FIX: do not try to manage the visibility of un-drawn ticks

tacaswell · tacaswell · commit b2f9cec6b022 · 2019-04-26T13:41:09.000-04:00
This reverts part of the changes from #13908 (in particular commit e908efe ) that tried to manage the visibility if the ticks that are not used. However, there was a bug in this that nothing would ever set ticks to be visible again. Because we currently cache / recycle ticks this meant that panning / zooming or resizing the figure would eventually lose ticks if the number of ticks ever went down and then back up. We could fix this by adding a `tick.set_visible(True)` for the drawn ticks, however this would break the (brittle) use case where users are reaching in and manually setting the visibility of individual ticks to False to hide them. Instead, we revert the consistency code altogether and accept that there will be `Tick` objects in `Axis.majorTicks` and `Axis.minorTicks` that are marked as visible, but are not drawn (because they are filtered by `_update_ticks`). Closes #14054
diff --git a/lib/matplotlib/axis.py b/lib/matplotlib/axis.py
@@ -1123,11 +1123,6 @@ def _update_ticks(self):
             tick.set_label2(label)
         ticks = [*major_ticks, *minor_ticks]
 
-        # mark the ticks that we will not be using as not visible
-        for t in (self.minorTicks[len(minor_locs):] +
-                  self.majorTicks[len(major_locs):]):
-            t.set_visible(False)
-
         view_low, view_high = self.get_view_interval()
         if view_low > view_high:
             view_low, view_high = view_high, view_low
diff --git a/lib/matplotlib/tests/test_ticker.py b/lib/matplotlib/tests/test_ticker.py
@@ -963,9 +963,3 @@ def test_remove_overlap(remove_overlapping_locs, expected_num):
     assert len(ax.xaxis.get_minor_ticks()) == expected_num
     assert len(ax.xaxis.get_minorticklabels()) == expected_num
     assert len(ax.xaxis.get_minorticklines()) == expected_num*2
-
-    # force a draw to call _update_ticks under the hood
-    fig.canvas.draw()
-    # check that the correct number of ticks report them selves as
-    # visible
-    assert sum(t.get_visible() for t in ax.xaxis.minorTicks) == expected_num
