    /**
     * Creates a visual theme for a Window
     *
     * @param {string} $ui
     * The name of the UI being created. Can not included spaces or special punctuation
     * (used in CSS class names).
     *
     * @param {number} [$ui-padding=$window-padding]
     * The padding of the Window
     *
     * @param {number} [$ui-border-radius=$window-border-radius]
     * The border-radius of the Window
     *
     * @param {color} [$ui-border-color=$window-border-color]
     * The border-color of the Window
     *
     * @param {number} [$ui-border-width=$window-border-width]
     * The border-width of the Window
     *
     * @param {color} [$ui-inner-border-color=$window-inner-border-color]
     * The inner border-color of the Window
     *
     * @param {number} [$ui-inner-border-width=$window-inner-border-width]
     * The inner border-width of the Window
     *
     * @param {color} [$ui-header-color=$window-header-color]
     * The text color of the Header
     *
     * @param {color} [$ui-header-background-color=$window-header-background-color]
     * The background-color of the Header
     *
     * @param {number/list} [$ui-header-padding=$window-header-padding]
     * The padding of the Header
     *
     * @param {string} [$ui-header-font-family=$window-header-font-family]
     * The font-family of the Header
     *
     * @param {number} [$ui-header-font-size=$window-header-font-size]
     * The font-size of the Header
     *
     * @param {string} [$ui-header-font-weight=$window-header-font-weight]
     * The font-weight of the Header
     *
     * @param {number} [$ui-header-line-height=$window-header-line-height]
     * The line-height of the Header
     *
     * @param {number/list} [$ui-header-text-padding=$window-header-text-padding]
     * The padding of the Header's text element
     *
     * @param {string} [$ui-header-text-transform=$window-header-text-transform]
     * The text-transform of the Header
     *
     * @param {color} [$ui-header-border-color=$ui-border-color]
     * The border-color of the Header
     *
     * @param {number} [$ui-header-border-width=$window-header-border-width]
     * The border-width of the Header
     *
     * @param {color} [$ui-header-inner-border-color=$window-header-inner-border-color]
     * The inner border-color of the Header
     *
     * @param {number} [$ui-header-inner-border-width=$window-header-inner-border-width]
     * The inner border-width of the Header
     *
     * @param {number} [$ui-header-icon-width=$window-header-icon-width]
     * The width of the Header icon
     *
     * @param {number} [$ui-header-icon-height=$window-header-icon-height]
     * The height of the Header icon
     *
     * @param {number} [$ui-header-icon-spacing=$window-header-icon-spacing]
     * The space between the Header icon and text
     *
     * @param {list} [$ui-header-icon-background-position=$window-header-icon-background-position]
     * The background-position of the Header icon
     *
     * @param {color} [$ui-header-glyph-color=$window-header-glyph-color]
     * The color of the Header glyph icon
     *
     * @param {number} [$ui-header-glyph-opacity=$window-header-glyph-opacity]
     * The opacity of the Header glyph icon
     *
     * @param {number} [$ui-tool-spacing=$window-tool-spacing]
     * The space between the {@link Ext.panel.Tool Tools}
     *
     * @param {string} [$ui-tool-background-image=$window-tool-background-image]
     * The background sprite to use for {@link Ext.panel.Tool Tools}
     *
     * @param {color} [$ui-body-border-color=$window-body-border-color]
     * The border-color of the Window body
     *
     * @param {color} [$ui-body-background-color=$window-body-background-color]
     * The background-color of the Window body
     *
     * @param {number} [$ui-body-border-width=$window-body-border-width]
     * The border-width of the Window body
     *
     * @param {string} [$ui-body-border-style=$window-body-border-style]
     * The border-style of the Window body
     *
     * @param {color} [$ui-body-color=$window-body-color]
     * The color of text inside the Window body
     *
     * @param {color} [$ui-background-color=$window-background-color]
     * The background-color of the Window
     *
     * @param {boolean} [$ui-force-header-border=$window-force-header-border]
     * True to force the window header to have a border on the side facing
     * the window body.  Overrides dock layout's border management border
     * removal rules.
     *
     * @param {boolean} [$ui-include-border-management-rules=$window-include-border-management-rules]
     * True to include neptune style border management rules.
     *
     * @param {color} [$ui-wrap-border-color=$window-wrap-border-color]
     * The color to apply to the border that wraps the body and docked items. The presence of
     * the wrap border is controlled by the {@link #border} config. Only applicable when
     * `$ui-include-border-management-rules` is `true`.
     *
     * @param {color} [$ui-wrap-border-width=$window-wrap-border-width]
     * The width to apply to the border that wraps the body and docked items. The presence of
     * the wrap border is controlled by the {@link #border} config. Only applicable when
     * `$ui-include-border-management-rules` is `true`.
     *
     * @member Ext.window.Window
     */
    @mixin extjs-window-ui(
        $ui: null,

        $ui-padding: $window-padding,
        $ui-border-radius: $window-border-radius,
        $ui-border-color: $window-border-color,
        $ui-border-width: $window-border-width,
        $ui-inner-border-color: $window-inner-border-color,
        $ui-inner-border-width: $window-inner-border-width,

        $ui-header-color: $window-header-color,
        $ui-header-background-color: $window-header-background-color,
        $ui-header-padding: $window-header-padding,
        $ui-header-font-family: $window-header-font-family,
        $ui-header-font-size: $window-header-font-size,
        $ui-header-font-weight: $window-header-font-weight,
        $ui-header-line-height: $window-header-line-height,
        $ui-header-text-padding: $window-header-text-padding,
        $ui-header-text-transform: $window-header-text-transform,
        $ui-header-border-color: $ui-border-color,
        $ui-header-border-width: $window-header-border-width,
        $ui-header-inner-border-color: $window-header-inner-border-color,
        $ui-header-inner-border-width: $window-header-inner-border-width,
        $ui-header-icon-width: $window-header-icon-width,
        $ui-header-icon-height: $window-header-icon-height,
        $ui-header-icon-spacing: $window-header-icon-spacing,
        $ui-header-icon-background-position: $window-header-icon-background-position,
        $ui-header-glyph-color: $window-header-glyph-color,
        $ui-header-glyph-opacity: $window-header-glyph-opacity,

        $ui-tool-spacing: $window-tool-spacing,
        $ui-tool-background-image: $window-tool-background-image,

        $ui-body-border-color: $window-body-border-color,
        $ui-body-background-color: $window-body-background-color,
        $ui-body-border-width: $window-body-border-width,
        $ui-body-border-style: $window-body-border-style,
        $ui-body-color: $window-body-color,
        $ui-body-font-size: $window-body-font-size,
        $ui-body-font-weight: $window-body-font-weight,
        $ui-body-font-family: $window-body-font-family,

        $ui-background-color: $window-background-color,

        // See the docs above
        $ui-force-header-border: $window-force-header-border,
        $ui-include-border-management-rules: $window-include-border-management-rules,
        $ui-wrap-border-color: $window-wrap-border-color,
        $ui-wrap-border-width: $window-wrap-border-width,

        // deprecated - use $ui instead
        $ui-label: null
    ){
        @if $ui == null {
            @if $ui-label != null {
                @warn '$ui-label is deprecated.  Use $ui instead';
                $ui: $ui-label;
            } @else {
                @warn "#{error('$ui is required')}";
            }
        }

        .#{$prefix}window-#{$ui} {
            @if not is-null($ui-border-color) { border-color: $ui-border-color; }
            @if not is-null($ui-border-radius) { @include border-radius($ui-border-radius); }

            @if $ui-inner-border-width != 0 {
                @include inner-border($ui-inner-border-width, $ui-inner-border-color);
            }
        }

        @if not is-null($ui-border-radius) and $ui-border-radius != 0{
            @include x-frame(
                'window',
                $ui,

                $border-radius: $ui-border-radius,
                $border-width: $ui-border-width,
                $padding: $ui-padding,
                $background-color: $ui-background-color
            );
        }

        .#{$prefix}window-body-#{$ui} {
            @if not is-null($ui-body-border-color) {
                border-color: $ui-body-border-color;
                border-width: $ui-body-border-width;
                border-style: $ui-body-border-style;
            }

            @if not is-null($ui-body-background-color) { background: $ui-body-background-color; }
            @if not is-null($ui-body-color) { color: $ui-body-color; }
            @if not is-null($ui-body-font-size) {        font-size: $ui-body-font-size; }
            @if not is-null($ui-body-font-weight) {      font-weight: $ui-body-font-weight; }
            @if not is-null($ui-body-font-family) {      font-family: $ui-body-font-family; }
        }

        .#{$prefix}window-header-#{$ui} {
            @if not is-null($ui-header-font-size) { font-size: $ui-header-font-size; }
            @if not is-null($ui-border-color) { border-color: $ui-border-color; }
            zoom:1;
            background-color: $ui-header-background-color;

            .#{$prefix}tool-img {
                @if $ui-tool-background-image != $tool-background-image {
                    background-image: theme-background-image($ui-tool-background-image);
                }
                // EXTJSIV-8846: partially transparent png images do not display correctly
                // in winXP/IE8m when the image element has a transparent background.
                // to fix this, we give the element the same background-color as the header.
                background-color: $ui-header-background-color;
            }
        }

        .#{$prefix}window-header-#{$ui}-vertical .#{$prefix}window-header-text-container {
            @include rotate-element($angle: 90, $background-color: $ui-header-background-color);
        }

        @if $include-rtl {
            .#{$prefix}window-header-#{$ui}-vertical .#{$prefix}rtl.#{$prefix}window-header-text-container {
                @include rotate-element($angle: 270, $background-color: $ui-header-background-color);
            }
        }

        .#{$prefix}window-header-text-container-#{$ui} {
            @if not is-null($ui-header-color) { color: $ui-header-color; }
            @if not is-null($ui-header-font-weight) { font-weight: $ui-header-font-weight; }

            line-height: $ui-header-line-height;
            font-family: $ui-header-font-family;
            font-size: $ui-header-font-size;
            padding: $ui-header-text-padding;
            text-transform: $ui-header-text-transform;
        }

        $header-border-bottom-width: 0;
        @if $ui-force-header-border {
            $header-border-bottom-width: bottom($ui-header-border-width);
        }

        $frame-top: max(top($ui-border-width), max(top($ui-border-radius), right($ui-border-radius)));
        $header-bottom-padding-adjust: $frame-top - top($ui-border-width);

        $header-expanded-padding:
            top($ui-header-padding),
            right($ui-header-padding),
            bottom($ui-header-padding) - $header-bottom-padding-adjust,
            left($ui-header-padding);

        @if not is-null($ui-border-radius) and $ui-border-radius != 0 {
            @include x-frame(
                $cls: 'window-header',
                $ui: '#{$ui}-top',
                $border-radius: top($ui-border-radius) right($ui-border-radius) 0 0,
                $border-width: top($ui-header-border-width) right($ui-header-border-width) $header-border-bottom-width left($ui-header-border-width),
                $padding: $header-expanded-padding,
                $background-color: $ui-header-background-color
            );

            @include x-frame(
                $cls: 'window-header',
                $ui: '#{$ui}-right',
                $border-radius: 0 top($ui-border-radius) right($ui-border-radius) 0,
                $border-width: left($ui-header-border-width) top($ui-header-border-width) right($ui-header-border-width) $header-border-bottom-width,
                $padding: rotate90($header-expanded-padding),
                $background-color: $ui-header-background-color,
                $include-frame-rtl: $include-rtl
            );

            @include x-frame(
                $cls: 'window-header',
                $ui: '#{$ui}-bottom',
                $border-radius: 0 0 top($ui-border-radius) left($ui-border-radius),
                $border-width: $header-border-bottom-width right($ui-header-border-width) top($ui-header-border-width) left($ui-header-border-width),
                $padding: rotate180($header-expanded-padding),
                $background-color: $ui-header-background-color
            );

            @include x-frame(
                $cls: 'window-header',
                $ui: '#{$ui}-left',
                $border-radius: right($ui-border-radius) 0 0 top($ui-border-radius),
                $border-width: right($ui-header-border-width) $header-border-bottom-width left($ui-header-border-width) top($ui-header-border-width),
                $padding: rotate270($header-expanded-padding),
                $background-color: $ui-header-background-color,
                $include-frame-rtl: $include-rtl
            );

            @include x-frame(
                $cls: 'window-header',
                $ui: '#{$ui}-collapsed-top',
                $border-radius: $ui-border-radius,
                $border-width: $ui-header-border-width,
                $padding: $ui-header-padding,
                $background-color: $ui-header-background-color
            );

            @include x-frame(
                $cls: 'window-header',
                $ui: '#{$ui}-collapsed-right',
                $border-radius: $ui-border-radius,
                $border-width: $ui-header-border-width,
                $padding: rotate90($ui-header-padding),
                $background-color: $ui-header-background-color,
                $include-frame-rtl: $include-rtl
            );

            @include x-frame(
                $cls: 'window-header',
                $ui: '#{$ui}-collapsed-bottom',
                $border-radius: $ui-border-radius,
                $border-width: $ui-header-border-width,
                $padding: rotate180($ui-header-padding),
                $background-color: $ui-header-background-color
            );

            @include x-frame(
                $cls: 'window-header',
                $ui: '#{$ui}-collapsed-left',
                $border-radius: $ui-border-radius,
                $border-width: $ui-header-border-width,
                $padding: rotate270($ui-header-padding),
                $background-color: $ui-header-background-color,
                $include-frame-rtl: $include-rtl
            );
        }

        @if $ui-header-inner-border-width != 0 {
            .#{$prefix}window-header-#{$ui}-top {
                @include inner-border($ui-header-inner-border-width, $ui-header-inner-border-color);
            }

            .#{$prefix}window-header-#{$ui}-right {
                @include inner-border(rotate90($ui-header-inner-border-width), $ui-inner-border-color);
            }

            .#{$prefix}window-header-#{$ui}-bottom {
                @include inner-border(rotate180($ui-header-inner-border-width), $ui-inner-border-color);
            }

            .#{$prefix}window-header-#{$ui}-left {
                @include inner-border(rotate270($ui-header-inner-border-width), $ui-inner-border-color);
            }
        }

        .#{$prefix}window-header-#{$ui} {
            .#{$prefix}window-header-icon {
                width: $ui-header-icon-width;
                height: $ui-header-icon-height;
                // color, font-size, and line-height are needed for glyph icons
                color: $ui-header-glyph-color;
                font-size: $ui-header-icon-height;
                line-height: $ui-header-icon-height;
                background-position: $window-header-icon-background-position;
            }
            .#{$prefix}window-header-glyph {
                color: $ui-header-glyph-color;
                font-size: $ui-header-icon-height;
                line-height: $ui-header-icon-height;

                @if $ui-header-glyph-opacity != 1 {
                    // do not use the opacity mixin because we do not want IE's filter version of
                    // opacity to be included.  We emulate the opacity setting in IE8m by mixing
                    // the icon color into the background color. (see below)
                    opacity: $ui-header-glyph-opacity;
                }
                // In IE8 and below when a glyph contains partially transparent pixels, we
                // can't apply an opacity filter to the glyph element, because IE8m will render
                // the partially transparent pixels of the glyph as black. To work around this,
                // we emulate the approximate color that the glyph would have if it had opacity
                // applied by mixing the glyph color with the header's background-color.
                @if $include-ie {
                    .#{$prefix}ie8m & {
                        color: mix($ui-header-glyph-color, $ui-header-background-color, $ui-header-glyph-opacity * 100);
                    }
                }
            }
        }

        $ui-header-icon-margin: 0 $window-header-icon-spacing 0 0;
        .#{$prefix}window-header-#{$ui}-horizontal {
            .#{$prefix}window-header-icon-before-title {
                margin: $ui-header-icon-margin;
            }

            @if $include-rtl {
                .#{$prefix}rtl.#{$prefix}window-header-icon-before-title {
                    margin: rtl($ui-header-icon-margin);
                }
            }

            .#{$prefix}window-header-icon-after-title {
                margin: rtl($ui-header-icon-margin);
            }

            @if $include-rtl {
                .#{$prefix}rtl.#{$prefix}window-header-icon-after-title {
                    margin: $ui-header-icon-margin;
                }
            }
        }

        .#{$prefix}window-header-#{$ui}-vertical {
            .#{$prefix}window-header-icon-before-title {
                margin: rotate90($ui-header-icon-margin);
            }

            @if $include-rtl {
                .#{$prefix}rtl.#{$prefix}window-header-icon-before-title {
                    margin: rotate270(rtl($ui-header-icon-margin));
                }
            }

            .#{$prefix}window-header-icon-after-title {
                margin: rotate90(rtl($ui-header-icon-margin));
            }

            @if $include-rtl {
                .#{$prefix}rtl.#{$prefix}window-header-icon-after-title {
                    margin: rotate270($ui-header-icon-margin);
                }
            }
        }

        $ui-tool-margin: 0 0 0 $ui-tool-spacing;
        .#{$prefix}window-header-#{$ui}-horizontal {
            .#{$prefix}tool-after-title {
                margin: $ui-tool-margin;
            }

            @if $include-rtl {
                .#{$prefix}rtl.#{$prefix}tool-after-title {
                    margin: rtl($ui-tool-margin);
                }
            }

            .#{$prefix}tool-before-title {
                margin: rtl($ui-tool-margin);
            }

            @if $include-rtl {
                .#{$prefix}rtl.#{$prefix}tool-before-title {
                    margin: $ui-tool-margin;
                }
            }
        }

        .#{$prefix}window-header-#{$ui}-vertical {
            .#{$prefix}tool-after-title {
                margin: rotate90($ui-tool-margin);
            }

            @if $include-rtl {
                .#{$prefix}rtl.#{$prefix}tool-after-title {
                    margin: rotate270(rtl($ui-tool-margin));
                }
            }

            .#{$prefix}tool-before-title {
                margin: rotate90(rtl($ui-tool-margin));
            }

            @if $include-rtl {
                .#{$prefix}rtl.#{$prefix}tool-before-title {
                    margin: rotate270($ui-tool-margin);
                }
            }
        }

        // !important is needed in the following rules to override dock layout's border
        // management rules.
        @if $ui-force-header-border {
            .#{$prefix}window-header-#{$ui} {
                border-width: $ui-header-border-width !important;
            }
        } @else {
            .#{$prefix}window-#{$ui}-collapsed .#{$prefix}window-header {
                border-width: $ui-header-border-width !important;
            }
        }

        @if $include-slicer-border-radius {
            .#{$prefix}nbr .#{$prefix}window-#{$ui}-collapsed .#{$prefix}window-header {
                border-width: 0 !important;
            }
        }

        // Window resizing.
        // If there's a border that's wider than the specified threshold (Sencha default is 2) then
        // embed the handles in the borders using -ve position and make resizable windows show overflow.
        // The dock layout should ensure that all constituent elements fit within the element.
        // The only exception is during animated resizing. Overflow inline style is set hidden during animation (AbstractComponent.animate)
        @if $ui-border-width > $border-width-threshold {
            .#{$prefix}window-#{$ui}-resizable {

                // Resizable Window element overflow must be visible for embedded handles to accept mouseovers.
                overflow: visible;

                .#{$prefix}window-handle-north-br {
                    top: -($ui-border-width);
                }
                .#{$prefix}window-handle-south-br {
                    bottom: -($ui-border-width);
                }
                .#{$prefix}window-handle-east-br {
                    right: -($ui-border-width);
                }
                .#{$prefix}window-handle-west-br {
                    left: -($ui-border-width);
                }
                .#{$prefix}window-handle-northwest-br {
                    left: -($ui-border-width);
                    top: -($ui-border-width);
                }
                .#{$prefix}window-handle-northeast-br {
                    right: -($ui-border-width);
                    top: -($ui-border-width);
                }
                .#{$prefix}window-handle-southeast-br {
                    right: -($ui-border-width);
                    bottom: -($ui-border-width);
                }
                .#{$prefix}window-handle-southwest-br {
                    left: -($ui-border-width);
                    bottom: -($ui-border-width);
                }
            }
        }

        @if $ui-include-border-management-rules {
            @include border-management(
                $parent-cls: window-#{$ui},
                $border-width: $ui-wrap-border-width,
                $border-color: $ui-wrap-border-color
            );
        }
    }

    .#{$prefix}window-ghost {
        @include opacity($window-ghost-opacity);
    }

    @if $include-window-default-ui {
        @include extjs-window-ui(
            $ui: 'default'
        );
    }