Function _parseScrollModifiers

src/parsetree/commands/basic.js:686–724

(parser)

}

function _parseScrollModifiers(parser) {
    parser.matchToken("the");
    var verticalPosition = parser.matchAnyToken("top", "middle", "bottom");
    var horizontalPosition = parser.matchAnyToken("left", "center", "right");
    if (verticalPosition || horizontalPosition) {
        parser.requireToken("of");
    }
    var target = parser.requireElement("unaryExpression");

    var plusOrMinus = parser.matchAnyOpToken("+", "-");
    var offset;
    if (plusOrMinus) {
        parser.pushFollow("px");
        try {
            offset = parser.requireElement("expression");
        } finally {
            parser.popFollow();
        }
    }
    parser.matchToken("px");

    var container;
    if (parser.matchToken("in")) {
        container = parser.requireElement("unaryExpression");
    }

    var smoothness = parser.matchAnyToken("smoothly", "instantly");

    var scrollOptions = { block: "start", inline: "nearest" };

    var blockMap = { top: "start", bottom: "end", middle: "center" };
    var inlineMap = { left: "start", center: "center", right: "end" };
    var behaviorMap = { smoothly: "smooth", instantly: "instant" };
    if (verticalPosition) scrollOptions.block = blockMap[verticalPosition.value];
    if (horizontalPosition) scrollOptions.inline = inlineMap[horizontalPosition.value];
    if (smoothness) scrollOptions.behavior = behaviorMap[smoothness.value];

    return { target, offset, plusOrMinus, scrollOptions, container };
}

function _parseSmoothness(parser) {
    var smoothness = parser.matchAnyToken("smoothly", "instantly");