Mercurial Repositories > eric / file comparison
comparison: E5Graphics/E5ArrowItem.py
E5Graphics/E5ArrowItem.py
- changeset 51
- 7d80b0f20ca6
- child 791
- 9ec2ac20e54e
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| 50:a36eecf45b2e | 51:7d80b0f20ca6 |
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| 1 # -*- coding: utf-8 -*- | |
| 2 | |
| 3 # Copyright (c) 2007 - 2010 Detlev Offenbach <detlev@die-offenbachs.de> | |
| 4 # | |
| 5 | |
| 6 """ | |
| 7 Module implementing a graphics item subclass for an arrow. | |
| 8 """ | |
| 9 | |
| 10 from math import * | |
| 11 | |
| 12 from PyQt4.QtCore import * | |
| 13 from PyQt4.QtGui import * | |
| 14 | |
| 15 NormalArrow = 1 | |
| 16 WideArrow = 2 | |
| 17 | |
| 18 ArrowheadAngleFactor = 0.26179938779914941 # 0.5 * atan(sqrt(3.0) / 3.0) | |
| 19 | |
| 20 class E5ArrowItem(QAbstractGraphicsShapeItem): | |
| 21 """ | |
| 22 Class implementing an arrow graphics item subclass. | |
| 23 """ | |
| 24 def __init__(self, origin = QPointF(), end = QPointF(), | |
| 25 filled = False, type = NormalArrow, parent = None): | |
| 26 """ | |
| 27 Constructor | |
| 28 | |
| 29 @param origin origin of the arrow (QPointF) | |
| 30 @param end end point of the arrow (QPointF) | |
| 31 @param filled flag indicating a filled arrow head (boolean) | |
| 32 @param type arrow type (NormalArrow, WideArrow) | |
| 33 @keyparam parent reference to the parent object (QGraphicsItem) | |
| 34 """ | |
| 35 QAbstractGraphicsShapeItem.__init__(self, parent) | |
| 36 | |
| 37 self._origin = origin | |
| 38 self._end = end | |
| 39 self._filled = filled | |
| 40 self._type = type | |
| 41 | |
| 42 self._halfLength = 13.0 | |
| 43 | |
| 44 self.setFlag(QGraphicsItem.ItemIsMovable, True) | |
| 45 self.setFlag(QGraphicsItem.ItemIsSelectable, True) | |
| 46 | |
| 47 def setPoints(self, xa, ya, xb, yb): | |
| 48 """ | |
| 49 Public method to set the start and end points of the line. | |
| 50 | |
| 51 <b>Note:</b> This method does not redraw the item. | |
| 52 | |
| 53 @param xa x-coordinate of the start point (float) | |
| 54 @param ya y-coordinate of the start point (float) | |
| 55 @param xb x-coordinate of the end point (float) | |
| 56 @param yb y-coordinate of the end point (float) | |
| 57 """ | |
| 58 self._origin = QPointF(xa, ya) | |
| 59 self._end = QPointF(xb, yb) | |
| 60 | |
| 61 def setStartPoint(self, x, y): | |
| 62 """ | |
| 63 Public method to set the start point. | |
| 64 | |
| 65 <b>Note:</b> This method does not redraw the item. | |
| 66 | |
| 67 @param x x-coordinate of the start point (float) | |
| 68 @param y y-coordinate of the start point (float) | |
| 69 """ | |
| 70 self._origin = QPointF(x, y) | |
| 71 | |
| 72 def setEndPoint(self, x, y): | |
| 73 """ | |
| 74 Public method to set the end point. | |
| 75 | |
| 76 <b>Note:</b> This method does not redraw the item. | |
| 77 | |
| 78 @param x x-coordinate of the end point (float) | |
| 79 @param y y-coordinate of the end point (float) | |
| 80 """ | |
| 81 self._end = QPointF(x, y) | |
| 82 | |
| 83 def boundingRect(self): | |
| 84 """ | |
| 85 Public method to return the bounding rectangle. | |
| 86 | |
| 87 @return bounding rectangle (QRectF) | |
| 88 """ | |
| 89 extra = self._halfLength / 2.0 | |
| 90 return QRectF(self._origin, QSizeF(self._end.x() - self._origin.x(), | |
| 91 self._end.y() - self._origin.y()))\ | |
| 92 .normalized()\ | |
| 93 .adjusted(-extra, -extra, extra, extra) | |
| 94 | |
| 95 def paint(self, painter, option, widget = None): | |
| 96 """ | |
| 97 Public method to paint the item in local coordinates. | |
| 98 | |
| 99 @param painter reference to the painter object (QPainter) | |
| 100 @param option style options (QStyleOptionGraphicsItem) | |
| 101 @param widget optional reference to the widget painted on (QWidget) | |
| 102 """ | |
| 103 if (option.state & QStyle.State_Selected) == QStyle.State(QStyle.State_Selected): | |
| 104 width = 2 | |
| 105 else: | |
| 106 width = 1 | |
| 107 | |
| 108 # draw the line first | |
| 109 line = QLineF(self._origin, self._end) | |
| 110 painter.setPen(QPen(Qt.black, width, Qt.SolidLine, Qt.FlatCap, Qt.MiterJoin)) | |
| 111 painter.drawLine(line) | |
| 112 | |
| 113 # draw the arrow head | |
| 114 arrowAngle = self._type * ArrowheadAngleFactor | |
| 115 slope = atan2(line.dy(), line.dx()) | |
| 116 | |
| 117 # Calculate left arrow point | |
| 118 arrowSlope = slope + arrowAngle | |
| 119 a1 = QPointF(self._end.x() - self._halfLength * cos(arrowSlope), | |
| 120 self._end.y() - self._halfLength * sin(arrowSlope)) | |
| 121 | |
| 122 # Calculate right arrow point | |
| 123 arrowSlope = slope - arrowAngle | |
| 124 a2 = QPointF(self._end.x() - self._halfLength * cos(arrowSlope), | |
| 125 self._end.y() - self._halfLength * sin(arrowSlope)) | |
| 126 | |
| 127 if self._filled: | |
| 128 painter.setBrush(Qt.black) | |
| 129 else: | |
| 130 painter.setBrush(Qt.white) | |
| 131 polygon = QPolygonF() | |
| 132 polygon.append(line.p2()) | |
| 133 polygon.append(a1) | |
| 134 polygon.append(a2) | |
| 135 painter.drawPolygon(polygon) |
