Module cursive_core::theme

Expand description

Handle colors and themes in the UI.

Colors

Characters can be printed in the terminal with a specific color. The Color enum represents the ways this can be set.

Palette

To achieve a customizable, yet unified look, Cursive uses a configurable palette of colors to be used through the entire application.

The PaletteColor enum defines possible entries in this palette.

These entries are:

Background: used to color the application background (around views). Defaults to blue.
Shadow: used to color shadow around views. Defaults to black.
View: used to color the background for views. Defaults to white.
Primary: used to print primary text. Defaults to black.
Secondary: used to print secondary text. Defaults to blue.
Tertiary: used to print tertiary text. Defaults to white.
TitlePrimary: used to print primary titles. Defaults to red.
TitleSecondary: used to print secondary titles. Defaults to yellow.
Highlight: used to highlight selected items. Defaults to red.
HighlightInactive: used to highlight selected but inactive items. Defaults to blue.
HighlightText: used to print primary text when highlighted Defaults to white.

A Palette then maps each of these to an actual Color.

Color Types

When drawing views, color can be picked in two way:

An exact Color can be given directly
A PaletteColor entry can be given, which will fetch whatever color is currently defined for this.

The ColorType enum abstract over these two choices.

Color Styles

To actually print anything, two colors must be picked: one for the foreground, and one for the background.

As such, a ColorStyle is made of a pair of ColorType.

Since some pairs are frequently used, ColorStyle defines some methods to create these usual values:

ColorStyle::background(): style used to print the application background.
- Its background color is Background.
- Its foreground color is unimportant as no characters are ever printed in the background.
ColorStyle::shadow(): style used to print shadows behind views.
- Its background color is Shadow.
- Here again, the foreground color is unimportant.
ColorStyle::primary(): style used to print primary text.
- Its background color is View.
- Its foreground color is Primary.
ColorStyle::secondary(): style used to print secondary text.
- Its background color is View.
- Its foreground color is Secondary.
ColorStyle::tertiary(): style used to print tertiary text.
- Its background color is View.
- Its foreground color is Tertiary.
ColorStyle::title_primary(): style used to print titles.
- Its background color is View.
- Its foreground color is TitlePrimary.
ColorStyle::title_secondary(): style used to print secondary titles.
- Its background color is View.
- Its foreground color is TitleSecondary.
ColorStyle::highlight(): style used to print selected items.
- Its background color is Highlight.
- Its foreground color is HighlightText.
ColorStyle::highlight_inactive(): style used to print selected, but inactive items.
- Its background color is HighlightInactive.
- Its foreground color is HighlightText.

Using one of these pairs when styling your application helps give it a coherent look.

Effects

On top of a color style, some effects can be applied on cells: Reverse, for instance, swaps the foreground and background colors of a cell.

Style

Finally, a style combine a ColorType and a set of Effects, to represent any way text should be printed on screen.

Themes

A Theme object defines the color palette an application will use, as well as various options to style views.

There are several ways to set a theme for the application:

Construct a Theme object by setting every field individually.
Get the current theme with Cursive::current_theme method and changing the required fields (for example see theme_manual example).
Using a toml file as a theme configuration (for example see theme example).

Configuring theme with toml

This requires the toml feature to be enabled.

[dependencies]
cursive = { version = "*", features = ["toml"] }

To use the theme in your application, load it with Cursive::load_toml method (or use theme::load_theme_file to aquire the theme object).

let mut siv = Cursive::new();
// Embed the theme with the binary.
siv.load_toml(include_str!("<path_to_theme_file>.toml")).unwrap();

Here are the possible entries (all fields are optional):


shadow = false  # Don't draw shadows around stacked views
borders = "simple"  # Alternatives are "none" and "outset"

[colors]
    background = "black"
    shadow     = ["#000000", "black"]
    view       = "#d3d7cf"

    primary   = ["#111111"]
    secondary = "#EEEEEE"
    tertiary  = "#444444"

    title_primary   = "#ff5555"
    title_secondary = "#ffff55"

    highlight          = "#F00"
    highlight_inactive = "#5555FF"