Version 1.19.0

This release introduces a number of major new features and enhancements, including the ability to add popups to your Bokeh figures, which allows you to drill down into subsets of your data easily.
Additionally, this release retains and uses pandas (multi-)indexes without unnecessary copies, providing significant benefits for working with wide data.
A major focus of this release has also been to improve the time it takes to plot large datasets, both by updating the data pipeline and reducing the amount of data send to the browser.
Furthermore, we have improved the developer experience, making it easier to contribute to HoloViews, see the developer guide.
Lastly bugs have been squashed and enhancements made to the existing features.

Thank you to @mirage007 and @WesleyTheGeolien for their first contributions and to the returning contributors @douglas-raillard-arm, @jj-github-jj, and @TheoMathurin.
Another thanks to the maintainers @ahuang11, @droumis, @maximlt, @philippjfr, and @hoxbro.

New features

• Add support for popups on selection streams (#6168, #6207, #6199)
• Add scalebar support (#6002)

Enhancements

• Override Curve's count aggregator default to self_intersect=False (#6030)
• Zoom tools automatically vertically scaled on subcoordinate_y overlays (#6051)
• Use tsdownsample library for downsampling if available (#6059, #6083)
• Add viewport downsample algorithm (#6017)
• Optimize downsample1d when data is shared between layers (#6075)
• Support dictionary cmaps for ImageStack (#6025)
• Expose hit_dilation in PointPlot (#6121)
• Improve autocompletion for lazy module (#6174)
• Subcoordinate_y: reverse the renderers by default (#6194)
• Add hover_tooltips, hover_mode, hover_formatters opts to easily modify hover (#6180)
• Expose setting hard navigable bounds (#6056)
• Add a zoom tool per subcoordinate_y group (#6122)
• Support all Bokeh Text style opts in hv.Labels and hv.Text (#6198)
• Implement support for retaining Pandas index (#6061)
• Add operation for group-wise normalisation (#6124)
• Allow Bars to be plotted on continuous axes (#6145)
• Add min_interval and max_interval to the RangeToolLink (#6134)
• Add support for rasterizing geopandas dataframes directly (#5958)
• Allow options for non-enabled backends (#6196)
• Support ImageStack in dynspread (#6024)
• Add support for cticks (#6257)
• Support title font size in Plotly backend (#5920)
• Hold rendering until a plot has been fully updated (#6265)
• Make Dimension.label source of truth for Dimension identity (#6262)
• Allow subcoordinates to be drawn from NdOverlay dimensions (#6209)
• Add stream transform (#6230)

Bug fixes

• Don't show figures toolbar on GridSpace (#6127)
• Update merge_tool (#6141)
• Don't raise KeyError if options don't contain None (#6153)
• Force vdims to strings for ImageStack (#6155)
• Fixes to Bokeh BoxWhisker (#6169)
• Improve groupby behavior for operation histogram (#6172)
• Ensure plot ranges for all renderers are combined in auto-ranging (#6173)
• Ensure that the downsample algorithm m4 n_out is always a multiple of 4 (#6195)
• Subcoordinate_y: respect ylim (#6190)
• Bug fix for player example pause button (#6212)
• Clone if a Tool is as Bokeh model (#6220)
• Fix violin plot in Plotly (#6237)
• Don't error on TypeError in DaskInterface when sorting (#6221)
• Fix hv.help if Info.store is None (#6250)
• Change how upper limit is taken for color_levels (#4898)
• Fix vectorfield hover (#6258)
• Ensure Range streams and RangeToolLink respect subcoordinate axis range (#6256)
• Fix pickling state (#6245)
• Fix colab rendering (#6269)
• Disable batching when subcoordinate_y is enabled (#6272)
• Ensure downsample works with non-contiguous arrays (#6271)
• Fix issue with range lookups in (y)-axis creation (#6274)

Dependencies updates

• Update param minimum version to 2.0 (#6230)
• Update numpy >=1.21, pandas >= 1.3, and Bokeh >=3.1 (#6253)

Compatibility

• Update test for Bokeh 3.4 (#6130)
• Test with dask-expr (#6259, #6149)
• Numpy 2.0 compatibility (#6238)
• Update to support cudf 2024.06 (#6263)

Documentation

• Minor typos (#6179, #6193)
• Update CSS for documentation (#6228)
• Fix links (#6246, #6036)
• Document subcoordinate_group_ranges by extending the EEG Viewer demo (#6243)

Maintenance

• Switch to Pixi for development / CI and hatchling for build system (#6182, #6200, #6251)
• Add test-gpu task for Pixi (#6217)
• Add sync-git-tags task to Pixi for sync git tags with upstream repo (#6215)
• Parallelize unit test (#6234)
• Use psutil for pytest-xdist logical option (#6213)
• Bump CI tests to use Python 3.12 (#5978)
• Only run test-suite on code change (#6035)
• Add skip statement to all steps to work with required (#6037)
• Add true if inputs.cache is not set (#6050)
• Dynamic generate unit test matrix and add cache option (#6043)
• Add prettier to markdown and yaml (#6040)
• Add taplo as toml formatter (#6227)
• Disable always on warnings (#6077)
• Updating Package workflow to a build and a publish step (#6031)
• Use the new conda package format (#6216)