Convert .btn and mixins to use CSS variables

This commit is contained in:
Mark Otto 2021-07-27 21:36:12 -07:00 committed by Mark Otto
parent 918a86b425
commit ef9d8538a0
4 changed files with 144 additions and 129 deletions

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@ -1,51 +1,98 @@
// stylelint-disable custom-property-empty-line-before
//
// Base styles
//
.btn {
// scss-docs-start btn-css-vars
--#{$variable-prefix}btn-padding-x: #{$btn-padding-x};
--#{$variable-prefix}btn-padding-y: #{$btn-padding-y};
--#{$variable-prefix}btn-font-family: #{$btn-font-family};
@include rfs($btn-font-size, --#{$variable-prefix}btn-font-size);
--#{$variable-prefix}btn-font-weight: #{$btn-font-weight};
--#{$variable-prefix}btn-line-height: #{$btn-line-height};
--#{$variable-prefix}btn-color: #{$body-color};
--#{$variable-prefix}btn-bg: transparent;
--#{$variable-prefix}btn-border-width: #{$btn-border-width};
--#{$variable-prefix}btn-border-color: transparent;
--#{$variable-prefix}btn-border-radius: #{$btn-border-radius};
--#{$variable-prefix}btn-box-shadow: #{$btn-box-shadow};
--#{$variable-prefix}btn-disabled-opacity: #{$btn-disabled-opacity};
--#{$variable-prefix}btn-focus-box-shadow: 0 0 0 #{$btn-focus-width} rgba(var(--#{$variable-prefix}btn-focus-shadow-rgb), .5);
// scss-docs-end btn-css-vars
display: inline-block;
font-family: $btn-font-family;
font-weight: $btn-font-weight;
line-height: $btn-line-height;
color: $body-color;
padding: var(--#{$variable-prefix}btn-padding-y) var(--#{$variable-prefix}btn-padding-x);
font-family: var(--#{$variable-prefix}btn-font-family);
font-size: var(--#{$variable-prefix}btn-font-size);
font-weight: var(--#{$variable-prefix}btn-font-weight);
line-height: var(--#{$variable-prefix}btn-line-height);
color: var(--#{$variable-prefix}btn-color);
text-align: center;
text-decoration: if($link-decoration == none, null, none);
white-space: $btn-white-space;
vertical-align: middle;
cursor: if($enable-button-pointers, pointer, null);
user-select: none;
background-color: transparent;
border: $btn-border-width solid transparent;
@include button-size($btn-padding-y, $btn-padding-x, $btn-font-size, $btn-border-radius);
border: var(--#{$variable-prefix}btn-border-width) solid var(--#{$variable-prefix}btn-border-color);
@include border-radius(var(--#{$variable-prefix}btn-border-radius));
@include gradient-bg(var(--#{$variable-prefix}btn-bg));
@include box-shadow(var(--#{$variable-prefix}btn-box-shadow));
@include transition($btn-transition);
&:hover {
color: $body-color;
color: var(--#{$variable-prefix}btn-hover-color);
text-decoration: if($link-hover-decoration == underline, none, null);
background-color: var(--#{$variable-prefix}btn-hover-bg);
border-color: var(--#{$variable-prefix}btn-hover-border-color);
}
.btn-check:focus + &,
&:focus {
color: var(--#{$variable-prefix}btn-hover-color);
@include gradient-bg(var(--#{$variable-prefix}btn-hover-bg));
border-color: var(--#{$variable-prefix}btn-hover-border-color);
outline: 0;
box-shadow: $btn-focus-box-shadow;
// Avoid using mixin so we can pass custom focus shadow properly
@if $enable-shadows {
box-shadow: var(--#{$variable-prefix}btn-box-shadow), var(--#{$variable-prefix}btn-focus-box-shadow);
} @else {
box-shadow: var(--#{$variable-prefix}btn-focus-box-shadow);
}
}
.btn-check:checked + &,
.btn-check:active + &,
&:active,
&.active {
@include box-shadow($btn-active-box-shadow);
&.active,
.show > &.dropdown-toggle {
color: var(--#{$variable-prefix}btn-active-color);
background-color: var(--#{$variable-prefix}btn-active-bg);
// Remove CSS gradients if they're enabled
background-image: if($enable-gradients, none, null);
border-color: var(--#{$variable-prefix}btn-active-border-color);
@include box-shadow(var(--#{$variable-prefix}btn-active-shadow));
&:focus {
@include box-shadow($btn-focus-box-shadow, $btn-active-box-shadow);
// Avoid using mixin so we can pass custom focus shadow properly
@if $enable-shadows {
box-shadow: var(--#{$variable-prefix}btn-active-shadow), var(--#{$variable-prefix}btn-focus-box-shadow);
} @else {
box-shadow: var(--#{$variable-prefix}btn-focus-box-shadow);
}
}
}
&:disabled,
&.disabled,
fieldset:disabled & {
color: var(--#{$variable-prefix}btn-disabled-color);
pointer-events: none;
opacity: $btn-disabled-opacity;
background-color: var(--#{$variable-prefix}btn-disabled-bg);
background-image: if($enable-gradients, none, null);
border-color: var(--#{$variable-prefix}btn-disabled-border-color);
opacity: var(--#{$variable-prefix}btn-disabled-opacity);
@include box-shadow(none);
}
}
@ -76,24 +123,24 @@
// Make a button look and behave like a link
.btn-link {
font-weight: $font-weight-normal;
color: $btn-link-color;
--#{$variable-prefix}btn-font-weight: #{$font-weight-normal};
--#{$variable-prefix}btn-color: #{$btn-link-color};
--#{$variable-prefix}btn-bg: transparent;
--#{$variable-prefix}btn-border-color: transparent;
--#{$variable-prefix}btn-hover-color: #{$btn-link-hover-color};
--#{$variable-prefix}btn-hover-border-color: transparent;
--#{$variable-prefix}btn-active-border-color: transparent;
--#{$variable-prefix}btn-disabled-color: #{$btn-link-disabled-color};
--#{$variable-prefix}btn-disabled-border-color: transparent;
--#{$variable-prefix}btn-box-shadow: none;
text-decoration: $link-decoration;
&:hover {
color: $btn-link-hover-color;
text-decoration: $link-hover-decoration;
}
&:hover,
&:focus {
text-decoration: $link-hover-decoration;
}
&:disabled,
&.disabled {
color: $btn-link-disabled-color;
}
// No need for an active state here
}

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@ -1,3 +1,5 @@
// stylelint-disable custom-property-empty-line-before
// Button variants
//
// Easily pump out default styles, as well as :hover, :focus, :active,
@ -18,59 +20,20 @@
$disabled-border: $border,
$disabled-color: color-contrast($disabled-background)
) {
color: $color;
@include gradient-bg($background);
border-color: $border;
@include box-shadow($btn-box-shadow);
&:hover {
color: $hover-color;
@include gradient-bg($hover-background);
border-color: $hover-border;
}
.btn-check:focus + &,
&:focus {
color: $hover-color;
@include gradient-bg($hover-background);
border-color: $hover-border;
@if $enable-shadows {
@include box-shadow($btn-box-shadow, 0 0 0 $btn-focus-width rgba(mix($color, $border, 15%), .5));
} @else {
// Avoid using mixin so we can pass custom focus shadow properly
box-shadow: 0 0 0 $btn-focus-width rgba(mix($color, $border, 15%), .5);
}
}
.btn-check:checked + &,
.btn-check:active + &,
&:active,
&.active,
.show > &.dropdown-toggle {
color: $active-color;
background-color: $active-background;
// Remove CSS gradients if they're enabled
background-image: if($enable-gradients, none, null);
border-color: $active-border;
&:focus {
@if $enable-shadows {
@include box-shadow($btn-active-box-shadow, 0 0 0 $btn-focus-width rgba(mix($color, $border, 15%), .5));
} @else {
// Avoid using mixin so we can pass custom focus shadow properly
box-shadow: 0 0 0 $btn-focus-width rgba(mix($color, $border, 15%), .5);
}
}
}
&:disabled,
&.disabled {
color: $disabled-color;
background-color: $disabled-background;
// Remove CSS gradients if they're enabled
background-image: if($enable-gradients, none, null);
border-color: $disabled-border;
}
--#{$variable-prefix}btn-color: #{$color};
--#{$variable-prefix}btn-bg: #{$background};
--#{$variable-prefix}btn-border-color: #{$border};
--#{$variable-prefix}btn-hover-color: #{$hover-color};
--#{$variable-prefix}btn-hover-bg: #{$hover-background};
--#{$variable-prefix}btn-hover-border-color: #{$hover-border};
--#{$variable-prefix}btn-focus-shadow-rgb: #{to-rgb(mix($color, $border, 15%))};
--#{$variable-prefix}btn-active-color: #{$active-color};
--#{$variable-prefix}btn-active-bg: #{$active-background};
--#{$variable-prefix}btn-active-border-color: #{$active-border};
--#{$variable-prefix}btn-active-shadow: #{$btn-active-box-shadow};
--#{$variable-prefix}btn-disabled-color: #{$disabled-color};
--#{$variable-prefix}btn-disabled-bg: #{$disabled-background};
--#{$variable-prefix}btn-disabled-border-color: #{$disabled-border};
}
// scss-docs-end btn-variant-mixin
@ -82,52 +45,26 @@
$active-border: $color,
$active-color: color-contrast($active-background)
) {
color: $color;
border-color: $color;
&:hover {
color: $color-hover;
background-color: $active-background;
border-color: $active-border;
}
.btn-check:focus + &,
&:focus {
box-shadow: 0 0 0 $btn-focus-width rgba($color, .5);
}
.btn-check:checked + &,
.btn-check:active + &,
&:active,
&.active,
&.dropdown-toggle.show {
color: $active-color;
background-color: $active-background;
border-color: $active-border;
&:focus {
@if $enable-shadows {
@include box-shadow($btn-active-box-shadow, 0 0 0 $btn-focus-width rgba($color, .5));
} @else {
// Avoid using mixin so we can pass custom focus shadow properly
box-shadow: 0 0 0 $btn-focus-width rgba($color, .5);
}
}
}
&:disabled,
&.disabled {
color: $color;
background-color: transparent;
}
--#{$variable-prefix}btn-color: #{$color};
--#{$variable-prefix}btn-border-color: #{$color};
--#{$variable-prefix}btn-hover-color: #{$color-hover};
--#{$variable-prefix}btn-hover-bg: #{$active-background};
--#{$variable-prefix}btn-hover-border-color: #{$active-border};
--#{$variable-prefix}btn-focus-shadow-rgb: #{to-rgb($color)};
--#{$variable-prefix}btn-active-color: #{$active-color};
--#{$variable-prefix}btn-active-bg: #{$active-background};
--#{$variable-prefix}btn-active-border-color: #{$active-border};
--#{$variable-prefix}btn-active-shadow: #{$btn-active-box-shadow};
--#{$variable-prefix}btn-disabled-color: #{$color};
--#{$variable-prefix}btn-disabled-bg: transparent;
--#{$variable-prefix}gradient: none;
}
// scss-docs-end btn-outline-variant-mixin
// scss-docs-start btn-size-mixin
@mixin button-size($padding-y, $padding-x, $font-size, $border-radius) {
padding: $padding-y $padding-x;
@include font-size($font-size);
// Manually declare to provide an override to the browser default
@include border-radius($border-radius, 0);
--#{$variable-prefix}btn-padding: #{$padding-y} #{$padding-x};
@include rfs($font-size, --#{$variable-prefix}btn-font-size);
--#{$variable-prefix}btn-radius: #{$border-radius};
}
// scss-docs-end btn-size-mixin

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@ -2,6 +2,7 @@
//
// Custom buttons for the docs.
// scss-docs-start btn-css-vars-example
.btn-bd-primary {
font-weight: 600;
color: $white;
@ -19,6 +20,7 @@
box-shadow: 0 0 0 3px rgba($bd-purple-bright, .25);
}
}
// scss-docs-end btn-css-vars-example
.btn-bd-download {
font-weight: 600;

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@ -72,13 +72,24 @@ Fancy larger or smaller buttons? Add `.btn-lg` or `.btn-sm` for additional sizes
<button type="button" class="btn btn-secondary btn-sm">Small button</button>
{{< /example >}}
You can even roll your own custom sizing with CSS variables:
{{< example >}}
<button type="button" class="btn btn-primary"
style="--bs-btn-padding: .25rem .5rem; --bs-btn-font-size: .75rem;">
Custom button
</button>
{{< /example >}}
## Disabled state
Make buttons look inactive by adding the `disabled` boolean attribute to any `<button>` element. Disabled buttons have `pointer-events: none` applied to, preventing hover and active states from triggering.
{{< example >}}
<button type="button" class="btn btn-lg btn-primary" disabled>Primary button</button>
<button type="button" class="btn btn-secondary btn-lg" disabled>Button</button>
<button type="button" class="btn btn-primary" disabled>Primary button</button>
<button type="button" class="btn btn-secondary" disabled>Button</button>
<button type="button" class="btn btn-outline-primary" disabled>Primary button</button>
<button type="button" class="btn btn-outline-secondary" disabled>Button</button>
{{< /example >}}
Disabled buttons using the `<a>` element behave a bit different:
@ -89,8 +100,8 @@ Disabled buttons using the `<a>` element behave a bit different:
- Disabled buttons using `<a>` *should not* include the `href` attribute.
{{< example >}}
<a class="btn btn-primary btn-lg disabled" role="button" aria-disabled="true">Primary link</a>
<a class="btn btn-secondary btn-lg disabled" role="button" aria-disabled="true">Link</a>
<a class="btn btn-primary disabled" role="button" aria-disabled="true">Primary link</a>
<a class="btn btn-secondary disabled" role="button" aria-disabled="true">Link</a>
{{< /example >}}
### Link functionality caveat
@ -98,8 +109,8 @@ Disabled buttons using the `<a>` element behave a bit different:
To cover cases where you have to keep the `href` attribute on a disabled link, the `.disabled` class uses `pointer-events: none` to try to disable the link functionality of `<a>`s. Note that this CSS property is not yet standardized for HTML, but all modern browsers support it. In addition, even in browsers that do support `pointer-events: none`, keyboard navigation remains unaffected, meaning that sighted keyboard users and users of assistive technologies will still be able to activate these links. So to be safe, in addition to `aria-disabled="true"`, also include a `tabindex="-1"` attribute on these links to prevent them from receiving keyboard focus, and use custom JavaScript to disable their functionality altogether.
{{< example >}}
<a href="#" class="btn btn-primary btn-lg disabled" tabindex="-1" role="button" aria-disabled="true">Primary link</a>
<a href="#" class="btn btn-secondary btn-lg disabled" tabindex="-1" role="button" aria-disabled="true">Link</a>
<a href="#" class="btn btn-primary disabled" tabindex="-1" role="button" aria-disabled="true">Primary link</a>
<a href="#" class="btn btn-secondary disabled" tabindex="-1" role="button" aria-disabled="true">Link</a>
{{< /example >}}
## Block buttons
@ -227,13 +238,31 @@ buttons.forEach(function (button) {
})
```
## Sass
## CSS
### Variables
<small class="d-inline-flex px-2 py-1 font-monospace text-muted border rounded-3">Added in v5.2.0</small>
As part of Bootstrap's evolving CSS variables approach, buttons now use local CSS variables on `.btn` for enhanced real-time customization. Values for the CSS variables are set via Sass, so Sass customization is still supported, too.
{{< scss-docs name="btn-css-vars" file="scss/_buttons.scss" >}}
Each `.btn-*` modifier class updates the appropriate CSS variables to minimize additional CSS rules with our `button-variant()`, `button-outline-variant()`, and `button-size()` mixins.
Here's an example of building a custom `.btn-*` modifier class like we do for the buttons unique to our docs by reassigning Bootstrap's CSS variables with a mixture of our own CSS and Sass variables.
<div class="bd-example">
<button type="button" class="btn btn-bd-primary">Custom button</button>
</div>
{{< scss-docs name="btn-css-vars-example" file="site/assets/scss/_buttons.scss" >}}
### Sass variables
{{< scss-docs name="btn-variables" file="scss/_variables.scss" >}}
### Mixins
### Sass mixins
There are three mixins for buttons: button and button outline variant mixins (both based on `$theme-colors`), plus a button size mixin.
@ -243,7 +272,7 @@ There are three mixins for buttons: button and button outline variant mixins (bo
{{< scss-docs name="btn-size-mixin" file="scss/mixins/_buttons.scss" >}}
### Loops
### Sass loops
Button variants (for regular and outline buttons) use their respective mixins with our `$theme-colors` map to generate the modifier classes in `scss/_buttons.scss`.