SVGExporter: Background color

[JensReimann]

SVGExporter generates an additional background tag of 100% width and height in generateSvg(). This tag uses rgba to define the color which seens not to be fully supported by the standard. I.e. inkscape won't recognize the color, causing it to appear black (BTW: the size is also not correct).

Short description

Background color rectangle is incorrectly rendered.

Code to reproduce

Call export from context menu and select SVG as output format. Press "Copy" button and insert SVG image to e.g. inkscape (tested with version 1.1).

Expected behavior

The background shall be filled by the selected color.

Real behavior

The background rectangle will be black no matter what color was selected. The size is also wrong.

Tested environment(s)

• PyQtGraph version: 0.12.3
• Qt Python binding: PySide2 5.13.2 Qt 5.12.9
• Python version: 3.8
• NumPy version: 1.20.1
• Operating system: Windows 10
• Installation method: conda

Additional context

Proposed solution: either use Qt SVGGenerator to generate the background rectangle or add an option to disable background export at all (no background rectangle to be generated).

[3fon3fonov]

I confirm this. I got the same with programs like "inkscape" and "convert"....An user also confirm the bug using CorelDraw.

However, I was able to make it work with "rsvg-convert"

I have a small bash script that converts from .svg to .pdf

#!/bin/bash

for i in $@; do
  rsvg-convert -f pdf -o $(basename $i .svg).pdf $(basename $i .svg).svg
done

E.g.,

$ bash svg2pdf.sh test.svg

produces the attached file (pdf-->.png shown), which is 1:1 with the .svg

However, notice that the top plot also exports the x-axis, whereas, the GraphicsScene should be:

[j9ac9k]

Well, I got the background issue sorted out; but the height/width is proving to be really problematic!

[j9ac9k]

Ok, figured out the scaling issue...that one was a doozy, but the diff ended up being tiny.

@3fon3fonov I would encourage you to open a separate issue for any issues with the SVG you have. Ideally with some code that I can replicate the issue you're having.

[3fon3fonov]

Dear Ogi, Many thanks! However, updating to the new pyqtgrapg leads to this: Traceback (most recent call last): File "exostriker_gui.py", line 2, in <module> import exostriker File "/home/trifonov/exostriker/exostriker/__init__.py", line 1, in <module> from exostriker import gui File "/home/trifonov/exostriker/exostriker/gui.py", line 51, in <module> import pyqtgraph as pg File "/home/trifonov/exostriker/exostriker/lib/pyqtgraph/__init__.py", line 205, in <module> from .graphicsItems.AxisItem import * File "/home/trifonov/exostriker/exostriker/lib/pyqtgraph/graphicsItems/AxisItem.py", line 11, in <module> from .GraphicsWidget import GraphicsWidget File "/home/trifonov/exostriker/exostriker/lib/pyqtgraph/graphicsItems/GraphicsWidget.py", line 2, in <module> from .GraphicsItem import GraphicsItem File "/home/trifonov/exostriker/exostriker/lib/pyqtgraph/graphicsItems/GraphicsItem.py", line 40, in <module> class GraphicsItem(object): File "/home/trifonov/exostriker/exostriker/lib/pyqtgraph/graphicsItems/GraphicsItem.py", line 613, in GraphicsItem nodes: dict[str, Element] TypeError: 'type' object is not subscriptable I am on Python3.8 & PyQt5==5.15.4 I cannot even open the exostriker. Again, many thanks for looking at the SVG exporter! #### EDIT ##### This seems to be Python3.8 problem. The following hint helps (around line 615): from typing import Dict,List,Tuple def generateSvg( self, nodes: Dict[str, Element] ) -> Optional[Tuple[Element, List[Element]]]: However, I am not sure how that will work on Python3.9 and above.... Can you please update GraphicsItem.py to be Python3.8+ compatible? Many thanks!

[j9ac9k]

PyQtGraph follows NEP-29 when it comes to deprecating support for Python and NumPy versions. We actually kept Python 3.8 super a few months after the date to remove it.

There are other PRs in the queue that will further break 3.8 support, so that ship has sailed.