[Summary view] [Print] [Text view]

   1  // Breakpoint viewport sizes and media queries.
   2  //
   3  // Breakpoints are defined as a map of (name: minimum width), order from small to large:
   4  //
   5  //    (xs: 0, sm: 576px, md: 768px, lg: 992px, xl: 1200px)
   6  //
   7  // The map defined in the `$grid-breakpoints` global variable is used as the `$breakpoints` argument by default.
   8  
   9  // Name of the next breakpoint, or null for the last breakpoint.
  10  //
  11  //    >> breakpoint-next(sm)
  12  //    md
  13  //    >> breakpoint-next(sm, (xs: 0, sm: 576px, md: 768px, lg: 992px, xl: 1200px))
  14  //    md
  15  //    >> breakpoint-next(sm, $breakpoint-names: (xs sm md lg xl))
  16  //    md
  17  @function breakpoint-next($name, $breakpoints: $grid-breakpoints, $breakpoint-names: map-keys($breakpoints)) {
  18    $n: index($breakpoint-names, $name);
  19    @if not $n {
  20      @error "breakpoint `#{$name}` not found in `#{$breakpoints}`";
  21    }
  22    @return if($n < length($breakpoint-names), nth($breakpoint-names, $n + 1), null);
  23  }
  24  
  25  // Minimum breakpoint width. Null for the smallest (first) breakpoint.
  26  //
  27  //    >> breakpoint-min(sm, (xs: 0, sm: 576px, md: 768px, lg: 992px, xl: 1200px))
  28  //    576px
  29  @function breakpoint-min($name, $breakpoints: $grid-breakpoints) {
  30    $min: map-get($breakpoints, $name);
  31    @return if($min != 0, $min, null);
  32  }
  33  
  34  // Maximum breakpoint width.
  35  // The maximum value is reduced by 0.02px to work around the limitations of
  36  // `min-` and `max-` prefixes and viewports with fractional widths.
  37  // See https://www.w3.org/TR/mediaqueries-4/#mq-min-max
  38  // Uses 0.02px rather than 0.01px to work around a current rounding bug in Safari.
  39  // See https://bugs.webkit.org/show_bug.cgi?id=178261
  40  //
  41  //    >> breakpoint-max(md, (xs: 0, sm: 576px, md: 768px, lg: 992px, xl: 1200px))
  42  //    767.98px
  43  @function breakpoint-max($name, $breakpoints: $grid-breakpoints) {
  44    $max: map-get($breakpoints, $name);
  45    @return if($max and $max > 0, $max - .02, null);
  46  }
  47  
  48  // Returns a blank string if smallest breakpoint, otherwise returns the name with a dash in front.
  49  // Useful for making responsive utilities.
  50  //
  51  //    >> breakpoint-infix(xs, (xs: 0, sm: 576px, md: 768px, lg: 992px, xl: 1200px))
  52  //    ""  (Returns a blank string)
  53  //    >> breakpoint-infix(sm, (xs: 0, sm: 576px, md: 768px, lg: 992px, xl: 1200px))
  54  //    "-sm"
  55  @function breakpoint-infix($name, $breakpoints: $grid-breakpoints) {
  56    @return if(breakpoint-min($name, $breakpoints) == null, "", "-#{$name}");
  57  }
  58  
  59  // Media of at least the minimum breakpoint width. No query for the smallest breakpoint.
  60  // Makes the @content apply to the given breakpoint and wider.
  61  @mixin media-breakpoint-up($name, $breakpoints: $grid-breakpoints) {
  62    $min: breakpoint-min($name, $breakpoints);
  63    @if $min {
  64      @media (min-width: $min) {
  65        @content;
  66      }
  67    } @else {
  68      @content;
  69    }
  70  }
  71  
  72  // Media of at most the maximum breakpoint width. No query for the largest breakpoint.
  73  // Makes the @content apply to the given breakpoint and narrower.
  74  @mixin media-breakpoint-down($name, $breakpoints: $grid-breakpoints) {
  75    $max: breakpoint-max($name, $breakpoints);
  76    @if $max {
  77      @media (max-width: $max) {
  78        @content;
  79      }
  80    } @else {
  81      @content;
  82    }
  83  }
  84  
  85  // Media that spans multiple breakpoint widths.
  86  // Makes the @content apply between the min and max breakpoints
  87  @mixin media-breakpoint-between($lower, $upper, $breakpoints: $grid-breakpoints) {
  88    $min: breakpoint-min($lower, $breakpoints);
  89    $max: breakpoint-max($upper, $breakpoints);
  90  
  91    @if $min != null and $max != null {
  92      @media (min-width: $min) and (max-width: $max) {
  93        @content;
  94      }
  95    } @else if $max == null {
  96      @include media-breakpoint-up($lower, $breakpoints) {
  97        @content;
  98      }
  99    } @else if $min == null {
 100      @include media-breakpoint-down($upper, $breakpoints) {
 101        @content;
 102      }
 103    }
 104  }
 105  
 106  // Media between the breakpoint's minimum and maximum widths.
 107  // No minimum for the smallest breakpoint, and no maximum for the largest one.
 108  // Makes the @content apply only to the given breakpoint, not viewports any wider or narrower.
 109  @mixin media-breakpoint-only($name, $breakpoints: $grid-breakpoints) {
 110    $min:  breakpoint-min($name, $breakpoints);
 111    $next: breakpoint-next($name, $breakpoints);
 112    $max:  breakpoint-max($next);
 113  
 114    @if $min != null and $max != null {
 115      @media (min-width: $min) and (max-width: $max) {
 116        @content;
 117      }
 118    } @else if $max == null {
 119      @include media-breakpoint-up($name, $breakpoints) {
 120        @content;
 121      }
 122    } @else if $min == null {
 123      @include media-breakpoint-down($next, $breakpoints) {
 124        @content;
 125      }
 126    }
 127  }