brush preview on draw/erase switch

src/app_layout.cpp

@@ -718,6 +718,7 @@ void App::brush_update()
 {
 //     brushes->select_brush(canvas->m_brush->id);
 //     stroke->set_params(canvas->m_brush);
+    stroke->update_controls();
 }
 
 void App::init_menu_layer()

src/canvas_modes.cpp

@@ -262,6 +262,7 @@ void CanvasModePen::enter(kCanvasMode prev)
     if (m_brush)
     {
         *Canvas::I->m_current_brush = *m_brush;
+        Canvas::I->m_current_brush->load();
         App::I.brush_update();
     }
     else

src/node_panel_stroke.cpp

@@ -209,6 +209,13 @@ void NodePanelStroke::update_controls()
 
     m_preview->m_brush = b;
     m_preview->draw_stroke();
+
+    if (m_brush_thumb->m_path != b->m_brush_thumb_path)
+        m_brush_thumb->set_image(b->m_brush_thumb_path);
+    if (m_dual_brush_thumb->m_path != b->m_dual_thumb_path)
+        m_dual_brush_thumb->set_image(b->m_dual_thumb_path);
+    if (m_pattern_thumb->m_path != b->m_pattern_thumb_path)
+        m_pattern_thumb->set_image(b->m_pattern_thumb_path);
 }
 
 void NodePanelStroke::init_fold(const std::string& name)