Open PyQt5 save file dialog from jupyter notebook to save matplotlib figure - matplotlib

Question

What I want to do
I am trying to make an interactive plot for a Jupyter Notebook. The functions are all written in different files, but their intended use is in interactive notebook sessions. I have a Button widget on a matplotlib figure, which, when clicked, I want to open a file dialog where a user can enter a filename to save the figure to. I am on Mac OSX (Mojave 10.14.6) and Tkinter is giving me major problems (complete system crashes), so I am trying to implement this with PyQt5.
The code
-----------
plotting.py
-----------
from . import file_dialog as fdo
import matplotlib.pyplot as plt
import matplotlib.widgets as wdgts
def plot_stack(stack):
fig, ax = plt.subplots(figsize=(8, 6))
plt.subplots_adjust(bottom=0.25, left=-0.1)
... # plotting happens here
# button for saving
def dosaveframe(event):
fname = fdo.save()
fig.savefig(fname) # to be changed to something more appropriate
savea = plt.axes([0.65, 0.8, 0.15, 0.05], facecolor=axcolor)
saveb = Button(savea, "save frame", hovercolor="yellow")
saveb.on_clicked(dosaveframe)
savea._button = saveb # for persistence
plt.show()
--------------
file_dialog.py
--------------
import sys
from PyQt5.QtWidgets import QApplication
from PyQt5.QtWidgets import (QWidget, QFileDialog)
class SaveFileDialog(QWidget):
def __init__(self, text="Save file", types="All Files (*)"):
super().__init__()
self.title = text
self.setWindowTitle(self.title)
self.types = types
self.filename = self.saveFileDialog()
self.show()
def saveFileDialog(self):
options = QFileDialog.Options()
options |= QFileDialog.DontUseNativeDialog
filename, _ = (
QFileDialog.getSaveFileName(self, "Enter filename",
self.types, options=options))
return filename
def save(directory='./', filters="All files (*)"):
"""Open a save file dialog"""
app = QApplication([directory])
ex = SaveFileDialog(types=filters)
return ex.filename
sys.exit(app.exec_())
What is not working
The save dialog opens and it responds to the mouse, but not to the keyboard. The keyboard stays connected to the notebook no matter if I select the little window, so when I press "s" it saves the notebook. As such, the user can not enter a file path. How can I make this work? I have Anaconda, PyQt 5.9.2, matplotlib 3.1.1, jupyter 1.0.0.

Answer 1

I found a very crappy, non-clean solution but it seems to work. For some reason, opening a QFileDialog directly does not allow me to activate it. It opens up behind the active window from where it was called (terminal window or browser in Jupyter Notebook) and does not respond to the keyboard. So the save function in the following block does NOT work as expected on Mac:
from PyQt5.QtWidgets import QApplication, QFileDialog
def save(directory='./', filters="All files (*)"):
app = QApplication([directory])
path, _ = QFileDialog.getSaveFileName(caption="Save to file",
filter=filters,
options=options)
return path
What does work is if the file dialog is opened from a widget. So working with a dummy widget that never shows up on the screen does work for me, at least from the command line:
from PyQt5.QtWidgets import (QApplication, QFileDialog, QWidget)
class DummySaveFileDialogWidget(QWidget):
def __init__(self, title="Save file", filters="All Files (*)"):
super().__init__()
self.title = title
self.filters = filters
self.fname = self.savefiledialog()
def savefiledialog(self):
filename, _ = QFileDialog.getSaveFileName(caption=self.title,
filter=self.filters,
options=options)
return filename
def save(directory='./', filters="All files (*)"):
app = QApplication([directory])
form = DummySaveFileDialogWidget()
return form.fname
If anyone finds a more elegant solution that works let me know
EDIT: this works when it is called from the command line, but still not from a Jupyter Notebook. Also tried this, no success. The file dialog stays behind the browser window and does not respond to the keyboard.