tdf#122393 move to overflow row on using left/right at end of other row

and on ctrl+page_up/ctrl+page_down

Change-Id: I3320abfb91655b7b4278886cc6fc4dceb637e4b1
Reviewed-on: https://gerrit.libreoffice.org/66510
Tested-by: Jenkins
Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>
diff --git a/vcl/unx/gtk3/gtk3gtkinst.cxx b/vcl/unx/gtk3/gtk3gtkinst.cxx
index b7f9249..8895d11 100644
--- a/vcl/unx/gtk3/gtk3gtkinst.cxx
+++ b/vcl/unx/gtk3/gtk3gtkinst.cxx
@@ -3068,6 +3068,8 @@ private:
    gulong m_nSwitchPageSignalId;
    gulong m_nOverFlowSwitchPageSignalId;
    gulong m_nSizeAllocateSignalId;
    gulong m_nFocusSignalId;
    gulong m_nChangeCurrentPageId;
    guint m_nLaunchSplitTimeoutId;
    bool m_bOverFlowBoxActive;
    bool m_bOverFlowBoxIsStart;
@@ -3431,6 +3433,55 @@ private:
        pThis->signal_notebook_size_allocate();
    }

    bool signal_focus(GtkDirectionType direction)
    {
        if (!m_bOverFlowBoxActive)
            return false;

        int nPage = gtk_notebook_get_current_page(m_pNotebook);
        if (direction == GTK_DIR_LEFT && nPage == 0)
        {
            auto nOverFlowLen = gtk_notebook_get_n_pages(m_pOverFlowNotebook) - 1;
            gtk_notebook_set_current_page(m_pOverFlowNotebook, nOverFlowLen - 1);
            return true;
        }
        else if (direction == GTK_DIR_RIGHT && nPage == gtk_notebook_get_n_pages(m_pNotebook) - 1)
        {
            gtk_notebook_set_current_page(m_pOverFlowNotebook, 0);
            return true;
        }

        return false;
    }

    static gboolean signalFocus(GtkNotebook* notebook, GtkDirectionType direction, gpointer widget)
    {
        // if the notebook widget itself has focus
        if (gtk_widget_is_focus(GTK_WIDGET(notebook)))
        {
            GtkInstanceNotebook* pThis = static_cast<GtkInstanceNotebook*>(widget);
            return pThis->signal_focus(direction);
        }
        return false;
    }

    // ctrl + page_up/ page_down
    bool signal_change_current_page(gint arg1)
    {
        bool bHandled = signal_focus(arg1 < 0 ? GTK_DIR_LEFT : GTK_DIR_RIGHT);
        if (bHandled)
            g_signal_stop_emission_by_name(m_pNotebook, "change-current-page");
        return false;
    }

    static gboolean signalChangeCurrentPage(GtkNotebook*, gint arg1, gpointer widget)
    {
        if (arg1 == 0)
            return true;
        GtkInstanceNotebook* pThis = static_cast<GtkInstanceNotebook*>(widget);
        return pThis->signal_change_current_page(arg1);
    }

public:
    GtkInstanceNotebook(GtkNotebook* pNotebook, bool bTakeOwnership)
        : GtkInstanceContainer(GTK_CONTAINER(pNotebook), bTakeOwnership)
@@ -3439,6 +3490,8 @@ public:
        , m_pOverFlowNotebook(GTK_NOTEBOOK(gtk_notebook_new()))
        , m_nSwitchPageSignalId(g_signal_connect(pNotebook, "switch-page", G_CALLBACK(signalSwitchPage), this))
        , m_nOverFlowSwitchPageSignalId(g_signal_connect(m_pOverFlowNotebook, "switch-page", G_CALLBACK(signalOverFlowSwitchPage), this))
        , m_nFocusSignalId(g_signal_connect(pNotebook, "focus", G_CALLBACK(signalFocus), this))
        , m_nChangeCurrentPageId(g_signal_connect(pNotebook, "change-current-page", G_CALLBACK(signalChangeCurrentPage), this))
        , m_nLaunchSplitTimeoutId(0)
        , m_bOverFlowBoxActive(false)
        , m_bOverFlowBoxIsStart(false)
@@ -3574,6 +3627,8 @@ public:
    virtual void disable_notify_events() override
    {
        g_signal_handler_block(m_pNotebook, m_nSwitchPageSignalId);
        g_signal_handler_block(m_pNotebook, m_nFocusSignalId);
        g_signal_handler_block(m_pNotebook, m_nChangeCurrentPageId);
        g_signal_handler_block(m_pOverFlowNotebook, m_nOverFlowSwitchPageSignalId);
        gtk_widget_freeze_child_notify(GTK_WIDGET(m_pOverFlowNotebook));
        GtkInstanceContainer::disable_notify_events();
@@ -3585,6 +3640,8 @@ public:
        gtk_widget_thaw_child_notify(GTK_WIDGET(m_pOverFlowNotebook));
        g_signal_handler_unblock(m_pOverFlowNotebook, m_nOverFlowSwitchPageSignalId);
        g_signal_handler_unblock(m_pNotebook, m_nSwitchPageSignalId);
        g_signal_handler_unblock(m_pNotebook, m_nFocusSignalId);
        g_signal_handler_unblock(m_pNotebook, m_nChangeCurrentPageId);
    }

    void reset_split_data()
@@ -3626,6 +3683,8 @@ public:
        if (m_nSizeAllocateSignalId)
            g_signal_handler_disconnect(m_pNotebook, m_nSizeAllocateSignalId);
        g_signal_handler_disconnect(m_pNotebook, m_nSwitchPageSignalId);
        g_signal_handler_disconnect(m_pNotebook, m_nFocusSignalId);
        g_signal_handler_disconnect(m_pNotebook, m_nChangeCurrentPageId);
        g_signal_handler_disconnect(m_pOverFlowNotebook, m_nOverFlowSwitchPageSignalId);
        gtk_widget_destroy(GTK_WIDGET(m_pOverFlowNotebook));
        if (m_pOverFlowBox)