{,Range}Slider: Add release notes for valfmt arguments

doronbehar · doronbehar · commit b1ca2a5a89da · 2025-08-05T10:36:48.000+03:00
diff --git a/doc/users/next_whats_new/sliders_callable_valfmt.rst b/doc/users/next_whats_new/sliders_callable_valfmt.rst
@@ -0,0 +1,9 @@
+Callable ``valfmt`` for ``Slider`` and ``RangeSlider``
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+The ``valfmt`` argument of the `~.matplotlib.widgets.Slider` and
+`~.matplotlib.widgets.RangeSlider` can be a callable now. It should accept the
+values as floats, and return a string to be displayed on the figure. In the
+case of `~.matplotlib.widgets.RangeSlider` the callable should accept 2 floats
+for the minimal and maximal value of the range, and in the case of
+`~.matplotlib.widgets.Slider` it should accept 1 float.
