fix some selection handling issues

packages/zefyr/lib/src/widgets/editable_text.dart

     _input.openOrCloseConnection(_focusNode,
         widget.controller.plainTextEditingValue, widget.keyboardAppearance, showKeyboard: showKeyboard);
     _cursorTimer.startOrStop(_focusNode, selection);
-    // updateKeepAlive();
+    updateKeepAlive();
   }
 
   void _handleRemoteValueChange(

packages/zefyr/lib/src/widgets/field.dart

       mode: _effectiveMode,
       toolbarDelegate: widget.toolbarDelegate,
       imageDelegate: widget.imageDelegate,
+      linkDelegate: widget.linkDelegate,
       physics: widget.physics,
       keyboardAppearance: widget.keyboardAppearance,
+      onSave: widget.onSave,
     );
 
     if (widget.height != null) {

packages/zefyr/lib/src/widgets/image.dart

 import 'package:zefyr/zefyr.dart';
 
 import 'editable_box.dart';
+import 'rich_text.dart';
 
 /// Provides interface for embedding images into Zefyr editor.
 // TODO: allow configuring image sources and related toolbar buttons.
 
     int nodeBase = node.documentOffset;
     int nodeExtent = nodeBase + node.length;
-    int base = math.max(0, documentSelection.baseOffset - nodeBase);
-    int extent =
-        math.min(documentSelection.extentOffset, nodeExtent) - nodeBase;
-    return documentSelection.copyWith(baseOffset: base, extentOffset: extent);
+    // int base = math.max(0, documentSelection.baseOffset - nodeBase);
+    // int extent =
+    //     math.min(documentSelection.extentOffset, nodeExtent) - nodeBase;
+    // return documentSelection.copyWith(baseOffset: base, extentOffset: extent);
+    return getSelectionRebase(nodeBase, nodeExtent, documentSelection);
   }
 
   @override
   bool intersectsWithSelection(TextSelection selection) {
     final int base = node.documentOffset;
     final int extent = base + node.length;
-    return base <= selection.extentOffset && selection.baseOffset <= extent;
+    // return base <= selection.extentOffset && selection.baseOffset <= extent;
+    return selectionIntersectsWith(base, extent, selection);
   }
 
   @override

packages/zefyr/lib/src/widgets/rich_text.dart

 import 'caret.dart';
 import 'editable_box.dart';
 
+bool selectionIntersectsWith(int base, int extent, TextSelection selection) {
+  return base <= selection.end && selection.start <= extent;
+}
+
+// return a point between base and extent no matter what!
+int selectionPointRestrict(int base, int extent, int point) {
+  if (point < base) return base;
+  if (point > extent) return extent;
+  return point;
+}
+
+TextSelection getSelectionRebase(
+    int base, int extent, TextSelection selection) {
+  if (!selectionIntersectsWith(base, extent, selection)) {
+    return null;
+  }
+
+  int newBase =
+      selectionPointRestrict(base, extent, selection.baseOffset) - base;
+  int newExtent =
+      selectionPointRestrict(base, extent, selection.extentOffset) - base;
+
+  return selection.copyWith(baseOffset: newBase, extentOffset: newExtent);
+}
+
 /// Represents single paragraph of Zefyr rich-text.
 class ZefyrRichText extends MultiChildRenderObjectWidget {
   ZefyrRichText({
 
   @override
   TextSelection getLocalSelection(TextSelection documentSelection) {
-    if (!intersectsWithSelection(documentSelection)) return null;
+    if (!intersectsWithSelection(documentSelection)) {
+      return null;
+    }
 
     int nodeBase = node.documentOffset;
     int nodeExtent = nodeBase + node.length;
-    int base = math.max(0, documentSelection.baseOffset - nodeBase);
-    int extent =
-        math.min(documentSelection.extentOffset, nodeExtent) - nodeBase;
-    return documentSelection.copyWith(baseOffset: base, extentOffset: extent);
+    // int base = math.max(0, documentSelection.baseOffset - nodeBase);
+    // int extent =
+    //     math.min(documentSelection.extentOffset, nodeExtent) - nodeBase;
+    // return documentSelection.copyWith(baseOffset: base, extentOffset: extent);
+    return getSelectionRebase(nodeBase, nodeExtent, documentSelection);
   }
 
   @override
     return super.getOffsetForCaret(localPosition, caretPrototype);
   }
 
+  // the trailing \n is not handled by the span, drop it from the sel.
+  // otherwise getBoxesForSelection fails on the web. (out of range)
+  TextSelection trimSelection(TextSelection selection) {
+    if (selection.baseOffset > node.length - 1) {
+      selection = selection.copyWith(baseOffset: node.length - 1);
+    }
+    if (selection.extentOffset > node.length - 1) {
+      selection = selection.copyWith(extentOffset: node.length - 1);
+    }
+    return selection;
+  }
+
   // This method works around some issues in getBoxesForSelection and handles
   // edge-case with our TextSpan objects not having last line-break character.
   @override
       ];
     }
 
-    int isBaseShifted = 0;
-    bool isExtentShifted = false;
-    if (local.baseOffset == node.length - 1 && local.baseOffset > 0) {
-      // Since we exclude last line-break from rendered TextSpan we have to
-      // handle end-of-line selection explicitly.
-      local = local.copyWith(baseOffset: local.baseOffset - 1);
-      isBaseShifted = -1;
-    } else if (local.baseOffset == 0 && local.isCollapsed) {
-      // This takes care of beginning of line position.
-      local = local.copyWith(baseOffset: local.baseOffset + 1);
-      isBaseShifted = 1;
-    }
-    if (text.codeUnitAt(local.extentOffset - 1) == 0xA) {
-      // This takes care of the rest end-of-line scenarios, where there are
-      // actually line-breaks in the TextSpan (e.g. in code blocks).
-      local = local.copyWith(extentOffset: local.extentOffset + 1);
-      isExtentShifted = true;
-    }
-    final result = getBoxesForSelection(local).toList();
-    if (isBaseShifted != 0) {
-      final box = result.first;
-      final dx = isBaseShifted == -1 ? box.right : box.left;
-      result.removeAt(0);
-      result.insert(
-          0, ui.TextBox.fromLTRBD(dx, box.top, dx, box.bottom, box.direction));
-    }
-    if (isExtentShifted) {
-      final box = result.last;
-      result.removeLast();
-      result.add(ui.TextBox.fromLTRBD(
-          box.left, box.top, box.left, box.bottom, box.direction));
-    }
+    // int isBaseShifted = 0;
+    // bool isExtentShifted = false;
+    // if (local.baseOffset == node.length - 1 && local.baseOffset > 0) {
+    //   // Since we exclude last line-break from rendered TextSpan we have to
+    //   // handle end-of-line selection explicitly.
+    //   local = local.copyWith(baseOffset: local.baseOffset - 1);
+    //   isBaseShifted = -1;
+    // } else if (local.baseOffset == 0 && local.isCollapsed) {
+    //   // This takes care of beginning of line position.
+    //   local = local.copyWith(baseOffset: local.baseOffset + 1);
+    //   isBaseShifted = 1;
+    // }
+    // if (text.codeUnitAt(local.extentOffset - 1) == 0xA) {
+    //   // This takes care of the rest end-of-line scenarios, where there are
+    //   // actually line-breaks in the TextSpan (e.g. in code blocks).
+    //   local = local.copyWith(extentOffset: local.extentOffset + 1);
+    //   isExtentShifted = true;
+    // }
+    final result = getBoxesForSelection(trimSelection(local)).toList();
+    // if (isBaseShifted != 0) {
+    //   final box = result.first;
+    //   final dx = isBaseShifted == -1 ? box.right : box.left;
+    //   result.removeAt(0);
+    //   result.insert(
+    //       0, ui.TextBox.fromLTRBD(dx, box.top, dx, box.bottom, box.direction));
+    // }
+    // if (isExtentShifted) {
+    //   final box = result.last;
+    //   result.removeLast();
+    //   result.add(ui.TextBox.fromLTRBD(
+    //       box.left, box.top, box.left, box.bottom, box.direction));
+    // }
     return result;
   }
 
   bool intersectsWithSelection(TextSelection selection) {
     final int base = node.documentOffset;
     final int extent = base + node.length;
-    return base <= selection.extentOffset && selection.baseOffset <= extent;
+    // return base <= selection.extentOffset && selection.baseOffset <= extent;
+    return selectionIntersectsWith(base, extent, selection);
   }
 
   TextSelection _lastPaintedSelection;
     if (_lastPaintedSelection != selection) {
       _selectionRects = null;
     }
-    _selectionRects ??= getBoxesForSelection(getLocalSelection(selection));
+    var localSel = getLocalSelection(selection);
+
+    _selectionRects ??= getBoxesForSelection(trimSelection(localSel));
     final Paint paint = Paint()..color = selectionColor;
     for (ui.TextBox box in _selectionRects) {
       context.canvas.drawRect(box.toRect().shift(offset), paint);

packages/zefyr/lib/src/widgets/selection.dart

 import 'dart:math' as math;
 import 'dart:ui' as ui;
 
+import 'package:flutter/foundation.dart';
 import 'package:flutter/gestures.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter/rendering.dart';
   }
 
   void showToolbar() {
+    if (kIsWeb) return;
     final toolbarOpacity = _toolbarController.view;
     _toolbar = OverlayEntry(
       builder: (context) => FadeTransition(
     Offset point;
     TextSelectionHandleType type;
 
-    switch (widget.position) {
+    // we invert base / extend if the selection is from bottom to top
+    var pos = widget.position;
+    if (selection.baseOffset > selection.extentOffset) {
+      pos = pos == _SelectionHandlePosition.base
+          ? _SelectionHandlePosition.extent
+          : _SelectionHandlePosition.base;
+    }
+
+    switch (pos) {
       case _SelectionHandlePosition.base:
         point = endpoints[0].point;
         type = _chooseType(endpoints[0], TextSelectionHandleType.left,