From 9ec4d0a74b856c231ac64d67a59950606fe8a060 Mon Sep 17 00:00:00 2001
From: jchanvfx <jjohnnycchan@gmail.com>
Date: Sat, 24 Aug 2019 16:32:55 +1200
Subject: [PATCH 1/6] doc string tweak

---
 NodeGraphQt/base/graph.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/NodeGraphQt/base/graph.py b/NodeGraphQt/base/graph.py
index f0d82123..7217ef49 100644
--- a/NodeGraphQt/base/graph.py
+++ b/NodeGraphQt/base/graph.py
@@ -390,8 +390,8 @@ def set_pipe_style(self, style=None):
         Set node graph pipes to be drawn straight or curved by default
         all pipes are set curved. (default=0)
 
-        PIPE_LAYOUT_CURVED = 0
-        PIPE_LAYOUT_STRAIGHT = 1
+        ``NodeGraphQt.constants.PIPE_LAYOUT_CURVED`` = 0
+        ``NodeGraphQt.constants.PIPE_LAYOUT_STRAIGHT`` = 1
 
         Args:
             style (int): pipe style.

From 524ec79d65e795a094cef1dbb7774080069e7a40 Mon Sep 17 00:00:00 2001
From: jchanvfx <jjohnnycchan@gmail.com>
Date: Sat, 24 Aug 2019 16:34:37 +1200
Subject: [PATCH 2/6] live pipe connection overhaul clean up.

---
 NodeGraphQt/qgraphics/pipe.py |  18 +++++-
 NodeGraphQt/widgets/viewer.py | 115 +++++++++++++++++++++-------------
 2 files changed, 88 insertions(+), 45 deletions(-)

diff --git a/NodeGraphQt/qgraphics/pipe.py b/NodeGraphQt/qgraphics/pipe.py
index a7ca6a97..a032f5a1 100644
--- a/NodeGraphQt/qgraphics/pipe.py
+++ b/NodeGraphQt/qgraphics/pipe.py
@@ -6,7 +6,8 @@
     PIPE_DEFAULT_COLOR, PIPE_ACTIVE_COLOR,
     PIPE_HIGHLIGHT_COLOR, PIPE_DISABLED_COLOR,
     PIPE_STYLE_DASHED, PIPE_STYLE_DEFAULT, PIPE_STYLE_DOTTED,
-    PIPE_LAYOUT_STRAIGHT, PIPE_WIDTH, IN_PORT, OUT_PORT, Z_VAL_PIPE
+    PIPE_LAYOUT_STRAIGHT, PIPE_WIDTH, IN_PORT, OUT_PORT, Z_VAL_PIPE,
+    Z_VAL_NODE_WIDGET
 )
 from NodeGraphQt.qgraphics.port import PortItem
 
@@ -130,7 +131,7 @@ def paint(self, painter, option, widget):
 
         painter.restore()  # QPaintDevice: Cannot destroy paint device that is being painted
 
-    def draw_path(self, start_port, end_port, cursor_pos=None):
+    def draw_path(self, start_port, end_port=None, cursor_pos=None):
         """
         Draws the path between ports.
 
@@ -182,6 +183,10 @@ def draw_path(self, start_port, end_port, cursor_pos=None):
         path.cubicTo(ctr_point1, ctr_point2, pos2)
         self.setPath(path)
 
+    def reset_path(self):
+        path = QtGui.QPainterPath(QtCore.QPointF(0.0, 0.0))
+        self.setPath(path)
+
     def calc_distance(self, p1, p2):
         x = math.pow((p2.x() - p1.x()), 2)
         y = math.pow((p2.y() - p1.y()), 2)
@@ -293,3 +298,12 @@ def delete(self):
         # TODO: not sure if we need this...?
         del self
 
+
+class LivePipe(Pipe):
+
+    def __init__(self, input_port=None, output_port=None):
+        super(LivePipe, self).__init__(input_port, output_port)
+        self.setZValue(Z_VAL_NODE_WIDGET + 1)
+        self.activate()
+        self.style = PIPE_STYLE_DASHED
+        self.shift_selected = False
diff --git a/NodeGraphQt/widgets/viewer.py b/NodeGraphQt/widgets/viewer.py
index e2dc29b0..ff70bbed 100644
--- a/NodeGraphQt/widgets/viewer.py
+++ b/NodeGraphQt/widgets/viewer.py
@@ -5,12 +5,10 @@
 from NodeGraphQt import QtGui, QtCore, QtWidgets
 from NodeGraphQt.constants import (IN_PORT, OUT_PORT,
                                    PIPE_LAYOUT_CURVED,
-                                   PIPE_STYLE_DASHED,
-                                   SCENE_AREA,
-                                   Z_VAL_NODE_WIDGET)
+                                   SCENE_AREA,)
 from NodeGraphQt.qgraphics.node_abstract import AbstractNodeItem
 from NodeGraphQt.qgraphics.node_backdrop import BackdropNodeItem
-from NodeGraphQt.qgraphics.pipe import Pipe
+from NodeGraphQt.qgraphics.pipe import Pipe, LivePipe
 from NodeGraphQt.qgraphics.port import PortItem
 from NodeGraphQt.qgraphics.slicer import SlicerPipe
 from NodeGraphQt.widgets.scene import NodeScene
@@ -55,7 +53,6 @@ def __init__(self, parent=None):
         self.resize(1000, 800)
 
         self._pipe_layout = PIPE_LAYOUT_CURVED
-        self._live_pipe = None
         self._detached_port = None
         self._start_port = None
         self._origin_pos = None
@@ -65,6 +62,11 @@ def __init__(self, parent=None):
         self._rubber_band = QtWidgets.QRubberBand(
             QtWidgets.QRubberBand.Rectangle, self
         )
+
+        self._live_pipe = LivePipe()
+        self._live_pipe.setVisible(False)
+        self.scene().addItem(self._live_pipe)
+
         self._pipe_slicer = SlicerPipe()
         self._pipe_slicer.setVisible(False)
         self.scene().addItem(self._pipe_slicer)
@@ -87,6 +89,9 @@ def __init__(self, parent=None):
         self.LMB_state = False
         self.RMB_state = False
         self.MMB_state = False
+        self.ALT_state = False
+        self.CTRL_state = False
+        self.SHIFT_state = False
 
     def __repr__(self):
         return '{}.{}()'.format(
@@ -123,7 +128,10 @@ def _items_near(self, pos, item_type=None, width=20, height=20):
         x, y = pos.x() - width, pos.y() - height
         rect = QtCore.QRectF(x, y, width, height)
         items = []
+        excl = [self._live_pipe, self._pipe_slicer]
         for item in self.scene().items(rect):
+            if item in excl:
+                continue
             if not item_type or isinstance(item, item_type):
                 items.append(item)
         return items
@@ -135,7 +143,8 @@ def _on_search_submitted(self, node_type):
     def _on_pipes_sliced(self, path):
         self.connection_sliced.emit([
             [i.input_port, i.output_port]
-            for i in self.scene().items(path) if isinstance(i, Pipe)
+            for i in self.scene().items(path)
+            if isinstance(i, Pipe) and i != self._live_pipe
         ])
 
     # --- reimplemented events ---
@@ -151,15 +160,13 @@ def contextMenuEvent(self, event):
             return super(NodeViewer, self).contextMenuEvent(event)
 
     def mousePressEvent(self, event):
-        alt_modifier = event.modifiers() == QtCore.Qt.AltModifier
-        shift_modifier = event.modifiers() == QtCore.Qt.ShiftModifier
-
         if event.button() == QtCore.Qt.LeftButton:
             self.LMB_state = True
         elif event.button() == QtCore.Qt.RightButton:
             self.RMB_state = True
         elif event.button() == QtCore.Qt.MiddleButton:
             self.MMB_state = True
+
         self._origin_pos = event.pos()
         self._previous_pos = event.pos()
         self._prev_selection = self.selected_nodes()
@@ -172,19 +179,21 @@ def mousePressEvent(self, event):
         map_pos = self.mapToScene(event.pos())
 
         # pipe slicer enabled.
-        if event.modifiers() == (QtCore.Qt.AltModifier | QtCore.Qt.ShiftModifier):
+        if self.ALT_state and self.SHIFT_state:
             self._pipe_slicer.draw_path(map_pos, map_pos)
             self._pipe_slicer.setVisible(True)
             return
 
-        if alt_modifier:
+        # pan mode.
+        if self.ALT_state:
             return
 
         items = self._items_near(map_pos, None, 20, 20)
         nodes = [i for i in items if isinstance(i, AbstractNodeItem)]
+        pipes = [i for i in items if isinstance(i, Pipe)]
 
         # toggle extend node selection.
-        if shift_modifier:
+        if self.SHIFT_state:
             for node in nodes:
                 node.selected = not node.selected
 
@@ -193,7 +202,7 @@ def mousePressEvent(self, event):
             {n: n.xy_pos for n in self.selected_nodes()}
         )
 
-        # show selection selection marquee
+        # show selection selection marquee.
         if self.LMB_state and not items:
             rect = QtCore.QRect(self._previous_pos, QtCore.QSize())
             rect = rect.normalized()
@@ -202,7 +211,8 @@ def mousePressEvent(self, event):
             self._rubber_band.setGeometry(rect)
             self._rubber_band.show()
 
-        if not shift_modifier:
+        # allow new live pipe with the shift modifier.
+        if not self.SHIFT_state or self.SHIFT_state and pipes:
             super(NodeViewer, self).mousePressEvent(event)
 
     def mouseReleaseEvent(self, event):
@@ -241,22 +251,21 @@ def mouseReleaseEvent(self, event):
         super(NodeViewer, self).mouseReleaseEvent(event)
 
     def mouseMoveEvent(self, event):
-        alt_modifier = event.modifiers() == QtCore.Qt.AltModifier
-        shift_modifier = event.modifiers() == QtCore.Qt.ShiftModifier
-        if event.modifiers() == (QtCore.Qt.AltModifier | QtCore.Qt.ShiftModifier):
-            if self.LMB_state:
+        if self.ALT_state and self.SHIFT_state:
+            if self.LMB_state and self._pipe_slicer.isVisible():
                 p1 = self._pipe_slicer.path().pointAtPercent(0)
                 p2 = self.mapToScene(self._previous_pos)
                 self._pipe_slicer.draw_path(p1, p2)
-                self._previous_pos = event.pos()
-                super(NodeViewer, self).mouseMoveEvent(event)
-                return
+                self._pipe_slicer.show()
+            self._previous_pos = event.pos()
+            super(NodeViewer, self).mouseMoveEvent(event)
+            return
 
-        if self.MMB_state and alt_modifier:
+        if self.MMB_state and self.ALT_state:
             pos_x = (event.x() - self._previous_pos.x())
             zoom = 0.1 if pos_x > 0 else -0.1
             self._set_viewer_zoom(zoom, 0.05)
-        elif self.MMB_state or (self.LMB_state and alt_modifier):
+        elif self.MMB_state or (self.LMB_state and self.ALT_state):
             pos_x = (event.x() - self._previous_pos.x())
             pos_y = (event.y() - self._previous_pos.y())
             self._set_viewer_pan(pos_x, pos_y)
@@ -270,7 +279,7 @@ def mouseMoveEvent(self, event):
             self.scene().setSelectionArea(path, QtCore.Qt.IntersectsItemShape)
             self.scene().update(map_rect)
 
-            if shift_modifier and self._prev_selection:
+            if self.SHIFT_state and self._prev_selection:
                 for node in self._prev_selection:
                     if node not in self.selected_nodes():
                         node.selected = True
@@ -309,6 +318,24 @@ def dragMoveEvent(self, event):
     def dragLeaveEvent(self, event):
         event.ignore()
 
+    def keyPressEvent(self, event):
+        self.ALT_state = event.modifiers() == QtCore.Qt.AltModifier
+        self.CTRL_state = event.modifiers() == QtCore.Qt.ControlModifier
+        self.SHIFT_state = event.modifiers() == QtCore.Qt.ShiftModifier
+
+        # Todo: find a better solution to catch modifier keys.
+        if event.modifiers() == (QtCore.Qt.AltModifier | QtCore.Qt.ShiftModifier):
+            self.ALT_state = True
+            self.SHIFT_state = True
+
+        super(NodeViewer, self).keyPressEvent(event)
+
+    def keyReleaseEvent(self, event):
+        self.ALT_state = event.modifiers() == QtCore.Qt.AltModifier
+        self.CTRL_state = event.modifiers() == QtCore.Qt.ControlModifier
+        self.SHIFT_state = event.modifiers() == QtCore.Qt.ShiftModifier
+        super(NodeViewer, self).keyReleaseEvent(event)
+
     # --- scene events ---
 
     def sceneMouseMoveEvent(self, event):
@@ -320,7 +347,7 @@ def sceneMouseMoveEvent(self, event):
             event (QtWidgets.QGraphicsSceneMouseEvent):
                 The event handler from the QtWidgets.QGraphicsScene
         """
-        if not self._live_pipe:
+        if not self._live_pipe.isVisible():
             return
         if not self._start_port:
             return
@@ -334,7 +361,7 @@ def sceneMouseMoveEvent(self, event):
             pos.setX(pos.x() + x)
             pos.setY(pos.y() + y)
 
-        self._live_pipe.draw_path(self._start_port, None, pos)
+        self._live_pipe.draw_path(self._start_port, cursor_pos=pos)
 
     def sceneMousePressEvent(self, event):
         """
@@ -347,10 +374,10 @@ def sceneMousePressEvent(self, event):
                 The event handler from the QtWidgets.QGraphicsScene
         """
         # pipe slicer enabled.
-        if event.modifiers() == (QtCore.Qt.AltModifier | QtCore.Qt.ShiftModifier):
+        if self.ALT_state and self.SHIFT_state:
             return
         # viewer pan mode.
-        if event.modifiers() == QtCore.Qt.AltModifier:
+        if self.ALT_state:
             return
 
         pos = event.scenePos()
@@ -384,13 +411,18 @@ def sceneMousePressEvent(self, event):
             if not self.LMB_state:
                 return
             pipe = pipe_items[0]
-            attr = {IN_PORT: 'output_port', OUT_PORT: 'input_port'}
             from_port = pipe.port_from_pos(pos, True)
             from_port._hovered = True
 
+            attr = {IN_PORT: 'output_port', OUT_PORT: 'input_port'}
             self._detached_port = getattr(pipe, attr[from_port.port_type])
             self.start_live_connection(from_port)
-            self._live_pipe.draw_path(self._start_port, None, pos)
+            self._live_pipe.draw_path(self._start_port, cursor_pos=pos)
+
+            if self.SHIFT_state:
+                self._live_pipe.shift_selected = True
+                return
+
             pipe.delete()
 
     def sceneMouseReleaseEvent(self, event):
@@ -402,7 +434,7 @@ def sceneMouseReleaseEvent(self, event):
             event (QtWidgets.QGraphicsSceneMouseEvent):
                 The event handler from the QtWidgets.QGraphicsScene
         """
-        if not self._live_pipe:
+        if not self._live_pipe.isVisible():
             return
 
         self._start_port._hovered = False
@@ -419,7 +451,7 @@ def sceneMouseReleaseEvent(self, event):
 
         # if port disconnected from existing pipe.
         if end_port is None:
-            if self._detached_port:
+            if self._detached_port and not self._live_pipe.shift_selected:
                 disconnected.append((self._start_port, self._detached_port))
                 self.connection_changed.emit(disconnected, connected)
 
@@ -477,29 +509,25 @@ def sceneMouseReleaseEvent(self, event):
     def start_live_connection(self, selected_port):
         """
         create new pipe for the connection.
-        (draws the live pipe from the port following the cursor position)
+        (show the live pipe visibility from the port following the cursor position)
         """
         if not selected_port:
             return
         self._start_port = selected_port
-        self._live_pipe = Pipe()
-        self._live_pipe.setZValue(Z_VAL_NODE_WIDGET)
-        self._live_pipe.activate()
-        self._live_pipe.style = PIPE_STYLE_DASHED
         if self._start_port.type == IN_PORT:
             self._live_pipe.input_port = self._start_port
         elif self._start_port == OUT_PORT:
             self._live_pipe.output_port = self._start_port
-        self.scene().addItem(self._live_pipe)
+        self._live_pipe.setVisible(True)
 
     def end_live_connection(self):
         """
         delete live connection pipe and reset start port.
-        (removes the pipe item used for drawing the live connection)
+        (hides the pipe item used for drawing the live connection)
         """
-        if self._live_pipe:
-            self._live_pipe.delete()
-            self._live_pipe = None
+        self._live_pipe.reset_path()
+        self._live_pipe.setVisible(False)
+        self._live_pipe.shift_selected = False
         self._start_port = None
 
     def establish_connection(self, start_port, end_port):
@@ -596,8 +624,9 @@ def save_dialog(self, current_dir=None, ext=None):
 
     def all_pipes(self):
         pipes = []
+        excl = [self._live_pipe, self._pipe_slicer]
         for item in self.scene().items():
-            if isinstance(item, Pipe):
+            if isinstance(item, Pipe) and item not in excl:
                 pipes.append(item)
         return pipes
 

From 13f404367b4a61a41cc6934909a37fc26f1c6b50 Mon Sep 17 00:00:00 2001
From: jchanvfx <jjohnnycchan@gmail.com>
Date: Sat, 24 Aug 2019 17:50:41 +1200
Subject: [PATCH 3/6] updated var names

---
 NodeGraphQt/widgets/viewer.py | 62 +++++++++++++++++------------------
 1 file changed, 31 insertions(+), 31 deletions(-)

diff --git a/NodeGraphQt/widgets/viewer.py b/NodeGraphQt/widgets/viewer.py
index ff70bbed..8b78ddb0 100644
--- a/NodeGraphQt/widgets/viewer.py
+++ b/NodeGraphQt/widgets/viewer.py
@@ -63,13 +63,13 @@ def __init__(self, parent=None):
             QtWidgets.QRubberBand.Rectangle, self
         )
 
-        self._live_pipe = LivePipe()
-        self._live_pipe.setVisible(False)
-        self.scene().addItem(self._live_pipe)
+        self._LIVE_PIPE = LivePipe()
+        self._LIVE_PIPE.setVisible(False)
+        self.scene().addItem(self._LIVE_PIPE)
 
-        self._pipe_slicer = SlicerPipe()
-        self._pipe_slicer.setVisible(False)
-        self.scene().addItem(self._pipe_slicer)
+        self._SLICER_PIPE = SlicerPipe()
+        self._SLICER_PIPE.setVisible(False)
+        self.scene().addItem(self._SLICER_PIPE)
 
         self._undo_stack = QtWidgets.QUndoStack(self)
         self._context_menu = QtWidgets.QMenu('main', self)
@@ -128,7 +128,7 @@ def _items_near(self, pos, item_type=None, width=20, height=20):
         x, y = pos.x() - width, pos.y() - height
         rect = QtCore.QRectF(x, y, width, height)
         items = []
-        excl = [self._live_pipe, self._pipe_slicer]
+        excl = [self._LIVE_PIPE, self._SLICER_PIPE]
         for item in self.scene().items(rect):
             if item in excl:
                 continue
@@ -144,7 +144,7 @@ def _on_pipes_sliced(self, path):
         self.connection_sliced.emit([
             [i.input_port, i.output_port]
             for i in self.scene().items(path)
-            if isinstance(i, Pipe) and i != self._live_pipe
+            if isinstance(i, Pipe) and i != self._LIVE_PIPE
         ])
 
     # --- reimplemented events ---
@@ -180,8 +180,8 @@ def mousePressEvent(self, event):
 
         # pipe slicer enabled.
         if self.ALT_state and self.SHIFT_state:
-            self._pipe_slicer.draw_path(map_pos, map_pos)
-            self._pipe_slicer.setVisible(True)
+            self._SLICER_PIPE.draw_path(map_pos, map_pos)
+            self._SLICER_PIPE.setVisible(True)
             return
 
         # pan mode.
@@ -224,11 +224,11 @@ def mouseReleaseEvent(self, event):
             self.MMB_state = False
 
         # hide pipe slicer.
-        if self._pipe_slicer.isVisible():
-            self._on_pipes_sliced(self._pipe_slicer.path())
+        if self._SLICER_PIPE.isVisible():
+            self._on_pipes_sliced(self._SLICER_PIPE.path())
             p = QtCore.QPointF(0.0, 0.0)
-            self._pipe_slicer.draw_path(p, p)
-            self._pipe_slicer.setVisible(False)
+            self._SLICER_PIPE.draw_path(p, p)
+            self._SLICER_PIPE.setVisible(False)
 
         # hide selection marquee
         if self._rubber_band.isVisible():
@@ -252,11 +252,11 @@ def mouseReleaseEvent(self, event):
 
     def mouseMoveEvent(self, event):
         if self.ALT_state and self.SHIFT_state:
-            if self.LMB_state and self._pipe_slicer.isVisible():
-                p1 = self._pipe_slicer.path().pointAtPercent(0)
+            if self.LMB_state and self._SLICER_PIPE.isVisible():
+                p1 = self._SLICER_PIPE.path().pointAtPercent(0)
                 p2 = self.mapToScene(self._previous_pos)
-                self._pipe_slicer.draw_path(p1, p2)
-                self._pipe_slicer.show()
+                self._SLICER_PIPE.draw_path(p1, p2)
+                self._SLICER_PIPE.show()
             self._previous_pos = event.pos()
             super(NodeViewer, self).mouseMoveEvent(event)
             return
@@ -347,7 +347,7 @@ def sceneMouseMoveEvent(self, event):
             event (QtWidgets.QGraphicsSceneMouseEvent):
                 The event handler from the QtWidgets.QGraphicsScene
         """
-        if not self._live_pipe.isVisible():
+        if not self._LIVE_PIPE.isVisible():
             return
         if not self._start_port:
             return
@@ -361,7 +361,7 @@ def sceneMouseMoveEvent(self, event):
             pos.setX(pos.x() + x)
             pos.setY(pos.y() + y)
 
-        self._live_pipe.draw_path(self._start_port, cursor_pos=pos)
+        self._LIVE_PIPE.draw_path(self._start_port, cursor_pos=pos)
 
     def sceneMousePressEvent(self, event):
         """
@@ -417,10 +417,10 @@ def sceneMousePressEvent(self, event):
             attr = {IN_PORT: 'output_port', OUT_PORT: 'input_port'}
             self._detached_port = getattr(pipe, attr[from_port.port_type])
             self.start_live_connection(from_port)
-            self._live_pipe.draw_path(self._start_port, cursor_pos=pos)
+            self._LIVE_PIPE.draw_path(self._start_port, cursor_pos=pos)
 
             if self.SHIFT_state:
-                self._live_pipe.shift_selected = True
+                self._LIVE_PIPE.shift_selected = True
                 return
 
             pipe.delete()
@@ -434,7 +434,7 @@ def sceneMouseReleaseEvent(self, event):
             event (QtWidgets.QGraphicsSceneMouseEvent):
                 The event handler from the QtWidgets.QGraphicsScene
         """
-        if not self._live_pipe.isVisible():
+        if not self._LIVE_PIPE.isVisible():
             return
 
         self._start_port._hovered = False
@@ -451,7 +451,7 @@ def sceneMouseReleaseEvent(self, event):
 
         # if port disconnected from existing pipe.
         if end_port is None:
-            if self._detached_port and not self._live_pipe.shift_selected:
+            if self._detached_port and not self._LIVE_PIPE.shift_selected:
                 disconnected.append((self._start_port, self._detached_port))
                 self.connection_changed.emit(disconnected, connected)
 
@@ -515,19 +515,19 @@ def start_live_connection(self, selected_port):
             return
         self._start_port = selected_port
         if self._start_port.type == IN_PORT:
-            self._live_pipe.input_port = self._start_port
+            self._LIVE_PIPE.input_port = self._start_port
         elif self._start_port == OUT_PORT:
-            self._live_pipe.output_port = self._start_port
-        self._live_pipe.setVisible(True)
+            self._LIVE_PIPE.output_port = self._start_port
+        self._LIVE_PIPE.setVisible(True)
 
     def end_live_connection(self):
         """
         delete live connection pipe and reset start port.
         (hides the pipe item used for drawing the live connection)
         """
-        self._live_pipe.reset_path()
-        self._live_pipe.setVisible(False)
-        self._live_pipe.shift_selected = False
+        self._LIVE_PIPE.reset_path()
+        self._LIVE_PIPE.setVisible(False)
+        self._LIVE_PIPE.shift_selected = False
         self._start_port = None
 
     def establish_connection(self, start_port, end_port):
@@ -624,7 +624,7 @@ def save_dialog(self, current_dir=None, ext=None):
 
     def all_pipes(self):
         pipes = []
-        excl = [self._live_pipe, self._pipe_slicer]
+        excl = [self._LIVE_PIPE, self._SLICER_PIPE]
         for item in self.scene().items():
             if isinstance(item, Pipe) and item not in excl:
                 pipes.append(item)

From bdeb335a2ef89ac910e9ab5da9d42472f9a0c25b Mon Sep 17 00:00:00 2001
From: jchanvfx <jjohnnycchan@gmail.com>
Date: Sat, 24 Aug 2019 18:05:33 +1200
Subject: [PATCH 4/6] updated draw logic in LivePipe

---
 NodeGraphQt/qgraphics/pipe.py | 73 ++++++++++++++++++++++++++++++++---
 NodeGraphQt/widgets/viewer.py |  2 +-
 2 files changed, 69 insertions(+), 6 deletions(-)

diff --git a/NodeGraphQt/qgraphics/pipe.py b/NodeGraphQt/qgraphics/pipe.py
index a032f5a1..379478f0 100644
--- a/NodeGraphQt/qgraphics/pipe.py
+++ b/NodeGraphQt/qgraphics/pipe.py
@@ -301,9 +301,72 @@ def delete(self):
 
 class LivePipe(Pipe):
 
-    def __init__(self, input_port=None, output_port=None):
-        super(LivePipe, self).__init__(input_port, output_port)
+    def __init__(self):
+        super(LivePipe, self).__init__()
         self.setZValue(Z_VAL_NODE_WIDGET + 1)
-        self.activate()
-        self.style = PIPE_STYLE_DASHED
-        self.shift_selected = False
+
+    def paint(self, painter, option, widget):
+        """
+        Draws the connection line.
+
+        Args:
+            painter (QtGui.QPainter): painter used for drawing the item.
+            option (QtGui.QStyleOptionGraphicsItem):
+                used to describe the parameters needed to draw.
+            widget (QtWidgets.QWidget): not used.
+        """
+        color = QtGui.QColor(*PIPE_ACTIVE_COLOR)
+        pen_style = PIPE_STYLES.get(PIPE_STYLE_DASHED)
+        pen_width = PIPE_WIDTH + 0.35
+
+        pen = QtGui.QPen(color, pen_width)
+        pen.setStyle(pen_style)
+        pen.setCapStyle(QtCore.Qt.RoundCap)
+
+        painter.save()
+        painter.setPen(pen)
+        painter.setRenderHint(painter.Antialiasing, True)
+        painter.drawPath(self.path())
+
+        cen_x = self.path().pointAtPercent(0.5).x()
+        cen_y = self.path().pointAtPercent(0.5).y()
+        loc_pt = self.path().pointAtPercent(0.9)
+        tgt_pt = self.path().pointAtPercent(1.0)
+
+        dist = math.hypot(tgt_pt.x() - cen_x, tgt_pt.y() - cen_y)
+        if dist < 0.05:
+            painter.restore()
+            return
+
+        # draw circle
+        size = 10 * (dist / 100)
+        if size > 10.0:
+            size = 10.0
+        elif size < 5.0:
+            size = 5.0
+        rect = QtCore.QRectF(cen_x-(size/2), cen_y-(size/2), size, size)
+        painter.setBrush(color)
+        painter.setPen(QtGui.QPen(color.darker(130), pen_width))
+        painter.drawEllipse(rect)
+
+        # draw arrow
+        color.setAlpha(255)
+        painter.setBrush(color.darker(200))
+
+        pen_width = 0.6
+        if dist < 1.0:
+            pen_width *= (1.0 + dist)
+        painter.setPen(QtGui.QPen(color, pen_width))
+
+        transform = QtGui.QTransform()
+        transform.translate(tgt_pt.x(), tgt_pt.y())
+
+        radians = math.atan2(tgt_pt.y() - loc_pt.y(),
+                             tgt_pt.x() - loc_pt.x())
+        degrees = math.degrees(radians) + 90
+        transform.rotate(degrees)
+
+        if dist < 10.0:
+            transform.scale(0.5, 0.5)
+        painter.drawPolygon(transform.map(self._arrow))
+        painter.restore()
diff --git a/NodeGraphQt/widgets/viewer.py b/NodeGraphQt/widgets/viewer.py
index 8b78ddb0..6ab43a01 100644
--- a/NodeGraphQt/widgets/viewer.py
+++ b/NodeGraphQt/widgets/viewer.py
@@ -5,7 +5,7 @@
 from NodeGraphQt import QtGui, QtCore, QtWidgets
 from NodeGraphQt.constants import (IN_PORT, OUT_PORT,
                                    PIPE_LAYOUT_CURVED,
-                                   SCENE_AREA,)
+                                   SCENE_AREA)
 from NodeGraphQt.qgraphics.node_abstract import AbstractNodeItem
 from NodeGraphQt.qgraphics.node_backdrop import BackdropNodeItem
 from NodeGraphQt.qgraphics.pipe import Pipe, LivePipe

From 1e8c50c0650bac8f61f40686f43fa530c67ae193 Mon Sep 17 00:00:00 2001
From: jchanvfx <jjohnnycchan@gmail.com>
Date: Sat, 24 Aug 2019 23:46:35 +1200
Subject: [PATCH 5/6] live pipe tweaks

---
 NodeGraphQt/qgraphics/pipe.py | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/NodeGraphQt/qgraphics/pipe.py b/NodeGraphQt/qgraphics/pipe.py
index 379478f0..4ae8e26f 100644
--- a/NodeGraphQt/qgraphics/pipe.py
+++ b/NodeGraphQt/qgraphics/pipe.py
@@ -339,11 +339,9 @@ def paint(self, painter, option, widget):
             return
 
         # draw circle
-        size = 10 * (dist / 100)
-        if size > 10.0:
-            size = 10.0
-        elif size < 5.0:
-            size = 5.0
+        size = 10.0
+        if dist < 50.0:
+            size *= (dist / 50.0)
         rect = QtCore.QRectF(cen_x-(size/2), cen_y-(size/2), size, size)
         painter.setBrush(color)
         painter.setPen(QtGui.QPen(color.darker(130), pen_width))
@@ -355,7 +353,7 @@ def paint(self, painter, option, widget):
 
         pen_width = 0.6
         if dist < 1.0:
-            pen_width *= (1.0 + dist)
+            pen_width *= 1.0 + dist
         painter.setPen(QtGui.QPen(color, pen_width))
 
         transform = QtGui.QTransform()
@@ -366,7 +364,9 @@ def paint(self, painter, option, widget):
         degrees = math.degrees(radians) + 90
         transform.rotate(degrees)
 
-        if dist < 10.0:
-            transform.scale(0.5, 0.5)
+        scale = 1.0
+        if dist < 20.0:
+            scale = dist / 20.0
+        transform.scale(scale, scale)
         painter.drawPolygon(transform.map(self._arrow))
         painter.restore()

From 8657d4e805c6d6db11bd01895239fa5ea3ce57c9 Mon Sep 17 00:00:00 2001
From: jchanvfx <jjohnnycchan@gmail.com>
Date: Mon, 26 Aug 2019 22:14:51 +1200
Subject: [PATCH 6/6] added cursor pos threshold.

---
 NodeGraphQt/qgraphics/pipe.py |  1 +
 NodeGraphQt/qgraphics/port.py |  8 ++++++++
 NodeGraphQt/widgets/viewer.py | 16 ++++++++++++----
 3 files changed, 21 insertions(+), 4 deletions(-)

diff --git a/NodeGraphQt/qgraphics/pipe.py b/NodeGraphQt/qgraphics/pipe.py
index 4ae8e26f..7d90bc80 100644
--- a/NodeGraphQt/qgraphics/pipe.py
+++ b/NodeGraphQt/qgraphics/pipe.py
@@ -304,6 +304,7 @@ class LivePipe(Pipe):
     def __init__(self):
         super(LivePipe, self).__init__()
         self.setZValue(Z_VAL_NODE_WIDGET + 1)
+        self.shift_selected = False
 
     def paint(self, painter, option, widget):
         """
diff --git a/NodeGraphQt/qgraphics/port.py b/NodeGraphQt/qgraphics/port.py
index 4d01431f..3d720ed8 100644
--- a/NodeGraphQt/qgraphics/port.py
+++ b/NodeGraphQt/qgraphics/port.py
@@ -166,6 +166,14 @@ def connected_ports(self):
             ports.append(getattr(pipe, port_types[self.port_type]))
         return ports
 
+    @property
+    def hovered(self):
+        return self._hovered
+
+    @hovered.setter
+    def hovered(self, value=False):
+        self._hovered = value
+
     @property
     def node(self):
         return self.parentItem()
diff --git a/NodeGraphQt/widgets/viewer.py b/NodeGraphQt/widgets/viewer.py
index 6ab43a01..ab89e102 100644
--- a/NodeGraphQt/widgets/viewer.py
+++ b/NodeGraphQt/widgets/viewer.py
@@ -1,6 +1,7 @@
 #!/usr/bin/python
 # -*- coding: utf-8 -*-
 import os
+import math
 
 from NodeGraphQt import QtGui, QtCore, QtWidgets
 from NodeGraphQt.constants import (IN_PORT, OUT_PORT,
@@ -412,7 +413,7 @@ def sceneMousePressEvent(self, event):
                 return
             pipe = pipe_items[0]
             from_port = pipe.port_from_pos(pos, True)
-            from_port._hovered = True
+            from_port.hovered = True
 
             attr = {IN_PORT: 'output_port', OUT_PORT: 'input_port'}
             self._detached_port = getattr(pipe, attr[from_port.port_type])
@@ -437,7 +438,7 @@ def sceneMouseReleaseEvent(self, event):
         if not self._LIVE_PIPE.isVisible():
             return
 
-        self._start_port._hovered = False
+        self._start_port.hovered = False
 
         # find the end port.
         end_port = None
@@ -452,8 +453,15 @@ def sceneMouseReleaseEvent(self, event):
         # if port disconnected from existing pipe.
         if end_port is None:
             if self._detached_port and not self._LIVE_PIPE.shift_selected:
-                disconnected.append((self._start_port, self._detached_port))
-                self.connection_changed.emit(disconnected, connected)
+                dist = math.hypot(self._previous_pos.x() - self._origin_pos.x(),
+                                  self._previous_pos.y() - self._origin_pos.y())
+                if dist <= 2.0:  # cursor pos threshold.
+                    self.establish_connection(self._start_port,
+                                              self._detached_port)
+                    self._detached_port = None
+                else:
+                    disconnected.append((self._start_port, self._detached_port))
+                    self.connection_changed.emit(disconnected, connected)
 
             self._detached_port = None
             self.end_live_connection()