From 3bc4fcf199bab75025dcfe6ede32522b3e75a6a0 Mon Sep 17 00:00:00 2001
From: 01zulfi <85733202+01zulfi@users.noreply.github.com>
Date: Mon, 9 Dec 2024 20:55:30 +0500
Subject: [PATCH] editor: add alt arrow keyboard shortcut * implementation from
 https://discuss.prosemirror.net/t/keymap-to-move-a-line/3645/5 * only
 supports moving paragraphs * TODO: add tests

Signed-off-by: 01zulfi <85733202+01zulfi@users.noreply.github.com>
---
 .../editor/src/extensions/key-map/key-map.ts  | 89 ++++++++++++++++++-
 1 file changed, 88 insertions(+), 1 deletion(-)

diff --git a/packages/editor/src/extensions/key-map/key-map.ts b/packages/editor/src/extensions/key-map/key-map.ts
index 148005836d..d8b071fd6c 100644
--- a/packages/editor/src/extensions/key-map/key-map.ts
+++ b/packages/editor/src/extensions/key-map/key-map.ts
@@ -17,11 +17,92 @@ You should have received a copy of the GNU General Public License
 along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-import { Extension } from "@tiptap/core";
+import { Editor, Extension } from "@tiptap/core";
 import { isInTable } from "@tiptap/pm/tables";
 import { CodeBlock } from "../code-block/index.js";
 import { showLinkPopup } from "../../toolbar/popups/link-popup.js";
 import { isListActive } from "../../utils/list.js";
+import { findParentNodeOfType } from "../../utils/prosemirror.js";
+import { Fragment, Node, Slice } from "@tiptap/pm/model";
+import { ReplaceStep } from "@tiptap/pm/transform";
+import { Selection } from "@tiptap/pm/state";
+import { Callout } from "../callout/callout.js";
+
+function mapChildren<T>(
+  node: Node | Fragment,
+  callback: (child: Node, index: number, frag: Fragment) => T
+): T[] {
+  const array = [];
+  for (let i = 0; i < node.childCount; i++) {
+    array.push(
+      callback(node.child(i), i, node instanceof Fragment ? node : node.content)
+    );
+  }
+  return array;
+}
+
+/**
+ * implementation from https://discuss.prosemirror.net/t/keymap-to-move-a-line/3645/5
+ */
+function moveNode(editor: Editor, dir: "up" | "down") {
+  const isDown = dir === "down";
+  const { state } = editor;
+  if (!state.selection.empty) {
+    return false;
+  }
+
+  const { $from } = state.selection;
+  const type = $from.node().type;
+  if (!type) {
+    return false;
+  }
+
+  const currentResolved = findParentNodeOfType(type)(state.selection);
+  if (!currentResolved) {
+    return false;
+  }
+
+  const { node: currentNode } = currentResolved;
+  const parentDepth = currentResolved.depth - 1;
+  const parent = $from.node(parentDepth);
+  const parentPos = $from.start(parentDepth);
+
+  if (currentNode.type !== type) {
+    return false;
+  }
+
+  let arr = mapChildren(parent, (node) => node);
+  let index = arr.indexOf(currentNode);
+  let swapWith = isDown ? index + 1 : index - 1;
+  if (swapWith >= arr.length || swapWith < 0) {
+    return false;
+  }
+  if (swapWith === 0 && parent.type.name === Callout.name) {
+    return false;
+  }
+
+  const swapWithNodeSize = arr[swapWith].nodeSize;
+
+  [arr[index], arr[swapWith]] = [arr[swapWith], arr[index]];
+
+  let tr = state.tr;
+  let replaceStart = parentPos;
+  let replaceEnd = $from.end(parentDepth);
+
+  const slice = new Slice(Fragment.fromArray(arr), 0, 0);
+
+  tr = tr.step(new ReplaceStep(replaceStart, replaceEnd, slice, false));
+  tr = tr.setSelection(
+    Selection.near(
+      tr.doc.resolve(
+        isDown ? $from.pos + swapWithNodeSize : $from.pos - swapWithNodeSize
+      )
+    )
+  );
+  tr.scrollIntoView();
+  editor.view.dispatch(tr);
+  return true;
+}
 
 export const KeyMap = Extension.create({
   name: "key-map",
@@ -70,6 +151,12 @@ export const KeyMap = Extension.create({
       "Mod-k": ({ editor }) => {
         showLinkPopup(editor);
         return true;
+      },
+      "Alt-ArrowUp": ({ editor }) => {
+        return moveNode(editor, "up");
+      },
+      "Alt-ArrowDown": ({ editor }) => {
+        return moveNode(editor, "down");
       }
     };
   }