import logging
import math
from qtpy.QtCore import QLineF, QPoint, QRectF, Qt
from qtpy.QtGui import (QContextMenuEvent, QKeyEvent, QMouseEvent, QPainter,
QPen, QShowEvent, QWheelEvent, QKeySequence)
from qtpy.QtWidgets import (QAction, QGraphicsView, QLineEdit, QMenu,
QTreeWidget, QTreeWidgetItem, QWidgetAction)
from .connection_graphics_object import ConnectionGraphicsObject
from .flow_scene import FlowScene
from .node_graphics_object import NodeGraphicsObject
logger = logging.getLogger(__name__)
[docs]class FlowView(QGraphicsView):
def __init__(self, scene, parent=None):
super().__init__(parent=parent)
self._clear_selection_action = None
self._delete_selection_action = None
self._scene = None
self._click_pos = None
self.setDragMode(QGraphicsView.ScrollHandDrag)
self.setRenderHint(QPainter.Antialiasing)
# setViewportUpdateMode(QGraphicsView.FullViewportUpdate)
# setViewportUpdateMode(QGraphicsView.MinimalViewportUpdate)
self.setHorizontalScrollBarPolicy(Qt.ScrollBarAlwaysOff)
self.setVerticalScrollBarPolicy(Qt.ScrollBarAlwaysOff)
self.setTransformationAnchor(QGraphicsView.AnchorUnderMouse)
self.setCacheMode(QGraphicsView.CacheBackground)
# setViewport(new QGLWidget(QGLFormat(QGL.SampleBuffers)))
if scene is not None:
self.setScene(scene)
self._style = self._scene.style_collection
self.setBackgroundBrush(self._style.flow_view.background_color)
[docs] def clear_selection_action(self) -> QAction:
"""
Clear selection action
Returns
-------
value : QAction
"""
return self._clear_selection_action
[docs] def delete_selection_action(self) -> QAction:
"""
Delete selection action
Returns
-------
value : QAction
"""
return self._delete_selection_action
[docs] def setScene(self, scene: FlowScene):
"""
setScene
Parameters
----------
scene : FlowScene
"""
self._scene = scene
super().setScene(self._scene)
# setup actions
del self._clear_selection_action
self._clear_selection_action = QAction("Clear Selection", self)
self._clear_selection_action.setShortcut(QKeySequence.Cancel)
self._clear_selection_action.triggered.connect(self._scene.clearSelection)
self.addAction(self._clear_selection_action)
del self._delete_selection_action
self._delete_selection_action = QAction("Delete Selection", self)
self._delete_selection_action.setShortcut(QKeySequence.Backspace)
self._delete_selection_action.setShortcut(QKeySequence.Delete)
self._delete_selection_action.triggered.connect(self.delete_selected)
self.addAction(self._delete_selection_action)
def scale_up(self):
step = 1.2
factor = step ** 1.0
t = self.transform()
if t.m11() <= 2.0:
self.scale(factor, factor)
def scale_down(self):
step = 1.2
factor = step ** -1.0
self.scale(factor, factor)
def delete_selected(self):
# Delete the selected connections first, ensuring that they won't be
# automatically deleted when selected nodes are deleted (deleting a node
# deletes some connections as well)
for item in self._scene.selectedItems():
if isinstance(item, ConnectionGraphicsObject):
self._scene.delete_connection(item.connection)
if not self._scene.allow_node_deletion:
return
# Delete the nodes; self will delete many of the connections.
# Selected connections were already deleted prior to self loop, otherwise
# qgraphicsitem_cast<NodeGraphicsObject*>(item) could be a use-after-free
# when a selected connection is deleted by deleting the node.
for item in self._scene.selectedItems():
if isinstance(item, NodeGraphicsObject):
self._scene.remove_node(item.node)
[docs] def wheelEvent(self, event: QWheelEvent):
"""
wheelEvent
Parameters
----------
event : QWheelEvent
"""
delta = event.angleDelta()
if delta.y() == 0:
event.ignore()
return
d = delta.y() / abs(delta.y())
if d > 0.0:
self.scale_up()
else:
self.scale_down()
[docs] def keyPressEvent(self, event: QKeyEvent):
"""
keyPressEvent
Parameters
----------
event : QKeyEvent
"""
if event.key() == Qt.Key_Shift:
self.setDragMode(QGraphicsView.RubberBandDrag)
super().keyPressEvent(event)
[docs] def keyReleaseEvent(self, event: QKeyEvent):
"""
keyReleaseEvent
Parameters
----------
event : QKeyEvent
"""
if event.key() == Qt.Key_Shift:
self.setDragMode(QGraphicsView.ScrollHandDrag)
super().keyReleaseEvent(event)
[docs] def mousePressEvent(self, event: QMouseEvent):
"""
mousePressEvent
Parameters
----------
event : QMouseEvent
"""
super().mousePressEvent(event)
if event.button() == Qt.LeftButton:
self._click_pos = self.mapToScene(event.pos())
[docs] def mouseMoveEvent(self, event: QMouseEvent):
"""
mouseMoveEvent
Parameters
----------
event : QMouseEvent
"""
super().mouseMoveEvent(event)
if self._scene.mouseGrabberItem() is None and event.buttons() == Qt.LeftButton:
# Make sure shift is not being pressed
if not (event.modifiers() & Qt.ShiftModifier):
difference = self._click_pos - self.mapToScene(event.pos())
self.setSceneRect(self.sceneRect().translated(difference.x(), difference.y()))
[docs] def drawBackground(self, painter: QPainter, r: QRectF):
"""
drawBackground
Parameters
----------
painter : QPainter
r : QRectF
"""
super().drawBackground(painter, r)
def draw_grid(grid_step):
window_rect = self.rect()
tl = self.mapToScene(window_rect.topLeft())
br = self.mapToScene(window_rect.bottomRight())
left = math.floor(tl.x() / grid_step - 0.5)
right = math.floor(br.x() / grid_step + 1.0)
bottom = math.floor(tl.y() / grid_step - 0.5)
top = math.floor(br.y() / grid_step + 1.0)
# vertical lines
lines = [
QLineF(xi * grid_step, bottom * grid_step, xi * grid_step, top * grid_step)
for xi in range(int(left), int(right) + 1)
]
# horizontal lines
lines.extend(
[QLineF(left * grid_step, yi * grid_step, right * grid_step, yi * grid_step)
for yi in range(int(bottom), int(top) + 1)
]
)
painter.drawLines(lines)
style = self._style.flow_view
# brush = self.backgroundBrush()
pfine = QPen(style.fine_grid_color, 1.0)
painter.setPen(pfine)
draw_grid(15)
p = QPen(style.coarse_grid_color, 1.0)
painter.setPen(p)
draw_grid(150)
[docs] def showEvent(self, event: QShowEvent):
"""
showEvent
Parameters
----------
event : QShowEvent
"""
self._scene.setSceneRect(QRectF(self.rect()))
super().showEvent(event)
@property
def scene(self) -> FlowScene:
"""
Scene
Returns
-------
value : FlowScene
"""
return self._scene