Move SessionManager to Core plugin

Sessions are independent from projects, and this allows for removal of
e.g. the dependency from Bookmarks to ProjectExplorer.

Includes moving the command line arguments (-lastsession, <session>) to
Core plugin.

Change-Id: I6c578fd15c4990902e7196501de20f39376e90e8
Reviewed-by: Christian Kandeler <christian.kandeler@qt.io>

src/plugins/coreplugin/sessionview.cpp

@@ -0,0 +1,152 @@
+// Copyright (C) 2023 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only WITH Qt-GPL-exception-1.0
+
+#include "sessionview.h"
+
+#include "session.h"
+
+#include <utils/algorithm.h>
+
+#include <QHeaderView>
+#include <QItemSelection>
+#include <QStringList>
+#include <QStyledItemDelegate>
+
+namespace Core {
+namespace Internal {
+
+// custom item delegate class
+class RemoveItemFocusDelegate : public QStyledItemDelegate
+{
+public:
+    RemoveItemFocusDelegate(QObject *parent = nullptr) : QStyledItemDelegate(parent) {
+    }
+
+protected:
+    void paint(QPainter* painter, const QStyleOptionViewItem& option, const QModelIndex& index) const override;
+};
+
+void RemoveItemFocusDelegate::paint(QPainter* painter, const QStyleOptionViewItem & option, const QModelIndex &index) const
+{
+    QStyleOptionViewItem opt = option;
+    opt.state &= ~QStyle::State_HasFocus;
+    QStyledItemDelegate::paint(painter, opt, index);
+}
+
+SessionView::SessionView(QWidget *parent)
+    : Utils::TreeView(parent)
+{
+    setItemDelegate(new RemoveItemFocusDelegate(this));
+    setSelectionBehavior(QAbstractItemView::SelectRows);
+    setSelectionMode(QAbstractItemView::ExtendedSelection);
+    setWordWrap(false);
+    setRootIsDecorated(false);
+    setSortingEnabled(true);
+
+    setModel(&m_sessionModel);
+    sortByColumn(0, Qt::AscendingOrder);
+
+    // Ensure that the full session name is visible.
+    header()->setSectionResizeMode(0, QHeaderView::ResizeToContents);
+
+    QItemSelection firstRow(m_sessionModel.index(0,0), m_sessionModel.index(
+        0, m_sessionModel.columnCount() - 1));
+    selectionModel()->select(firstRow, QItemSelectionModel::QItemSelectionModel::
+        SelectCurrent);
+
+    connect(this, &Utils::TreeView::activated, [this](const QModelIndex &index){
+        emit sessionActivated(m_sessionModel.sessionAt(index.row()));
+    });
+    connect(selectionModel(), &QItemSelectionModel::selectionChanged, [this] {
+        emit sessionsSelected(selectedSessions());
+    });
+
+    connect(&m_sessionModel, &SessionModel::sessionSwitched,
+        this, &SessionView::sessionSwitched);
+    connect(&m_sessionModel, &SessionModel::modelReset,
+        this, &SessionView::selectActiveSession);
+    connect(&m_sessionModel, &SessionModel::sessionCreated,
+        this, &SessionView::selectSession);
+ }
+
+void SessionView::createNewSession()
+{
+    m_sessionModel.newSession(this);
+}
+
+void SessionView::deleteSelectedSessions()
+{
+    deleteSessions(selectedSessions());
+}
+
+void SessionView::deleteSessions(const QStringList &sessions)
+{
+    m_sessionModel.deleteSessions(sessions);
+}
+
+void SessionView::cloneCurrentSession()
+{
+    m_sessionModel.cloneSession(this, currentSession());
+}
+
+void SessionView::renameCurrentSession()
+{
+    m_sessionModel.renameSession(this, currentSession());
+}
+
+void SessionView::switchToCurrentSession()
+{
+    m_sessionModel.switchToSession(currentSession());
+}
+
+QString SessionView::currentSession()
+{
+    return m_sessionModel.sessionAt(selectionModel()->currentIndex().row());
+}
+
+SessionModel *SessionView::sessionModel()
+{
+    return &m_sessionModel;
+}
+
+void SessionView::selectActiveSession()
+{
+    selectSession(SessionManager::activeSession());
+}
+
+void SessionView::selectSession(const QString &sessionName)
+{
+    int row = m_sessionModel.indexOfSession(sessionName);
+    selectionModel()->setCurrentIndex(model()->index(row, 0),
+        QItemSelectionModel::ClearAndSelect | QItemSelectionModel::Rows);
+}
+
+void SessionView::showEvent(QShowEvent *event)
+{
+    Utils::TreeView::showEvent(event);
+    selectActiveSession();
+    setFocus();
+}
+
+void SessionView::keyPressEvent(QKeyEvent *event)
+{
+    if (event->key() != Qt::Key_Delete && event->key() != Qt::Key_Backspace) {
+        TreeView::keyPressEvent(event);
+        return;
+    }
+    const QStringList sessions = selectedSessions();
+    if (!sessions.contains("default") && !Utils::anyOf(sessions,
+            [](const QString &session) { return session == SessionManager::activeSession(); })) {
+        deleteSessions(sessions);
+    }
+}
+
+QStringList SessionView::selectedSessions() const
+{
+    return Utils::transform(selectionModel()->selectedRows(), [this](const QModelIndex &index) {
+        return m_sessionModel.sessionAt(index.row());
+    });
+}
+
+} // namespace Internal
+} // namespace Core