silx.view.Viewer : New feature to display multiple curves in a new window

[RebeloAlexis]

A new feature has been added, allowing the display of multiple curves by selecting values for X or Y. Only 1D files are taken into account.
How to access :

    - Open silx view
    - Select a file
    - Open the 'plot selection' window (View -> plot selection)
    - Drag and drop dataset to the new window
    - Admire the results :)

All the code is in silx.view.CustomPlotSelectionWindow

[t20100]

Nice!

I left a few suggestions.

There is an issue with test with PySide6, I guess None is not accepted byt QStandardItem.appendRow:

/opt/hostedtoolcache/Python/3.8.18/x64/lib/python3.8/site-packages/silx/app/view/test/test_view.py:89: 
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 
/opt/hostedtoolcache/Python/3.8.18/x64/lib/python3.8/site-packages/silx/app/view/Viewer.py:120: in __init__
    self._customPlotSelectionWindow = CustomPlotSelectionWindow(self)
/opt/hostedtoolcache/Python/3.8.18/x64/lib/python3.8/site-packages/silx/app/view/CustomPlotSelectionWindow.py:460: in __init__
    model = _FileListModel(self.plot1D)
/opt/hostedtoolcache/Python/3.8.18/x64/lib/python3.8/site-packages/silx/app/view/CustomPlotSelectionWindow.py:118: in __init__
    self._addYFile("")
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 

self = <silx.app.view.CustomPlotSelectionWindow._FileListModel(0x5585b7632640) at 0x7f4d1daa2480>
filename = '', curve = None, node = 'X'

    def _addYFile(self, filename, curve=None, node="X"):
        fileItem, iconItem, removeItem = self._createRowItems(filename, curve)
        if not filename:
            fileItem.setData(qt.QSize(0, 30), qt.Qt.SizeHintRole)
    
        if self.getYParent().rowCount() == 0:
>           self.getYParent().appendRow([None, fileItem])
E           TypeError: 'PySide6.QtGui.QStandardItem.appendRow' called with wrong argument types:
E             PySide6.QtGui.QStandardItem.appendRow(list)
E           Supported signatures:
E             PySide6.QtGui.QStandardItem.appendRow(PySide6.QtGui.QStandardItem)
E             PySide6.QtGui.QStandardItem.appendRow(Sequence[PySide6.QtGui.QStandardItem])

[payno]

Very nice PR 💪
Minor comments.

If we want to be picky a couple of lines could be added to the PR to explain how to use it:

• open silx view
• select a file
• open the 'plot selection' window (Views -> plot selection)
• drag and drop dataset to the new window
• admire the results :)

But I think the documentation part will come in another PR right ?.
Else nice user experience 😄

[payno]

maybe a 'painter' context would be more pythonic. Something which handle the save and the restore function

with painter_state_context(painter):  # not very inspired by the name
    painter.setPen(self.__highlightDropPen)
    painter.drawRect(option.rect.adjusted(1, 1, -1, -1))

[RebeloAlexis]

I don't know much about it, and I'm not used to using "with", so for the moment I'll leave it at that.

[payno]

This condition was not 'straightforward' for me (maybe I am tired).
Anyway to help understanding here are options:

1. add typing to filename.
   because from outside for this condition, according to the context we can consider filename to be a string or None. If you provide

def _addYFile(self, filename: str, curve=None, node="X"):

Then this will allow us to remove one use case
2. provide a simple comment

        if not filename:
            # provide size hint for 'empty' item

[RebeloAlexis]

Yes, typing and docString will be added to the next PR.