fix: Keyboard accessible context menus (#1768)

- Makes menus fully accessible and keyboard driven
- Currently adds 2.8% to initial bundle size due to the inclusion of Reakit and its dependency, popperjs.
- Converts all menus to functional components
- Remove old custom menu system
- Various layout and flow improvements around the menus

closes #1766

app/components/ContextMenu/Header.js

@@ -0,0 +1,13 @@
+// @flow
+import styled from "styled-components";
+
+const Header = styled.h3`
+  font-size: 11px;
+  font-weight: 600;
+  text-transform: uppercase;
+  color: ${(props) => props.theme.sidebarText};
+  letter-spacing: 0.04em;
+  margin: 1em 12px 0.5em;
+`;
+
+export default Header;

app/components/ContextMenu/MenuItem.js

@@ -0,0 +1,98 @@
+// @flow
+import { CheckmarkIcon } from "outline-icons";
+import * as React from "react";
+import { MenuItem as BaseMenuItem } from "reakit/Menu";
+import styled from "styled-components";
+
+type Props = {
+  onClick?: (SyntheticEvent<>) => void | Promise<void>,
+  children?: React.Node,
+  selected?: boolean,
+  disabled?: boolean,
+  as?: string | React.ComponentType<*>,
+};
+
+const MenuItem = ({
+  onClick,
+  children,
+  selected,
+  disabled,
+  as,
+  ...rest
+}: Props) => {
+  return (
+    <BaseMenuItem
+      onClick={disabled ? undefined : onClick}
+      disabled={disabled}
+      {...rest}
+    >
+      {(props) => (
+        <MenuAnchor as={onClick ? "button" : as} {...props}>
+          {selected !== undefined && (
+            <>
+              {selected ? <CheckmarkIcon /> : <Spacer />}
+              &nbsp;
+            </>
+          )}
+          {children}
+        </MenuAnchor>
+      )}
+    </BaseMenuItem>
+  );
+};
+
+const Spacer = styled.div`
+  width: 24px;
+  height: 24px;
+`;
+
+export const MenuAnchor = styled.a`
+  display: flex;
+  margin: 0;
+  border: 0;
+  padding: 6px 12px;
+  width: 100%;
+  min-height: 32px;
+  background: none;
+  color: ${(props) =>
+    props.disabled ? props.theme.textTertiary : props.theme.textSecondary};
+  justify-content: left;
+  align-items: center;
+  font-size: 15px;
+  cursor: default;
+  user-select: none;
+
+  svg:not(:last-child) {
+    margin-right: 8px;
+  }
+
+  svg {
+    flex-shrink: 0;
+    opacity: ${(props) => (props.disabled ? ".5" : 1)};
+  }
+
+  ${(props) =>
+    props.disabled
+      ? "pointer-events: none;"
+      : `
+
+  &:hover,
+  &.focus-visible {
+    color: ${props.theme.white};
+    background: ${props.theme.primary};
+    box-shadow: none;
+    cursor: pointer;
+
+    svg {
+      fill: ${props.theme.white};
+    }
+  }
+
+  &:focus {
+    color: ${props.theme.white};
+    background: ${props.theme.primary};
+  }
+  `};
+`;
+
+export default MenuItem;

app/components/ContextMenu/OverflowMenuButton.js

@@ -0,0 +1,21 @@
+// @flow
+import { MoreIcon } from "outline-icons";
+import * as React from "react";
+import { MenuButton } from "reakit/Menu";
+import NudeButton from "components/NudeButton";
+
+export default function OverflowMenuButton({
+  iconColor,
+  className,
+  ...rest
+}: any) {
+  return (
+    <MenuButton {...rest}>
+      {(props) => (
+        <NudeButton className={className} {...props}>
+          <MoreIcon color={iconColor} />
+        </NudeButton>
+      )}
+    </MenuButton>
+  );
+}

app/components/ContextMenu/Separator.js

@@ -0,0 +1,16 @@
+// @flow
+import * as React from "react";
+import { MenuSeparator } from "reakit/Menu";
+import styled from "styled-components";
+
+export default function Separator(rest: {}) {
+  return (
+    <MenuSeparator {...rest}>
+      {(props) => <HorizontalRule {...props} />}
+    </MenuSeparator>
+  );
+}
+
+const HorizontalRule = styled.hr`
+  margin: 0.5em 12px;
+`;

app/components/ContextMenu/Template.js

@@ -0,0 +1,169 @@
+// @flow
+import { ExpandedIcon } from "outline-icons";
+import * as React from "react";
+import { useTranslation } from "react-i18next";
+import { Link } from "react-router-dom";
+import {
+  useMenuState,
+  MenuButton,
+  MenuItem as BaseMenuItem,
+} from "reakit/Menu";
+import styled from "styled-components";
+import MenuItem, { MenuAnchor } from "./MenuItem";
+import Separator from "./Separator";
+import ContextMenu from ".";
+
+type TMenuItem =
+  | {|
+      title: React.Node,
+      to: string,
+      visible?: boolean,
+      selected?: boolean,
+      disabled?: boolean,
+    |}
+  | {|
+      title: React.Node,
+      onClick: (event: SyntheticEvent<>) => void | Promise<void>,
+      visible?: boolean,
+      selected?: boolean,
+      disabled?: boolean,
+    |}
+  | {|
+      title: React.Node,
+      href: string,
+      visible?: boolean,
+      selected?: boolean,
+      disabled?: boolean,
+    |}
+  | {|
+      title: React.Node,
+      visible?: boolean,
+      disabled?: boolean,
+      style?: Object,
+      hover?: boolean,
+      items: TMenuItem[],
+    |}
+  | {|
+      type: "separator",
+      visible?: boolean,
+    |}
+  | {|
+      type: "heading",
+      visible?: boolean,
+      title: React.Node,
+    |};
+
+type Props = {|
+  items: TMenuItem[],
+|};
+
+const Disclosure = styled(ExpandedIcon)`
+  transform: rotate(270deg);
+  justify-self: flex-end;
+`;
+
+const Submenu = React.forwardRef(({ templateItems, title, ...rest }, ref) => {
+  const { t } = useTranslation();
+  const menu = useMenuState({ modal: true });
+
+  return (
+    <>
+      <MenuButton ref={ref} {...menu} {...rest}>
+        {(props) => (
+          <MenuAnchor {...props}>
+            {title} <Disclosure color="currentColor" />
+          </MenuAnchor>
+        )}
+      </MenuButton>
+      <ContextMenu {...menu} aria-label={t("Submenu")}>
+        <Template {...menu} items={templateItems} />
+      </ContextMenu>
+    </>
+  );
+});
+
+function Template({ items, ...menu }: Props): React.Node {
+  let filtered = items.filter((item) => item.visible !== false);
+
+  // this block literally just trims unneccessary separators
+  filtered = filtered.reduce((acc, item, index) => {
+    // trim separators from start / end
+    if (item.type === "separator" && index === 0) return acc;
+    if (item.type === "separator" && index === filtered.length - 1) return acc;
+
+    // trim double separators looking ahead / behind
+    const prev = filtered[index - 1];
+    if (prev && prev.type === "separator" && item.type === "separator")
+      return acc;
+
+    // otherwise, continue
+    return [...acc, item];
+  }, []);
+
+  return filtered.map((item, index) => {
+    if (item.to) {
+      return (
+        <MenuItem
+          as={Link}
+          to={item.to}
+          key={index}
+          disabled={item.disabled}
+          selected={item.selected}
+          {...menu}
+        >
+          {item.title}
+        </MenuItem>
+      );
+    }
+
+    if (item.href) {
+      return (
+        <MenuItem
+          href={item.href}
+          key={index}
+          disabled={item.disabled}
+          selected={item.selected}
+          target="_blank"
+          {...menu}
+        >
+          {item.title}
+        </MenuItem>
+      );
+    }
+
+    if (item.onClick) {
+      return (
+        <MenuItem
+          as="button"
+          onClick={item.onClick}
+          disabled={item.disabled}
+          selected={item.selected}
+          key={index}
+          {...menu}
+        >
+          {item.title}
+        </MenuItem>
+      );
+    }
+
+    if (item.items) {
+      return (
+        <BaseMenuItem
+          key={index}
+          as={Submenu}
+          templateItems={item.items}
+          title={item.title}
+          {...menu}
+        />
+      );
+    }
+
+    if (item.type === "separator") {
+      return <Separator key={index} />;
+    }
+
+    return null;
+  });
+}
+
+export default React.memo<Props>(Template);

app/components/ContextMenu/index.js

@@ -0,0 +1,77 @@
+// @flow
+import { rgba } from "polished";
+import * as React from "react";
+import { Menu } from "reakit/Menu";
+import styled from "styled-components";
+import { fadeAndScaleIn } from "shared/styles/animations";
+import usePrevious from "hooks/usePrevious";
+
+type Props = {|
+  "aria-label": string,
+  visible?: boolean,
+  animating?: boolean,
+  children: React.Node,
+  onOpen?: () => void,
+  onClose?: () => void,
+|};
+
+export default function ContextMenu({
+  children,
+  onOpen,
+  onClose,
+  ...rest
+}: Props) {
+  const previousVisible = usePrevious(rest.visible);
+
+  React.useEffect(() => {
+    if (rest.visible && !previousVisible) {
+      if (onOpen) {
+        onOpen();
+      }
+    }
+    if (!rest.visible && previousVisible) {
+      if (onClose) {
+        onClose();
+      }
+    }
+  }, [onOpen, onClose, previousVisible, rest.visible]);
+
+  return (
+    <Menu {...rest}>
+      {(props) => (
+        <Position {...props}>
+          <Background>
+            {rest.visible || rest.animating ? children : null}
+          </Background>
+        </Position>
+      )}
+    </Menu>
+  );
+}
+
+const Position = styled.div`
+  position: absolute;
+  z-index: ${(props) => props.theme.depths.menu};
+`;
+
+const Background = styled.div`
+  animation: ${fadeAndScaleIn} 200ms ease;
+  transform-origin: ${(props) => (props.left !== undefined ? "25%" : "75%")} 0;
+  background: ${(props) => rgba(props.theme.menuBackground, 0.95)};
+  border: ${(props) =>
+    props.theme.menuBorder ? `1px solid ${props.theme.menuBorder}` : "none"};
+  border-radius: 2px;
+  padding: 0.5em 0;
+  min-width: 180px;
+  overflow: hidden;
+  overflow-y: auto;
+  max-height: 75vh;
+  max-width: 276px;
+  box-shadow: ${(props) => props.theme.menuShadow};
+  pointer-events: all;
+  font-weight: normal;
+
+  @media print {
+    display: none;
+  }
+`;