--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/E5Graphics/E5ArrowItem.py Tue Jan 12 18:04:41 2010 +0000
@@ -0,0 +1,135 @@
+# -*- coding: utf-8 -*-
+
+# Copyright (c) 2007 - 2010 Detlev Offenbach <detlev@die-offenbachs.de>
+#
+
+"""
+Module implementing a graphics item subclass for an arrow.
+"""
+
+from math import *
+
+from PyQt4.QtCore import *
+from PyQt4.QtGui import *
+
+NormalArrow = 1
+WideArrow = 2
+
+ArrowheadAngleFactor = 0.26179938779914941 # 0.5 * atan(sqrt(3.0) / 3.0)
+
+class E5ArrowItem(QAbstractGraphicsShapeItem):
+ """
+ Class implementing an arrow graphics item subclass.
+ """
+ def __init__(self, origin = QPointF(), end = QPointF(),
+ filled = False, type = NormalArrow, parent = None):
+ """
+ Constructor
+
+ @param origin origin of the arrow (QPointF)
+ @param end end point of the arrow (QPointF)
+ @param filled flag indicating a filled arrow head (boolean)
+ @param type arrow type (NormalArrow, WideArrow)
+ @keyparam parent reference to the parent object (QGraphicsItem)
+ """
+ QAbstractGraphicsShapeItem.__init__(self, parent)
+
+ self._origin = origin
+ self._end = end
+ self._filled = filled
+ self._type = type
+
+ self._halfLength = 13.0
+
+ self.setFlag(QGraphicsItem.ItemIsMovable, True)
+ self.setFlag(QGraphicsItem.ItemIsSelectable, True)
+
+ def setPoints(self, xa, ya, xb, yb):
+ """
+ Public method to set the start and end points of the line.
+
+ <b>Note:</b> This method does not redraw the item.
+
+ @param xa x-coordinate of the start point (float)
+ @param ya y-coordinate of the start point (float)
+ @param xb x-coordinate of the end point (float)
+ @param yb y-coordinate of the end point (float)
+ """
+ self._origin = QPointF(xa, ya)
+ self._end = QPointF(xb, yb)
+
+ def setStartPoint(self, x, y):
+ """
+ Public method to set the start point.
+
+ <b>Note:</b> This method does not redraw the item.
+
+ @param x x-coordinate of the start point (float)
+ @param y y-coordinate of the start point (float)
+ """
+ self._origin = QPointF(x, y)
+
+ def setEndPoint(self, x, y):
+ """
+ Public method to set the end point.
+
+ <b>Note:</b> This method does not redraw the item.
+
+ @param x x-coordinate of the end point (float)
+ @param y y-coordinate of the end point (float)
+ """
+ self._end = QPointF(x, y)
+
+ def boundingRect(self):
+ """
+ Public method to return the bounding rectangle.
+
+ @return bounding rectangle (QRectF)
+ """
+ extra = self._halfLength / 2.0
+ return QRectF(self._origin, QSizeF(self._end.x() - self._origin.x(),
+ self._end.y() - self._origin.y()))\
+ .normalized()\
+ .adjusted(-extra, -extra, extra, extra)
+
+ def paint(self, painter, option, widget = None):
+ """
+ Public method to paint the item in local coordinates.
+
+ @param painter reference to the painter object (QPainter)
+ @param option style options (QStyleOptionGraphicsItem)
+ @param widget optional reference to the widget painted on (QWidget)
+ """
+ if (option.state & QStyle.State_Selected) == QStyle.State(QStyle.State_Selected):
+ width = 2
+ else:
+ width = 1
+
+ # draw the line first
+ line = QLineF(self._origin, self._end)
+ painter.setPen(QPen(Qt.black, width, Qt.SolidLine, Qt.FlatCap, Qt.MiterJoin))
+ painter.drawLine(line)
+
+ # draw the arrow head
+ arrowAngle = self._type * ArrowheadAngleFactor
+ slope = atan2(line.dy(), line.dx())
+
+ # Calculate left arrow point
+ arrowSlope = slope + arrowAngle
+ a1 = QPointF(self._end.x() - self._halfLength * cos(arrowSlope),
+ self._end.y() - self._halfLength * sin(arrowSlope))
+
+ # Calculate right arrow point
+ arrowSlope = slope - arrowAngle
+ a2 = QPointF(self._end.x() - self._halfLength * cos(arrowSlope),
+ self._end.y() - self._halfLength * sin(arrowSlope))
+
+ if self._filled:
+ painter.setBrush(Qt.black)
+ else:
+ painter.setBrush(Qt.white)
+ polygon = QPolygonF()
+ polygon.append(line.p2())
+ polygon.append(a1)
+ polygon.append(a2)
+ painter.drawPolygon(polygon)
\ No newline at end of file
