+ * See the COPYING file for more information.
+ */
+
+#include <Swift/QtUI/Trellis/QtDynamicGridLayout.h>
+
+#include <cassert>
+
+#include <QApplication>
+#include <QEvent>
+#include <QGridLayout>
+#include <QLayoutItem>
+#include <QtDebug>
+
+#include <Swiften/Base/Log.h>
+
+#include <Swift/QtUI/QtSwiftUtil.h>
+#include <Swift/QtUI/QtTabWidget.h>
+#include <Swift/QtUI/QtTabbable.h>
+#include <Swift/QtUI/Trellis/QtDNDTabBar.h>
+
+namespace Swift {
+
+QtDynamicGridLayout::QtDynamicGridLayout(bool future, QWidget* parent, bool enableDND) : QWidget(parent), dndEnabled_(enableDND), movingTab_(nullptr), future_(future) {
+    gridLayout_ = new QGridLayout(this);
+    setContentsMargins(0,0,0,0);
+    setDimensions(QSize(1,1));
+    connect(qApp, SIGNAL(focusChanged(QWidget*, QWidget*)), this, SLOT(handleApplicationFocusChanged(QWidget*,QWidget*)));
+}
+
+QtDynamicGridLayout::~QtDynamicGridLayout() {
+}
+
+int QtDynamicGridLayout::addTab(QtTabbable* tab, const QString& title) {
+    assert(gridLayout_->rowCount() > 0 && gridLayout_->columnCount() > 0);
+
+    QPoint lastPos(0,0);
+    if (tabPositions_.contains(P2QSTRING(tab->getID()))) {
+        lastPos = tabPositions_[P2QSTRING(tab->getID())];
+    }
+
+    lastPos = QPoint(qMin(lastPos.x(), gridLayout_->columnCount() - 1), qMin(lastPos.y(), gridLayout_->rowCount() - 1));
+
+    QLayoutItem* item = gridLayout_->itemAtPosition(lastPos.y(), lastPos.x());
+    QtTabWidget* tabWidget = dynamic_cast<QtTabWidget*>(item ? item->widget() : nullptr);
+    if (tabWidget) {
+        tabWidget->addTab(tab, title);
+    }
+    tab->setEmphasiseFocus(getDimension().width() > 1 || getDimension().height() > 1);
+    if (future_) {
+        showHideFirstTabs(); // FIXME: Putting it here as a workaround until I work out why it doesn't work initially
+    }
+    return tabWidget ? indexOf(tab) : -1;
+}
+
+int QtDynamicGridLayout::count() const {
+    int count = 0;
+    for (int y = 0; y < gridLayout_->rowCount(); y++) {
+        for (int x = 0; x < gridLayout_->columnCount(); x++) {
+            QLayoutItem* layoutItem = gridLayout_->itemAtPosition(y, x);
+            QtTabWidget* tabWidget = dynamic_cast<QtTabWidget*>(layoutItem->widget());
+            if (tabWidget) {
+                count += tabWidget->count();
+            }
+        }
+    }
+    return count;
+}
+
+QWidget* QtDynamicGridLayout::widget(int index) const {
+    QWidget* widgetAtIndex = nullptr;
+    for (int y = 0; y < gridLayout_->rowCount(); y++) {
+        for (int x = 0; x < gridLayout_->columnCount(); x++) {
+            QLayoutItem* layoutItem = gridLayout_->itemAtPosition(y, x);
+            QtTabWidget* tabWidget = dynamic_cast<QtTabWidget*>(layoutItem ? layoutItem->widget() : nullptr);
+            if (tabWidget) {
+                if (index < tabWidget->count()) {
+                    widgetAtIndex = tabWidget->widget(index);
+                    return widgetAtIndex;
+                }
+                else {
+                    index -= tabWidget->count();
+                }
+            }
+        }
+    }
+    return widgetAtIndex;
+}
+
+int QtDynamicGridLayout::indexOf(const QWidget* widget) const {
+    int index = 0;
+    if (widget) {
+        for (int y = 0; y < gridLayout_->rowCount(); y++) {
+            for (int x = 0; x < gridLayout_->columnCount(); x++) {
+                QLayoutItem* layoutItem = gridLayout_->itemAtPosition(y, x);
+                QtTabWidget* tabWidget = dynamic_cast<QtTabWidget*>(layoutItem->widget());
+                if (tabWidget) {
+                    for (int n = 0; n < tabWidget->count(); n++) {
+                        QWidget* nthWidget = tabWidget->widget(n);
+                        if (nthWidget == widget) {
+                            return index;
+                        }
+                        index++;
+                    }
+                }
+            }
+        }
+    }
+    return -1;
+}
+
+void QtDynamicGridLayout::handleApplicationFocusChanged(QWidget*, QWidget* newFocus) {
+    if (movingTab_ || resizing_) {
+        return;
+    }
+
+    if (newFocus) {
+        if (isAncestorOf(newFocus)) {
+            QtTabbable *newTab = dynamic_cast<QtTabbable*>(newFocus->parentWidget());
+            if (newTab) {
+                onCurrentIndexChanged(currentIndex());
+            }
+        }
+    }
+}
+
+int QtDynamicGridLayout::currentIndex() const {
+    return indexOf(currentWidget());
+}
+
+void QtDynamicGridLayout::setCurrentIndex(int index) {
+    int tabIndex = -1;
+    QtTabWidget* tabWidget = indexToTabWidget(index, tabIndex);
+    if (tabIndex >= 0) {
+        tabWidget->setCurrentIndex(tabIndex);
+        if (!tabWidget->hasFocus()) {
+            tabWidget->widget(tabIndex)->setFocus(Qt::TabFocusReason);
+        }
+    } else {
+        assert(false);
+    }
+}
+
+void QtDynamicGridLayout::removeTab(int index) {
+    int tabIndex = -1;
+    QtTabWidget* tabWidget = indexToTabWidget(index, tabIndex);
+    if (tabWidget) {
+        QWidget* tab = tabWidget->widget(tabIndex);
+        tabWidget->removeTab(tabIndex);
+        tab->setParent(nullptr);
+    }
+}
+
+/**
+ * This event filter serves the purpose of filtering out all QEvent::Show events targeted at
+ * all widgets excepts the currently moving widget.
+ * It is required because of the way Qt internally implements the QTabBar::moveTab method.
+ * It does not move the actual tab in the underlying structure, but instead removes it from
+ * a stacked layout and later adds it again.
+ * Both the remove and insert produce a lot signal emission and focus changes. Most of which
+ * the application MUST NOT react on because of the QTabBar and the corresponding QTabWidget
+ * being out of sync in an inconsistent state.
+ */
+bool QtDynamicGridLayout::eventFilter(QObject* object, QEvent* event) {
+    QtTabbable* tab = qobject_cast<QtTabbable*>(object);
+    if (!tab) {
+        return false;
+    }
+    if (tab && (tab != movingTab_)) {
+        if (event->type() == QEvent::Show) {
+            return true;
+        }
+    }
+    return false;
+}
+
+QWidget* QtDynamicGridLayout::currentWidget() const {
+    QWidget* current = nullptr;
+    current = focusWidget();
+    while (current && !dynamic_cast<QtTabbable*>(current)) {
+        if (current->parentWidget()) {
+            current = current->parentWidget();
+        } else {
+            current = nullptr;
+            break;
+        }
+    }
+    if (!current) {
+        current = widget(0);
+    }
+    return current;
+}
+
+void QtDynamicGridLayout::setCurrentWidget(QWidget* widget) {
+    if (widget) {
+        for (int y = 0; y < gridLayout_->rowCount(); y++) {
+            for (int x = 0; x < gridLayout_->columnCount(); x++) {
+                QLayoutItem* layoutItem = gridLayout_->itemAtPosition(y, x);
+                QtTabWidget* tabWidget = dynamic_cast<QtTabWidget*>(layoutItem->widget());
+                if (tabWidget) {
+                    for (int n = 0; n < tabWidget->count(); n++) {
+                        if (tabWidget->widget(n) == widget) {
+                            tabWidget->setCurrentWidget(widget);
+                        }
+                    }
+                }
+            }
+        }
+    }
+}
+
+QtTabWidget* QtDynamicGridLayout::indexToTabWidget(int index, int& tabIndex) {
+    for (int y = 0; y < gridLayout_->rowCount(); y++) {
+        for (int x = 0; x < gridLayout_->columnCount(); x++) {
+            QLayoutItem* layoutItem = gridLayout_->itemAtPosition(y, x);
+            QtTabWidget* tabWidget = dynamic_cast<QtTabWidget*>(layoutItem->widget());
+            if (tabWidget) {
+                if (index < tabWidget->count()) {
+                    tabIndex = index;
+                    return tabWidget;
+                }
+                else {
+                    index -= tabWidget->count();
+                    if (index < 0) {
+                        qWarning() << "Called QtDynamicGridLayout::setCurrentIndex with index out of bounds: index = " << index;
+                        tabIndex = -1;
+                        return nullptr;
+                    }
+                }
+            }
+        }
+    }
+    tabIndex = -1;
+    return nullptr;
+}
+
+bool QtDynamicGridLayout::isDNDEnabled() const {
+    return dndEnabled_;
+}
+
+QHash<QString, QPoint> QtDynamicGridLayout::getTabPositions() const {
+    return tabPositions_;
+}
+
+void QtDynamicGridLayout::setTabPositions(const QHash<QString, QPoint> positions) {
+    tabPositions_ = positions;
+}
+
+QSize QtDynamicGridLayout::getDimension() const {
+    return QSize(gridLayout_->columnCount(), gridLayout_->rowCount());
+}
+
+void QtDynamicGridLayout::setDimensions(const QSize& dim) {
+    resizing_ = true;
+    assert(dim.width() > 0 && dim.height() > 0);
+    setUpdatesEnabled(false);
+
+    QWidget* restoredWidget = currentWidget();
+
+    QGridLayout* oldLayout = dynamic_cast<QGridLayout*>(layout());
+    QGridLayout* newLayout = new QGridLayout(this);
+    newLayout->setSpacing(4);
+    newLayout->setContentsMargins(0,0,0,0);
+
+    int oldWidth = oldLayout->columnCount();
+    int oldHeight = oldLayout->rowCount();
+    int maxCol = qMax(oldWidth, dim.width());
+    int minCol = qMin(oldWidth, dim.width());
+    int maxRow = qMax(oldHeight, dim.height());
+    int minRow = qMin(oldHeight, dim.height());
+
+    for (int row = 0; row < maxRow; row++) {
+        for (int col = 0; col < maxCol; col++) {
+            QLayoutItem* oldItem = oldLayout->itemAtPosition(row, col);
+            QLayoutItem* newItem = newLayout->itemAtPosition(row, col);
+            bool removeRow = !(row < dim.height());
+            bool removeCol = !(col < dim.width());
+
+            if (removeCol || removeRow) {
+                if (oldItem) {
+                    int squeezeRow = removeRow ? (minRow - 1) : row;
+                    int squeezeCol = removeCol ? (minCol - 1) : col;
+                    newItem = newLayout->itemAtPosition(squeezeRow, squeezeCol);
+                    if (!newItem) {
+                        newLayout->addWidget(createDNDTabWidget(this), squeezeRow, squeezeCol);
+                        newItem = newLayout->itemAtPosition(squeezeRow, squeezeCol);
+                    }
+                    QtTabWidget* oldTabWidget = dynamic_cast<QtTabWidget*>(oldItem->widget());
+                    QtTabWidget* newTabWidget = dynamic_cast<QtTabWidget*>(newItem->widget());
+                    assert(oldTabWidget && newTabWidget);
+
+                    oldTabWidget->hide();
+                    while(oldTabWidget->count()) {
+                        QIcon icon = oldTabWidget->tabIcon(0);
+                        QString text = oldTabWidget->tabText(0);
+                        QWidget* movingTab = oldTabWidget->widget(0);
+                        //If handling was allowed, QtChatTabs::handleWidgetShown() would be triggered when newTabWidget has no tabs.
+                        //That would access indices of the gridLayout_ that are null because they have been migrated to the newLayout.
+                        movingTab->blockSignals(true);
+                        newTabWidget->addTab(movingTab, icon, text);
+                        movingTab->blockSignals(false);
+                    }
+                    delete oldTabWidget;
+                }
+            } else {
+                if (oldItem) {
+                    newLayout->addWidget(oldItem->widget(), row, col);
+                    newItem = newLayout->itemAtPosition(row, col);
+                } else {
+                    newLayout->addWidget(createDNDTabWidget(this), row, col);
+                }
+            }
+        }
+    }
+
+    for (int col = 0; col < dim.width(); col++) {
+        newLayout->setColumnStretch(col, 1);
+    }
+    for (int row = 0; row < dim.height(); row++) {
+        newLayout->setRowStretch(row, 1);
+    }
+
+    setUpdatesEnabled(true);
+    delete layout();
+    setLayout(newLayout);
+    gridLayout_ = newLayout;
+
+    resizing_ = false;
+    setCurrentWidget(restoredWidget);
+
+    updateEmphasiseFocusOnTabs();
+
+    if (future_) {
+        showHideFirstTabs();
+    }
+}
+
+void QtDynamicGridLayout::showHideFirstTabs() {
+    int tmp;
+    auto firstTabs = indexToTabWidget(0, tmp);
+
+    if (firstTabs) {
+        if (gridLayout_->columnCount() == 1 && gridLayout_->rowCount() == 1) {
+            firstTabs->tabBar()->hide();
+        }
+        else {
+            firstTabs->tabBar()->show();
+        }
+    }
+}
+
+void QtDynamicGridLayout::updateEmphasiseFocusOnTabs() {
+    const auto currentDimensions = getDimension();
+
+    for (int y = 0; y < gridLayout_->rowCount(); y++) {
+        for (int x = 0; x < gridLayout_->columnCount(); x++) {
+            QLayoutItem* layoutItem = gridLayout_->itemAtPosition(y, x);
+            QtTabWidget* tabWidget = dynamic_cast<QtTabWidget*>(layoutItem->widget());
+            assert(tabWidget);
+            for (int index = 0; index < tabWidget->count(); index++) {
+                QtTabbable* tab = dynamic_cast<QtTabbable*>(tabWidget->widget(index));
+                assert(tab);
+                tab->setEmphasiseFocus(currentDimensions.height() > 1 || currentDimensions.width() > 1);
+            }
+        }
+    }
+}
+
+void QtDynamicGridLayout::moveCurrentTabRight() {
+    int index = currentIndex();
+    if (index >= 0) {
+        int tabIndex = -1;
+        QtTabWidget* tabWidget = indexToTabWidget(index, tabIndex);
+        assert(tabWidget);
+        int newTabIndex = (tabIndex + 1) % tabWidget->count();
+        moveTab(tabWidget, tabIndex, newTabIndex);
+    }
+}
+
+void QtDynamicGridLayout::moveCurrentTabLeft() {
+    int index = currentIndex();
+    if (index >= 0) {
+        int tabIndex = -1;
+        QtTabWidget* tabWidget = indexToTabWidget(index, tabIndex);
+        assert(tabWidget);
+        int newTabIndex = (tabWidget->count() + tabIndex - 1) % tabWidget->count();
+        moveTab(tabWidget, tabIndex, newTabIndex);
+    }
+}
+
+void QtDynamicGridLayout::moveCurrentTabToNextGroup() {
+    int index = currentIndex();
+    if (index >= 0) {
+        int tabIndex = -1;
+        QtTabWidget* tabWidget = indexToTabWidget(index, tabIndex);
+
+        int row = -1;
+        int col = -1;
+        int tmp;
+        gridLayout_->getItemPosition(gridLayout_->indexOf(tabWidget), &row, &col, &tmp, &tmp);
+
+        // calculate next cell
+        col++;
+        if (!(col < gridLayout_->columnCount())) {
+            col = 0;
+            row++;
+            if (!(row < gridLayout_->rowCount())) {
+                row = 0;
+            }
+        }
+
+        QtTabWidget* targetTabWidget = dynamic_cast<QtTabWidget*>(gridLayout_->itemAtPosition(row, col)->widget());
+        assert(tabWidget);
+        assert(targetTabWidget);
+
+        // fetch tab information
+        QWidget* tab = tabWidget->widget(tabIndex);
+        QString tabText = tabWidget->tabText(tabIndex);
+
+        // move tab
+        tab->blockSignals(true);
+        targetTabWidget->addTab(tab, tabText);
+        tab->blockSignals(false);
+        tab->setFocus(Qt::TabFocusReason);
+
+        updateTabPositions();
+    }
+}
+
+void QtDynamicGridLayout::moveCurrentTabToPreviousGroup() {
+    int index = currentIndex();
+    if (index >= 0) {
+        int tabIndex = -1;
+        QtTabWidget* tabWidget = indexToTabWidget(index, tabIndex);
+
+        int row = -1;
+        int col = -1;
+        int tmp;
+        gridLayout_->getItemPosition(gridLayout_->indexOf(tabWidget), &row, &col, &tmp, &tmp);
+
+        // calculate next cell
+        col--;
+        if (col < 0) {
+            col = gridLayout_->columnCount() - 1;
+            row--;
+            if (row < 0) {
+                row = gridLayout_->rowCount() - 1;
+            }
+        }
+
+        QtTabWidget* targetTabWidget = dynamic_cast<QtTabWidget*>(gridLayout_->itemAtPosition(row, col)->widget());
+        assert(tabWidget);
+        assert(targetTabWidget);
+
+        // fetch tab information
+        QWidget* tab = tabWidget->widget(tabIndex);
+        QString tabText = tabWidget->tabText(tabIndex);
+
+        // move tab
+        tab->blockSignals(true);
+        targetTabWidget->addTab(tab, tabText);
+        tab->blockSignals(false);
+        tab->setFocus(Qt::TabFocusReason);
+
+        updateTabPositions();
+    }
+}
+
+void QtDynamicGridLayout::handleTabCloseRequested(int index) {
+    updateTabPositions();
+    QtTabWidget* tabWidgetSender = dynamic_cast<QtTabWidget*>(sender());
+    for (int y = 0; y < gridLayout_->rowCount(); y++) {
+        for (int x = 0; x < gridLayout_->columnCount(); x++) {
+            QLayoutItem* layoutItem = gridLayout_->itemAtPosition(y, x);
+            QtTabWidget* tabWidget = dynamic_cast<QtTabWidget*>(layoutItem->widget());
+            if (tabWidget == tabWidgetSender) {
+                tabCloseRequested(index);
+            }
+            else {
+                index += tabWidget->count();
+            }
+        }
+    }
+}
+
+void QtDynamicGridLayout::handleTabCurrentChanged(int index) {
+    if (movingTab_) {
+        return;
+    }
+
+    if (index >= 0) {
+        QTabWidget* sendingTabWidget = dynamic_cast<QTabWidget*>(sender());
+        assert(sendingTabWidget);
+        sendingTabWidget->widget(index)->setFocus();
+    }
+}
+
+void QtDynamicGridLayout::updateTabPositions() {
+    for (int y = 0; y < gridLayout_->rowCount(); y++) {
+        for (int x = 0; x < gridLayout_->columnCount(); x++) {
+            QLayoutItem* layoutItem = gridLayout_->itemAtPosition(y, x);
+            QtTabWidget* tabWidget = dynamic_cast<QtTabWidget*>(layoutItem->widget());
+            assert(tabWidget);
+            for (int index = 0; index < tabWidget->count(); index++) {
+                QtTabbable* tab = dynamic_cast<QtTabbable*>(tabWidget->widget(index));
+                assert(tab);
+                tabPositions_.insert(P2QSTRING(tab->getID()), QPoint(x, y));
+            }
+        }
+    }
+}
+
+void QtDynamicGridLayout::moveTab(QtTabWidget* tabWidget, int oldIndex, int newIndex) {
+#if QT_VERSION >= 0x040500
+    SWIFT_LOG_ASSERT(movingTab_ == nullptr, error);
+    movingTab_ = qobject_cast<QtTabbable*>(tabWidget->widget(oldIndex));
+    SWIFT_LOG_ASSERT(movingTab_ != nullptr, error);
+
+    if (movingTab_) {
+        // Install event filter that filters out events issued during the internal movement of the
+        // tab but not targeted at the moving tab.
+        qApp->installEventFilter(this);
+
+        tabWidget->tabBar()->moveTab(oldIndex, newIndex);
+
+        qApp->removeEventFilter(this);
+        SWIFT_LOG_ASSERT(movingTab_ == tabWidget->widget(newIndex), error);
+    }
+    movingTab_ = nullptr;
+    tabWidget->widget(newIndex)->setFocus();
+#else
+#warning Qt 4.5 or later is needed. Trying anyway, some things will be disabled.
+#endif
+}
+
+QtTabWidget* QtDynamicGridLayout::createDNDTabWidget(QWidget* parent) {
+    QtTabWidget* tab = new QtTabWidget(parent);
+    if (dndEnabled_) {
+        QtDNDTabBar* tabBar = new QtDNDTabBar(tab);
+        connect(tabBar, SIGNAL(onDropSucceeded()), this, SLOT(updateTabPositions()));
+        tab->setTabBar(tabBar);
+    }
+    tab->setUsesScrollButtons(true);
+    tab->setElideMode(Qt::ElideRight);
+#if QT_VERSION >= 0x040500
+    /*For Macs, change the tab rendering.*/
+    tab->setDocumentMode(true);
+    /*Closable tabs are only in Qt4.5 and later*/
+    tab->setTabsClosable(true);
+    tab->setMovable(true);
+    connect(tab, SIGNAL(tabCloseRequested(int)), this, SLOT(handleTabCloseRequested(int)));
+    connect(tab, SIGNAL(currentChanged(int)), this, SLOT(handleTabCurrentChanged(int)));
+#else
+#warning Qt 4.5 or later is needed. Trying anyway, some things will be disabled.
+#endif
+    return tab;
+}
+
+}
diff --git a/Swift/QtUI/Trellis/QtDynamicGridLayout.h b/Swift/QtUI/Trellis/QtDynamicGridLayout.h
new file mode 100644
index 0000000..f3a2e96
--- /dev/null
+++ b/Swift/QtUI/Trellis/QtDynamicGridLayout.h
@@ -0,0 +1,84 @@
+/*
+ * Copyright (c) 2014-2016 Isode Limited.
+ * All rights reserved.
+ * See the COPYING file for more information.
+ */
+
+#pragma once
+
+#include <QGridLayout>
+#include <QHash>
+#include <QPoint>
+#include <QSize>
+#include <QString>
+#include <QWidget>
+
+namespace Swift {
+    class QtTabbable;
+    class QtTabWidget;
+
+    class QtDynamicGridLayout : public QWidget {
+        Q_OBJECT
+    public:
+        explicit QtDynamicGridLayout(bool future, QWidget* parent = nullptr, bool enableDND = false);
+        virtual ~QtDynamicGridLayout();
+
+        QSize getDimension() const;
+
+        // emulate QtTabWidget API
+        int addTab(QtTabbable* tab, const QString& title);
+        void removeTab(int index);
+        int count() const;
+
+        QWidget* widget(int index) const;
+        QWidget* currentWidget() const;
+        void setCurrentWidget(QWidget* widget);
+
+        QtTabWidget* indexToTabWidget(int index, int& tabIndex);
+
+        int indexOf(const QWidget* widget) const;
+        int currentIndex() const;
+        void setCurrentIndex(int index);
+
+        bool isDNDEnabled() const;
+
+        QHash<QString, QPoint> getTabPositions() const;
+        void setTabPositions(const QHash<QString, QPoint> positions);
+
+        bool eventFilter(QObject* object, QEvent* event);
+
+    signals:
+        void tabCloseRequested(int index);
+        void onCurrentIndexChanged(int newIndex);
+
+    public slots:
+        void setDimensions(const QSize& dim);
+
+        // Tab Management
+        void moveCurrentTabRight();
+        void moveCurrentTabLeft();
+        void moveCurrentTabToNextGroup();
+        void moveCurrentTabToPreviousGroup();
+
+        void updateTabPositions();
+
+    private slots:
+        void handleTabCloseRequested(int index);
+        void handleTabCurrentChanged(int index);
+        void handleApplicationFocusChanged(QWidget* oldFocus, QWidget* newFocus);
+
+    private:
+        void moveTab(QtTabWidget* tabWidget, int oldIndex, int newIndex);
+        QtTabWidget* createDNDTabWidget(QWidget* parent);
+        void updateEmphasiseFocusOnTabs();
+        void showHideFirstTabs();
+
+    private:
+        QGridLayout *gridLayout_;
+        bool dndEnabled_;
+        QHash<QString, QPoint> tabPositions_;
+        QtTabbable* movingTab_;
+        bool resizing_ = false;
+        bool future_ = false;
+    };
+}
diff --git a/Swift/QtUI/Trellis/QtGridSelectionDialog.cpp b/Swift/QtUI/Trellis/QtGridSelectionDialog.cpp
new file mode 100644
index 0000000..e922e07
--- /dev/null
+++ b/Swift/QtUI/Trellis/QtGridSelectionDialog.cpp
@@ -0,0 +1,194 @@
+/*
+ * Copyright (c) 2014-2018 Isode Limited.
+ * All rights reserved.
+ * See the COPYING file for more information.
+ */
+
+#include <Swift/QtUI/Trellis/QtGridSelectionDialog.h>
+
+#include <QApplication>
+#include <QCursor>
+#include <QPaintEvent>
+#include <QPainter>
+#include <QStyle>
+#include <QStyleOption>
+
+namespace Swift {
+
+QtGridSelectionDialog::QtGridSelectionDialog(QWidget* parent) : QWidget(parent), descriptionText(tr("Select the number of rows and columns for your layout. You can change the size by moving the mouse or cursor keys.")) {
+    frameSize = QSize(28,28) * 2;
+    maxGridSize = QSize(7,7);
+    minGridSize = QSize(1,1);
+    currentGridSize = QSize(1,1);
+    padding = 4;
+    setWindowFlags(Qt::FramelessWindowHint);
+    setCursor(Qt::SizeAllCursor);
+    horizontalMargin = style()->pixelMetric(QStyle::PM_LayoutLeftMargin);
+    verticalMargin = style()->pixelMetric(QStyle::PM_LayoutBottomMargin);
+}
+
+QSize QtGridSelectionDialog::sizeHint() const {
+    // PM_MenuVMargin | frameSize | ( padding | frameSize ) * | PM_MenuVMargin
+    int width = horizontalMargin + frameSize.width() + (padding + frameSize.width()) * (currentGridSize.width() - 1) + horizontalMargin;
+    int height = verticalMargin + frameSize.height() + (padding + frameSize.height()) * (currentGridSize.height() - 1) + verticalMargin;
+
+    height += getDescriptionTextHeight(width);
+
+    return QSize(width, height);
+}
+
+void QtGridSelectionDialog::setCurrentGridSize(const QSize& size) {
+    currentGridSize = size;
+    emit currentGridSizeChanged(size);
+}
+
+QSize QtGridSelectionDialog::getCurrentGridSize() const {
+    return currentGridSize;
+}
+
+void QtGridSelectionDialog::setMinGridSize(const QSize& size) {
+    minGridSize = size;
+    emit minGridSizeChanged(size);
+}
+
+QSize QtGridSelectionDialog::getMinGridSize() const {
+    return minGridSize;
+}
+
+void QtGridSelectionDialog::setMaxGridSize(const QSize& size) {
+    maxGridSize = size;
+    emit maxGridSizeChanged(size);
+}
+
+QSize QtGridSelectionDialog::getMaxGridSize() const {
+    return maxGridSize;
+}
+
+QSize QtGridSelectionDialog::getFrameSize() const {
+    return frameSize;
+}
+
+int QtGridSelectionDialog::getDescriptionTextHeight() const {
+    auto width = horizontalMargin + frameSize.width() + (padding + frameSize.width()) * (currentGridSize.width() - 1) + horizontalMargin;
+    return getDescriptionTextHeight(width);
+}
+
+int QtGridSelectionDialog::getDescriptionTextHeight(int width) const {
+    // Height of descriptive centered text below trellis
+    auto fontMetrics = QFontMetrics(QApplication::font());
+    auto descriptionBB = fontMetrics.boundingRect(QRect(0, 0, width - 2 * horizontalMargin, 1000), Qt::TextWordWrap, descriptionText, 0, nullptr);
+
+    return (descriptionBB.height() + descriptionBB.y());
+}
+
+void QtGridSelectionDialog::keyReleaseEvent(QKeyEvent* event) {
+    if (event) {
+        QSize newGridSize = currentGridSize;
+        if (event->key() == Qt::Key_Up) {
+            newGridSize += QSize(0, -1);
+        }
+        else if (event->key() == Qt::Key_Down) {
+            newGridSize += QSize(0, 1);
+        }
+        else if (event->key() == Qt::Key_Left) {
+            newGridSize += QSize(-1, 0);
+        }
+        else if (event->key() == Qt::Key_Right) {
+            newGridSize += QSize(1, 0);
+        }
+        else if (event->key() == Qt::Key_Return) {
+            hide();
+            setCurrentGridSize(currentGridSize);
+        }
+        else if (event->key() == Qt::Key_Escape) {
+            hide();
+        }
+
+        if (minGridSize.expandedTo(newGridSize).boundedTo(maxGridSize) != currentGridSize) {
+            currentGridSize = minGridSize.expandedTo(newGridSize).boundedTo(maxGridSize);
+
+            QSize newSizeHint = sizeHint();
+            resize(newSizeHint);
+            QCursor::setPos(mapToGlobal(QPoint(newSizeHint.width(), newSizeHint.height()- getDescriptionTextHeight()) - QPoint(frameSize.width() / 2, frameSize.height() / 2)));
+        }
+    }
+}
+
+void QtGridSelectionDialog::mousePressEvent(QMouseEvent*) {
+    hide();
+    setCurrentGridSize(currentGridSize);
+}
+
+void QtGridSelectionDialog::paintEvent(QPaintEvent*) {
+    QPainter painter(this);
+    // draw grid
+    QRect gridCell = QRect(QPoint(0,0), frameSize);
+    painter.setBrush(palette().highlight());
+    painter.setPen(Qt::NoPen);
+    for (int x = 0; x < currentGridSize.width(); x++) {
+        for (int y = 0; y < currentGridSize.height(); y++) {
+            int xPos = horizontalMargin + (x * (frameSize.width() + padding));
+            int yPos = verticalMargin + (y * (frameSize.height() + padding));
+            gridCell.moveTo(QPoint(xPos, yPos));
+            painter.drawRect(gridCell);
+        }
+    }
+
+    // draw description text
+    auto fontMetrics = QFontMetrics(QApplication::font());
+    auto descriptionBB = fontMetrics.boundingRect(QRect(0,0, width() - 2 * horizontalMargin,0), Qt::AlignHCenter | Qt::AlignTop | Qt::TextWordWrap, descriptionText, 0, nullptr);
+
+    QStyleOption opt;
+    opt.initFrom(this);
+    int textY = verticalMargin + (currentGridSize.height() * (frameSize.height() + padding));
+    int textX = (size().width() - descriptionBB.width()) / 2;
+    style()->drawItemText(&painter, QRect(textX, textY, descriptionBB.width(), descriptionBB.height()), Qt::AlignHCenter | Qt::AlignTop | Qt::TextWordWrap, opt.palette, true, descriptionText, foregroundRole());
+}
+
+void QtGridSelectionDialog::showEvent(QShowEvent*) {
+    timerId = startTimer(1000 / 25);
+}
+
+void QtGridSelectionDialog::hideEvent(QHideEvent*) {
+    killTimer(timerId);
+}
+
+void QtGridSelectionDialog::timerEvent(QTimerEvent*) {
+
+    const QPoint diff = QCursor::pos() - frameGeometry().topLeft() - QPoint(horizontalMargin, verticalMargin);
+    const auto toleranceFactor = 4; // Ratio of how far (1/tolerance) the mouse should move for the next frame to be plotted
+    // dx, dy - mouse position with respect to first top-left square
+    const auto dx = diff.x();
+    const auto dy = diff.y();
+    // width, height - dimension of each square with padding
+    const auto width = frameSize.width() + padding;
+    const auto height = frameSize.height() + padding;
+    // xThreshold, yThreshold - how far the mouse should be moved so that a new square is added or the existing one is hidden
+    const auto xThreshold = width / toleranceFactor;
+    const auto yThreshold = height / toleranceFactor;
+
+    const auto getSize = [](int length, int threshold, int delta) {
+        if (delta < length + threshold) {
+            return 1;
+        }
+        else {
+            return (delta + (length - threshold)) / length;
+        }
+    };
+    const QSize newGridSize(getSize(width, xThreshold, dx), getSize(height, yThreshold, dy));
+
+    if (minGridSize.expandedTo(newGridSize).boundedTo(maxGridSize) != currentGridSize) {
+        currentGridSize = minGridSize.expandedTo(newGridSize).boundedTo(maxGridSize);
+        resize(sizeHint());
+    }
+}
+bool QtGridSelectionDialog::event(QEvent* event) {
+    // Hide the window when it becomes a non-top-level window.
+    if (event->type() == QEvent::WindowDeactivate) {
+        hide();
+        return true;
+    }
+    return QWidget::event(event);
+}
+
+}
diff --git a/Swift/QtUI/Trellis/QtGridSelectionDialog.h b/Swift/QtUI/Trellis/QtGridSelectionDialog.h
new file mode 100644
index 0000000..c448979
--- /dev/null
+++ b/Swift/QtUI/Trellis/QtGridSelectionDialog.h
@@ -0,0 +1,66 @@
+/*
+ * Copyright (c) 2014-2017 Isode Limited.
+ * All rights reserved.
+ * See the COPYING file for more information.
+ */
+
+#pragma once
+
+#include <QSize>
+#include <QWidget>
+
+namespace Swift {
+
+    class QtGridSelectionDialog : public QWidget {
+            Q_OBJECT
+
+            Q_PROPERTY(QSize currentGridSize READ getCurrentGridSize WRITE setCurrentGridSize NOTIFY currentGridSizeChanged)
+            Q_PROPERTY(QSize minGridSize READ getMinGridSize WRITE setMinGridSize NOTIFY minGridSizeChanged)
+            Q_PROPERTY(QSize maxGridSize READ getMaxGridSize WRITE setMaxGridSize NOTIFY maxGridSizeChanged)
+        public:
+            explicit QtGridSelectionDialog(QWidget* parent = nullptr);
+
+            virtual QSize sizeHint() const;
+
+            void setCurrentGridSize(const QSize& size);
+            QSize getCurrentGridSize() const;
+            void setMinGridSize(const QSize& size);
+            QSize getMinGridSize() const;
+            void setMaxGridSize(const QSize& size);
+            QSize getMaxGridSize() const;
+
+            QSize getFrameSize() const;
+            int getDescriptionTextHeight() const;
+
+        signals:
+            void currentGridSizeChanged(QSize);
+            void minGridSizeChanged(QSize);
+            void maxGridSizeChanged(QSize);
+
+        protected:
+            void keyReleaseEvent(QKeyEvent* event);
+            void mousePressEvent(QMouseEvent* event);
+            void paintEvent(QPaintEvent* event);
+            void showEvent(QShowEvent* event);
+            void hideEvent(QHideEvent* event);
+            bool event(QEvent* event);
+            void timerEvent(QTimerEvent* event);
+
+    private:
+        int getDescriptionTextHeight(int width) const;
+
+        private:
+            int padding;
+            int horizontalMargin;
+            int verticalMargin;
+            int timerId = -1;
+
+            QSize frameSize;
+
+            QSize currentGridSize;
+            QSize minGridSize;
+            QSize maxGridSize;
+
+            const QString descriptionText;
+    };
+}