Selection square

BlueprintNodeGraph/interface.py

@@ -362,6 +362,18 @@ def selected_nodes(self):
             nodes.append(Node(node=node._node_item))
         return nodes
 
+    def select_all(self):
+        """
+        Select all nodes in the current node graph.
+        """
+        self._viewer.select_all_nodes()
+
+    def clear_selection(self):
+        """
+        Clears the selection in the node graph.
+        """
+        self._viewer.clear_selection()
+
     def get_node(self, name):
         """
         Returns a node object that matches the name.

BlueprintNodeGraph/pipe.py

@@ -41,9 +41,10 @@ def __str__(self):
             input_node, input_name, output_node, output_name
         )
 
-    def mousePressEvent(self, event):
-        super(Pipe, self).mousePressEvent(event)
-        self.viewer_start_connection(event.scenePos())
+    # disabled as pipe selection is done in the viewer.
+    # def mousePressEvent(self, event):
+    #     super(Pipe, self).mousePressEvent(event)
+    #     self.viewer_start_connection(event.scenePos())
 
     def paint(self, painter, option, widget):
         color = self._color
@@ -124,12 +125,13 @@ def port_from_pos(self, pos, reverse=False):
             port = self.input_port if reverse else self.output_port
         return port
 
-    def viewer_start_connection(self, pos):
-        if not self.scene():
-            return
-        start_port = self.port_from_pos(pos, True)
-        viewer = self.scene().viewer()
-        viewer.start_connection(start_port)
+    # disabled as pipe selection is done in the viewer.
+    # def viewer_start_connection(self, pos):
+    #     if not self.scene():
+    #         return
+    #     start_port = self.port_from_pos(pos, True)
+    #     viewer = self.scene().viewer()
+    #     viewer.start_connection(start_port)
 
     def viewer_pipe_layout(self):
         if self.scene():

BlueprintNodeGraph/viewer.py

@@ -25,8 +25,9 @@ def __init__(self, parent=None, scene=None):
         self._connection_pipe = None
         self._active_pipe = None
         self._start_port = None
-        self._cursor_pos = (0.0, 0.0)
-
+        self._origin_pos = None
+        self._previous_pos = None
+        self._rubber_band = QtGui.QRubberBand(QtGui.QRubberBand.Rectangle, self)
         self.LMB_state = False
         self.RMB_state = False
         self.MMB_state = False
@@ -36,9 +37,6 @@ def __init__(self, parent=None, scene=None):
     def __str__(self):
         return '{}()'.format(self.__class__.__name__)
 
-    def _set_cursor_pos(self, event):
-        self._cursor_pos = (event.x(), event.y())
-
     def _set_viewer_zoom(self, value):
         max_zoom = 12
         min_zoom = max_zoom * -1
@@ -64,15 +62,21 @@ def _set_viewer_pan(self, pos_x, pos_y):
         scroll_x.setValue(scroll_x.value() - pos_x)
         scroll_y.setValue(scroll_y.value() - pos_y)
 
-    def _delete_selection(self):
-        nodes = self.selected_nodes()
-        if not nodes:
-            return
-        self.delete_nodes(nodes)
-
-    def _select_all(self):
-        for node in self.all_nodes():
-            node.setSelected(True)
+    def _items_near(self, pos, item_type=None, size=20):
+        x, y = (pos.x() - (size / 2)), (pos.y() - (size / 2))
+        rect = QtCore.QRect(x, y, size, size)
+        items = []
+        for item in self.scene().items(rect):
+            if not item_type or isinstance(item, item_type):
+                items.append(item)
+        return items
+
+    def _map_scene_rect(self, rect=None):
+        map_pos = self.mapToScene(rect.x(), rect.y())
+        map_rect = QtCore.QRect(
+            map_pos.x(), map_pos.y(), rect.width(), rect.height()
+        )
+        return map_rect
 
     def _setup_shortcuts(self):
         open_actn = QtGui.QAction('Open Session Layout', self)
@@ -87,24 +91,38 @@ def _setup_shortcuts(self):
         fit_zoom_actn.triggered.connect(self.center_selection)
         sel_all_actn = QtGui.QAction('Select All', self)
         sel_all_actn.setShortcut('Ctrl+A')
-        sel_all_actn.triggered.connect(self._select_all)
+        sel_all_actn.triggered.connect(self.select_all_nodes)
         del_node_actn = QtGui.QAction('Delete Selection', self)
         del_node_actn.setShortcuts(['Del', 'Backspace'])
-        del_node_actn.triggered.connect(self._delete_selection)
+        del_node_actn.triggered.connect(self.delete_selected_nodes)
         self.addAction(open_actn)
         self.addAction(save_actn)
         self.addAction(fit_zoom_actn)
         self.addAction(sel_all_actn)
         self.addAction(del_node_actn)
 
+    def resizeEvent(self, event):
+        super(NodeViewer, self).resizeEvent(event)
+
     def mousePressEvent(self, event):
+        modifiers = QtGui.QApplication.keyboardModifiers()
+        alt_pressed = modifiers == QtCore.Qt.AltModifier
         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._set_cursor_pos(event)
+        self._origin_pos = event.pos()
+        self._previous_pos = event.pos()
+
+        items = self._items_near(self.mapToScene(event.pos()), None, 20)
+        if (self.LMB_state and not alt_pressed) and not items:
+            rect = QtCore.QRect(self._previous_pos, QtCore.QSize()).normalized()
+            map_rect = self._map_scene_rect(self._rubber_band.rect())
+            self.scene().update(map_rect)
+            self._rubber_band.setGeometry(rect)
+            self._rubber_band.show()
         super(NodeViewer, self).mousePressEvent(event)
 
     def mouseReleaseEvent(self, event):
@@ -114,22 +132,35 @@ def mouseReleaseEvent(self, event):
             self.RMB_state = False
         elif event.button() == QtCore.Qt.MiddleButton:
             self.MMB_state = False
-        self._set_cursor_pos(event)
+
+        if self._rubber_band.isVisible():
+            map_rect = self._map_scene_rect(self._rubber_band.rect())
+            self._rubber_band.hide()
+            self.scene().update(map_rect)
         super(NodeViewer, self).mouseReleaseEvent(event)
 
     def mouseMoveEvent(self, event):
         modifiers = QtGui.QApplication.keyboardModifiers()
         alt_pressed = modifiers == QtCore.Qt.AltModifier
         if self.MMB_state or (self.LMB_state and alt_pressed):
-            pos_x = (event.x() - self._cursor_pos[0])
-            pos_y = (event.y() - self._cursor_pos[1])
+            pos_x = (event.x() - self._previous_pos.x())
+            pos_y = (event.y() - self._previous_pos.y())
             self._set_viewer_pan(pos_x, pos_y)
-            self._set_cursor_pos(event)
         elif self.RMB_state:
-            pos_x = (event.x() - self._cursor_pos[0])
+            pos_x = (event.x() - self._previous_pos.x())
             zoom = 0.1 if pos_x > 0 else -0.1
             self._set_viewer_zoom(zoom)
-            self._set_cursor_pos(event)
+
+        if self.LMB_state and self._rubber_band.isVisible():
+            rect = QtCore.QRect(self._origin_pos, event.pos()).normalized()
+            map_rect = self._map_scene_rect(rect)
+            path = QtGui.QPainterPath()
+            path.addRect(map_rect)
+            self._rubber_band.setGeometry(rect)
+            self.scene().setSelectionArea(path, QtCore.Qt.ContainsItemShape)
+            self.scene().update(map_rect)
+
+        self._previous_pos = event.pos()
         super(NodeViewer, self).mouseMoveEvent(event)
 
     def wheelEvent(self, event):
@@ -216,7 +247,7 @@ def make_pipe_connection(self, start_port, end_port):
     def sceneMouseMoveEvent(self, event):
         """
         triggered mouse move event for the scene.
-        redraw the connection pipe.
+         - redraw the connection pipe.
 
         Args:
             event (QtGui.QGraphicsSceneMouseEvent): 
@@ -237,6 +268,7 @@ def sceneMouseMoveEvent(self, event):
     def sceneMousePressEvent(self, event):
         """
         triggered mouse press event for the scene.
+         - detect selected pipe and start connection.
 
         Args:
             event (QtGui.QGraphicsScenePressEvent):
@@ -245,16 +277,18 @@ def sceneMousePressEvent(self, event):
         if event.modifiers() == QtCore.Qt.ShiftModifier:
             event.setModifiers(QtCore.Qt.ControlModifier)
 
-        for item in self.scene().items(event.scenePos()):
-            if isinstance(item, Pipe):
-                self._active_pipe = item
-                self._active_pipe.activate()
-                break
+        pipe_items = self._items_near(event.scenePos(), Pipe, 20)
+        pipe = pipe_items[0] if pipe_items else None
+        if pipe:
+            self._active_pipe = pipe
+            self._active_pipe.activate()
+            port = self._active_pipe.port_from_pos(event.scenePos(), True)
+            self.start_connection(port)
 
     def sceneMouseReleaseEvent(self, event):
         """
         triggered mouse release event for the scene.
-        verify to make a the connection Pipe().
+         - verify to make a the connection Pipe().
 
         Args:
             event (QtGui.QGraphicsSceneMouseEvent): 
@@ -315,6 +349,15 @@ def delete_nodes(self, nodes):
             if isinstance(node, NodeItem):
                 node.delete()
 
+    def delete_selected_nodes(self):
+        nodes = self.selected_nodes()
+        if nodes:
+            self.delete_nodes(nodes)
+
+    def select_all_nodes(self):
+        for node in self.all_nodes():
+            node.setSelected(True)
+
     def connect_ports(self, from_port, to_port):
         if not isinstance(from_port, PortItem):
             return
@@ -352,6 +395,9 @@ def clear_scene(self):
         for item in self.scene().items():
             self.scene().removeItem(item)
 
+    def clear_selection(self):
+        self.scene().clearSelection()
+
     def center_selection(self, nodes=None):
         if not nodes:
             if self.selected_nodes():

README.md

@@ -1,9 +1,9 @@
-### Blueprint Node Graph
+### Node Graph
 
 This repository contains a work in progress node graph that I'm working on in my spare time, as
 I wanted to learn how to write a node graph in python using [PySide](http://pyside.github.io/docs/pyside/).
 
-`Blueprint Node Graph` is a node graph widget that can be implemented and repurposed into applications
+A node graph widget that can be implemented and repurposed into applications
 that supports PySide.
 
 ![screencap01](https://raw.githubusercontent.com/jchanvfx/bpNodeGraph/master/screenshot.png)
@@ -18,4 +18,3 @@ select all nodes : `Ctrl + A`<br/>
 delete selected node(s) : `Backspace` or `Delete`<br/>
 save session layout : `Ctrl + S` <br/>
 open session layout : `Ctrl + O` <br/>
->*`(node graph saved in json format with ".ngraph" file extension)`*