svelte-headroom/index.mjs

Svelte component with headroom

function noop() { }
function assign(tar, src) {
    // @ts-ignore
    for (const k in src)
        tar[k] = src[k];
    return tar;
}
function run(fn) {
    return fn();
}
function blank_object() {
    return Object.create(null);
}
function run_all(fns) {
    fns.forEach(run);
}
function is_function(thing) {
    return typeof thing === 'function';
}
function safe_not_equal(a, b) {
    return a != a ? b == b : a !== b || ((a && typeof a === 'object') || typeof a === 'function');
}
function create_slot(definition, ctx, fn) {
    if (definition) {
        const slot_ctx = get_slot_context(definition, ctx, fn);
        return definition[0](slot_ctx);
    }
}
function get_slot_context(definition, ctx, fn) {
    return definition[1]
        ? assign({}, assign(ctx.$$scope.ctx, definition[1](fn ? fn(ctx) : {})))
        : ctx.$$scope.ctx;
}
function get_slot_changes(definition, ctx, changed, fn) {
    return definition[1]
        ? assign({}, assign(ctx.$$scope.changed || {}, definition[1](fn ? fn(changed) : {})))
        : ctx.$$scope.changed || {};
}
function null_to_empty(value) {
    return value == null ? '' : value;
}

function append(target, node) {
    target.appendChild(node);
}
function insert(target, node, anchor) {
    target.insertBefore(node, anchor || null);
}
function detach(node) {
    node.parentNode.removeChild(node);
}
function element(name) {
    return document.createElement(name);
}
function listen(node, event, handler, options) {
    node.addEventListener(event, handler, options);
    return () => node.removeEventListener(event, handler, options);
}
function attr(node, attribute, value) {
    if (value == null)
        node.removeAttribute(attribute);
    else
        node.setAttribute(attribute, value);
}
function children(element) {
    return Array.from(element.childNodes);
}
function custom_event(type, detail) {
    const e = document.createEvent('CustomEvent');
    e.initCustomEvent(type, false, false, detail);
    return e;
}

let current_component;
function set_current_component(component) {
    current_component = component;
}
function createEventDispatcher() {
    const component = current_component;
    return (type, detail) => {
        const callbacks = component.$$.callbacks[type];
        if (callbacks) {
            // TODO are there situations where events could be dispatched
            // in a server (non-DOM) environment?
            const event = custom_event(type, detail);
            callbacks.slice().forEach(fn => {
                fn.call(component, event);
            });
        }
    };
}

const dirty_components = [];
const binding_callbacks = [];
const render_callbacks = [];
const flush_callbacks = [];
const resolved_promise = Promise.resolve();
let update_scheduled = false;
function schedule_update() {
    if (!update_scheduled) {
        update_scheduled = true;
        resolved_promise.then(flush);
    }
}
function add_render_callback(fn) {
    render_callbacks.push(fn);
}
function flush() {
    const seen_callbacks = new Set();
    do {
        // first, call beforeUpdate functions
        // and update components
        while (dirty_components.length) {
            const component = dirty_components.shift();
            set_current_component(component);
            update(component.$$);
        }
        while (binding_callbacks.length)
            binding_callbacks.pop()();
        // then, once components are updated, call
        // afterUpdate functions. This may cause
        // subsequent updates...
        for (let i = 0; i < render_callbacks.length; i += 1) {
            const callback = render_callbacks[i];
            if (!seen_callbacks.has(callback)) {
                callback();
                // ...so guard against infinite loops
                seen_callbacks.add(callback);
            }
        }
        render_callbacks.length = 0;
    } while (dirty_components.length);
    while (flush_callbacks.length) {
        flush_callbacks.pop()();
    }
    update_scheduled = false;
}
function update($$) {
    if ($$.fragment) {
        $$.update($$.dirty);
        run_all($$.before_update);
        $$.fragment.p($$.dirty, $$.ctx);
        $$.dirty = null;
        $$.after_update.forEach(add_render_callback);
    }
}
const outroing = new Set();
let outros;
function transition_in(block, local) {
    if (block && block.i) {
        outroing.delete(block);
        block.i(local);
    }
}
function transition_out(block, local, detach, callback) {
    if (block && block.o) {
        if (outroing.has(block))
            return;
        outroing.add(block);
        outros.c.push(() => {
            outroing.delete(block);
            if (callback) {
                if (detach)
                    block.d(1);
                callback();
            }
        });
        block.o(local);
    }
}
function mount_component(component, target, anchor) {
    const { fragment, on_mount, on_destroy, after_update } = component.$$;
    fragment.m(target, anchor);
    // onMount happens before the initial afterUpdate
    add_render_callback(() => {
        const new_on_destroy = on_mount.map(run).filter(is_function);
        if (on_destroy) {
            on_destroy.push(...new_on_destroy);
        }
        else {
            // Edge case - component was destroyed immediately,
            // most likely as a result of a binding initialising
            run_all(new_on_destroy);
        }
        component.$$.on_mount = [];
    });
    after_update.forEach(add_render_callback);
}
function destroy_component(component, detaching) {
    if (component.$$.fragment) {
        run_all(component.$$.on_destroy);
        component.$$.fragment.d(detaching);
        // TODO null out other refs, including component.$$ (but need to
        // preserve final state?)
        component.$$.on_destroy = component.$$.fragment = null;
        component.$$.ctx = {};
    }
}
function make_dirty(component, key) {
    if (!component.$$.dirty) {
        dirty_components.push(component);
        schedule_update();
        component.$$.dirty = blank_object();
    }
    component.$$.dirty[key] = true;
}
function init(component, options, instance, create_fragment, not_equal, prop_names) {
    const parent_component = current_component;
    set_current_component(component);
    const props = options.props || {};
    const $$ = component.$$ = {
        fragment: null,
        ctx: null,
        // state
        props: prop_names,
        update: noop,
        not_equal,
        bound: blank_object(),
        // lifecycle
        on_mount: [],
        on_destroy: [],
        before_update: [],
        after_update: [],
        context: new Map(parent_component ? parent_component.$$.context : []),
        // everything else
        callbacks: blank_object(),
        dirty: null
    };
    let ready = false;
    $$.ctx = instance
        ? instance(component, props, (key, ret, value = ret) => {
            if ($$.ctx && not_equal($$.ctx[key], $$.ctx[key] = value)) {
                if ($$.bound[key])
                    $$.bound[key](value);
                if (ready)
                    make_dirty(component, key);
            }
            return ret;
        })
        : props;
    $$.update();
    ready = true;
    run_all($$.before_update);
    $$.fragment = create_fragment($$.ctx);
    if (options.target) {
        if (options.hydrate) {
            // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
            $$.fragment.l(children(options.target));
        }
        else {
            // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
            $$.fragment.c();
        }
        if (options.intro)
            transition_in(component.$$.fragment);
        mount_component(component, options.target, options.anchor);
        flush();
    }
    set_current_component(parent_component);
}
class SvelteComponent {
    $destroy() {
        destroy_component(this, 1);
        this.$destroy = noop;
    }
    $on(type, callback) {
        const callbacks = (this.$$.callbacks[type] || (this.$$.callbacks[type] = []));
        callbacks.push(callback);
        return () => {
            const index = callbacks.indexOf(callback);
            if (index !== -1)
                callbacks.splice(index, 1);
        };
    }
    $set() {
        // overridden by instance, if it has props
    }
}

const warn = (msg, val) => console.warn(`[svelte-headroom]:`, msg, val);

function validate({ duration, offset, tolerance }) {
  if (typeof offset !== "number")
    warn("The `offset` prop is not a number: ", offset);
  if (typeof tolerance !== "number")
    warn("The `tolerance` prop is not a number: ", tolerance);
  if (typeof duration !== "string")
    warn("The `duration` prop is not a string such as '200ms': ", duration);
}

/* src/index.svelte generated by Svelte v3.12.1 */

function add_css() {
	var style = element("style");
	style.id = 'svelte-1ql6gaa-style';
	style.textContent = "div.svelte-1ql6gaa{position:fixed;width:100%;top:0;transition:transform 300ms linear;transform:translateY(0%)}.svelte-headroom--unpin.svelte-1ql6gaa{transform:translateY(-100%)}";
	append(document.head, style);
}

function create_fragment(ctx) {
	var scrolling = false, clear_scrolling = () => { scrolling = false; }, scrolling_timeout, div, div_class_value, action_action, current, dispose;

	add_render_callback(ctx.onwindowscroll);

	const default_slot_template = ctx.$$slots.default;
	const default_slot = create_slot(default_slot_template, ctx, null);

	return {
		c() {
			div = element("div");

			if (default_slot) default_slot.c();

			attr(div, "class", div_class_value = "" + null_to_empty(ctx.headerClass) + " svelte-1ql6gaa");
			dispose = listen(window, "scroll", () => {
				scrolling = true;
				clearTimeout(scrolling_timeout);
				scrolling_timeout = setTimeout(clear_scrolling, 100);
				ctx.onwindowscroll();
			});
		},

		l(nodes) {
			if (default_slot) default_slot.l(div_nodes);
		},

		m(target, anchor) {
			insert(target, div, anchor);

			if (default_slot) {
				default_slot.m(div, null);
			}

			action_action = ctx.action.call(null, div) || {};
			current = true;
		},

		p(changed, ctx) {
			if (changed.y && !scrolling) {
				scrolling = true;
				clearTimeout(scrolling_timeout);
				scrollTo(window.pageXOffset, ctx.y);
				scrolling_timeout = setTimeout(clear_scrolling, 100);
			}

			if (default_slot && default_slot.p && changed.$$scope) {
				default_slot.p(
					get_slot_changes(default_slot_template, ctx, changed, null),
					get_slot_context(default_slot_template, ctx, null)
				);
			}

			if ((!current || changed.headerClass) && div_class_value !== (div_class_value = "" + null_to_empty(ctx.headerClass) + " svelte-1ql6gaa")) {
				attr(div, "class", div_class_value);
			}
		},

		i(local) {
			if (current) return;
			transition_in(default_slot, local);
			current = true;
		},

		o(local) {
			transition_out(default_slot, local);
			current = false;
		},

		d(detaching) {
			if (detaching) {
				detach(div);
			}

			if (default_slot) default_slot.d(detaching);
			if (action_action && typeof action_action.destroy === 'function') action_action.destroy();
			dispose();
		}
	};
}

let prefix = "svelte-headroom--";

function instance($$self, $$props, $$invalidate) {
	

  let { duration = "300ms", offset = 0, tolerance = 0 } = $$props;

  let headerClass = "";
  let lastHeaderClass = "";
  let y = 0;
  let lastY = 0;

  const dispatch = createEventDispatcher();

  function deriveClass(y = 0, scrolled = 0) {
    if (y < offset) return "";
    if (Math.abs(scrolled) < tolerance) return headerClass;
    if (scrolled > 0) return "";
    if (scrolled < 0) return `${prefix}unpin`;
    return headerClass;
  }

  function updateClass(y = 0) {
    const scrolledPxs = lastY - y;
    const result = deriveClass(y, scrolledPxs);
    lastY = y;
    return result;
  }

  function action(node) {
    node.style.transitionDuration = duration;
  }

	let { $$slots = {}, $$scope } = $$props;

	function onwindowscroll() {
		y = window.pageYOffset; $$invalidate('y', y);
	}

	$$self.$set = $$props => {
		if ('duration' in $$props) $$invalidate('duration', duration = $$props.duration);
		if ('offset' in $$props) $$invalidate('offset', offset = $$props.offset);
		if ('tolerance' in $$props) $$invalidate('tolerance', tolerance = $$props.tolerance);
		if ('$$scope' in $$props) $$invalidate('$$scope', $$scope = $$props.$$scope);
	};

	$$self.$$.update = ($$dirty = { duration: 1, offset: 1, tolerance: 1, y: 1, headerClass: 1, lastHeaderClass: 1 }) => {
		if ($$dirty.duration || $$dirty.offset || $$dirty.tolerance || $$dirty.y || $$dirty.headerClass || $$dirty.lastHeaderClass) { {
        validate({ duration, offset, tolerance });
        $$invalidate('headerClass', headerClass = updateClass(y));
        if (headerClass !== lastHeaderClass) {
          dispatch(headerClass ? "unpin" : "pin");
        }
        $$invalidate('lastHeaderClass', lastHeaderClass = headerClass);
      } }
	};

	return {
		duration,
		offset,
		tolerance,
		headerClass,
		y,
		action,
		onwindowscroll,
		$$slots,
		$$scope
	};
}

class Index extends SvelteComponent {
	constructor(options) {
		super();
		if (!document.getElementById("svelte-1ql6gaa-style")) add_css();
		init(this, options, instance, create_fragment, safe_not_equal, ["duration", "offset", "tolerance"]);
	}
}

export default Index;