From da24351fcf93b40c135e337f0ae54341dfe7b6bc Mon Sep 17 00:00:00 2001
From: Neil Vaytet <neil.vaytet@ess.eu>
Date: Wed, 10 Jun 2026 16:51:42 +0200
Subject: [PATCH 1/4] remove plotly backend

---
 src/plopp/backends/plotly/__init__.py     |   2 -
 src/plopp/backends/plotly/canvas.py       | 373 ----------------------
 src/plopp/backends/plotly/figure.py       |  44 ---
 src/plopp/backends/plotly/line.py         | 319 ------------------
 tests/backends/plotly/conftest.py         |  13 -
 tests/backends/plotly/plotly_line_test.py | 114 -------
 tests/conftest.py                         |   5 +-
 tests/graphics/artists_test.py            |  17 -
 tests/graphics/canvas_test.py             |   7 -
 tests/graphics/figures_test.py            |   7 -
 tests/plotting/plot_1d_test.py            |  18 --
 11 files changed, 2 insertions(+), 917 deletions(-)
 delete mode 100644 src/plopp/backends/plotly/__init__.py
 delete mode 100644 src/plopp/backends/plotly/canvas.py
 delete mode 100644 src/plopp/backends/plotly/figure.py
 delete mode 100644 src/plopp/backends/plotly/line.py
 delete mode 100644 tests/backends/plotly/conftest.py
 delete mode 100644 tests/backends/plotly/plotly_line_test.py

diff --git a/src/plopp/backends/plotly/__init__.py b/src/plopp/backends/plotly/__init__.py
deleted file mode 100644
index 012cd010c..000000000
--- a/src/plopp/backends/plotly/__init__.py
+++ /dev/null
@@ -1,2 +0,0 @@
-# SPDX-License-Identifier: BSD-3-Clause
-# Copyright (c) 2024 Scipp contributors (https://github.com/scipp)
diff --git a/src/plopp/backends/plotly/canvas.py b/src/plopp/backends/plotly/canvas.py
deleted file mode 100644
index 0c704ef70..000000000
--- a/src/plopp/backends/plotly/canvas.py
+++ /dev/null
@@ -1,373 +0,0 @@
-# SPDX-License-Identifier: BSD-3-Clause
-# Copyright (c) 2023 Scipp contributors (https://github.com/scipp)
-
-from typing import Literal
-
-import plotly.graph_objects as go
-import scipp as sc
-
-from ...core.utils import maybe_variable_to_number
-from ...graphics.bbox import BoundingBox
-from ...utils import parse_mutually_exclusive
-
-
-class Canvas:
-    """
-    Plotly-based canvas used to render 2D graphics.
-    It provides a figure and some axes, as well as functions for controlling the zoom,
-    panning, and the scale of the axes.
-
-    Parameters
-    ----------
-    figsize:
-        The width and height of the figure, in inches.
-    title:
-        The title to be placed above the figure.
-    user_vmin:
-        The minimum value for the vertical axis. If a number (without a unit) is
-        supplied, it is assumed that the unit is the same as the current vertical axis
-        unit.
-    user_vmax:
-        The maximum value for the vertical axis. If a number (without a unit) is
-        supplied, it is assumed that the unit is the same as the current vertical axis
-        unit.
-    """
-
-    def __init__(
-        self,
-        figsize: tuple[float, float] | None = None,
-        title: str | None = None,
-        user_vmin: sc.Variable | float | None = None,
-        user_vmax: sc.Variable | float | None = None,
-        xmin: sc.Variable | float | None = None,
-        xmax: sc.Variable | float | None = None,
-        ymin: sc.Variable | float | None = None,
-        ymax: sc.Variable | float | None = None,
-        logx: bool | None = None,
-        logy: bool | None = None,
-        xlabel: str | None = None,
-        ylabel: str | None = None,
-        norm: Literal['linear', 'log'] | None = None,
-        **ignored,
-    ):
-        # Note on the `**ignored`` keyword arguments: the figure which owns the canvas
-        # creates both the canvas and an artist object (Line or Image). The figure
-        # accepts keyword arguments, and has to somehow forward them to the canvas and
-        # the artist. Since the figure has no detailed knowledge of the underlying
-        # backend that implements the canvas, it cannot have specific arguments (such
-        # as `layout` for specifying a Plotly layout).
-        # Instead, we forward all the kwargs from the figure to both the canvas and the
-        # artist, and filter out the artist kwargs with `**ignored`.
-
-        ymin = parse_mutually_exclusive(vmin=user_vmin, ymin=ymin)
-        ymax = parse_mutually_exclusive(vmax=user_vmax, ymax=ymax)
-        logy = parse_mutually_exclusive(norm=norm, logy=logy)
-
-        self.fig = go.FigureWidget(
-            layout={
-                'modebar_remove': [
-                    'zoom',
-                    'pan',
-                    'select',
-                    'toImage',
-                    'zoomIn',
-                    'zoomOut',
-                    'autoScale',
-                    'resetScale',
-                    'lasso2d',
-                ],
-                'margin': {'l': 0, 'r': 0, 't': 0 if title is None else 40, 'b': 0},
-                'dragmode': False,
-                'width': 600 if figsize is None else figsize[0],
-                'height': 400 if figsize is None else figsize[1],
-            }
-        )
-        self.figsize = figsize
-        self._xmin = xmin
-        self._xmax = xmax
-        self._ymin = ymin
-        self._ymax = ymax
-        self._xlabel = xlabel
-        self._ylabel = ylabel
-        self.units = {}
-        self.dims = {}
-        self._own_axes = False
-        if title:
-            self.title = title
-        self.bbox = BoundingBox()
-
-        logx = False if logx is None else logx
-        logy = False if logy is None else logy
-        if logx:
-            self.xscale = 'log'
-        if logy:
-            self.yscale = 'log'
-        if xlabel is not None:
-            self.xlabel = xlabel
-        if ylabel is not None:
-            self.ylabel = ylabel
-
-    def to_widget(self):
-        return self.fig
-
-    def save(self, filename: str):
-        """
-        Save the figure to file.
-        The default directory for writing the file is the same as the
-        directory where the script or notebook is running.
-
-        Parameters
-        ----------
-        filename:
-            Name of the output file. Possible file extensions are ``.jpg``, ``.png``,
-            ``.svg``, ``.pdf``, and ``.html`.
-        """
-        ext = filename.split('.')[-1]
-        if ext == 'html':
-            self.fig.write_html(filename)
-        else:
-            self.fig.write_image(filename)
-
-    def set_axes(self, dims, units, dtypes):
-        """
-        Set the axes dimensions and units.
-
-        Parameters
-        ----------
-        dims:
-            The dimensions of the data.
-        units:
-            The units of the data.
-        dtypes:
-            The data types of the data.
-        """
-        self.dims = dims
-        self.units = units
-        self.dtypes = dtypes
-        key = 'y' if 'y' in self.units else 'data'
-        self.bbox = BoundingBox(
-            xmin=maybe_variable_to_number(self._xmin, unit=self.units['x']),
-            xmax=maybe_variable_to_number(self._xmax, unit=self.units['x']),
-            ymin=maybe_variable_to_number(self._ymin, unit=self.units[key]),
-            ymax=maybe_variable_to_number(self._ymax, unit=self.units[key]),
-        )
-
-    @property
-    def empty(self) -> bool:
-        """
-        Check if the canvas is empty.
-        """
-        return not self.dims
-
-    @property
-    def title(self) -> str:
-        """
-        Get or set the title of the plot.
-        """
-        return self.fig.layout.title.text
-
-    @title.setter
-    def title(self, text: str):
-        layout = self.fig.layout
-        if not text:
-            layout.margin.t = 0
-        elif layout.margin.t == 0:
-            layout.margin.t = 40
-        layout.title = text
-
-    @property
-    def xlabel(self) -> str:
-        """
-        Get or set the label of the x-axis.
-        """
-        return self.fig.layout.xaxis.title.text
-
-    @xlabel.setter
-    def xlabel(self, lab: str):
-        self.fig.layout.xaxis.title = lab
-
-    @property
-    def ylabel(self) -> str:
-        """
-        Get or set the label of the y-axis.
-        """
-        return self.fig.layout.yaxis.title.text
-
-    @ylabel.setter
-    def ylabel(self, lab: str):
-        self.fig.layout.yaxis.title = lab
-
-    @property
-    def xscale(self) -> Literal['linear', 'log']:
-        """
-        Get or set the scale of the x-axis ('linear' or 'log').
-        """
-        return self.fig.layout.xaxis.type or 'linear'
-
-    @xscale.setter
-    def xscale(self, scale: Literal['linear', 'log']):
-        self.fig.update_xaxes(type=scale)
-
-    @property
-    def yscale(self) -> Literal['linear', 'log']:
-        """
-        Get or set the scale of the y-axis ('linear' or 'log').
-        """
-        return self.fig.layout.yaxis.type or 'linear'
-
-    @yscale.setter
-    def yscale(self, scale: Literal['linear', 'log']):
-        self.fig.update_yaxes(type=scale)
-
-    @property
-    def xmin(self) -> float:
-        """
-        Get or set the lower (left) bound of the x-axis.
-        """
-        return self.fig.layout.xaxis.range[0]
-
-    @xmin.setter
-    def xmin(self, value: float):
-        self.fig.layout.xaxis.range = [value, self.xmax]
-
-    @property
-    def xmax(self) -> float:
-        """
-        Get or set the upper (right) bound of the x-axis.
-        """
-        return self.fig.layout.xaxis.range[1]
-
-    @xmax.setter
-    def xmax(self, value: float):
-        self.fig.layout.xaxis.range = [self.xmin, value]
-
-    @property
-    def xrange(self) -> tuple[float, float]:
-        """
-        Get or set the range/limits of the x-axis.
-        """
-        return self.fig.layout.xaxis.range
-
-    @xrange.setter
-    def xrange(self, value: tuple[float, float]):
-        self.fig.layout.xaxis.range = value
-
-    @property
-    def ymin(self) -> float:
-        """
-        Get or set the lower (bottom) bound of the y-axis.
-        """
-        return self.fig.layout.yaxis.range[0]
-
-    @ymin.setter
-    def ymin(self, value: float):
-        self.fig.layout.yaxis.range = [value, self.ymax]
-
-    @property
-    def ymax(self) -> float:
-        """
-        Get or set the upper (top) bound of the y-axis.
-        """
-        return self.fig.layout.yaxis.range[1]
-
-    @ymax.setter
-    def ymax(self, value: float):
-        self.fig.layout.yaxis.range = [self.ymin, value]
-
-    @property
-    def yrange(self) -> tuple[float, float]:
-        """
-        Get or set the range/limits of the y-axis.
-        """
-        return self.fig.layout.yaxis.range
-
-    @yrange.setter
-    def yrange(self, value: tuple[float, float]):
-        self.fig.layout.yaxis.range = value
-
-    @property
-    def logx(self) -> bool:
-        """
-        Get or set whether the x-axis is in logarithmic scale.
-        """
-        return self.xscale == 'log'
-
-    @logx.setter
-    def logx(self, value: bool):
-        self.xscale = 'log' if value else 'linear'
-
-    @property
-    def logy(self) -> bool:
-        """
-        Get or set whether the y-axis is in logarithmic scale.
-        """
-        return self.yscale == 'log'
-
-    @logy.setter
-    def logy(self, value: bool):
-        self.yscale = 'log' if value else 'linear'
-
-    def reset_mode(self):
-        """
-        Reset the modebar mode to nothing, to disable all zoom/pan tools.
-        """
-        self.fig.update_layout(dragmode=False)
-
-    def zoom(self):
-        """
-        Activate the underlying Plotly zoom tool.
-        """
-        self.fig.update_layout(dragmode='zoom')
-
-    def pan(self):
-        """
-        Activate the underlying Plotly pan tool.
-        """
-        self.fig.update_layout(dragmode='pan')
-
-    def panzoom(self, value: Literal['pan', 'zoom'] | None):
-        """
-        Activate or deactivate the pan or zoom tool, depending on the input value.
-        """
-        if value == 'zoom':
-            self.zoom()
-        elif value == 'pan':
-            self.pan()
-        elif value is None:
-            self.reset_mode()
-
-    def download_figure(self):
-        """
-        Save the figure to a PNG file via a pop-up dialog.
-        """
-        self.fig.write_image('figure.png')
-
-    def toggle_logx(self):
-        """
-        Toggle the scale between ``linear`` and ``log`` along the horizontal axis.
-        """
-        self.xscale = 'log' if self.xscale in ('linear', None) else 'linear'
-
-    def toggle_logy(self):
-        """
-        Toggle the scale between ``linear`` and ``log`` along the vertical axis.
-        """
-        self.yscale = 'log' if self.yscale in ('linear', None) else 'linear'
-
-    def draw(self):
-        pass
-
-    def update_legend(self):
-        pass
-
-    def has_user_xlabel(self) -> bool:
-        """
-        Return ``True`` if the user has set an x-axis label.
-        """
-        return self._xlabel is not None
-
-    def has_user_ylabel(self) -> bool:
-        """
-        Return ``True`` if the user has set a y-axis label.
-        """
-        return self._ylabel is not None
diff --git a/src/plopp/backends/plotly/figure.py b/src/plopp/backends/plotly/figure.py
deleted file mode 100644
index 30cddf6f8..000000000
--- a/src/plopp/backends/plotly/figure.py
+++ /dev/null
@@ -1,44 +0,0 @@
-# SPDX-License-Identifier: BSD-3-Clause
-# Copyright (c) 2023 Scipp contributors (https://github.com/scipp)
-
-from ipywidgets import HBox, VBox
-
-from ...graphics import BaseFig
-from ...widgets import HBar, VBar, make_toolbar_canvas2d
-
-
-class Figure(BaseFig, VBox):
-    """
-    Create an interactive figure to represent one-dimensional data.
-    """
-
-    def __init__(self, View, *args, **kwargs):
-        self.interactive = True
-        self.view = View(*args, **kwargs)
-        self.toolbar = make_toolbar_canvas2d(view=self.view)
-        self.left_bar = VBar([self.toolbar])
-        self.right_bar = VBar()
-        self.bottom_bar = HBar()
-        self.top_bar = HBar()
-
-        super().__init__(
-            [
-                self.top_bar,
-                HBox([self.left_bar, self.view.canvas.to_widget(), self.right_bar]),
-                self.bottom_bar,
-            ]
-        )
-
-    def save(self, filename, **kwargs):
-        """
-        Save the figure to file.
-        The default directory for writing the file is the same as the
-        directory where the script or notebook is running.
-
-        Parameters
-        ----------
-        filename:
-            Name of the output file. Possible file extensions are ``.jpg``, ``.png``,
-            ``.svg``, ``.pdf``, and ``html``.
-        """
-        return self.view.canvas.save(filename, **kwargs)
diff --git a/src/plopp/backends/plotly/line.py b/src/plopp/backends/plotly/line.py
deleted file mode 100644
index b670fcc14..000000000
--- a/src/plopp/backends/plotly/line.py
+++ /dev/null
@@ -1,319 +0,0 @@
-# SPDX-License-Identifier: BSD-3-Clause
-# Copyright (c) 2023 Scipp contributors (https://github.com/scipp)
-
-import uuid
-from typing import Literal
-
-import numpy as np
-import plotly.graph_objects as go
-import scipp as sc
-from plotly.colors import qualitative as plotly_colors
-
-from ...graphics.bbox import BoundingBox
-from ..common import check_ndim, make_line_bbox, make_line_data
-from .canvas import Canvas
-
-
-def _parse_dicts_in_kwargs(kwargs, name):
-    out = {}
-    for key, value in kwargs.items():
-        if isinstance(value, dict):
-            if name in value:
-                out[key] = value[name]
-        else:
-            out[key] = value
-    return out
-
-
-class Line:
-    """
-    Artist to represent one-dimensional data.
-    If the coordinate is bin centers, the line is (by default) a set of markers.
-    If the coordinate is bin edges, the line is a step function.
-
-    Parameters
-    ----------
-    canvas:
-        The canvas that will display the line.
-    data:
-        The initial data to create the line from.
-    uid:
-        The unique identifier of the artist. If None, a random UUID is generated.
-    artist_number:
-        The canvas keeps track of how many lines have been added to it. This number is
-        used to set the color and marker parameters of the line.
-    errorbars:
-        Show errorbars if ``True``.
-    mask_color:
-        The color to be used to represent the masks.
-    mode:
-        The mode of the line, either 'markers' or 'lines'.
-    marker:
-        The marker style to use.
-    """
-
-    def __init__(
-        self,
-        canvas: Canvas,
-        data: sc.DataArray,
-        uid: str | None = None,
-        artist_number: int = 0,
-        errorbars: bool = True,
-        mask_color: str = 'black',
-        mode: str | None = None,
-        marker: str | None = None,
-        **kwargs,
-    ):
-        check_ndim(data, ndim=1, origin='Line')
-        self.uid = uid if uid is not None else uuid.uuid4().hex
-        self._fig = canvas.fig
-        self._data = data
-
-        line_args = _parse_dicts_in_kwargs(kwargs, name=data.name)
-
-        self._line = None
-        self._mask = None
-        self._error = None
-        self._unit = None
-        self.label = data.name
-        self._dim = self._data.dim
-        self._unit = self._data.unit
-        self._coord = self._data.coords[self._dim]
-
-        line_data = make_line_data(data=self._data, dim=self._dim)
-
-        default_colors = plotly_colors.Plotly
-        default_line_style = {
-            'color': default_colors[artist_number % len(default_colors)]
-        }
-        default_marker_style = {
-            'symbol': artist_number % 52  # Plotly has 52 marker styles
-        }
-
-        line_shape = None
-
-        if mode is None:
-            if line_data["hist"]:
-                line_shape = 'vh'
-                mode = 'lines'
-            else:
-                mode = 'markers'
-
-        marker_style = default_marker_style if marker is None else marker
-        line_style = {**default_line_style, **line_args}
-
-        self._line = go.Scatter(
-            x=np.asarray(line_data['values']['x']),
-            y=np.asarray(line_data['values']['y']),
-            name=self.label,
-            mode=mode,
-            marker=marker_style,
-            line_shape=line_shape,
-            line=line_style,
-        )
-
-        if errorbars and (line_data['stddevs'] is not None):
-            self._error = go.Scatter(
-                x=np.asarray(line_data['stddevs']['x']),
-                y=np.asarray(line_data['stddevs']['y']),
-                line=line_style,
-                name=self.label,
-                mode='markers',
-                marker={'opacity': 0},
-                error_y={'type': 'data', 'array': line_data['stddevs']['e']},
-                showlegend=False,
-            )
-
-        marker_line_style = {'width': 3, 'color': mask_color}
-        if 'line' in marker_style:
-            marker_style['line'].update(marker_line_style)
-        else:
-            marker_style['line'] = marker_line_style
-        if 'width' in line_style:
-            line_style['width'] *= 5
-        else:
-            line_style['width'] = 5
-        if 'lines' in mode:
-            line_style['color'] = mask_color
-
-        self._mask = go.Scatter(
-            x=np.asarray(line_data['mask']['x']),
-            y=np.asarray(line_data['mask']['y']),
-            name=self.label,
-            mode=mode,
-            marker=marker_style,
-            line_shape=line_shape,
-            line=line_style,
-            visible=line_data['mask']['visible'],
-            showlegend=False,
-        )
-
-        # Below, we need to re-define the line because it seems that the Scatter trace
-        # that ends up in the figure is a copy of the one above.
-        # Plotly has no concept of zorder, so we need to add the traces in a specific
-        # order
-        if 'lines' in mode:
-            self._fig.add_trace(self._mask)
-            self._mask = self._fig.data[-1]
-            self._fig.add_trace(self._line)
-            self._line = self._fig.data[-1]
-            if self._error is not None:
-                self._fig.add_trace(self._error)
-                self._error = self._fig.data[-1]
-        else:
-            self._fig.add_trace(self._line)
-            self._line = self._fig.data[-1]
-            if self._error is not None:
-                self._fig.add_trace(self._error)
-                self._error = self._fig.data[-1]
-            self._fig.add_trace(self._mask)
-            self._mask = self._fig.data[-1]
-
-        self._line._plopp_id = self.uid
-        self._mask._plopp_id = self.uid
-        if self._error is not None:
-            self._error._plopp_id = self.uid
-
-    def update(self, new_values: sc.DataArray):
-        """
-        Update the x and y positions of the data points from new data.
-
-        Parameters
-        ----------
-        new_values:
-            New data to update the line values, masks, errorbars from.
-        """
-        check_ndim(new_values, ndim=1, origin='Line')
-        self._data = new_values
-        line_data = make_line_data(data=self._data, dim=self._dim)
-
-        with self._fig.batch_update():
-            self._line.update(
-                {'x': line_data['values']['x'], 'y': line_data['values']['y']}
-            )
-
-            if (self._error is not None) and (line_data['stddevs'] is not None):
-                self._error.update(
-                    {
-                        'x': line_data['stddevs']['x'],
-                        'y': line_data['stddevs']['y'],
-                        'error_y': {'array': line_data['stddevs']['e']},
-                    }
-                )
-
-            if line_data['mask']['visible']:
-                update = {'x': line_data['mask']['x'], 'y': line_data['mask']['y']}
-                self._mask.update(update)
-                self._mask.visible = True
-            else:
-                self._mask.visible = False
-
-    def remove(self):
-        """
-        Remove the line, masks and errorbar artists from the canvas.
-        """
-        self._fig.data = [
-            trace for trace in list(self._fig.data) if trace._plopp_id != self.uid
-        ]
-
-    @property
-    def color(self) -> str:
-        """
-        The line color.
-        """
-        return self._line.line.color
-
-    @color.setter
-    def color(self, val: str):
-        self._line.line.color = val
-
-    @property
-    def style(self) -> str:
-        """
-        The line style.
-        """
-        return self._line.mode
-
-    @style.setter
-    def style(self, val: str):
-        self._line.mode = val
-
-    @property
-    def width(self) -> float:
-        """
-        The line width.
-        """
-        return self._line.line.width
-
-    @width.setter
-    def width(self, val: float):
-        self._line.line.width = val
-
-    @property
-    def marker(self) -> str:
-        """
-        The marker style.
-        """
-        return self._line.marker
-
-    @marker.setter
-    def marker(self, val: str):
-        self._line.marker = val
-        self._mask.marker = val
-
-    @property
-    def visible(self) -> bool:
-        """
-        The visibility of the line.
-        """
-        return self._line.visible
-
-    @visible.setter
-    def visible(self, val: bool):
-        self._line.visible = val
-        self._mask.visible = val
-        if self._error is not None:
-            self._error.visible = val
-
-    @property
-    def opacity(self) -> float:
-        """
-        The opacity of the line.
-        """
-        return self._line.opacity
-
-    @opacity.setter
-    def opacity(self, val: float):
-        self._line.opacity = val
-        self._mask.opacity = val
-        if self._error is not None:
-            self._error.opacity = val
-
-    def bbox(
-        self, xscale: Literal['linear', 'log'], yscale: Literal['linear', 'log']
-    ) -> BoundingBox:
-        """
-        The bounding box of the line.
-        This includes the x and y bounds of the line and optionally the error bars.
-
-        Parameters
-        ----------
-        xscale:
-            The scale of the x-axis.
-        yscale:
-            The scale of the y-axis.
-        """
-        out = make_line_bbox(
-            data=self._data,
-            dim=self._dim,
-            errorbars=self._error is not None,
-            xscale=xscale,
-            yscale=yscale,
-        )
-        if xscale == 'log':
-            out.xmin = np.log10(out.xmin)
-            out.xmax = np.log10(out.xmax)
-        if yscale == 'log':
-            out.ymin = np.log10(out.ymin)
-            out.ymax = np.log10(out.ymax)
-        return out
diff --git a/tests/backends/plotly/conftest.py b/tests/backends/plotly/conftest.py
deleted file mode 100644
index 2e5e092fc..000000000
--- a/tests/backends/plotly/conftest.py
+++ /dev/null
@@ -1,13 +0,0 @@
-# SPDX-License-Identifier: BSD-3-Clause
-# Copyright (c) 2023 Scipp contributors (https://github.com/scipp)
-
-import pytest
-
-import plopp as pp
-
-
-@pytest.fixture(autouse=True, scope='module')
-def _use_plotly():
-    pp.backends['2d'] = 'plotly'
-    yield
-    pp.backends.reset()
diff --git a/tests/backends/plotly/plotly_line_test.py b/tests/backends/plotly/plotly_line_test.py
deleted file mode 100644
index 5dc87d56e..000000000
--- a/tests/backends/plotly/plotly_line_test.py
+++ /dev/null
@@ -1,114 +0,0 @@
-# SPDX-License-Identifier: BSD-3-Clause
-# Copyright (c) 2023 Scipp contributors (https://github.com/scipp)
-
-import numpy as np
-import pytest
-import scipp as sc
-
-pytest.importorskip("plotly")
-
-
-from plopp.backends.plotly.canvas import Canvas
-from plopp.backends.plotly.line import Line
-from plopp.data.testing import data_array
-
-
-def test_line_creation():
-    da = data_array(ndim=1, unit='K')
-    line = Line(canvas=Canvas(), data=da)
-    assert line._unit == 'K'
-    assert line._dim == 'xx'
-    assert len(line._line.x) == da.sizes['xx']
-    assert np.allclose(line._line.x, da.coords['xx'].values)
-    assert np.allclose(line._line.y, da.values)
-    assert line._error is None
-    assert not line._mask.visible
-
-
-def test_line_creation_bin_edges():
-    da = data_array(ndim=1, binedges=True)
-    line = Line(canvas=Canvas(), data=da)
-    assert len(line._line.x) == da.sizes['xx'] + 1
-
-
-def test_line_with_errorbars():
-    da = data_array(ndim=1, variances=True)
-    line = Line(canvas=Canvas(), data=da)
-    assert np.allclose(line._error.error_y['array'], sc.stddevs(da.data).values)
-
-
-def test_line_with_bin_edges_and_errorbars():
-    da = data_array(ndim=1, binedges=True, variances=True)
-    line = Line(canvas=Canvas(), data=da)
-    assert np.allclose(line._error.x, sc.midpoints(da.coords['xx']).values)
-
-
-def test_line_hide_errorbars():
-    da = data_array(ndim=1, variances=True)
-    line = Line(canvas=Canvas(), data=da, errorbars=False)
-    assert line._error is None
-
-
-def test_line_with_mask():
-    da = data_array(ndim=1, masks=True)
-    line = Line(canvas=Canvas(), data=da)
-    assert line._mask.visible
-
-
-def test_line_with_mask_and_binedges():
-    da = data_array(ndim=1, binedges=True, masks=True)
-    line = Line(canvas=Canvas(), data=da)
-    assert line._mask.visible
-
-
-def test_line_with_two_masks():
-    da = data_array(ndim=1, masks=True)
-    da.masks['two'] = da.coords['xx'] > sc.scalar(25, unit='m')
-    line = Line(canvas=Canvas(), data=da)
-    expected = da.data[da.masks['mask'] | da.masks['two']].values
-    y = line._mask.y
-    assert np.allclose(y[~np.isnan(y)], expected)
-
-
-def test_line_update():
-    da = data_array(ndim=1)
-    line = Line(canvas=Canvas(), data=da)
-    assert np.allclose(line._line.x, da.coords['xx'].values)
-    assert np.allclose(line._line.y, da.values)
-    line.update(da * 2.5)
-    assert np.allclose(line._line.x, da.coords['xx'].values)
-    assert np.allclose(line._line.y, da.values * 2.5)
-
-
-def test_line_update_with_errorbars():
-    da = data_array(ndim=1, variances=True)
-    line = Line(canvas=Canvas(), data=da)
-    assert np.allclose(line._line.y, da.values)
-    assert np.allclose(line._error.error_y['array'], sc.stddevs(da.data).values)
-    new_values = da * 3.3
-    new_values.variances = da.variances
-    line.update(new_values)
-    assert np.allclose(line._line.y, da.values * 3.3)
-    assert np.allclose(line._error.error_y['array'], sc.stddevs(da.data).values)
-    new_values = 1.0 * da
-    new_values.variances = da.variances * 4.0
-    line.update(new_values)
-    assert np.allclose(line._line.y, da.values)
-    assert np.allclose(line._error.error_y['array'], sc.stddevs(da.data).values * 2.0)
-
-
-def test_line_datetime_binedges_with_errorbars():
-    t = np.arange(
-        np.datetime64('2017-03-16T20:58:17'), np.datetime64('2017-03-16T21:15:17'), 20
-    )
-    time = sc.array(dims=['time'], values=t)
-    v = np.random.rand(time.sizes['time'] - 1)
-    da = sc.DataArray(
-        data=sc.array(dims=['time'], values=10 * v, variances=v), coords={'time': time}
-    )
-    xint = t.astype(int)
-    xmid = (0.5 * (xint[1:] + xint[:-1])).astype(int)
-    expected = np.array(xmid, dtype=t.dtype)
-    line = Line(canvas=Canvas(), data=da)
-    # Note that allclose does not work on datetime dtypes
-    assert np.allclose(line._error.x.astype(int), expected.astype(int))
diff --git a/tests/conftest.py b/tests/conftest.py
index 68377fb1c..662c2ac6b 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -46,7 +46,6 @@ def pytest_sessionfinish(session, exitstatus):
 
 BACKENDS_MPL = [('2d', 'mpl-static'), ('2d', 'mpl-interactive')]
 BACKENDS_MPL_INTERACTIVE = [('2d', 'mpl-interactive')]
-BACKENDS_PLOTLY = [('2d', 'plotly')] if util.find_spec('plotly') is not None else []
 
 
 def _select_backend(backend):
@@ -75,12 +74,12 @@ def _parametrize_mpl_backends(request):
     _select_backend(request.param)
 
 
-@pytest.fixture(**_make_fixture_args(BACKENDS_MPL + BACKENDS_PLOTLY))
+@pytest.fixture(**_make_fixture_args(BACKENDS_MPL))
 def _parametrize_all_backends(request):
     _select_backend(request.param)
 
 
-@pytest.fixture(**_make_fixture_args(BACKENDS_MPL_INTERACTIVE + BACKENDS_PLOTLY))
+@pytest.fixture(**_make_fixture_args(BACKENDS_MPL_INTERACTIVE))
 def _parametrize_interactive_1d_backends(request):
     _select_backend(request.param)
 
diff --git a/tests/graphics/artists_test.py b/tests/graphics/artists_test.py
index 3a622ba44..88d0c2f96 100644
--- a/tests/graphics/artists_test.py
+++ b/tests/graphics/artists_test.py
@@ -69,23 +69,6 @@
     ),
 }
 
-if util.find_spec('plotly') is not None:
-    CASES.update(
-        {
-            "line-plotly": (('2d', 'plotly'), pp.plot, {'obj': pp.data.data1d()}),
-            "line-plotly-masks": (
-                ('2d', 'plotly'),
-                pp.plot,
-                {'obj': pp.data.data1d(masks=True)},
-            ),
-            "line-plotly-errorbars": (
-                ('2d', 'plotly'),
-                pp.plot,
-                {'obj': pp.data.data1d(variances=True)},
-            ),
-        }
-    )
-
 
 @pytest.mark.parametrize(("backend", "func", "data"), CASES.values(), ids=CASES.keys())
 class TestArtists:
diff --git a/tests/graphics/canvas_test.py b/tests/graphics/canvas_test.py
index 882a3bb15..e37deb26a 100644
--- a/tests/graphics/canvas_test.py
+++ b/tests/graphics/canvas_test.py
@@ -40,13 +40,6 @@
     ),
 }
 
-if util.find_spec('plotly') is not None:
-    CASES.update(
-        {
-            "linefigure-plotly": (('2d', 'plotly'), linefigure, data1d),
-        }
-    )
-
 
 @pytest.mark.parametrize(
     ("backend", "figure", "data"), CASES.values(), ids=CASES.keys()
diff --git a/tests/graphics/figures_test.py b/tests/graphics/figures_test.py
index dd50370dc..fb278dc25 100644
--- a/tests/graphics/figures_test.py
+++ b/tests/graphics/figures_test.py
@@ -26,13 +26,6 @@
     ),
 }
 
-if util.find_spec('plotly') is not None:
-    PLOTCASES.update(
-        {
-            "linefigure-plotly": (('2d', 'plotly'), linefigure, data1d),
-        }
-    )
-
 
 SCATTERCASES = {
     "scatterfigure-mpl-static": (
diff --git a/tests/plotting/plot_1d_test.py b/tests/plotting/plot_1d_test.py
index 633c4b0c0..486f70f58 100644
--- a/tests/plotting/plot_1d_test.py
+++ b/tests/plotting/plot_1d_test.py
@@ -14,16 +14,6 @@
 pytestmark = pytest.mark.usefixtures("_parametrize_all_backends")
 
 
-def _skip_if_kaleido_not_installed():
-    if pp.backends['2d'] == 'plotly':
-        try:
-            import kaleido as kldo
-        except ImportError:
-            kldo = None
-        if kldo is None:
-            pytest.skip("Skipping because kaleido is not installed")
-
-
 def test_plot_ndarray():
     pp.plot(np.arange(50.0))
 
@@ -195,7 +185,6 @@ def test_use_non_dimension_coords_dataset():
 
 @pytest.mark.parametrize('ext', ['jpg', 'png', 'pdf', 'svg'])
 def test_save_to_disk_1d(ext):
-    _skip_if_kaleido_not_installed()
     da = data_array(ndim=1)
     fig = pp.plot(da)
     with tempfile.TemporaryDirectory() as path:
@@ -205,7 +194,6 @@ def test_save_to_disk_1d(ext):
 
 
 def test_save_to_disk_with_bad_extension_raises():
-    _skip_if_kaleido_not_installed()
     da = data_array(ndim=1)
     fig = pp.plot(da)
     with pytest.raises(ValueError, match='txt'):
@@ -356,8 +344,6 @@ def test_plot_1d_datetime_coord_with_mask_and_binedges():
 
 
 def test_plot_1d_datetime_coord_log():
-    if pp.backends['2d'] == 'plotly':
-        pytest.skip('Log scale with datetime not supported in plotly')
     t = np.arange(
         np.datetime64('2017-03-16T20:58:17'), np.datetime64('2017-03-16T21:15:17'), 20
     )
@@ -371,8 +357,6 @@ def test_plot_1d_datetime_coord_log():
 
 
 def test_plot_1d_datetime_coord_log_binedges():
-    if pp.backends['2d'] == 'plotly':
-        pytest.skip('Log scale with datetime not supported in plotly')
     t = np.arange(
         np.datetime64('2017-03-16T20:58:17'), np.datetime64('2017-03-16T21:15:17'), 20
     )
@@ -386,8 +370,6 @@ def test_plot_1d_datetime_coord_log_binedges():
 
 
 def test_plot_1d_datetime_coord_log_with_mask():
-    if pp.backends['2d'] == 'plotly':
-        pytest.skip('Log scale with datetime not supported in plotly')
     t = np.arange(
         np.datetime64('2017-03-16T20:58:17'), np.datetime64('2017-03-16T21:15:17'), 20
     )

From cb83fa9c9755b49f1b88cffc61ded1c73a0a4055 Mon Sep 17 00:00:00 2001
From: Neil Vaytet <neil.vaytet@ess.eu>
Date: Wed, 10 Jun 2026 16:53:21 +0200
Subject: [PATCH 2/4] also remove from tox and ci

---
 .github/workflows/ci.yml                   | 2 +-
 .github/workflows/weekly_windows_macos.yml | 2 +-
 tox.ini                                    | 5 -----
 3 files changed, 2 insertions(+), 7 deletions(-)

diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 2f5d822b5..bd9b5a800 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -39,7 +39,7 @@ jobs:
       matrix:
         os: ['ubuntu-24.04']
         python: ['${{needs.formatting.outputs.min_python}}']
-        tox-env: ['${{needs.formatting.outputs.min_tox_env}}', 'package-test', 'minimal', 'noplotly']
+        tox-env: ['${{needs.formatting.outputs.min_tox_env}}', 'package-test', 'minimal']
     uses: ./.github/workflows/test.yml
     with:
       os-variant: ${{ matrix.os }}
diff --git a/.github/workflows/weekly_windows_macos.yml b/.github/workflows/weekly_windows_macos.yml
index c9983b5b9..0dfb2442c 100644
--- a/.github/workflows/weekly_windows_macos.yml
+++ b/.github/workflows/weekly_windows_macos.yml
@@ -26,7 +26,7 @@ jobs:
       matrix:
         os: ['macos-latest', 'windows-latest']
         python: ['${{needs.pytox.outputs.min_python}}']
-        tox-env: ['${{needs.pytox.outputs.min_tox_env}}', 'package-test', 'minimal', 'noplotly']
+        tox-env: ['${{needs.pytox.outputs.min_tox_env}}', 'package-test', 'minimal']
     uses: ./.github/workflows/test.yml
     with:
       os-variant: ${{ matrix.os }}
diff --git a/tox.ini b/tox.ini
index 7c279e065..909ec1a03 100644
--- a/tox.ini
+++ b/tox.ini
@@ -15,11 +15,6 @@ deps =
   pytest
 commands = pytest tests/minimal_plot_test.py
 
-[testenv:noplotly]
-description = Test that plotly tests are skipped if plotly is not installed
-deps = -r requirements/noplotly.txt
-commands = pytest tests
-
 [testenv:package-test]
 description = Test the package can be imported
 deps =

From 790f66c7d44061c6dd715575071884a0730181ed Mon Sep 17 00:00:00 2001
From: Neil Vaytet <neil.vaytet@ess.eu>
Date: Wed, 10 Jun 2026 17:19:36 +0200
Subject: [PATCH 3/4] remove unused imports

---
 tests/conftest.py              | 2 --
 tests/graphics/artists_test.py | 1 -
 tests/graphics/canvas_test.py  | 1 -
 tests/graphics/figures_test.py | 1 -
 4 files changed, 5 deletions(-)

diff --git a/tests/conftest.py b/tests/conftest.py
index 662c2ac6b..8b5e88b3d 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -1,8 +1,6 @@
 # SPDX-License-Identifier: BSD-3-Clause
 # Copyright (c) 2023 Scipp contributors (https://github.com/scipp)
 
-from importlib import util
-
 import matplotlib
 import matplotlib.pyplot as plt
 import pytest
diff --git a/tests/graphics/artists_test.py b/tests/graphics/artists_test.py
index 88d0c2f96..b2641b0a6 100644
--- a/tests/graphics/artists_test.py
+++ b/tests/graphics/artists_test.py
@@ -2,7 +2,6 @@
 # Copyright (c) 2025 Scipp contributors (https://github.com/scipp)
 
 from functools import partial
-from importlib import util
 
 import pytest
 
diff --git a/tests/graphics/canvas_test.py b/tests/graphics/canvas_test.py
index e37deb26a..17d7cd94f 100644
--- a/tests/graphics/canvas_test.py
+++ b/tests/graphics/canvas_test.py
@@ -2,7 +2,6 @@
 # Copyright (c) 2024 Scipp contributors (https://github.com/scipp)
 
 from functools import partial
-from importlib import util
 
 import pytest
 
diff --git a/tests/graphics/figures_test.py b/tests/graphics/figures_test.py
index fb278dc25..f951241ee 100644
--- a/tests/graphics/figures_test.py
+++ b/tests/graphics/figures_test.py
@@ -2,7 +2,6 @@
 # Copyright (c) 2024 Scipp contributors (https://github.com/scipp)
 
 from functools import partial
-from importlib import util
 
 import pytest
 import scipp as sc

From a42b54e3a0a8d6f5a3996e704e92c6936b4d8302 Mon Sep 17 00:00:00 2001
From: Neil Vaytet <neil.vaytet@ess.eu>
Date: Wed, 10 Jun 2026 21:27:03 +0200
Subject: [PATCH 4/4] remove plotly from api docs

---
 docs/api-reference/index.md  |  1 -
 docs/api-reference/plotly.md | 12 ------------
 2 files changed, 13 deletions(-)
 delete mode 100644 docs/api-reference/plotly.md

diff --git a/docs/api-reference/index.md b/docs/api-reference/index.md
index 40cf57466..c43bb2c2e 100644
--- a/docs/api-reference/index.md
+++ b/docs/api-reference/index.md
@@ -92,6 +92,5 @@
    :maxdepth: 1
 
    matplotlib
-   plotly
    pythreejs
 ```
diff --git a/docs/api-reference/plotly.md b/docs/api-reference/plotly.md
deleted file mode 100644
index 76386c6be..000000000
--- a/docs/api-reference/plotly.md
+++ /dev/null
@@ -1,12 +0,0 @@
-# Plotly backend
-
-```{eval-rst}
-.. currentmodule:: plopp
-
-.. autosummary::
-   :toctree: ../generated
-
-   backends.plotly.canvas.Canvas
-   backends.plotly.figure.Figure
-   backends.plotly.line.Line
-```