mpl widgets: LassoSelector/RectangleSelector

Hi,

I build a backend for this package in vaex, so vaex is showing many rows/particles in this matplotlib backend. However, I'd like to select things using the lasso or rectangular selector, the rectangular works ok, it draws sth on the screen (see also screenshot). To enabled it I used a ipywidget togglebuttons, but it doesn't play nice with the other buttons (for instance, how would I switch between zoom rectangle and the rectangleselector?). And the lasso selector doesn't draw anything on the screen. Would be really nice to have this, it would be the first time you could do a lasso selection in the notebook to do a freehand selection for ~1 billion rows.

vaex/notebook/ipympl.pyを確認し、ipywidgetのトグルボタンが現在どのようにツールを切り替えているかを理解します。次に、セレクターの有効化と描画動作について、notebookのウィジェット統合を調査します。ズーム、矩形選択、ラッソ選択を確実に切り替えられ、ラッソが視覚的に描画されてnotebookでの選択をサポートできれば完了です。