I am trying to tag x-spans of a data trace and populate a table with tagNames, starting x value, and the ending x value. I am using a dictionary of 'highlight' objects to keep track of the x-spans in case they need to be edited (increased or decreased) later. The dictionary maps the x Start value to the highlight object, as the x start values are expected to be unique (there is no overlap of x-spans for the tagging).
In order to do this, I am emitting a signal when the user beings to edit a cell on the table. The function that the first signal connects to emits another signal (ideally for whether the xStart is changed vs. the xEnd, but I have only implemented the xStart thus far), which actually changes the appearance of the span to match the edit.
I asked a similar question a few weeks ago but wasn't able to get an answer. The old question is here: PyQT5 slot parameters not updating after first call. In response to the tips given there, I wrote the following example:
import sys
from PyQt5.QtWidgets import *
from PyQt5 import QtCore
from PyQt5.QtCore import *
from PyQt5.QtGui import *
from matplotlib.backends.backend_qt5agg import FigureCanvasQTAgg as FigureCanvas
from matplotlib.figure import Figure
import matplotlib.widgets as mwidgets
from functools import partial
class Window(QMainWindow):
def __init__(self, parent = None):
super(Window, self).__init__(parent)
self.resize(1600, 800)
self.MyUI()
def MyUI(self):
canvas = Canvas(self, width=14, height=12, dpi=100)
canvas.move(0,0)
#use this object in the dictionary to hold onto all the spans.
class highlight:
def __init__(self, tag, xStart, xEnd, highlightObj):
self.tag = tag
self.xStart = xStart
self.xEnd = xEnd
self.highlightObj = highlightObj
class Canvas(FigureCanvas):
def __init__(self, parent, width = 14, height = 12, dpi = 100):
Plot = Figure(figsize=(width, height), dpi=dpi)
self.Axes = Plot.add_subplot(111)
self.Axes.set_position([0.05, 0.58, 0.66, 0.55])
self.rowCount = 0
super().__init__(Plot)
self.setParent(parent)
##add all relevant lines to plot
self.Axes.plot([0,1,2,3,4], [3, 4, 5, 6, 7])
self.Axes.set_xlabel('Frame', fontsize = 10)
self.Axes.grid()
self.Axes.set_aspect(1)
Plot.canvas.draw()
self.highlights = {} #empty dictionary to store all the tags.
##define a table to hold the values postselection
self.taggingTable = QTableWidget(self)
self.taggingTable.setColumnCount(3)
self.taggingTable.setRowCount(100)
self.taggingTable.setGeometry(QRect(1005,85, 330, 310))
self.taggingTable.setHorizontalHeaderLabels(['Behavior','Start Frame', 'End Frame'])
Canvas.span = mwidgets.SpanSelector(self.Axes, self.onHighlight, "horizontal",
interactive = True, useblit=True, props=dict(alpha=0.5, facecolor="blue"),)
self.draw_idle()
self.taggingTable.selectionModel().selectionChanged.connect(self.onCellSelect)
self.draw_idle()
##highlighting adds a highlight item to the directory.
def onHighlight(self, xStart, xEnd):
tagName = "No Tag"
self.taggingTable.setItem(self.rowCount, 0, QTableWidgetItem(tagName))
self.taggingTable.setItem(self.rowCount, 1, QTableWidgetItem(str(int(xStart))))
self.taggingTable.setItem(self.rowCount, 2, QTableWidgetItem(str(int(xEnd))))
self.rowCount = self.rowCount + 1
highlightObj = self.Axes.axvspan(xStart, xEnd, color = 'blue', alpha = 0.5)
self.highlights[int(xStart)] = highlight(tagName, xStart, xEnd, highlightObj)
self.draw_idle()
def xStartChanged(self, xStart, rowVal):
if self.inCounter == 0:
print("xStart in slot: ", xStart)
xEnd = self.highlights[xStart].xEnd
xStartNew = int(self.taggingTable.item(rowVal, 1).text())
self.highlights[xStart].highlightObj.remove() #remove old from the plot
del self.highlights[xStart] #remove old from directory
highlightObj = self.Axes.axvspan(xStartNew, xEnd, color = 'blue', alpha = 0.5) #add new to plot
self.highlights[xStartNew] = highlight("No tagName", xStartNew, xEnd, highlightObj) #add new to directory
self.taggingTable.clearSelection() #deselect value from table
self.draw_idle()
self.inCounter = self.inCounter + 1
def onCellSelect(self):
index = self.taggingTable.selectedIndexes()
if len(index) != 0:
rowVal = index[0].row()
if not (self.taggingTable.item(rowVal, 1) is None):
xStart = int(self.taggingTable.item(rowVal, 1).text())
print("--------------")
print("xStart in signal: ", xStart)
self.inCounter = 0
self.taggingTable.itemChanged.connect(lambda: self.xStartChanged(xStart, rowVal))
app = QApplication(sys.argv)
window = Window()
window.show()
app.exec()
A test I run is when I highlight two traces:
and then I successfully change a first trace:
However, when I attempt to edit the second trace, the program crashes:
To debug, I tried to check what the signals were emitting and receiving. it produces the following output:
--------------
xStart in signal: 0
xStart in slot: 0 ##First slot call gets correct signal
--------------
xStart in signal: 3
xStart in slot: 0 ## Second slot gets the first signal instead of the second
Traceback (most recent call last):
File "//Volumes/path/file.py", line 105, in <lambda>
self.taggingTable.itemChanged.connect(lambda: self.xStartChanged(xStart, rowVal))
File "//Volumes/path/file.py", line 86, in xStartChanged
xEnd = self.highlights[xStart].xEnd
KeyError: 0
zsh: abort python Volumes/path file.py
I tried to use information online on unique connections but I am not sure how to implement them. Thank you in advance for any help.