Auto-enable/disable keys only when selection contains a plugin

source/carla_patchbay.py

@@ -103,6 +103,7 @@ class CarlaPatchbayW(QFrame):
 
         self.scene.scaleChanged.connect(self.slot_canvasScaleChanged)
         self.scene.sceneGroupMoved.connect(self.slot_canvasItemMoved)
+        self.scene.pluginSelected.connect(self.slot_canvasPluginSelected)
 
         self.fMiniCanvasPreview.miniCanvasMoved.connect(self.slot_miniCanvasMoved)
 
@@ -348,6 +349,10 @@ class CarlaPatchbayW(QFrame):
     def slot_canvasItemMoved(self, group_id, split_mode, pos):
         self.fMiniCanvasPreview.update()
 
+    @pyqtSlot(list)
+    def slot_canvasPluginSelected(self, pluginList):
+        self.fKeys.setEnabled(len(pluginList) != 0)
+
     @pyqtSlot(float, float)
     def slot_miniCanvasMoved(self, xp, yp):
         self.fMovingViaMiniCanvas = True

source/patchcanvas.py

@@ -1096,6 +1096,7 @@ def CanvasRemoveItemFX(item):
 class PatchScene(QGraphicsScene):
     scaleChanged    = pyqtSignal(float)
     sceneGroupMoved = pyqtSignal(int, int, QPointF)
+    pluginSelected  = pyqtSignal(list)
 
     def __init__(self, parent, view):
         QGraphicsScene.__init__(self, parent)
@@ -1110,6 +1111,8 @@ class PatchScene(QGraphicsScene):
         if not self.m_view:
             qFatal("PatchCanvas::PatchScene() - invalid view")
 
+        self.selectionChanged.connect(self.slot_selectionChanged)
+
     def addRubberBand(self):
         self.m_rubberband = self.addRect(QRectF(0, 0, 0, 0))
         self.m_rubberband.setZValue(-1)
@@ -1190,6 +1193,30 @@ class PatchScene(QGraphicsScene):
         self.m_view.resetTransform()
         self.scaleChanged.emit(1.0)
 
+    @pyqtSlot()
+    def slot_selectionChanged(self):
+        items_list = self.selectedItems()
+
+        if len(items_list) == 0:
+            self.pluginSelected.emit([])
+            return
+
+        plugin_list = []
+
+        for item in items_list:
+            if item and item.isVisible():
+                group_item = None
+
+                if item.type() == CanvasBoxType:
+                    group_item = item
+                elif item.type() == CanvasPortType:
+                    group_item = item.parentItem()
+
+                if group_item is not None and group_item.m_plugin_id >= 0:
+                    plugin_list.append(group_item.m_plugin_id)
+
+        self.pluginSelected.emit(plugin_list)
+
     def keyPressEvent(self, event):
         if not self.m_view:
             return event.ignore()