feat: alt+click to add block above (#2988)

frontend/appflowy_flutter/lib/core/raw_keyboard_extension.dart

@@ -0,0 +1,11 @@
+import 'package:flutter/services.dart';
+
+extension RawKeyboardExtension on RawKeyboard {
+  bool get isAltPressed => keysPressed.any(
+        (key) => [
+          LogicalKeyboardKey.alt,
+          LogicalKeyboardKey.altLeft,
+          LogicalKeyboardKey.altRight,
+        ].contains(key),
+      );
+}

frontend/appflowy_flutter/lib/plugins/document/presentation/editor_page.dart

@@ -312,7 +312,7 @@ class _AppFlowyEditorPageState extends State<AppFlowyEditorPage> {
       builder.actionBuilder = (context, state) {
         final padding = context.node.type == HeadingBlockKeys.type
             ? const EdgeInsets.only(top: 8.0)
-            : const EdgeInsets.all(0);
+            : EdgeInsets.zero;
         return Padding(
           padding: padding,
           child: BlockActionList(
@@ -320,9 +320,7 @@ class _AppFlowyEditorPageState extends State<AppFlowyEditorPage> {
             blockComponentState: state,
             editorState: widget.editorState,
             actions: actions,
-            showSlashMenu: () => showSlashMenu(
-              widget.editorState,
-            ),
+            showSlashMenu: () => showSlashMenu(widget.editorState),
           ),
         );
       };

frontend/appflowy_flutter/lib/plugins/document/presentation/editor_plugins/actions/block_action_add_button.dart

@@ -1,6 +1,12 @@
+import 'dart:io';
+
+import 'package:appflowy/core/raw_keyboard_extension.dart';
+import 'package:appflowy/generated/locale_keys.g.dart';
 import 'package:appflowy/plugins/document/presentation/editor_plugins/actions/block_action_button.dart';
 import 'package:appflowy_editor/appflowy_editor.dart';
+import 'package:easy_localization/easy_localization.dart';
 import 'package:flutter/material.dart';
+import 'package:flutter/services.dart';
 
 class BlockAddButton extends StatelessWidget {
   const BlockAddButton({
@@ -21,25 +27,41 @@ class BlockAddButton extends StatelessWidget {
   Widget build(BuildContext context) {
     return BlockActionButton(
       svgName: 'editor/add',
-      richMessage: const TextSpan(
+      richMessage: TextSpan(
         children: [
           TextSpan(
-            // todo: l10n.
-            text: 'Click to add below',
+            text: LocaleKeys.blockActions_addBelowTooltip.tr(),
+          ),
+          const TextSpan(text: '\n'),
+          TextSpan(
+            text: Platform.isMacOS
+                ? LocaleKeys.blockActions_addAboveMacCmd.tr()
+                : LocaleKeys.blockActions_addAboveCmd.tr(),
+          ),
+          const TextSpan(text: ' '),
+          TextSpan(
+            text: LocaleKeys.blockActions_addAboveTooltip.tr(),
           ),
         ],
       ),
       onTap: () {
+        final isAltPressed = RawKeyboard.instance.isAltPressed;
+
         final transaction = editorState.transaction;
-        // if the current block is not a empty paragraph block, then insert a new block below the current block.
+
+        // If the current block is not an empty paragraph block,
+        // then insert a new block above/below the current block.
         final node = blockComponentContext.node;
         if (node.type != ParagraphBlockKeys.type ||
             (node.delta?.isNotEmpty ?? true)) {
-          transaction.insertNode(node.path.next, paragraphNode());
-          transaction.afterSelection = Selection.collapse(node.path.next, 0);
+          final path = isAltPressed ? node.path : node.path.next;
+
+          transaction.insertNode(path, paragraphNode());
+          transaction.afterSelection = Selection.collapse(path, 0);
         } else {
           transaction.afterSelection = Selection.collapse(node.path, 0);
         }
+
         // show the slash menu.
         editorState.apply(transaction).then(
               (_) => WidgetsBinding.instance.addPostFrameCallback(

frontend/resources/translations/en.json

@@ -8,6 +8,12 @@
   "title": "Title",
   "youCanAlso": "You can also",
   "and": "and",
+  "blockActions": {
+    "addBelowTooltip": "Click to add below",
+    "addAboveCmd": "Alt+click",
+    "addAboveMacCmd": "Option+click",
+    "addAboveTooltip": "to add above"
+  },
   "signUp": {
     "buttonText": "Sign Up",
     "title": "Sign Up to @:appName",