I know someone mentioned a related issue, but I want to talk about it.
Personal feelings 
Now, I know there are plugins associated with this.
But the plugin is not easy to use, in fact it is only able to use.
And for a long time I didn't know there was a plugin that could do that, he bothered me for a while, and out of love for him, I've been using it.
I hope joplin can bring this with himself and do it better, if a person who has just used joplin doesn't understand the plugin, it will really cause trouble and even cause him to abandon the app.
And in the Android app can not install the plug-in, so the Android side does not have an outline.
And I think it's a very basic feature, at least I think so.
If I can, I'd like to talk about what I think is the ideal outline design.
Outline design expectations 
style
First of all I think the outline should not take up too much space.
Like the outline in the image below, when he opens it takes up too much space, he will not be able to continue recording.
I think the outline is to help the author understand the structure of the article, and I learned that an indented outline is a good way to do it. For ease of understanding, I recorded videos .
space
On the question of how much space the outline bar takes up, I think it takes up space just as well as the notes bar.
New ideas that are not related to the outline 
Forgive me for being so sudden that I had a new idea.
Nowadays, simple and elegant pages are very popular, and I have seen some review content of note-taking software on some sharing forums and short video websites, and some people have mentioned that the joplin page is not beautiful enough.
I guess he's not saying "not pretty enough" and isn't referring to the outdated joplin design, he might think it's not concise enough. I think the joplin interface is still pretty, at least he attracted me at first sight.
The picture below is of a piece of software called "panwriter", which I think is more concise, and I have to admit that it is really appealing.
Actually the two columns on the left side of your notes actually take up a certain amount of space as well, and to some extent also affect your attention (for example, when you are recording, you may notice what is on the left and then think about what was recorded yesterday or the day before yesterday, resulting in you not being able to focus on the current recording activity)
Can we achieve a clean and elegant interface like "panwriter"? Below I provide my solution for your reference.
Forgive me for always citing other software for comparison, I like joplin so much, I just want him to be perfect.
Can you, provide a select button, click on it, let's hide them for the time being, in fact it is the outline-related plugin mentioned above that inspired me.
Note that the buttons I mentioned here are not by dragging and dropping with the mouse, I think that is very inconvenient, easy to understand, I recorded the video.
The image below represents what I think is the ideal note page.
I dragged them with the mouse to reduce the space, although it wasn't completely hidden.
Thank you for your patience in reading, you can discuss by replying to me.
I'm looking forward to joplin becoming more perfect. 
