crossterm/docs/mdbook/src/styling.md
Robert Vojta beb05b4b1e
Add deprecation warning to the book
Signed-off-by: Robert Vojta <rvojta@me.com>
2019-10-02 09:24:52 +02:00

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# Styling Module
> **WARNING**: This book is deprecated, no longer maintained and will be
> removed soon.
Crossterm provides options for you to style your text and terminal. Take for example coloring output and applying attributes.
**Color support**
Windows systems with versions less than 10 will only have support for 16 colors and don't have any support for attributes. Most UNIX-terminal is supporting lots of colors and attributes.
## Colors
There are 16 base colors which available for almost all terminals even windows 7 and 8.
| Light Variant | Dark Variant |
| :-------------| :------------- |
| Grey | Black |
| Red | DarkRed |
| Green | DarkGreen |
| Yellow | DarkYellow |
| Blue | DarkBlue |
| Magenta | DarkMagenta|
| Cyan | DarkCyan |
| White | DarkWhite |
In addition to 16 colors, most UNIX terminals and Windows 10 consoles are also supporting more colors.
Those colors could be: [True color (24-bit)](https://en.wikipedia.org/wiki/Color_depth#True_color_(24-bit)) coloring scheme, which allows you to use [RGB](https://nl.wikipedia.org/wiki/RGB-kleursysteem), and [256 (Xterm, 8-bit)](https://jonasjacek.github.io/colors/) colors.
Checkout the [examples](https://github.com/crossterm-rs/crossterm/blob/master/examples/style.rs) on how to use this feature.
## Attributes
Only UNIX and Windows 10 terminals are supporting attributes on top of the text. Crossterm allows you to add attributes to the text.
Not all attributes are widely supported for all terminals, keep that in mind when working with this.
Crossterm implements almost all attributes shown in this [Wikipedia-list](https://en.wikipedia.org/wiki/ANSI_escape_code#SGR_(Select_Graphic_Rendition)_parameters).
| Attribute | Support | Note |
| :-------------: | :-------------: | :-------------: |
| Reset | Windows, UNIX | This will reset all current set attributes. |
| Bold | Windows, UNIX | This will increase the text sensitivity also known as bold. |
| Dim | Windows, UNIX | This will decrease the text sensitivity also known as bold. |
| Italic | Not widely supported, sometimes treated as inverse. | This will make the text italic. |
| Underlined | Windows, UNIX | A line under a word, especially in order to show its importance. |
| SlowBlink | Not widely supported, sometimes treated as inverse. | less than 150 per minute |
| RapidBlink | Not widely supported | MS-DOS ANSI.SYS; 150+ per minute; |
| Reverse | Windows, UNIX | foreground and background colors |
| Hidden | Windows, UNIX | | Also known as 'Conceal'
| Fraktur | UNIX | characters legible, but marked for deletion. |
| DefaultForegroundColor | Unknown | Implementation defined (according to standard) |
| DefaultBackgroundColor | Unknown | Implementation defined (according to standard) |
| Framed | Not widely supported | Framed text.
| Encircled | Unknown | This will turn on the encircled attribute. |
| OverLined | Unknown | This will draw a line at the top of the text. |
(There are a few attributes who disable one of the above attributes, I did not write those down to keep the list short).
Now we have covered the basics of styling lets go over to some examples.
# Example
_setup the basics_
```rust
use crossterm::{Colored, Color, Attribute, Styler, Colorize};
fn main() {
/* your code here */
}
```
There are a couple of ways to style the terminal output with crossterm. The most important part of the styling module is `StyledObject`.
A `StyledObject` is just a wrapper crossterm uses to store the text and style together.
A `StyledObject` implements `Display` and thus you could use it inside `print!`, `println!` etc.
Without further ado let's get straight into it.
## Coloring
There are a few ways to do the coloring, the first one is by using the `Colored` enum.
### Using Enum
```rust
println!("{} Red foreground color", Colored::Fg(Color::Red));
println!("{} Blue background color", Colored::Bg(Color::Blue));
```
`Colored::Bg` will set the background color, and `Colored::Fg` will set the foreground color to the provided color.
The provided color is of type `Color` and has a bunch of enum values you could choose out.
Because `Colored` implements `Display` you are able to use it inside any write statement.
### Using Methods
You can do the same as the above in a slightly different way. Instead of enabling it for all text you could also color the only piece of text.
(Make sure to include the `crossterm::Coloring` trait).
```rust
let styled_text = "Red forground color on blue background.".red().on_blue();
println!("{}", styled_text);
```
As you see in the above example you could call coloring methods on a string. How is this possible you might ask..?
Well, the trait `Coloring`, who you need to include, is implemented for `&'static str`.
When calling a method on this string crossterm transforms it into a `StyledObject` who you could use in your write statements.
### RGB
Most UNIX terminals and all Windows 10 consoles are supporting [True color(24-bit)](https://en.wikipedia.org/wiki/Color_depth#True_color_(24-bit)) coloring scheme.
You can set the color of the terminal by using `Color::RGB(r,g,b)`.
```
// custom rgb value (Windows 10 and UNIX systems)
println!("{}{} 'Light green' text on 'Black' background", Colored::Fg(Color::Rgb { r: 0, g: 255, b: 128 }), Colored::Bg(Color::Rgb {r: 0, g: 0, b: 0}));
```
This will print some light green text on black background.
### Custom ANSI color value
When working on UNIX or Windows 10 you could also specify a custom ANSI value ranging up from 0 to 256.
See [256 (Xterm, 8-bit) colors](https://jonasjacek.github.io/colors/) for more information.
```
// custom ansi color value (Windows 10 and UNIX systems)
println!("{} some colored text", Colored::Fg(Color::AnsiValue(10)));
```
## Attributes
When working with UNIX or Windows 10 terminals you could also use attributes to style your text. For example, you could cross your text with a line and make it bold.
See [this](styling.md#Attributes) for more information.
### Using Enum
You could use the `Attribute` enum for styling text with attributes.
`Attribute` implements `Display`, thus crossterm will enable the attribute style when using it in any writing operation.
```
println!(
"{} Underlined {} No Underline",
Attribute::Underlined,
Attribute::NoUnderline
);
```
### Using Method
You can do the same as the above in a slightly different way. Instead of enabling it for all text you could also style only one piece of text.
(Make sure to include the `crossterm::Styler` trait).
```
println!("{}", "Bold text".bold();
println!("{}", "Underlined text".underlined();
println!("{}", "Negative text".negative();
```
As you see in the above example you could call attributes methods on a string. How is this possible you might ask..?
Well, the trait `Styling`, who you need to include, is implemented for `&'static str`.
When calling a method on any string crossterm transforms will transform it into a `StyledObject` who you could use in your write statements.
---------------------------------------------------------------------------------------------------------------------------------------------
More examples could be found at this [link](https://github.com/crossterm-rs/crossterm/blob/master/examples/style.rs).