list button implementation

lib/formatter.dart

@@ -1,16 +1,25 @@
 import 'package:flutter/services.dart';
 
-extension on String {
+extension Utilities on String {
-  int getBeginningOfPreviousLine(int startingIndex) {
+  int getBeginningOfTheLine(int startingIndex) {
+    if (startingIndex <= 0) return 0;
     for (var i = startingIndex; i >= 0; i--) {
       if (this[i] == '\n') return i + 1;
     }
     return 0;
   }
 
+  int getEndOfTheLine(int from) {
+    for (var i = from; i < length; i++) {
+      if (this[i] == '\n') return i;
+    }
+
+    return length - 1;
+  }
+
   // returns the line that ends at endingIndex
   String lineBefore(int endingIndex) {
-    return substring(getBeginningOfPreviousLine(endingIndex), endingIndex + 1);
+    return substring(getBeginningOfTheLine(endingIndex), endingIndex + 1);
   }
 }
 

lib/util/text_lines_iterator.dart

@@ -0,0 +1,89 @@
+import 'package:flutter/widgets.dart';
+
+/// utililty class for traversing through multiline text
+class TextLinesIterator extends Iterator {
+  String text;
+  int beg;
+  int end;
+  TextSelection? selection;
+
+  TextLinesIterator(this.text, {this.selection})
+      : end = -1,
+        beg = -1;
+
+  factory TextLinesIterator.fromController(TextEditingController controller) =>
+      TextLinesIterator(controller.text, selection: controller.selection);
+
+  bool get isWithinSelection {
+    final selection = this.selection;
+    if (selection == null || beg == -1) {
+      return false;
+    } else {
+      return (selection.end >= beg && beg >= selection.start) ||
+          (selection.end >= end && end >= selection.start) ||
+          (end >= selection.start && selection.start >= beg) ||
+          (end >= selection.end && selection.end >= beg) ||
+          (beg <= selection.start &&
+              selection.start <= end &&
+              beg <= selection.end &&
+              selection.end <= end);
+    }
+  }
+
+  @override
+  String get current {
+    return text.substring(beg, end);
+  }
+
+  set current(String newVal) {
+    final selected = isWithinSelection;
+    text = text.replaceRange(beg, end, newVal);
+    final wordLen = end - beg;
+    final dif = newVal.length - wordLen;
+    end += dif;
+
+    final selection = this.selection;
+    if (selection == null) return;
+
+    if (selected || selection.baseOffset > end) {
+      this.selection =
+          selection.copyWith(extentOffset: selection.extentOffset + dif);
+    }
+  }
+
+  void reset() {
+    end = -1;
+    beg = -1;
+  }
+
+  @override
+  bool moveNext() {
+    if (end == text.length) {
+      return false;
+    }
+    if (beg == -1) {
+      end = 0;
+      beg = 0;
+    } else {
+      end += 1;
+      beg = end;
+    }
+    for (; end < text.length; end++) {
+      if (text[end] == '\n') {
+        return true;
+      }
+    }
+    end = text.length;
+    return true;
+  }
+
+  /// returns the lines as a list but also moves the pointer to the back
+  List<String> get asList {
+    reset();
+    final list = <String>[];
+    while (moveNext()) {
+      list.add(current);
+    }
+    return list;
+  }
+}

lib/widgets/editor/toolbar.dart

@@ -1,7 +1,9 @@
 import 'package:flutter/material.dart';
 import 'package:flutter_hooks/flutter_hooks.dart';
 
+import '../../formatter.dart';
 import '../../util/extensions/spaced.dart';
+import '../../util/text_lines_iterator.dart';
 
 class Reformat {
   final String text;
@@ -43,6 +45,54 @@ extension on TextEditingController {
         ));
   }
 
+  String get firstSelectedLine {
+    if (text.isEmpty) return '';
+    return text.substring(text.getBeginningOfTheLine(selection.start - 1),
+        text.getEndOfTheLine(selection.end));
+  }
+
+  void removeAtBeginningOfEverySelectedLine(String s) {
+    final lines = TextLinesIterator.fromController(this);
+    var linesCount = 0;
+    while (lines.moveNext()) {
+      if (lines.isWithinSelection) {
+        if (lines.current.startsWith(RegExp.escape(s))) {
+          lines.current = lines.current.substring(s.length);
+          linesCount++;
+        }
+      }
+    }
+
+    value = value.copyWith(
+      text: lines.text,
+      selection: selection.copyWith(
+        baseOffset: selection.baseOffset - s.length,
+        extentOffset: selection.extentOffset - s.length * linesCount,
+      ),
+    );
+  }
+
+  void insertAtBeginningOfEverySelectedLine(String s) {
+    final lines = TextLinesIterator.fromController(this);
+    var linesCount = 0;
+    while (lines.moveNext()) {
+      if (lines.isWithinSelection) {
+        if (!lines.current.startsWith(RegExp.escape(s))) {
+          lines.current = '$s${lines.current}';
+          linesCount++;
+        }
+      }
+    }
+
+    value = value.copyWith(
+      text: lines.text,
+      selection: selection.copyWith(
+        baseOffset: selection.baseOffset + s.length,
+        extentOffset: selection.extentOffset + s.length * linesCount,
+      ),
+    );
+  }
+
   void reformat(Reformat Function(String selection) reformatter) {
     final beg = beforeSelectionText;
     final mid = selectionText;
@@ -101,9 +151,7 @@ class Toolbar extends HookWidget {
                 icon: const Icon(Icons.person),
               ),
               IconButton(
-                onPressed: () {
+                onPressed: () {},
-                  //
-                },
                 icon: const Icon(Icons.home),
               ),
               IconButton(
@@ -119,7 +167,17 @@ class Toolbar extends HookWidget {
                 icon: const Icon(Icons.format_quote),
               ),
               IconButton(
-                  onPressed: () {},
+                  onPressed: () {
+                    final line = controller.firstSelectedLine;
+
+                    if (line.startsWith(RegExp.escape('* '))) {
+                      controller.removeAtBeginningOfEverySelectedLine('* ');
+                    } else if (line.startsWith('- ')) {
+                      controller.removeAtBeginningOfEverySelectedLine('- ');
+                    } else {
+                      controller.insertAtBeginningOfEverySelectedLine('- ');
+                    }
+                  },
                   icon: const Icon(Icons.format_list_bulleted)),
               IconButton(
                 onPressed: () => controller.surround('`'),