...

4 files changed, 142 insertions, 0 deletions

diff --git a/FrontEnd/src/utilities/mediaQuery.ts b/FrontEnd/src/utilities/mediaQuery.ts
new file mode 100644
index 00000000..ad55c3c0
--- /dev/null
+++ b/FrontEnd/src/utilities/mediaQuery.ts
@@ -0,0 +1,5 @@
+import { useMediaQuery } from "react-responsive";
+
+export function useIsSmallScreen(): boolean {
+  return useMediaQuery({ maxWidth: 576 });
+}
diff --git a/FrontEnd/src/utilities/url.ts b/FrontEnd/src/utilities/url.ts
new file mode 100644
index 00000000..4f2a6ecd
--- /dev/null
+++ b/FrontEnd/src/utilities/url.ts
@@ -0,0 +1,17 @@
+export function applyQueryParameters<T>(url: string, query: T): string {
+  if (query == null) return url;
+
+  const params = new URLSearchParams();
+
+  for (const [key, value] of Object.entries(query)) {
+    if (value == null) void 0;
+    else if (typeof value === "string") params.set(key, value);
+    else if (typeof value === "number") params.set(key, String(value));
+    else if (typeof value === "boolean") params.set(key, String(value));
+    else if (value instanceof Date) params.set(key, value.toISOString());
+    else {
+      console.error("Unknown query parameter type. Param: ", value);
+    }
+  }
+  return url + "?" + params.toString();
+}
diff --git a/FrontEnd/src/utilities/useReverseScrollPositionRemember.ts b/FrontEnd/src/utilities/useReverseScrollPositionRemember.ts
new file mode 100644
index 00000000..a5812808
--- /dev/null
+++ b/FrontEnd/src/utilities/useReverseScrollPositionRemember.ts
@@ -0,0 +1,77 @@
+import React from "react";
+
+let on = false;
+
+let reverseScrollPosition = getReverseScrollPosition();
+let reverseScrollToPosition: number | null = null;
+let lastScrollPosition = window.scrollY;
+
+export function getReverseScrollPosition(): number {
+  if (document.documentElement.scrollHeight <= window.innerHeight) {
+    return 0;
+  } else {
+    return (
+      document.documentElement.scrollHeight -
+      document.documentElement.scrollTop -
+      window.innerHeight
+    );
+  }
+}
+
+export function scrollToReverseScrollPosition(reversePosition: number): void {
+  if (document.documentElement.scrollHeight <= window.innerHeight) return;
+
+  const old = document.documentElement.style.scrollBehavior;
+  document.documentElement.style.scrollBehavior = "auto";
+
+  const newPosition =
+    document.documentElement.scrollHeight -
+    window.innerHeight -
+    reversePosition;
+
+  reverseScrollToPosition = newPosition;
+
+  window.scrollTo(0, newPosition);
+
+  document.documentElement.style.scrollBehavior = old;
+}
+
+const scrollListener = (): void => {
+  if (
+    reverseScrollToPosition != null &&
+    Math.abs(window.scrollY - reverseScrollToPosition) > 50
+  ) {
+    scrollToReverseScrollPosition(reverseScrollPosition);
+    return;
+  }
+  if (
+    reverseScrollToPosition == null &&
+    Math.abs(window.scrollY - lastScrollPosition) > 1000
+  ) {
+    scrollToReverseScrollPosition(reverseScrollPosition);
+    return;
+  }
+
+  reverseScrollToPosition = null;
+  lastScrollPosition = window.scrollY;
+  reverseScrollPosition = getReverseScrollPosition();
+};
+
+const resizeObserver = new ResizeObserver(() => {
+  scrollToReverseScrollPosition(reverseScrollPosition);
+});
+
+export default function useReverseScrollPositionRemember(): void {
+  React.useEffect(() => {
+    if (on) return;
+    on = true;
+    window.addEventListener("scroll", scrollListener);
+    resizeObserver.observe(document.documentElement);
+
+    return () => {
+      window.removeEventListener("scroll", scrollListener);
+      resizeObserver.disconnect();
+      on = false;
+    };
+  }, []);
+}
diff --git a/FrontEnd/src/utilities/useScrollToTop.ts b/FrontEnd/src/utilities/useScrollToTop.ts
new file mode 100644
index 00000000..892e3545
--- /dev/null
+++ b/FrontEnd/src/utilities/useScrollToTop.ts
@@ -0,0 +1,43 @@
+import React from "react";
+import { fromEvent } from "rxjs";
+import { filter, throttleTime } from "rxjs/operators";
+
+function useScrollToTop(
+  handler: () => void,
+  enable = true,
+  option = {
+    maxOffset: 50,
+    throttle: 1000,
+  }
+): void {
+  const handlerRef = React.useRef<(() => void) | null>(null);
+
+  React.useEffect(() => {
+    handlerRef.current = handler;
+
+    return () => {
+      handlerRef.current = null;
+    };
+  }, [handler]);
+
+  React.useEffect(() => {
+    const subscription = fromEvent(window, "scroll")
+      .pipe(
+        filter(() => {
+          return window.scrollY <= option.maxOffset;
+        }),
+        throttleTime(option.throttle)
+      )
+      .subscribe(() => {
+        if (enable) {
+          handlerRef.current?.();
+        }
+      });
+
+    return () => {
+      subscription.unsubscribe();
+    };
+  }, [enable, option.maxOffset, option.throttle]);
+}
+
+export default useScrollToTop;