modelverse/sketchUI/graphics_sketch_group.py

from PyQt5.QtWidgets import QGraphicsItemGroup, QGraphicsRectItem, QGraphicsEllipseItem
from PyQt5.QtCore import QRect
from graphics_sketch_line import SketchedLineItem


class SketchGroup(QGraphicsItemGroup):
    def __init__(self):
        QGraphicsItemGroup.__init__(self)
        self._prev_pos = self.scenePos()  # empty initially (why?)

    def get_item_coord_relative(self, item):
        """
        Returns the item coordinate description, relative to the group.
        Depending on the type of item, the return type will differ (rectangle for rectangle and ellipse, two points
        for line)
        """
        if item not in self.childItems():
            return None

        sketch_brect = self.sceneBoundingRect()
        if isinstance(item, QGraphicsRectItem) or isinstance(item, QGraphicsEllipseItem):
            item_brect = item.sceneBoundingRect()
            top_left = (item_brect.topLeft() - sketch_brect.topLeft()).toPoint()
            return QRect(top_left.x(), top_left.y(), int(item_brect.width()), int(item_brect.height()))
        elif isinstance(item, SketchedLineItem):
            return (item.get_p1() - sketch_brect.topLeft()).toPoint(), (item.get_p2() - sketch_brect.topLeft()).toPoint()
        else:
            return None

    def mousePressEvent(self, event):
        self._prev_pos = self.scenePos()
        #print("Mouse pressed on group, coord {}".format(self._prev_pos))
        QGraphicsItemGroup.mousePressEvent(self, event)

    def mouseReleaseEvent(self, event):
        cur_pos = self.scenePos()
        #print("Mouse released on group, coord {}".format(cur_pos))
        diff_point = cur_pos - self._prev_pos
        #print("Diff is {}".format(diff_point))

        # update line coordinates since we moved the group
        for item in self.childItems():
            if isinstance(item, SketchedLineItem):
                #print("Updating coordinates of line")
                new_p1 = item.get_p1() + diff_point
                new_p2 = item.get_p2() + diff_point
                item.set_p1(new_p1)
                item.set_p2(new_p2)

        QGraphicsItemGroup.mouseReleaseEvent(self, event)