diff -r 4e8b98454baa -r 800c432b34c8 eric7/E5Graphics/E5ArrowItem.py
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/eric7/E5Graphics/E5ArrowItem.py Sat May 15 18:45:04 2021 +0200
@@ -0,0 +1,163 @@
+# -*- coding: utf-8 -*-
+
+# Copyright (c) 2007 - 2021 Detlev Offenbach <detlev@die-offenbachs.de>
+#
+
+"""
+Module implementing a graphics item subclass for an arrow.
+"""
+
+import enum
+import math
+
+from PyQt5.QtCore import QPointF, QRectF, QSizeF, QLineF, Qt
+from PyQt5.QtGui import QPen, QPolygonF, QColor
+from PyQt5.QtWidgets import QAbstractGraphicsShapeItem, QGraphicsItem, QStyle
+
+ArrowheadAngleFactor = 0.26179938779914941
+# That is: 0.5 * math.atan(math.sqrt(3.0) / 3.0)
+
+
+class E5ArrowType(enum.Enum):
+ """
+ Class defining the arrow types.
+ """
+ NORMAL = 1
+ WIDE = 2
+
+
+class E5ArrowItem(QAbstractGraphicsShapeItem):
+ """
+ Class implementing an arrow graphics item subclass.
+ """
+ def __init__(self, origin=None, end=None,
+ filled=False, arrowType=E5ArrowType.NORMAL, colors=None,
+ parent=None):
+ """
+ Constructor
+
+ @param origin origin of the arrow
+ @type QPointF
+ @param end end point of the arrow
+ @type QPointF
+ @param filled flag indicating a filled arrow head
+ @type bool
+ @param arrowType arrow type
+ @type E5ArrowType
+ @param colors tuple containing the foreground and background colors
+ @type tuple of (QColor, QColor)
+ @param parent reference to the parent object
+ @type QGraphicsItem
+ """
+ super().__init__(parent)
+
+ self._origin = QPointF() if origin is None else QPointF(origin)
+ self._end = QPointF() if end is None else QPointF(end)
+ self._filled = filled
+ self.__type = arrowType
+
+ if colors is None:
+ self._colors = (QColor(Qt.GlobalColor.black),
+ QColor(Qt.GlobalColor.white))
+ else:
+ self._colors = colors
+
+ self._halfLength = 13.0
+
+ self.setFlag(QGraphicsItem.GraphicsItemFlag.ItemIsMovable, True)
+ self.setFlag(QGraphicsItem.GraphicsItemFlag.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)
+ """
+ width = 2 if (
+ (option.state & QStyle.StateFlag.State_Selected) ==
+ QStyle.State(QStyle.StateFlag.State_Selected)
+ ) else 1
+
+ # draw the line first
+ line = QLineF(self._origin, self._end)
+ painter.setPen(
+ QPen(self._colors[0], width, Qt.PenStyle.SolidLine,
+ Qt.PenCapStyle.FlatCap, Qt.PenJoinStyle.MiterJoin))
+ painter.drawLine(line)
+
+ # draw the arrow head
+ arrowAngle = (
+ ArrowheadAngleFactor
+ if self.__type == E5ArrowType.NORMAL else
+ 2 * ArrowheadAngleFactor
+ )
+ slope = math.atan2(line.dy(), line.dx())
+
+ # Calculate left arrow point
+ arrowSlope = slope + arrowAngle
+ a1 = QPointF(self._end.x() - self._halfLength * math.cos(arrowSlope),
+ self._end.y() - self._halfLength * math.sin(arrowSlope))
+
+ # Calculate right arrow point
+ arrowSlope = slope - arrowAngle
+ a2 = QPointF(self._end.x() - self._halfLength * math.cos(arrowSlope),
+ self._end.y() - self._halfLength * math.sin(arrowSlope))
+
+ if self._filled:
+ painter.setBrush(self._colors[0])
+ else:
+ painter.setBrush(self._colors[1])
+ polygon = QPolygonF()
+ polygon.append(line.p2())
+ polygon.append(a1)
+ polygon.append(a2)
+ painter.drawPolygon(polygon)
