# -*- coding: utf-8 -*-
"""
A module containing Graphic representation of :class:`~node_editor.node_scene.Scene`
"""
import math
from qtpy.QtWidgets import QGraphicsScene, QWidget
from qtpy.QtCore import Signal, QRect, QLine, Qt
from qtpy.QtGui import QColor, QPen, QFont, QPainter
from node_editor.utils import dumpException
from node_editor.node_graphics_view import STATE_STRING, DEBUG_STATE
[docs]class QDMGraphicsScene(QGraphicsScene):
"""Class representing Graphic of :class:`~node_editor.node_scene.Scene`"""
#: pyqtSignal emitted when some item is selected in the `Scene`
itemSelected = Signal()
#: pyqtSignal emitted when items are deselected in the `Scene`
itemsDeselected = Signal()
def __init__(self, scene: 'Scene', parent: QWidget=None):
"""
:param scene: reference to the :class:`~node_editor.node_scene.Scene`
:type scene: :class:`~nodeeditor.node_scene.Scene`
:param parent: parent widget
:type parent: QWidget
"""
super().__init__(parent)
self.scene = scene
# There is an issue when reconnecting edges -> mouseMove and trying to delete/remove them
# the edges stayed in the scene in Qt, however python side was deleted
# this caused a lot of troubles...
#
# I've spend months to find this sh*t!!
#
# https://bugreports.qt.io/browse/QTBUG-18021
# https://bugreports.qt.io/browse/QTBUG-50691
# Affected versions: 4.7.1, 4.7.2, 4.8.0, 5.5.1, 5.7.0 - LOL!
self.setItemIndexMethod(QGraphicsScene.NoIndex)
# settings
self.gridSize = 20
self.gridSquares = 5
self.initAssets()
self.setBackgroundBrush(self._color_background)
[docs] def initAssets(self):
"""Initialize ``QObjects`` like ``QColor``, ``QPen`` and ``QBrush``"""
self._color_background = QColor("#393939")
self._color_light = QColor("#2f2f2f")
self._color_dark = QColor("#292929")
self._color_state = QColor("#ccc")
self._pen_light = QPen(self._color_light)
self._pen_light.setWidth(1)
self._pen_dark = QPen(self._color_dark)
self._pen_dark.setWidth(2)
self._pen_state = QPen(self._color_state)
self._font_state = QFont("Ubuntu", 16)
# the drag events won't be allowed until dragMoveEvent is overriden
[docs] def dragMoveEvent(self, event):
"""Overriden Qt's dragMoveEvent to enable Qt's Drag Events"""
pass
[docs] def setGrScene(self, width: int, height: int):
"""Set `width` and `height` of the `Graphics Scene`"""
self.setSceneRect(-width // 2, -height // 2, width, height)
[docs] def drawBackground(self, painter:QPainter, rect:QRect):
"""Draw background scene grid"""
super().drawBackground(painter, rect)
# here we create our grid
left = int(math.floor(rect.left()))
right = int(math.ceil(rect.right()))
top = int(math.floor(rect.top()))
bottom = int(math.ceil(rect.bottom()))
first_left = left - (left % self.gridSize)
first_top = top - (top % self.gridSize)
# compute all lines to be drawn
lines_light, lines_dark = [], []
for x in range(first_left, right, self.gridSize):
if (x % (self.gridSize*self.gridSquares) != 0): lines_light.append(QLine(x, top, x, bottom))
else: lines_dark.append(QLine(x, top, x, bottom))
for y in range(first_top, bottom, self.gridSize):
if (y % (self.gridSize*self.gridSquares) != 0): lines_light.append(QLine(left, y, right, y))
else: lines_dark.append(QLine(left, y, right, y))
# draw the lines
painter.setPen(self._pen_light)
try: painter.drawLines(*lines_light) # supporting PyQt5
except TypeError: painter.drawLines(lines_light) # supporting PySide2
painter.setPen(self._pen_dark)
try: painter.drawLines(*lines_dark) # supporting PyQt5
except TypeError: painter.drawLines(lines_dark) # supporting PySide2
if DEBUG_STATE:
try:
painter.setFont(self._font_state)
painter.setPen(self._pen_state)
painter.setRenderHint(QPainter.TextAntialiasing)
offset = 14
rect_state = QRect(rect.x()+offset, rect.y()+offset, rect.width()-2*offset, rect.height()-2*offset)
painter.drawText(rect_state, Qt.AlignRight | Qt.AlignTop, STATE_STRING[self.views()[0].mode].upper())
except: dumpException()