See, I know the value of each control port this way: static void port_event(LV2UI_Handle ui, uint32_t port_index, uint32_t buffer_size, uint32_t format, const void * buffer) { KisGUI *self = (KisGUI *) ui; if (port_index == 3) cout << "Volume is " << (*static_cast<const float*>(buffer)) << " Format is " << format << endl; cout << "Port event on index " << port_index << " Format is " << format << endl; return; } It's call at session opening, so that would already solve the problem at /that/ time. But how can I access the UI widget to pass it the value? The problem is to find documentation on NTK... All plugin sources that I can find use Qt or GTK... But either way, I need to uderstad te logic of it : How does the UI *read* values? On 17/10/14 13:30, Phil CM wrote: -- Philippe "xaccrocheur" Coatmeur http://bitbucket.org/xaccrocheur / https://github.com/xaccrocheur http://opensimo.org/play/

On 17/10/14 15:56, Harry van Haaren wrote: In this very example, value() seems to be a method of graph object, but when I look at it : { graph = new Avtk::Crusher(5, 36, 150, 126, "graph"); graph->box(FL_UP_BOX); graph->color((Fl_Color)179); graph->selection_color(FL_INACTIVE_COLOR); graph->labeltype(FL_NO_LABEL); graph->labelfont(0); graph->labelsize(14); graph->labelcolor(FL_FOREGROUND_COLOR); graph->callback((Fl_Callback*)cb_graph); graph->align(Fl_Align(FL_ALIGN_BOTTOM)); graph->when(FL_WHEN_CHANGED); } // Avtk::Crusher* graph Still can't see the setValue() you are talking about... I do see when(FL_WHEN_CHANGED); used a lot in your plugins, is when() what I'm looking for? Thanks -Phil -- Philippe "xaccrocheur" Coatmeur http://bitbucket.org/xaccrocheur / https://github.com/xaccrocheur http://opensimo.org/play/