Cut connections by Control+MButton3

Simple click removes connections, which are too close to pointer
(for now 1px, but would be nice to make configurable).
Dragging cuts all connections on the way.

source/patchcanvas.py

@@ -24,6 +24,8 @@ from carla_config import *
 # ------------------------------------------------------------------------------------------------------------
 # Imports (Global)
 
+from math import floor
+
 if config_UseQt5:
     from PyQt5.QtCore import pyqtSignal, pyqtSlot, qCritical, qFatal, qWarning, Qt, QObject
     from PyQt5.QtCore import QAbstractAnimation, QLineF, QPointF, QRectF, QSizeF, QSettings, QTimer
@@ -1212,6 +1214,8 @@ class PatchScene(QGraphicsScene):
         self.m_ctrl_down = False
         self.m_mouse_down_init = False
         self.m_mouse_rubberband = False
+        self.m_mouse2_down = False
+        self.pointer_border = QRectF(0.0, 0.0, 1.0, 1.0)
 
         self.addRubberBand()
 
@@ -1363,6 +1367,15 @@ class PatchScene(QGraphicsScene):
     def mousePressEvent(self, event):
         self.m_mouse_down_init  = bool(event.button() == Qt.LeftButton)
         self.m_mouse_rubberband = False
+        if event.button() == Qt.MidButton and self.m_ctrl_down:
+            self.m_mouse2_down = True
+            pos = event.scenePos()
+            self.pointer_border.moveTo(floor(pos.x()), floor(pos.y()))
+
+            items = self.items(self.pointer_border)
+            for item in items:
+                if item and item.type() in [CanvasLineType, CanvasBezierLineType]:
+                    item.delete()
         QGraphicsScene.mousePressEvent(self, event)
 
     def mouseMoveEvent(self, event):
@@ -1391,9 +1404,20 @@ class PatchScene(QGraphicsScene):
             self.m_rubberband.setRect(x, y, abs(pos.x() - self.m_rubberband_orig_point.x()), abs(pos.y() - self.m_rubberband_orig_point.y()))
             return event.accept()
 
+        if self.m_mouse2_down and self.m_ctrl_down:
+            trail = QPolygonF([event.scenePos(), event.lastScenePos(), event.scenePos()])
+            items = self.items(trail)
+            for item in items:
+                if item and item.type() in [CanvasLineType, CanvasBezierLineType]:
+                    item.delete()
+
         QGraphicsScene.mouseMoveEvent(self, event)
 
     def mouseReleaseEvent(self, event):
+        if event.button() == Qt.MidButton:
+            self.m_mouse2_down = False
+            return event.accept()
+
         if self.m_rubberband_selection:
             items_list = self.items()
             if len(items_list) > 0:
@@ -1536,6 +1560,12 @@ class CanvasLine(QGraphicsLineItem):
         self.m_lineSelected = yesno
         self.updateLineGradient()
 
+    def delete(self):
+        for connection in canvas.connection_list:
+            if (connection.port_out_id == self.item1.getPortId() and connection.port_in_id == self.item2.getPortId()):
+                canvas.callback(ACTION_PORTS_DISCONNECT, connection.connection_id, 0, "")
+                break
+
     def updateLinePos(self):
         if self.item1.getPortMode() == PORT_MODE_OUTPUT:
             line = QLineF(self.item1.scenePos().x() + self.item1.getPortWidth() + 12,
@@ -1629,6 +1659,12 @@ class CanvasBezierLine(QGraphicsPathItem):
         self.m_lineSelected = yesno
         self.updateLineGradient()
 
+    def delete(self):
+        for connection in canvas.connection_list:
+            if (connection.port_out_id == self.item1.getPortId() and connection.port_in_id == self.item2.getPortId()):
+                canvas.callback(ACTION_PORTS_DISCONNECT, connection.connection_id, 0, "")
+                break
+
     def updateLinePos(self):
         if self.item1.getPortMode() == PORT_MODE_OUTPUT:
             item1_x = self.item1.scenePos().x() + self.item1.getPortWidth() + 12

source/widgets/draggablegraphicsview.py

@@ -40,6 +40,7 @@ class DraggableGraphicsView(QGraphicsView):
         QGraphicsView.__init__(self, parent)
 
         self.fPanning = False
+        self.m_ctrl_down = False
 
         try:
             self.fMiddleButton = Qt.MiddleButton
@@ -47,7 +48,7 @@ class DraggableGraphicsView(QGraphicsView):
             self.fMiddleButton = Qt.MidButton
 
     def mousePressEvent(self, event):
-        if event.button() == self.fMiddleButton:
+        if event.button() == self.fMiddleButton and not self.m_ctrl_down:
             self.fPanning = True
             self.setDragMode(QGraphicsView.ScrollHandDrag)
             event = QMouseEvent(event.type(), event.pos(), Qt.LeftButton, Qt.LeftButton, event.modifiers())
@@ -63,3 +64,13 @@ class DraggableGraphicsView(QGraphicsView):
         self.fPanning = False
         self.setDragMode(QGraphicsView.NoDrag)
         self.setCursor(QCursor(Qt.ArrowCursor))
+
+    def keyPressEvent(self, event):
+        if event.key() == Qt.Key_Control:
+            self.m_ctrl_down = True
+        QGraphicsView.keyPressEvent(self, event)
+
+    def keyReleaseEvent(self, event):
+        if event.key() == Qt.Key_Control:
+            self.m_ctrl_down = False
+        QGraphicsView.keyReleaseEvent(self, event)