rqt_decision_graph: interactive_graphics

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00001 """
00002 Copyright (c) 2011, Dirk Thomas, TU Darmstadt
00003 All rights reserved.
00004 
00005 Redistribution and use in source and binary forms, with or without
00006 modification, are permitted provided that the following conditions
00007 are met:
00008 
00009   * Redistributions of source code must retain the above copyright
00010     notice, this list of conditions and the following disclaimer.
00011   * Redistributions in binary form must reproduce the above
00012     copyright notice, this list of conditions and the following
00013     disclaimer in the documentation and/or other materials provided
00014     with the distribution.
00015   * Neither the name of the TU Darmstadt nor the names of its
00016     contributors may be used to endorse or promote products derived
00017     from this software without specific prior written permission.
00018 
00019 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
00020 "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
00021 LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
00022 FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
00023 COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
00024 INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
00025 BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
00026 LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
00027 CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
00028 LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
00029 ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
00030 POSSIBILITY OF SUCH DAMAGE.
00031 
00032 Note: This is modified version by Cogniteam
00033 """
00034 
00035 from __future__ import division
00036 
00037 from python_qt_binding.QtCore import QPointF, QRectF, Qt
00038 from python_qt_binding.QtGui import QGraphicsView, QTransform
00039 
00040 
00041 class InteractiveGraphicsView(QGraphicsView):
00042 
00043     def __init__(self, parent=None):
00044         super(InteractiveGraphicsView, self).__init__(parent)
00045         self.setObjectName('InteractiveGraphicsView')
00046 
00047         self._last_pan_point = None
00048         self._last_scene_center = None
00049 
00050     def mousePressEvent(self, mouse_event):
00051         self._last_pan_point = mouse_event.pos()
00052         self._last_scene_center = self._map_to_scene_f(QRectF(self.frameRect()).center())
00053         self.setCursor(Qt.ClosedHandCursor)
00054         QGraphicsView.mousePressEvent(self, mouse_event)
00055 
00056     def mouseReleaseEvent(self, mouse_event):
00057         self.setCursor(Qt.OpenHandCursor)
00058         self._last_pan_point = None
00059 
00060     def mouseMoveEvent(self, mouse_event):
00061         if self._last_pan_point is not None:
00062             delta_scene = self.mapToScene(mouse_event.pos()) - self.mapToScene(self._last_pan_point)
00063             if not delta_scene.isNull():
00064                 self.centerOn(self._last_scene_center - delta_scene)
00065                 self._last_scene_center -= delta_scene
00066             self._last_pan_point = mouse_event.pos()
00067         QGraphicsView.mouseMoveEvent(self, mouse_event)
00068 
00069     def wheelEvent(self, wheel_event):
00070         if wheel_event.modifiers() == Qt.NoModifier:
00071             delta = wheel_event.delta()
00072             delta = max(min(delta, 480), -480)
00073             mouse_before_scale_in_scene = self.mapToScene(wheel_event.pos())
00074 
00075             scale_factor = 1 + (0.2 * (delta / 120.0))
00076             scaling = QTransform(scale_factor, 0, 0, scale_factor, 0, 0)
00077             self.setTransform(self.transform() * scaling)
00078 
00079             mouse_after_scale_in_scene = self.mapToScene(wheel_event.pos())
00080             center_in_scene = self.mapToScene(self.frameRect().center())
00081             self.centerOn(center_in_scene + mouse_before_scale_in_scene - mouse_after_scale_in_scene)
00082 
00083             wheel_event.accept()
00084         else:
00085             QGraphicsView.wheelEvent(self, wheel_event)
00086 
00087     def _map_to_scene_f(self, pointf):
00088         point = pointf.toPoint()
00089         if pointf.x() == point.x() and pointf.y() == point.y():
00090             # map integer coordinates
00091             return self.mapToScene(point)
00092         elif pointf.x() == point.x():
00093             # map integer x and decimal y coordinates
00094             pointA = self.mapToScene((pointf + QPointF(0, -0.5)).toPoint())
00095             pointB = self.mapToScene((pointf + QPointF(0, 0.5)).toPoint())
00096             return (pointA + pointB) / 2.0
00097         elif pointf.y() == point.y():
00098             # map decimal x  and integer y and coordinates
00099             pointA = self.mapToScene((pointf + QPointF(-0.5, 0)).toPoint())
00100             pointB = self.mapToScene((pointf + QPointF(0.5, 0)).toPoint())
00101             return (pointA + pointB) / 2.0
00102         else:
00103             # map decimal coordinates
00104             pointA = self.mapToScene((pointf + QPointF(-0.5, -0.5)).toPoint())
00105             pointB = self.mapToScene((pointf + QPointF(-0.5, 0.5)).toPoint())
00106             pointC = self.mapToScene((pointf + QPointF(0.5, -0.5)).toPoint())
00107             pointD = self.mapToScene((pointf + QPointF(0.5, 0.5)).toPoint())
00108             return (pointA + pointB + pointC + pointD) / 4.0