From d9fd6f9c4b3b41adaeb164b1029d17d862b03255 Mon Sep 17 00:00:00 2001
From: nicholasbishop <nicholasbishop@users.sourceforge.net>
Date: Tue, 14 Aug 2007 09:00:10 +0000
Subject: [PATCH] Filter effects dialog:

* Added autoscrolling during connection drag/drop. If a connection is dragged towards the top or bottom of the primitives treeview, the view will scroll with it.
---
 src/ui/dialog/filter-effects-dialog.cpp | 47 +++++++++++++++++++++++++
 src/ui/dialog/filter-effects-dialog.h   |  3 ++
 2 files changed, 50 insertions(+)

diff --git a/src/ui/dialog/filter-effects-dialog.cpp b/src/ui/dialog/filter-effects-dialog.cpp
index 315b73d99..6cc5d0fa8 100644
--- a/src/ui/dialog/filter-effects-dialog.cpp
+++ b/src/ui/dialog/filter-effects-dialog.cpp
@@ -1502,6 +1502,8 @@ bool FilterEffectsDialog::PrimitiveList::on_button_press_event(GdkEventButton* e
     }
 
     if(_in_drag) {
+        _scroll_connection = Glib::signal_timeout().connect(sigc::mem_fun(*this, &PrimitiveList::on_scroll_timeout), 150);
+        _autoscroll = 0;
         get_selection()->select(path);
         return true;
     }
@@ -1511,6 +1513,28 @@ bool FilterEffectsDialog::PrimitiveList::on_button_press_event(GdkEventButton* e
 
 bool FilterEffectsDialog::PrimitiveList::on_motion_notify_event(GdkEventMotion* e)
 {
+    const int speed = 10;
+    const int limit = 15;
+
+    Gdk::Rectangle vis;
+    get_visible_rect(vis);
+    int vis_x, vis_y;
+    tree_to_widget_coords(vis.get_x(), vis.get_y(), vis_x, vis_y);
+    const int top = vis_y + vis.get_height();
+
+    // When autoscrolling during a connection drag, set the speed based on
+    // where the mouse is in relation to the edges.
+    if(e->y < vis_y)
+        _autoscroll = -(int)(speed + (vis_y - e->y) / 5);
+    else if(e->y < vis_y + limit)
+        _autoscroll = -speed;
+    else if(e->y > top)
+        _autoscroll = (int)(speed + (e->y - top) / 5);
+    else if(e->y > top - limit)
+        _autoscroll = speed;
+    else
+        _autoscroll = 0;
+
     queue_draw();
 
     return Gtk::TreeView::on_motion_notify_event(e);
@@ -1520,6 +1544,8 @@ bool FilterEffectsDialog::PrimitiveList::on_button_release_event(GdkEventButton*
 {
     SPFilterPrimitive *prim = get_selected(), *target;
 
+    _scroll_connection.disconnect();
+
     if(_in_drag && prim) {
         Gtk::TreePath path;
         Gtk::TreeViewColumn* col;
@@ -1692,6 +1718,27 @@ void FilterEffectsDialog::PrimitiveList::on_drag_end(const Glib::RefPtr<Gdk::Dra
     sp_document_done(filter->document, SP_VERB_DIALOG_FILTER_EFFECTS, _("Reorder filter primitive"));
 }
 
+// If a connection is dragged towards the top or bottom of the list, the list should scroll to follow.
+bool FilterEffectsDialog::PrimitiveList::on_scroll_timeout()
+{
+    if(_autoscroll) {
+        Gtk::Adjustment& a = *dynamic_cast<Gtk::ScrolledWindow*>(get_parent())->get_vadjustment();
+        double v;
+
+        v = a.get_value() + _autoscroll;
+        if(v < 0)
+            v = 0;
+        if(v > a.get_upper() - a.get_page_size())
+            v = a.get_upper() - a.get_page_size();
+
+        a.set_value(v);
+
+        queue_draw();
+    }
+
+    return true;
+}
+
 int FilterEffectsDialog::PrimitiveList::primitive_count() const
 {
     return _model->children().size();
diff --git a/src/ui/dialog/filter-effects-dialog.h b/src/ui/dialog/filter-effects-dialog.h
index 95dafaff2..ace6e68bd 100644
--- a/src/ui/dialog/filter-effects-dialog.h
+++ b/src/ui/dialog/filter-effects-dialog.h
@@ -197,6 +197,7 @@ private:
                              const int x1, const int y1, const int row_count);
         void sanitize_connections(const Gtk::TreeIter& prim_iter);
         void on_primitive_selection_changed();
+        bool on_scroll_timeout();
 
         FilterEffectsDialog& _dialog;
         Glib::RefPtr<Gtk::ListStore> _model;
@@ -207,6 +208,8 @@ private:
         int _in_drag;
         SPFilterPrimitive* _drag_prim;
         sigc::signal<void> _signal_primitive_changed;
+        sigc::connection _scroll_connection;
+        int _autoscroll;
         std::auto_ptr<SignalObserver> _observer;
     };
 
-- 
2.30.2