chore: Cleanup editor menu handlers (#5174

* wip

* wip

* refactor

shared/editor/extensions/BlockMenu.tsx

@@ -0,0 +1,99 @@
+import { PlusIcon } from "outline-icons";
+import { Plugin } from "prosemirror-state";
+import { findParentNode } from "prosemirror-utils";
+import { Decoration, DecorationSet } from "prosemirror-view";
+import * as React from "react";
+import ReactDOM from "react-dom";
+import { SuggestionsMenuType } from "../plugins/Suggestions";
+import { EventType } from "../types";
+import Suggestion from "./Suggestion";
+
+export default class BlockMenu extends Suggestion {
+  get defaultOptions() {
+    return {
+      type: SuggestionsMenuType.Block,
+      openRegex: /^\/(\w+)?$/,
+      closeRegex: /(^(?!\/(\w+)?)(.*)$|^\/(([\w\W]+)\s.*|\s)$|^\/((\W)+)$)/,
+    };
+  }
+
+  get name() {
+    return "blockmenu";
+  }
+
+  get plugins() {
+    const button = document.createElement("button");
+    button.className = "block-menu-trigger";
+    button.type = "button";
+    ReactDOM.render(<PlusIcon />, button);
+
+    return [
+      ...super.plugins,
+      new Plugin({
+        props: {
+          decorations: (state) => {
+            const parent = findParentNode(
+              (node) => node.type.name === "paragraph"
+            )(state.selection);
+
+            if (!parent) {
+              return;
+            }
+
+            const isTopLevel = state.selection.$from.depth === 1;
+            if (!isTopLevel) {
+              return;
+            }
+
+            const decorations: Decoration[] = [];
+            const isEmptyNode = parent && parent.node.content.size === 0;
+            const isSlash = parent && parent.node.textContent === "/";
+
+            if (isEmptyNode) {
+              decorations.push(
+                Decoration.widget(
+                  parent.pos,
+                  () => {
+                    button.addEventListener("click", () => {
+                      this.editor.events.emit(EventType.SuggestionsMenuOpen, {
+                        type: SuggestionsMenuType.Block,
+                        query: "",
+                      });
+                    });
+                    return button;
+                  },
+                  {
+                    key: "block-trigger",
+                  }
+                )
+              );
+
+              const isEmptyDoc = state.doc.textContent === "";
+              if (!isEmptyDoc) {
+                decorations.push(
+                  Decoration.node(
+                    parent.pos,
+                    parent.pos + parent.node.nodeSize,
+                    {
+                      class: "placeholder",
+                      "data-empty-text": this.options.dictionary.newLineEmpty,
+                    }
+                  )
+                );
+              }
+            } else if (isSlash) {
+              decorations.push(
+                Decoration.node(parent.pos, parent.pos + parent.node.nodeSize, {
+                  class: "placeholder",
+                  "data-empty-text": `  ${this.options.dictionary.newLineWithSlash}`,
+                })
+              );
+            }
+
+            return DecorationSet.create(state.doc, decorations);
+          },
+        },
+      }),
+    ];
+  }
+}