Add support for pagination in the CLI wallet #1894
Conversation
| let page_rows = (rows - 4) as usize; // make room for the header and prompt | ||
|
|
||
| loop { | ||
| line_editor.clear_screen().expect("Should not fail normally"); |
There was a problem hiding this comment.
Let's make paginate_output return a Result and propagate all errors properly.
|
|
||
| let commands = match (current_index, end_index) { | ||
| (0, end) if end == body.len() => "Press 'q' to quit", | ||
| (0, _) => "Press 'j' for down, 'q' to quit", |
| header: String, | ||
| body: String, |
There was a problem hiding this comment.
IMO "paginate" should accept a more structured data, where "header" is a list of column names and "body" is a table.
A TODO would be fine too for now.
| crossterm::terminal::enable_raw_mode().expect("Should not fail normally"); | ||
| let event = crossterm::event::read().expect("Should not fail normally"); | ||
| crossterm::terminal::disable_raw_mode().expect("Should not fail normally"); |
There was a problem hiding this comment.
-
Probably the more correct way is to switch to the raw mode once at the beginning and switch back via
OnceDestructor.
(and probably we should first check that the terminal is not in the raw mode already).The problem is that
println!(and thereforeConsoleOutput::print_line) won't work properly, because "\n" won't return the cursor to the beginning of the line ("\r" is needed for that).
But we can just add a separate functionConsoleOutput::print(so that the line separator can be chosen by the caller) and mention in comments that the existingprint_lineandprint_errorare not suitable for a terminal in a raw mode.(though I'm not sure if the current implementation has any drawbacks, besides not looking nice).
-
We probably need a way of pausing logging while in the pagination mode, because when the loop is waiting for a key press, the terminal is in the raw mode either way. So if a logging event happens, it won't be printed correctly (due to "\n" not returning the cursor).
Let's maybe at least add some TODOs for this.
| if let crossterm::event::Event::Key(key_event) = event { | ||
| match key_event.code { | ||
| reedline::KeyCode::Char('j') | reedline::KeyCode::Down | ||
| if end_index < body.len() => | ||
| { | ||
| let next_text = body.get(current_index..).expect("safe point").lines(); | ||
| let limit = compute_visible_text_limit(next_text, cols, 1); | ||
| current_index = std::cmp::min(body.len(), current_index + limit); | ||
| } | ||
| reedline::KeyCode::Char('k') | reedline::KeyCode::Up if current_index > 0 => { | ||
| let prev_text = body.get(..current_index).expect("safe point").lines().rev(); | ||
| let limit = compute_visible_text_limit(prev_text, cols, 1); | ||
| current_index = current_index.saturating_sub(limit); | ||
| } | ||
| reedline::KeyCode::Char('q') | reedline::KeyCode::Esc => { | ||
| break; // Exit pagination | ||
| } | ||
| _ => {} // Ignore other keys | ||
| } | ||
| } |
There was a problem hiding this comment.
Let's avoid calling clear_screen if a wrong key was pressed (including "j" and "k" when they are not applicable), to avoid screen flickering.
| FoldWhile::Continue((new_total_rows, new_end_index)) | ||
| } else { | ||
| let rows_available = page_rows - current_rows; | ||
| // make sure we cut it on the start of a utf-8 char boundary |
There was a problem hiding this comment.
It's either "on the start of a utf-8 char" or "at a utf-8 char boundary"
| let new_end_index = current_index | ||
| + (1..=rows_available * cols) | ||
| .rev() | ||
| .find(|&i| line.is_char_boundary(i)) | ||
| // 0 is always a safe char boundary | ||
| .unwrap_or(0); | ||
| FoldWhile::Done((page_rows, new_end_index)) |
There was a problem hiding this comment.
-
Regaring unicode handling:
-
This won't work correctly in the "k" case, because here you calculate the number of bytes from the beginning of the line to some char boundary and the caller will subtract this value from
current_index, treating it as the number of bytes from the end of the line to a char boundary. -
rows_available * colsshould be the number of characters and not bytes.
-
-
Even in the ascii case this doesn't work well in the "k" case, because the partial row shown at the top will always have "cols" characters.
E.g. here is how I see a top row when the size of the terminal is small.
Initially:| db76bb89b8e14daeed2caba4aeb28493c95eef39cd1ea4dc71c53d77c913d0d5 | 297962 | 1726820532 |After presing "j":
| 1726820532 |And after pressing "j" again and then "k":
2caba4aeb28493c95eef39cd1ea4dc71c53d77c913d0d5 | 297962 | 1726820532 |
I think you should build some kind of "layout" object once (well, maybe rebuilding it on Resize), and the "k"/"j" should only scroll over the lines of that "layout" and not do any text parsing.
(In the current implementation the "layout" can be a Vec<&str>, where each element represents a separate line of the output)
| let event = crossterm::event::read().expect("Should not fail normally"); | ||
| crossterm::terminal::disable_raw_mode().expect("Should not fail normally"); | ||
|
|
||
| if let crossterm::event::Event::Key(key_event) = event { |
There was a problem hiding this comment.
It would be nice to handle the Resize event as well (a TODO is fine for me)
No description provided.