Source Code for Module rocon_gateway_graph.interactive_graphics_view

 1  #!/usr/bin/env python 
 2  # 
 3  # License: BSD 
 4  #   https://raw.github.com/robotics-in-concert/rocon_multimaster/master/rocon_gateway_graph/LICENSE  
 5  # 
 6  ############################################################################## 
 7  # Imports 
 8  ############################################################################## 
 9   
10  from __future__ import division 
11   
12  from python_qt_binding.QtCore import QPointF, QRectF, Qt 
13  from python_qt_binding.QtGui import QGraphicsView, QTransform 
14   
15  ############################################################################## 
16  # Class 
17  ############################################################################## 
18   
19   
20 -class InteractiveGraphicsView(QGraphicsView): 
21   
22 -    def __init__(self, parent=None): 
23          super(InteractiveGraphicsView, self).__init__(parent) 
24          self.setObjectName('InteractiveGraphicsView') 
25   
26          self._last_pan_point = None 
27          self._last_scene_center = None 
28   
29 -    def mousePressEvent(self, mouse_event): 
30          self._last_pan_point = mouse_event.pos() 
31          self._last_scene_center = self._map_to_scene_f(QRectF(self.frameRect()).center()) 
32          self.setCursor(Qt.ClosedHandCursor) 
33   
34 -    def mouseReleaseEvent(self, mouse_event): 
35          self.setCursor(Qt.OpenHandCursor) 
36          self._last_pan_point = None 
37   
38 -    def mouseMoveEvent(self, mouse_event): 
39          if self._last_pan_point is not None: 
40              delta_scene = self.mapToScene(mouse_event.pos()) - self.mapToScene(self._last_pan_point) 
41              if not delta_scene.isNull(): 
42                  self.centerOn(self._last_scene_center - delta_scene) 
43                  self._last_scene_center -= delta_scene 
44              self._last_pan_point = mouse_event.pos() 
45          QGraphicsView.mouseMoveEvent(self, mouse_event) 
46   
47 -    def wheelEvent(self, wheel_event): 
48          if wheel_event.modifiers() == Qt.NoModifier: 
49              num_degrees = wheel_event.delta() / 8.0 
50              num_steps = num_degrees / 15.0 
51              mouse_before_scale_in_scene = self.mapToScene(wheel_event.pos()) 
52   
53              scale_factor = 1.2 * num_steps 
54              if num_steps < 0: 
55                  scale_factor = -1.0 / scale_factor 
56              scaling = QTransform(scale_factor, 0, 0, scale_factor, 0, 0) 
57              self.setTransform(self.transform() * scaling) 
58   
59              mouse_after_scale_in_scene = self.mapToScene(wheel_event.pos()) 
60              center_in_scene = self.mapToScene(self.frameRect().center()) 
61              self.centerOn(center_in_scene + mouse_before_scale_in_scene - mouse_after_scale_in_scene) 
62   
63              wheel_event.accept() 
64          else: 
65              QGraphicsView.wheelEvent(self, wheel_event) 
66   
67 -    def _map_to_scene_f(self, pointf): 
68          point = pointf.toPoint() 
69          if pointf.x() == point.x() and pointf.y() == point.y(): 
70              # map integer coordinates 
71              return self.mapToScene(point) 
72          elif pointf.x() == point.x(): 
73              # map integer x and decimal y coordinates 
74              pointA = self.mapToScene((pointf + QPointF(0, -0.5)).toPoint()) 
75              pointB = self.mapToScene((pointf + QPointF(0, 0.5)).toPoint()) 
76              return (pointA + pointB) / 2.0 
77          elif pointf.y() == point.y(): 
78              # map decimal x  and integer y and coordinates 
79              pointA = self.mapToScene((pointf + QPointF(-0.5, 0)).toPoint()) 
80              pointB = self.mapToScene((pointf + QPointF(0.5, 0)).toPoint()) 
81              return (pointA + pointB) / 2.0 
82          else: 
83              # map decimal coordinates 
84              pointA = self.mapToScene((pointf + QPointF(-0.5, -0.5)).toPoint()) 
85              pointB = self.mapToScene((pointf + QPointF(-0.5, 0.5)).toPoint()) 
86              pointC = self.mapToScene((pointf + QPointF(0.5, -0.5)).toPoint()) 
87              pointD = self.mapToScene((pointf + QPointF(0.5, 0.5)).toPoint()) 
88              return (pointA + pointB + pointC + pointD) / 4.0 
89