These are simple opinionated methods for creating a terminal that is
useful to use in most apps. The new init method creates a crossterm
backend writing to stdout, enables raw mode, enters the alternate
screen, and sets a panic handler that restores the terminal on panic.
A minimal hello world now looks a bit like:
```rust
use ratatui::{
crossterm::event::{self, Event},
text::Text,
Frame,
};
fn main() {
let mut terminal = ratatui::init();
loop {
terminal
.draw(|frame: &mut Frame| frame.render_widget(Text::raw("Hello World!"), frame.area()))
.expect("Failed to draw");
if matches!(event::read().expect("failed to read event"), Event::Key(_)) {
break;
}
}
ratatui::restore();
}
```
A type alias `DefaultTerminal` is added to represent this terminal
type and to simplify any cases where applications need to pass this
terminal around. It is equivalent to:
`Terminal<CrosstermBackend<Stdout>>`
We also added `ratatui::try_init()` and `try_restore()`, for situations
where you might want to handle initialization errors yourself instead
of letting the panic handler fire and cleanup. Simple Apps should
prefer the `init` and `restore` functions over these functions.
Corresponding functions to allow passing a `TerminalOptions` with
a `Viewport` (e.g. inline, fixed) are also available
(`init_with_options`,
and `try_init_with_options`).
The existing code to create a backend and terminal will remain and
is not deprecated by this approach. This just provides a simple one
line initialization using the common options.
---------
Co-authored-by: Orhun Parmaksız <orhunparmaksiz@gmail.com>
This is a simplification of the public API that is helpful for new users
that are not familiar with how rust re-exports work, and helps avoid
clashes with other modules in the backends that are named terminal.
BREAKING CHANGE: The `terminal` module is now private and can not be
used directly. The types under this module are exported from the root of
the crate.
```diff
- use ratatui::terminal::{CompletedFrame, Frame, Terminal, TerminalOptions, ViewPort};
+ use ratatui::{CompletedFrame, Frame, Terminal, TerminalOptions, ViewPort};
```
Fixes: https://github.com/ratatui-org/ratatui/issues/1210
Consensus is that explicit imports make it easier to understand the
example code. This commit removes the prelude import from all examples
and replaces it with the necessary imports, and expands other glob
imports (widget::*, Constraint::*, KeyCode::*, etc.) everywhere else.
Prelude glob imports not in examples are not covered by this PR.
See https://github.com/ratatui-org/ratatui/issues/1150 for more details.
`crossterm`, `termion`, and `termwiz` can now be accessed as
`ratatui::{crossterm, termion, termwiz}` respectively. This makes it
possible to just add the Ratatui crate as a dependency and use the
backend of choice without having to add the backend crates as
dependencies.
To update existing code, replace all instances of `crossterm::` with
`ratatui::crossterm::`, `termion::` with `ratatui::termion::`, and
`termwiz::` with `ratatui::termwiz::`.
`Block::bordered()` is shorter than
`Block::new().borders(Borders::ALL)`, requires one less import
(`Borders`) and in case `Block::default()` was used before can even be
`const`.
Fixes many not yet enabled lints (mostly pedantic) on everything that is
not the lib (examples, benchs, tests). Therefore, this is not containing
anything that can be a breaking change.
Lints are not enabled as that should be the job of #974. I created this
as a separate PR as its mostly independent and would only clutter up the
diff of #974 even more.
Also see
https://github.com/ratatui-org/ratatui/pull/974#discussion_r1506458743
---------
Co-authored-by: Josh McKinney <joshka@users.noreply.github.com>
In a recent commit we added Rec::split, but this feels more ergonomic as
Layout::areas. This also adds Layout::spacers to get the spacers between
the areas.
This change simplifys UI code that uses the Frame type. E.g.:
```rust
fn draw<B: Backend>(frame: &mut Frame<B>) {
// ...
}
```
Frame was generic over Backend because it stored a reference to the
terminal in the field. Instead it now directly stores the viewport area
and current buffer. These are provided at creation time and are valid
for the duration of the frame.
BREAKING CHANGE: Frame is no longer generic over Backend. Code that
accepted `Frame<Backend>` will now need to accept `Frame`. To migrate
existing code, remove any generic parameters from code that uses an
instance of a Frame. E.g. the above code becomes:
```rust
fn draw(frame: &mut Frame) {
// ...
}
```
This helps to keep the prelude small and less likely to conflict with
other crates.
- remove widgets module from prelude as the entire module can be just as
easily imported with `use ratatui::widgets::*;`
- move prelude module into its own file
- update examples to import widgets module instead of just prelude
- added several modules to prelude to make it possible to qualify
imports that collide with other types that have similar names
- merge `Style` and `StyleDiff` together. `Style` now is used to activate or deactivate certain
style rules not to overidden all of them.
- update all impacted widgets, examples and tests.
* Update the `Shape` trait. Instead of returning an iterator of point, all
shapes are now aware of the surface they will be drawn to through a `Painter`.
In order to draw themselves, they paint points of the "braille grid".
* Rewrite how lines are drawn using a common line drawing algorithm (Bresenham).
Most widgets can be drawn directly based on the input parameters. However, some
features may require some kind of associated state to be implemented.
For example, the `List` widget can highlight the item currently selected. This
can be translated in an offset, which is the number of elements to skip in
order to have the selected item within the viewport currently allocated to this
widget. The widget can therefore only provide the following behavior: whenever
the selected item is out of the viewport scroll to a predefined position (make
the selected item the last viewable item or the one in the middle).
Nonetheless, if the widget has access to the last computed offset then it can
implement a natural scrolling experience where the last offset is reused until
the selected item is out of the viewport.
To allow such behavior within the widgets, this commit introduces the following
changes:
- Add a `StatefulWidget` trait with an associated `State` type. Widgets that
can take advantage of having a "memory" between two draw calls needs to
implement this trait.
- Add a `render_stateful_widget` method on `Frame` where the associated
state is given as a parameter.
The chosen approach is thus to let the developers manage their widgets' states
themselves as they are already responsible for the lifecycle of the wigets
(given that the crate exposes an immediate mode api).
The following changes were also introduced:
- `Widget::render` has been deleted. Developers should use `Frame::render_widget`
instead.
- `Widget::background` has been deleted. Developers should use `Buffer::set_background`
instead.
- `SelectableList` has been deleted. Developers can directly use `List` where
`SelectableList` features have been back-ported.
It basically never makes sense to render without syncing the size.
Without resizing, if shrinking, we get artefacts. If growing, we may get
panics (before this change the Rustbox sample (the only one which didn't
handle resizing on its own) panicked because the widget would get an
updated size, while the terminal would not).
