René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"[MNT]: sort out renderers","articleBody":"### Summary\n\nVarious methods require a renderer, in particular `get_tightbbox` and `get_window_extent`.  We have quite a few inconsistencies here.\r\n\r\nMany implementations of `get_window_extent` have `renderer` as an optional kwarg, and fallback:  fallbacks are `self.figure._cachedRenderer` (`Text`, `Legend`) and some other `get_window_extent` don't need the renderer.  \r\n\r\n`get_tightbbox` always needs the renderer, but largely to pass to `get_window_extent` calls on `Text` objects.  \r\n\r\n`tight_layout` and `constrained_layout` need the renderer, but that is only because they want to pass it to the `get_tightbbox`.  \r\n\r\n\n\n### Proposed fix\n\n\r\nIt _seems_ that we don't need to specify the renderer most of the time in `get_window_extent`, but can safely fall back on the `_cachedRenderer` or `fig.canvas.get_renderer`, so it seems more consistent to just make this argument always optional.  However, perhaps I'm missing a subtlety where the user may want to call `get_window_extent(renderer=different_renderer)`, but I have no idea what that use case is.  \r\n\r\n1. make renderer a kwarg in all `get_window_extent` methods.\r\n3. improve the fallbacks in all the `get_window_extents`: I'm not sure `_cachedRenderer` is adequate, and we probably want `Figure._get_cachedRenderer` that has some fallbacks in `_cachedRenderer` is None, or fakes a draw to fill the cache.  \r\n4. make renderer an optional kwarg in all `get_tightbbox` methods.  \r\n\r\nThis needs comment though from folks who understand the renderer system better: @QuLogic @anntzer @tacaswell ?  Thanks!","author":{"url":"https://github.com/jklymak","@type":"Person","name":"jklymak"},"datePublished":"2022-03-31T07:45:23.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":6},"url":"https://github.com/22744/matplotlib/issues/22744"}