TriggerBox: implement basic TriggerSlot DnD

gtk2_ardour/triggerbox_ui.cc

@@ -726,6 +726,7 @@ TriggerEntry::follow_button_event (GdkEvent* ev)
 TriggerBoxUI::TriggerBoxUI (ArdourCanvas::Item* parent, TriggerBox& tb)
 	: Rectangle (parent)
 	, _triggerbox (tb)
+	, _drag_active (false)
 {
 	set_layout_sensitive (true); // why???
 
@@ -750,6 +751,15 @@ TriggerBoxUI::TriggerBoxUI (ArdourCanvas::Item* parent, TriggerBox& tb)
 	gtkcanvas->signal_drag_motion ().connect (sigc::mem_fun (*this, &TriggerBoxUI::drag_motion));
 	gtkcanvas->signal_drag_leave ().connect (sigc::mem_fun (*this, &TriggerBoxUI::drag_leave));
 	gtkcanvas->signal_drag_data_received ().connect (sigc::mem_fun (*this, &TriggerBoxUI::drag_data_received));
+
+	/* DnD Source */
+	std::vector<Gtk::TargetEntry> source_table;
+	source_table.push_back (Gtk::TargetEntry ("x-ardour/region.pbdid", Gtk::TARGET_SAME_APP));
+	_dnd_src = Gtk::TargetList::create (source_table);
+
+	gtkcanvas->signal_drag_begin ().connect (sigc::mem_fun (*this, &TriggerBoxUI::drag_begin));
+	gtkcanvas->signal_drag_end ().connect (sigc::mem_fun (*this, &TriggerBoxUI::drag_end));
+	gtkcanvas->signal_drag_data_get ().connect (sigc::mem_fun (*this, &TriggerBoxUI::drag_data_get));
 }
 
 TriggerBoxUI::~TriggerBoxUI ()
@@ -788,9 +798,7 @@ TriggerBoxUI::build ()
 
 		_slots.push_back (te);
 
-#if 0
 		te->Event.connect (sigc::bind (sigc::mem_fun (*this, &TriggerBoxUI::event), n));
-#endif
 
 		++n;
 	}
@@ -910,6 +918,101 @@ TriggerBoxUI::drag_data_received (Glib::RefPtr<Gdk::DragContext> const& context,
 	context->drag_finish (true, false, time);
 }
 
+bool
+TriggerBoxUI::event (GdkEvent* ev, uint64_t n)
+{
+	assert (n < _slots.size ());
+	if (!_slots[n]->trigger()->region ()) {
+		return false;
+	}
+
+	switch (ev->type) {
+		case GDK_2BUTTON_PRESS:
+				gdk_pointer_ungrab (GDK_CURRENT_TIME);
+			break;
+
+		case GDK_BUTTON_RELEASE:
+				gdk_pointer_ungrab (GDK_CURRENT_TIME);
+			break;
+
+		case GDK_BUTTON_PRESS:
+			if (!_drag_active) {
+				GdkEventButton* bev = (GdkEventButton*)ev;
+				if (bev->button == 1) {
+					_drag_start_x = bev->x;
+					_drag_start_y = bev->y;
+					gdk_pointer_grab (bev->window, false, GdkEventMask (Gdk::POINTER_MOTION_MASK | Gdk::BUTTON_PRESS_MASK |Gdk::BUTTON_RELEASE_MASK), NULL, NULL, bev->time);
+				} else {
+					_drag_start_x = -1;
+					_drag_start_y = -1;
+				}
+			}
+			break;
+
+		case GDK_MOTION_NOTIFY:
+			if (!_drag_active) {
+				int x, y;
+				Gdk::ModifierType mask;
+
+				GtkCanvas* gtkcanvas = static_cast<GtkCanvas*> (canvas ());
+				gtkcanvas->get_window()->get_pointer (x, y, mask);
+
+				if (mask & GDK_BUTTON1_MASK) {
+					if (gtkcanvas->drag_check_threshold (_drag_start_x, _drag_start_y, x, y)) {
+						_drag_active = true;
+						gtkcanvas->drag_begin (_dnd_src, Gdk::ACTION_COPY, 1, ev);
+						// -> save a reference to the dragged slot, for use in ::drag_begin ::drag_data_get()
+						return true;
+					}
+				}
+			}
+		default:
+			break;
+	}
+	return false;
+}
+
+void
+TriggerBoxUI::drag_begin (Glib::RefPtr<Gdk::DragContext> const& context)
+{
+#if 0
+	int width  = 130;
+	int height = 20;
+	GtkCanvas* gtkcanvas = static_cast<GtkCanvas*> (canvas ());
+	Glib::RefPtr<Gdk::Pixmap> pixmap = Gdk::Pixmap::create (gtkcanvas->get_root_window(), width, height);
+	cairo_t *cr = gdk_cairo_create (Glib::unwrap (pixmap));
+	cairo_set_source_rgb (cr, 1, 0, 0);
+	cairo_rectangle (cr, 0, 0, width, height);
+	cairo_fill (cr);
+	cairo_destroy (cr);
+	context->set_icon (pixmap->get_colormap(), pixmap, Glib::RefPtr<Gdk::Bitmap>(NULL), width / 2, height / 2);
+#endif
+}
+
+void
+TriggerBoxUI::drag_end (Glib::RefPtr<Gdk::DragContext> const&)
+{
+	_drag_active = false;
+}
+
+void
+TriggerBoxUI::drag_data_get (Glib::RefPtr<Gdk::DragContext> const&, Gtk::SelectionData& data, guint, guint)
+{
+	if (data.get_target () != "x-ardour/region.pbdid") {
+		return;
+	}
+
+	boost::shared_ptr<Region> region;
+	/* use selection, for now */
+	TriggerSelection ts = PublicEditor::instance ().get_selection ().triggers;
+	for (auto& te : ts) {
+		region = te->trigger()->region ();
+	}
+	if (region) {
+		data.set (data.get_target (), region->id ().to_s ());
+	}
+}
+
 void
 TriggerBoxUI::start_updating ()
 {

gtk2_ardour/triggerbox_ui.h

@@ -102,6 +102,12 @@ private:
 	ARDOUR::TriggerBox&     _triggerbox;
 	Slots                   _slots;
 
+	int  _drag_start_x;
+	int  _drag_start_y;
+	bool _drag_active;
+
+	Glib::RefPtr<Gtk::TargetList> _dnd_src;
+
 	void build ();
 	void rapid_update ();
 
@@ -111,6 +117,11 @@ private:
 	void drag_leave (Glib::RefPtr<Gdk::DragContext> const&, guint);
 	void drag_data_received (Glib::RefPtr<Gdk::DragContext> const&, int, int, Gtk::SelectionData const&, guint, guint);
 
+	bool event (GdkEvent*, uint64_t n);
+	void drag_begin (Glib::RefPtr<Gdk::DragContext> const&);
+	void drag_end (Glib::RefPtr<Gdk::DragContext> const&);
+	void drag_data_get (Glib::RefPtr<Gdk::DragContext> const&, Gtk::SelectionData&, guint, guint);
+
 	bool triggerbox_event (GdkEvent*);
 
 	uint64_t slot_at_y (int) const;