Module: Sass::Script::Functions

Defined in:
lib/inline-gradient.rb

Instance Method Summary collapse

Instance Method Details

#inline_gradient(type = DEFAULT_TYPE, width = DEFAULT_WIDTH, height = DEFAULT_HEIGHT, angle = DEFAULT_ANGLE, *color_stops) ⇒ Object 



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# File 'lib/inline-gradient.rb', line 88

def inline_gradient(type = DEFAULT_TYPE, width = DEFAULT_WIDTH, height = DEFAULT_HEIGHT, angle = DEFAULT_ANGLE , *color_stops)

    assert_type(type, :String)
    assert_type(width, :Number)
    assert_type(height, :Number)

    if color_stops.size == 0
        color_stops = DEFAULT_COLOR_STOPS
    end

    if type.to_s == "linear"
        return self.inline_linear_gradient(width, height, angle, color_stops)
    elsif type.to_s == "radial"
        #return self.inline_radial_gradient(width, height, angle, color_stops)
    end

end

#inline_linear_gradient(width, height, angle, color_stops) ⇒ Object 



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# File 'lib/inline-gradient.rb', line 106

def inline_linear_gradient(width, height, angle, color_stops)
    <<-DOC
        I use http://www.w3.org/TR/css3-images/#linear-gradient-syntax

        <linear-gradient> = linear-gradient(
            [ [ <angle> | to <side-or-corner> ] ,]?
            <color-stop>[, <color-stop>]+
        )
        <side-or-corner> = [left | right] || [top | bottom]

        it means that
            - angle is string <angle> | to <side-or-corner>
            - color_stops is string of <color-stop> string

        example: inline-gradient(linear, 100, 100, to left, #1e5799 0%, #2989d8 50%, #207cca 51%, #7db9e8 100%)
    DOC

    if color_stops.class != Array
        color_stops = color_stops.split(',')
    end

    # The vertical gradient needs to change sides to be like horizonlat
    # After creation vertical gradient just needs to be rotated
    angle = side2angle(angle)
    if angle % 180 == 0
        width, height = height, width
    end

    need_rotation = angle != 90

    #get info from first stop color
    first_color_stop = color_stops.shift()
    first_color_stop_arr = first_color_stop.to_s.strip.split(' ')
    first_color = color2hex(first_color_stop_arr[0])
    first_color_distance = first_color_stop_arr[1]

    prev_distance = distance2px(first_color_distance, width)
    prev_color = first_color

    image_list = Magick::ImageList.new

    color_stops.each do |color_stop|
        # Making a single image for each pair of "color stop" values in color_stops.
        # Images concats after this iterator.
        # In this iterator there is no matter is gradient vertical or horizontal.
        # Vertical gradient will just rotate after images concatination
        color_stop_arr = color_stop.to_s.strip.split(' ')

        current_color = color2hex(color_stop_arr[0])
        current_distance = distance2px(color_stop_arr[1], width)

        new_image_width = current_distance.minus(prev_distance).value.ceil

        fill = Magick::GradientFill.new(0, 0, 0, new_image_width, prev_color, current_color)
        image_list.new_image(new_image_width, height.to_i, fill);

        prev_distance = current_distance
        prev_color = current_color
    end

    image = image_list.append(false) #concat from left to right

    if need_rotation
        # Magick has a different start point, difference is -90deg
        angle = angle - 90;
        if angle % 90 != 0
            deg2rad = angle / 180.0 * Math::PI
            adding_delta_x = Math.cos( (90 - angle) / 180.0 * Math::PI ) * height.to_i
            adding_delta_y = Math.tan(deg2rad) * width.to_i
            adding_delta_x = adding_delta_x.abs.ceil
            adding_delta_y = adding_delta_y.abs.ceil
            image.scale!(width.to_i + adding_delta_x, height.to_i + adding_delta_y)
            image.rotate!(angle)
            image.crop!(adding_delta_x / 2, adding_delta_y / 2, width.to_i + adding_delta_x / 2, height.to_i + adding_delta_y / 2)
        elsif angle != 0#TODO check
            image.rotate!(angle)
        end
    end

    data_uri_image = image2base64(image)
    Sass::Script::String.new("url(data:image/png;base64," + data_uri_image + ")")
end