Source code for orangecanvas.canvas.scene

Canvas Graphics Scene

import typing
from typing import Dict, List, Optional, Any, Type, Tuple, Union

import logging
import itertools

from operator import attrgetter

from xml.sax.saxutils import escape

from AnyQt.QtWidgets import QGraphicsScene, QGraphicsItem
from AnyQt.QtGui import QPainter, QColor, QFont
from AnyQt.QtCore import (
    Qt, QPointF, QRectF, QSizeF, QLineF, QBuffer, QObject, QSignalMapper,
    QParallelAnimationGroup, QT_VERSION
from AnyQt.QtSvg import QSvgGenerator
from AnyQt.QtCore import pyqtSignal as Signal

from ..registry import (
    WidgetRegistry, WidgetDescription, CategoryDescription,
    InputSignal, OutputSignal
from .. import scheme
from ..scheme import Scheme, SchemeNode, SchemeLink, BaseSchemeAnnotation
from . import items
from .items import NodeItem, LinkItem
from .items.annotationitem import Annotation

from .layout import AnchorLayout

if typing.TYPE_CHECKING:
    from ..document.interactions import UserInteraction
    T = typing.TypeVar("T", bound=QGraphicsItem)

__all__ = [
    "CanvasScene", "grab_svg"

log = logging.getLogger(__name__)

[docs]class CanvasScene(QGraphicsScene): """ A Graphics Scene for displaying an :class:`~.scheme.Scheme` instance. """ #: Signal emitted when a :class:`NodeItem` has been added to the scene. node_item_added = Signal(object) #: Signal emitted when a :class:`NodeItem` has been removed from the #: scene. node_item_removed = Signal(object) #: Signal emitted when a new :class:`LinkItem` has been added to the #: scene. link_item_added = Signal(object) #: Signal emitted when a :class:`LinkItem` has been removed. link_item_removed = Signal(object) #: Signal emitted when a :class:`Annotation` item has been added. annotation_added = Signal(object) #: Signal emitted when a :class:`Annotation` item has been removed. annotation_removed = Signal(object) #: Signal emitted when the position of a :class:`NodeItem` has changed. node_item_position_changed = Signal(object, QPointF) #: Signal emitted when an :class:`NodeItem` has been double clicked. node_item_double_clicked = Signal(object) #: An node item has been activated (double-clicked) node_item_activated = Signal(object) #: An node item has been hovered node_item_hovered = Signal(object) #: Link item has been activated (double-clicked) link_item_activated = Signal(object) #: Link item has been hovered link_item_hovered = Signal(object) def __init__(self, *args, **kwargs): # type: (Any, Any) -> None super().__init__(*args, **kwargs) self.scheme = None # type: Optional[Scheme] self.registry = None # type: Optional[WidgetRegistry] # All node items self.__node_items = [] # type: List[NodeItem] # Mapping from SchemeNodes to canvas items self.__item_for_node = {} # type: Dict[SchemeNode, NodeItem] # All link items self.__link_items = [] # type: List[LinkItem] # Mapping from SchemeLinks to canvas items. self.__item_for_link = {} # type: Dict[SchemeLink, LinkItem] # All annotation items self.__annotation_items = [] # type: List[Annotation] # Mapping from SchemeAnnotations to canvas items. self.__item_for_annotation = {} # type: Dict[BaseSchemeAnnotation, Annotation] # Is the scene editable self.editable = True # Anchor Layout self.__anchor_layout = AnchorLayout() self.addItem(self.__anchor_layout) self.__channel_names_visible = True self.__node_animation_enabled = True self.__animations_temporarily_disabled = False self.user_interaction_handler = None # type: Optional[UserInteraction] self.activated_mapper = QSignalMapper(self) self.activated_mapper.mappedObject.connect( lambda node: self.node_item_activated.emit(node) ) self.hovered_mapper = QSignalMapper(self) self.hovered_mapper.mappedObject.connect( lambda node: self.node_item_hovered.emit(node) ) self.position_change_mapper = QSignalMapper(self) self.position_change_mapper.mappedObject.connect( self._on_position_change ) self.link_activated_mapper = QSignalMapper(self) self.link_activated_mapper.mappedObject.connect( lambda node: self.link_item_activated.emit(node) ) self.__anchors_opened = False
[docs] def clear_scene(self): # type: () -> None """ Clear (reset) the scene. """ if self.scheme is not None: self.scheme.node_added.disconnect(self.add_node) self.scheme.node_removed.disconnect(self.remove_node) self.scheme.link_added.disconnect(self.add_link) self.scheme.link_removed.disconnect(self.remove_link) self.scheme.annotation_added.disconnect(self.add_annotation) self.scheme.annotation_removed.disconnect(self.remove_annotation) # Remove all items to make sure all signals from scheme items # to canvas items are disconnected. for annot in self.scheme.annotations: if annot in self.__item_for_annotation: self.remove_annotation(annot) for link in self.scheme.links: if link in self.__item_for_link: self.remove_link(link) for node in self.scheme.nodes: if node in self.__item_for_node: self.remove_node(node) self.scheme = None self.__node_items = [] self.__item_for_node = {} self.__link_items = [] self.__item_for_link = {} self.__annotation_items = [] self.__item_for_annotation = {} self.__anchor_layout.deleteLater() self.user_interaction_handler = None self.clear()
[docs] def set_scheme(self, scheme): # type: (Scheme) -> None """ Set the scheme to display. Populates the scene with nodes and links already in the scheme. Any further change to the scheme will be reflected in the scene. Parameters ---------- scheme : :class:`~.scheme.Scheme` """ if self.scheme is not None: # Clear the old scheme self.clear_scene() self.scheme = scheme if self.scheme is not None: self.scheme.node_added.connect(self.add_node) self.scheme.node_removed.connect(self.remove_node) self.scheme.link_added.connect(self.add_link) self.scheme.link_removed.connect(self.remove_link) self.scheme.annotation_added.connect(self.add_annotation) self.scheme.annotation_removed.connect(self.remove_annotation) for node in scheme.nodes: self.add_node(node) for link in scheme.links: self.add_link(link) for annot in scheme.annotations: self.add_annotation(annot) self.__anchor_layout.activate()
[docs] def set_registry(self, registry): # type: (WidgetRegistry) -> None """ Set the widget registry. """ # TODO: Remove/Deprecate. Is used only to get the category/background # color. That should be part of the SchemeNode/WidgetDescription. self.registry = registry
[docs] def set_anchor_layout(self, layout): """ Set an :class:`~.layout.AnchorLayout` """ if self.__anchor_layout != layout: if self.__anchor_layout: self.__anchor_layout.deleteLater() self.__anchor_layout = None self.__anchor_layout = layout
[docs] def anchor_layout(self): """ Return the anchor layout instance. """ return self.__anchor_layout
[docs] def set_channel_names_visible(self, visible): # type: (bool) -> None """ Set the channel names visibility. """ self.__channel_names_visible = visible for link in self.__link_items: link.setChannelNamesVisible(visible)
[docs] def channel_names_visible(self): # type: () -> bool """ Return the channel names visibility state. """ return self.__channel_names_visible
[docs] def set_node_animation_enabled(self, enabled): # type: (bool) -> None """ Set node animation enabled state. """ if self.__node_animation_enabled != enabled: self.__node_animation_enabled = enabled for node in self.__node_items: node.setAnimationEnabled(enabled) for link in self.__link_items: link.setAnimationEnabled(enabled)
[docs] def add_node_item(self, item): # type: (NodeItem) -> NodeItem """ Add a :class:`.NodeItem` instance to the scene. """ if item in self.__node_items: raise ValueError("%r is already in the scene." % item) if item.pos().isNull(): if self.__node_items: pos = self.__node_items[-1].pos() + QPointF(150, 0) else: pos = QPointF(150, 150) item.setPos(pos) item.setFont(self.font()) # Set signal mappings self.activated_mapper.setMapping(item, item) item.activated.connect( self.hovered_mapper.setMapping(item, item) item.hovered.connect( self.position_change_mapper.setMapping(item, item) item.positionChanged.connect( self.addItem(item) self.__node_items.append(item) self.clearSelection() item.setSelected(True) self.node_item_added.emit(item) return item
[docs] def add_node(self, node): # type: (SchemeNode) -> NodeItem """ Add and return a default constructed :class:`.NodeItem` for a :class:`SchemeNode` instance `node`. If the `node` is already in the scene do nothing and just return its item. """ if node in self.__item_for_node: # Already added return self.__item_for_node[node] item = self.new_node_item(node.description) if node.position: pos = QPointF(*node.position) item.setPos(pos) item.setTitle(node.title) item.setProcessingState(node.processing_state) item.setProgress(node.progress) item.inputAnchorItem.setAnchorOpen(self.__anchors_opened) item.outputAnchorItem.setAnchorOpen(self.__anchors_opened) for message in node.state_messages(): item.setStateMessage(message) item.setStatusMessage(node.status_message()) self.__item_for_node[node] = item node.position_changed.connect(self.__on_node_pos_changed) node.title_changed.connect(item.setTitle) node.progress_changed.connect(item.setProgress) node.processing_state_changed.connect(item.setProcessingState) node.state_message_changed.connect(item.setStateMessage) node.status_message_changed.connect(item.setStatusMessage) return self.add_node_item(item)
[docs] def new_node_item(self, widget_desc, category_desc=None): # type: (WidgetDescription, Optional[CategoryDescription]) -> NodeItem """ Construct an new :class:`.NodeItem` from a `WidgetDescription`. Optionally also set `CategoryDescription`. """ item = items.NodeItem() item.setWidgetDescription(widget_desc) if category_desc is None and self.registry and widget_desc.category: category_desc = self.registry.category(widget_desc.category) if category_desc is None and self.registry is not None: try: category_desc = self.registry.category(widget_desc.category) except KeyError: pass if category_desc is not None: item.setWidgetCategory(category_desc) item.setAnimationEnabled(self.__node_animation_enabled) return item
[docs] def remove_node_item(self, item): # type: (NodeItem) -> None """ Remove `item` (:class:`.NodeItem`) from the scene. """ desc = item.widget_description self.activated_mapper.removeMappings(item) self.hovered_mapper.removeMappings(item) self.position_change_mapper.removeMappings(item) self.link_activated_mapper.removeMappings(item) item.hide() self.removeItem(item) self.__node_items.remove(item) self.node_item_removed.emit(item)
[docs] def remove_node(self, node): # type: (SchemeNode) -> None """ Remove the :class:`.NodeItem` instance that was previously constructed for a :class:`SchemeNode` `node` using the `add_node` method. """ item = self.__item_for_node.pop(node) node.position_changed.disconnect(self.__on_node_pos_changed) node.title_changed.disconnect(item.setTitle) node.progress_changed.disconnect(item.setProgress) node.processing_state_changed.disconnect(item.setProcessingState) node.state_message_changed.disconnect(item.setStateMessage) self.remove_node_item(item)
[docs] def node_items(self): # type: () -> List[NodeItem] """ Return all :class:`.NodeItem` instances in the scene. """ return list(self.__node_items)
[docs] def add_annotation_item(self, annotation): # type: (Annotation) -> Annotation """ Add an :class:`.Annotation` item to the scene. """ self.__annotation_items.append(annotation) self.addItem(annotation) self.annotation_added.emit(annotation) return annotation
[docs] def add_annotation(self, scheme_annot): # type: (BaseSchemeAnnotation) -> Annotation """ Create a new item for :class:`SchemeAnnotation` and add it to the scene. If the `scheme_annot` is already in the scene do nothing and just return its item. """ if scheme_annot in self.__item_for_annotation: # Already added return self.__item_for_annotation[scheme_annot] if isinstance(scheme_annot, scheme.SchemeTextAnnotation): item = items.TextAnnotation() x, y, w, h = scheme_annot.rect item.setPos(x, y) item.resize(w, h) item.setTextInteractionFlags(Qt.TextEditorInteraction) font = font_from_dict(scheme_annot.font, item.font()) item.setFont(font) item.setContent(scheme_annot.content, scheme_annot.content_type) scheme_annot.content_changed.connect(item.setContent) elif isinstance(scheme_annot, scheme.SchemeArrowAnnotation): item = items.ArrowAnnotation() start, end = scheme_annot.start_pos, scheme_annot.end_pos item.setLine(QLineF(QPointF(*start), QPointF(*end))) item.setColor(QColor(scheme_annot.color)) scheme_annot.geometry_changed.connect( self.__on_scheme_annot_geometry_change ) self.add_annotation_item(item) self.__item_for_annotation[scheme_annot] = item return item
[docs] def remove_annotation_item(self, annotation): # type: (Annotation) -> None """ Remove an :class:`.Annotation` instance from the scene. """ self.__annotation_items.remove(annotation) self.removeItem(annotation) self.annotation_removed.emit(annotation)
[docs] def remove_annotation(self, scheme_annotation): # type: (BaseSchemeAnnotation) -> None """ Remove an :class:`.Annotation` instance that was previously added using :func:`add_anotation`. """ item = self.__item_for_annotation.pop(scheme_annotation) scheme_annotation.geometry_changed.disconnect( self.__on_scheme_annot_geometry_change ) if isinstance(scheme_annotation, scheme.SchemeTextAnnotation): scheme_annotation.content_changed.disconnect(item.setContent) self.remove_annotation_item(item)
[docs] def annotation_items(self): # type: () -> List[Annotation] """ Return all :class:`.Annotation` items in the scene. """ return self.__annotation_items.copy()
def item_for_annotation(self, scheme_annotation): # type: (BaseSchemeAnnotation) -> Annotation return self.__item_for_annotation[scheme_annotation] def annotation_for_item(self, item): # type: (Annotation) -> BaseSchemeAnnotation rev = {v: k for k, v in self.__item_for_annotation.items()} return rev[item]
[docs] def commit_scheme_node(self, node): """ Commit the `node` into the scheme. """ if not self.editable: raise Exception("Scheme not editable.") if node not in self.__item_for_node: raise ValueError("No 'NodeItem' for node.") item = self.__item_for_node[node] try: self.scheme.add_node(node) except Exception: log.error("An error occurred while committing node '%s'", node, exc_info=True) # Cleanup (remove the node item) self.remove_node_item(item) raise log.debug("Commited node '%s' from '%s' to '%s'" % \ (node, self, self.scheme))
[docs] def node_for_item(self, item): # type: (NodeItem) -> SchemeNode """ Return the `SchemeNode` for the `item`. """ rev = dict([(v, k) for k, v in self.__item_for_node.items()]) return rev[item]
[docs] def item_for_node(self, node): # type: (SchemeNode) -> NodeItem """ Return the :class:`NodeItem` instance for a :class:`SchemeNode`. """ return self.__item_for_node[node]
[docs] def selected_node_items(self): # type: () -> List[NodeItem] """ Return the selected :class:`NodeItem`'s. """ return [item for item in self.__node_items if item.isSelected()]
def selected_link_items(self): # type: () -> List[LinkItem] return [item for item in self.__link_items if item.isSelected()]
[docs] def selected_annotation_items(self): # type: () -> List[Annotation] """ Return the selected :class:`Annotation`'s """ return [item for item in self.__annotation_items if item.isSelected()]
[docs] def neighbor_nodes(self, node_item): # type: (NodeItem) -> List[NodeItem] """ Return a list of `node_item`'s (class:`NodeItem`) neighbor nodes. """ neighbors = list(map(attrgetter("sourceItem"), self.node_input_links(node_item))) neighbors.extend(map(attrgetter("sinkItem"), self.node_output_links(node_item))) return neighbors
def set_widget_anchors_open(self, enabled: bool): if self.__anchors_opened == enabled: return self.__anchors_opened = enabled for item in self.node_items(): item.inputAnchorItem.setAnchorOpen(enabled) item.outputAnchorItem.setAnchorOpen(enabled) def _on_position_change(self, item): # type: (NodeItem) -> None # Invalidate the anchor point layout for the node and schedule a layout. self.__anchor_layout.invalidateNode(item) self.node_item_position_changed.emit(item, item.pos()) def __on_node_pos_changed(self, pos): # type: (Tuple[float, float]) -> None node = self.sender() item = self.__item_for_node[node] item.setPos(*pos) def __on_scheme_annot_geometry_change(self): # type: () -> None annot = self.sender() item = self.__item_for_annotation[annot] if isinstance(annot, scheme.SchemeTextAnnotation): item.setGeometry(QRectF(*annot.rect)) elif isinstance(annot, scheme.SchemeArrowAnnotation): p1 = item.mapFromScene(QPointF(*annot.start_pos)) p2 = item.mapFromScene(QPointF(*annot.end_pos)) item.setLine(QLineF(p1, p2)) else: pass
[docs] def item_at(self, pos, type_or_tuple=None, buttons=Qt.NoButton): # type: (QPointF, Optional[Type[T]], Qt.MouseButtons) -> Optional[T] """Return the item at `pos` that is an instance of the specified type (`type_or_tuple`). If `buttons` (`Qt.MouseButtons`) is given only return the item if it is the top level item that would accept any of the buttons (`QGraphicsItem.acceptedMouseButtons`). """ rect = QRectF(pos, QSizeF(1, 1)) items = self.items(rect) if buttons: items_iter = itertools.dropwhile( lambda item: not item.acceptedMouseButtons() & buttons, items ) items = list(items_iter)[:1] if type_or_tuple: items = [i for i in items if isinstance(i, type_or_tuple)] return items[0] if items else None
[docs] def mousePressEvent(self, event): if self.user_interaction_handler and \ self.user_interaction_handler.mousePressEvent(event): return # Right (context) click on the node item. If the widget is not # in the current selection then select the widget (only the widget). # Else simply return and let customContextMenuRequested signal # handle it shape_item = self.item_at(event.scenePos(), items.NodeItem) if shape_item and event.button() == Qt.RightButton and \ shape_item.flags() & QGraphicsItem.ItemIsSelectable: if not shape_item.isSelected(): self.clearSelection() shape_item.setSelected(True) return super().mousePressEvent(event)
[docs] def mouseMoveEvent(self, event): if self.user_interaction_handler and \ self.user_interaction_handler.mouseMoveEvent(event): return super().mouseMoveEvent(event)
[docs] def mouseReleaseEvent(self, event): if self.user_interaction_handler and \ self.user_interaction_handler.mouseReleaseEvent(event): return super().mouseReleaseEvent(event)
[docs] def mouseDoubleClickEvent(self, event): if self.user_interaction_handler and \ self.user_interaction_handler.mouseDoubleClickEvent(event): return super().mouseDoubleClickEvent(event)
[docs] def keyPressEvent(self, event): if self.user_interaction_handler and \ self.user_interaction_handler.keyPressEvent(event): return super().keyPressEvent(event)
[docs] def keyReleaseEvent(self, event): if self.user_interaction_handler and \ self.user_interaction_handler.keyReleaseEvent(event): return super().keyReleaseEvent(event)
[docs] def contextMenuEvent(self, event): if self.user_interaction_handler and \ self.user_interaction_handler.contextMenuEvent(event): return super().contextMenuEvent(event)
[docs] def dragEnterEvent(self, event): if self.user_interaction_handler and \ self.user_interaction_handler.dragEnterEvent(event): return super().dragEnterEvent(event)
[docs] def dragMoveEvent(self, event): if self.user_interaction_handler and \ self.user_interaction_handler.dragMoveEvent(event): return super().dragMoveEvent(event)
[docs] def dragLeaveEvent(self, event): if self.user_interaction_handler and \ self.user_interaction_handler.dragLeaveEvent(event): return super().dragLeaveEvent(event)
[docs] def dropEvent(self, event): if self.user_interaction_handler and \ self.user_interaction_handler.dropEvent(event): return super().dropEvent(event)
def set_user_interaction_handler(self, handler): # type: (UserInteraction) -> None if self.user_interaction_handler and \ not self.user_interaction_handler.isFinished(): self.user_interaction_handler.cancel() log.debug("Setting interaction '%s' to '%s'" % (handler, self)) self.user_interaction_handler = handler if handler: if self.__node_animation_enabled: self.__animations_temporarily_disabled = True self.set_node_animation_enabled(False) handler.start() elif self.__animations_temporarily_disabled: self.__animations_temporarily_disabled = False self.set_node_animation_enabled(True) def __str__(self): return "%s(objectName=%r, ...)" % \ (type(self).__name__, str(self.objectName()))
def font_from_dict(font_dict, font=None): # type: (dict, Optional[QFont]) -> QFont if font is None: font = QFont() else: font = QFont(font) if "family" in font_dict: font.setFamily(font_dict["family"]) if "size" in font_dict: font.setPixelSize(font_dict["size"]) return font if QT_VERSION >= 0x50900 and \ QSvgGenerator().metric(QSvgGenerator.PdmDevicePixelRatioScaled) == 1: # QTBUG-63159 class _QSvgGenerator(QSvgGenerator): # type: ignore def metric(self, metric): if metric == QSvgGenerator.PdmDevicePixelRatioScaled: return int(1 * QSvgGenerator.devicePixelRatioFScale()) else: return super().metric(metric) else: _QSvgGenerator = QSvgGenerator # type: ignore
[docs]def grab_svg(scene: QGraphicsScene) -> str: """ Return a SVG rendering of the scene contents. Parameters ---------- scene : :class:`CanvasScene` """ svg_buffer = QBuffer() gen = _QSvgGenerator() views = scene.views() if views: screen = views[0].screen() if screen is not None: res = screen.physicalDotsPerInch() gen.setResolution(int(res)) gen.setOutputDevice(svg_buffer) items_rect = scene.itemsBoundingRect().adjusted(-10, -10, 10, 10) if items_rect.isNull(): items_rect = QRectF(0, 0, 10, 10) width, height = items_rect.width(), items_rect.height() rect_ratio = float(width) / height # Keep a fixed aspect ratio. aspect_ratio = 1.618 if rect_ratio > aspect_ratio: height = int(height * rect_ratio / aspect_ratio) else: width = int(width * aspect_ratio / rect_ratio) target_rect = QRectF(0, 0, width, height) source_rect = QRectF(0, 0, width, height) source_rect.moveCenter( gen.setSize(target_rect.size().toSize()) gen.setViewBox(target_rect) painter = QPainter(gen) # Draw background. painter.setPen(Qt.NoPen) painter.setBrush(scene.palette().base()) painter.drawRect(target_rect) # Render the scene scene.render(painter, target_rect, source_rect) painter.end() buffer_str = bytes(svg_buffer.buffer()) return buffer_str.decode("utf-8")