import string
from math import atan2
from .. import functions as fn
from ..Point import Point
from ..Qt import QtCore, QtGui
from .GraphicsObject import GraphicsObject
from .ScatterPlotItem import Symbols
from .TextItem import TextItem
from .UIGraphicsItem import UIGraphicsItem
from .ViewBox import ViewBox
__all__ = ['TargetItem', 'TargetLabel']
class TargetItem(UIGraphicsItem):
"""Draws a draggable target symbol (circle plus crosshair).
The size of TargetItem will remain fixed on screen even as the view is zoomed.
Includes an optional text label.
"""
sigPositionChanged = QtCore.Signal(object)
sigPositionChangeFinished = QtCore.Signal(object)
def __init__(
self,
pos=None,
size=10,
symbol="crosshair",
pen=None,
hoverPen=None,
brush=None,
hoverBrush=None,
movable=True,
label=None,
labelOpts=None,
):
r"""
Parameters
----------
pos : list, tuple, QPointF, QPoint, Optional
Initial position of the symbol. Default is (0, 0)
size : int
Size of the symbol in pixels. Default is 10.
pen : QPen, tuple, list or str
Pen to use when drawing line. Can be any arguments that are valid
for :func:`~pyqtgraph.mkPen`. Default pen is transparent yellow.
brush : QBrush, tuple, list, or str
Defines the brush that fill the symbol. Can be any arguments that
is valid for :func:`~pyqtgraph.mkBrush`. Default is transparent
blue.
movable : bool
If True, the symbol can be dragged to a new position by the user.
hoverPen : QPen, tuple, list, or str
Pen to use when drawing symbol when hovering over it. Can be any
arguments that are valid for :func:`~pyqtgraph.mkPen`. Default pen
is red.
hoverBrush : QBrush, tuple, list or str
Brush to use to fill the symbol when hovering over it. Can be any
arguments that is valid for :func:`~pyqtgraph.mkBrush`. Default is
transparent blue.
symbol : QPainterPath or str
QPainterPath to use for drawing the target, should be centered at
``(0, 0)`` with ``max(width, height) == 1.0``. Alternatively a string
which can be any symbol accepted by
:func:`~pyqtgraph.ScatterPlotItem.setSymbol`
label : bool, str or callable, optional
Text to be displayed in a label attached to the symbol, or None to
show no label (default is None). May optionally include formatting
strings to display the symbol value, or a callable that accepts x
and y as inputs. If True, the label is ``x = {: >.3n}\ny = {: >.3n}``
False or None will result in no text being displayed
labelOpts : dict
A dict of keyword arguments to use when constructing the text
label. See :class:`TargetLabel` and :class:`~pyqtgraph.TextItem`
"""
super().__init__()
self.movable = movable
self.moving = False
self._label = None
self.mouseHovering = False
if pen is None:
pen = (255, 255, 0)
self.setPen(pen)
if hoverPen is None:
hoverPen = (255, 0, 255)
self.setHoverPen(hoverPen)
if brush is None:
brush = (0, 0, 255, 50)
self.setBrush(brush)
if hoverBrush is None:
hoverBrush = (0, 255, 255, 100)
self.setHoverBrush(hoverBrush)
self.currentPen = self.pen
self.currentBrush = self.brush
self._shape = None
self._pos = Point(0, 0)
if pos is None:
pos = Point(0, 0)
self.setPos(pos)
if isinstance(symbol, str):
try:
self._path = Symbols[symbol]
except KeyError:
raise KeyError("symbol name found in available Symbols")
elif isinstance(symbol, QtGui.QPainterPath):
self._path = symbol
else:
raise TypeError("Unknown type provided as symbol")
self.scale = size
self.setPath(self._path)
self.setLabel(label, labelOpts)
def setPos(self, *args):
"""Method to set the position to ``(x, y)`` within the plot view
Parameters
----------
args : tuple or list or QtCore.QPointF or QtCore.QPoint or Point or float
Two float values or a container that specifies ``(x, y)`` position where the
TargetItem should be placed
Raises
------
TypeError
If args cannot be used to instantiate a Point
"""
try:
newPos = Point(*args)
except TypeError:
raise
except Exception:
raise TypeError(f"Could not make Point from arguments: {args!r}")
if self._pos != newPos:
self._pos = newPos
super().setPos(self._pos)
self.sigPositionChanged.emit(self)
def setBrush(self, *args, **kwargs):
"""Set the brush that fills the symbol. Allowable arguments are any that
are valid for :func:`~pyqtgraph.mkBrush`.
"""
self.brush = fn.mkBrush(*args, **kwargs)
if not self.mouseHovering:
self.currentBrush = self.brush
self.update()
def setHoverBrush(self, *args, **kwargs):
"""Set the brush that fills the symbol when hovering over it. Allowable
arguments are any that are valid for :func:`~pyqtgraph.mkBrush`.
"""
self.hoverBrush = fn.mkBrush(*args, **kwargs)
if self.mouseHovering:
self.currentBrush = self.hoverBrush
self.update()
def setPen(self, *args, **kwargs):
"""Set the pen for drawing the symbol. Allowable arguments are any that
are valid for :func:`~pyqtgraph.mkPen`."""
self.pen = fn.mkPen(*args, **kwargs)
if not self.mouseHovering:
self.currentPen = self.pen
self.update()
def setHoverPen(self, *args, **kwargs):
"""Set the pen for drawing the symbol when hovering over it. Allowable
arguments are any that are valid for
:func:`~pyqtgraph.mkPen`."""
self.hoverPen = fn.mkPen(*args, **kwargs)
if self.mouseHovering:
self.currentPen = self.hoverPen
self.update()
def boundingRect(self):
return self.shape().boundingRect()
def paint(self, p, *_):
p.setPen(self.currentPen)
p.setBrush(self.currentBrush)
p.drawPath(self.shape())
def setPath(self, path):
if path != self._path:
self._path = path
self._shape = None
return None
def shape(self):
if self._shape is None:
s = self.generateShape()
if s is None:
return self._path
self._shape = s
# beware--this can cause the view to adjust
# which would immediately invalidate the shape.
self.prepareGeometryChange()
return self._shape
def generateShape(self):
dt = self.deviceTransform()
if dt is None:
self._shape = self._path
return None
v = dt.map(QtCore.QPointF(1, 0)) - dt.map(QtCore.QPointF(0, 0))
dti = fn.invertQTransform(dt)
devPos = dt.map(QtCore.QPointF(0, 0))
tr = QtGui.QTransform()
tr.translate(devPos.x(), devPos.y())
va = atan2(v.y(), v.x())
tr.rotateRadians(va)
tr.scale(self.scale, self.scale)
return dti.map(tr.map(self._path))
def mouseDragEvent(self, ev):
if not self.movable or ev.button() != QtCore.Qt.MouseButton.LeftButton:
return
ev.accept()
if ev.isStart():
self.symbolOffset = self.pos() - self.mapToView(ev.buttonDownPos())
self.moving = True
if not self.moving:
return
self.setPos(self.symbolOffset + self.mapToView(ev.pos()))
if ev.isFinish():
self.moving = False
self.sigPositionChangeFinished.emit(self)
def mouseClickEvent(self, ev):
if self.moving and ev.button() == QtCore.Qt.MouseButton.RightButton:
ev.accept()
self.moving = False
self.sigPositionChanged.emit(self)
self.sigPositionChangeFinished.emit(self)
def setMouseHover(self, hover):
# Inform the item that the mouse is(not) hovering over it
if self.mouseHovering is hover:
return
self.mouseHovering = hover
if hover:
self.currentBrush = self.hoverBrush
self.currentPen = self.hoverPen
else:
self.currentBrush = self.brush
self.currentPen = self.pen
self.update()
def hoverEvent(self, ev):
if self.movable and (not ev.isExit()) and ev.acceptDrags(QtCore.Qt.MouseButton.LeftButton):
self.setMouseHover(True)
else:
self.setMouseHover(False)
def viewTransformChanged(self):
GraphicsObject.viewTransformChanged(self)
self._shape = None # invalidate shape, recompute later if requested.
self.update()
def pos(self):
"""Provides the current position of the TargetItem
Returns
-------
Point
pg.Point of the current position of the TargetItem
"""
return self._pos
def label(self):
"""Provides the TargetLabel if it exists
Returns
-------
TargetLabel or None
If a TargetLabel exists for this TargetItem, return that, otherwise
return None
"""
return self._label
def setLabel(self, text=None, labelOpts=None):
"""Method to call to enable or disable the TargetLabel for displaying text
Parameters
----------
text : Callable or str, optional
Details how to format the text, by default None
If None, do not show any text next to the TargetItem
If Callable, then the label will display the result of ``text(x, y)``
If a fromatted string, then the output of ``text.format(x, y)`` will be
displayed
If a non-formatted string, then the text label will display ``text``, by
default None
labelOpts : dict, optional
These arguments are passed on to :class:`~pyqtgraph.TextItem`
"""
if not text:
if self._label is not None and self._label.scene() is not None:
# remove the label if it's already added
self._label.scene().removeItem(self._label)
self._label = None
else:
# provide default text if text is True
if text is True:
# convert to default value or empty string
text = "x = {: .3n}\ny = {: .3n}"
labelOpts = {} if labelOpts is None else labelOpts
if self._label is not None:
self._label.scene().removeItem(self._label)
self._label = TargetLabel(self, text=text, **labelOpts)
class TargetLabel(TextItem):
"""A TextItem that attaches itself to a TargetItem.
This class extends TextItem with the following features :
* Automatically positions adjacent to the symbol at a fixed position.
* Automatically reformats text when the symbol location has changed.
Parameters
----------
target : TargetItem
The TargetItem to which this label will be attached to.
text : str or callable, Optional
Governs the text displayed, can be a fixed string or a format string
that accepts the x, and y position of the target item; or be a callable
method that accepts a tuple (x, y) and returns a string to be displayed.
If None, an empty string is used. Default is None
offset : tuple or list or QPointF or QPoint
Position to set the anchor of the TargetLabel away from the center of
the target in pixels, by default it is (20, 0).
anchor : tuple or list or QPointF or QPoint
Position to rotate the TargetLabel about, and position to set the
offset value to see :class:`~pyqtgraph.TextItem` for more information.
kwargs : dict
kwargs contains arguments that are passed onto
:class:`~pyqtgraph.TextItem` constructor, excluding text parameter
"""
def __init__(
self,
target,
text="",
offset=(20, 0),
anchor=(0, 0.5),
**kwargs,
):
if isinstance(offset, Point):
self.offset = offset
elif isinstance(offset, (tuple, list)):
self.offset = Point(*offset)
elif isinstance(offset, (QtCore.QPoint, QtCore.QPointF)):
self.offset = Point(offset.x(), offset.y())
else:
raise TypeError("Offset parameter is the wrong data type")
super().__init__(anchor=anchor, **kwargs)
self.setParentItem(target)
self.target = target
self.setFormat(text)
self.target.sigPositionChanged.connect(self.valueChanged)
self.valueChanged()
def format(self):
return self._format
def setFormat(self, text):
"""Method to set how the TargetLabel should display the text. This
method should be called from TargetItem.setLabel directly.
Parameters
----------
text : Callable or str
Details how to format the text.
If Callable, then the label will display the result of ``text(x, y)``
If a fromatted string, then the output of ``text.format(x, y)`` will be
displayed
If a non-formatted string, then the text label will display ``text``
"""
if not callable(text):
parsed = list(string.Formatter().parse(text))
if parsed and parsed[0][1] is not None:
self.setProperty("formattableText", True)
else:
self.setText(text)
self.setProperty("formattableText", False)
else:
self.setProperty("formattableText", False)
self._format = text
self.valueChanged()
def valueChanged(self):
x, y = self.target.pos()
if self.property("formattableText"):
self.setText(self._format.format(float(x), float(y)))
elif callable(self._format):
self.setText(self._format(x, y))
def viewTransformChanged(self):
viewbox = self.getViewBox()
if isinstance(viewbox, ViewBox):
viewPixelSize = viewbox.viewPixelSize()
scaledOffset = QtCore.QPointF(
self.offset.x() * viewPixelSize[0], self.offset.y() * viewPixelSize[1]
)
self.setPos(scaledOffset)
return super().viewTransformChanged()
def mouseClickEvent(self, ev):
return self.parentItem().mouseClickEvent(ev)
def mouseDragEvent(self, ev):
targetItem = self.parentItem()
if not targetItem.movable or ev.button() != QtCore.Qt.MouseButton.LeftButton:
return
ev.accept()
if ev.isStart():
targetItem.symbolOffset = targetItem.pos() - self.mapToView(
ev.buttonDownPos()
)
targetItem.moving = True
if not targetItem.moving:
return
targetItem.setPos(targetItem.symbolOffset + self.mapToView(ev.pos()))
if ev.isFinish():
targetItem.moving = False
targetItem.sigPositionChangeFinished.emit(self)