add scrollBottomInset

lib/widgets/editor.dart

@@ -119,6 +119,7 @@ class QuillEditor extends StatefulWidget {
     required this.focusNode,
     required this.scrollController,
     required this.scrollable,
+    required this.scrollBottomInset,
     required this.padding,
     required this.autoFocus,
     required this.readOnly,
@@ -133,7 +134,12 @@ class QuillEditor extends StatefulWidget {
     this.keyboardAppearance = Brightness.light,
     this.scrollPhysics,
     this.onLaunchUrl,
-    this.embedBuilder = _defaultEmbedBuilder,
+    this.onTapDown,
+    this.onTapUp,
+    this.onSingleLongTapStart,
+    this.onSingleLongTapMoveUpdate,
+    this.onSingleLongTapEnd,
+    this.embedBuilder = _defaultEmbedBuilder
   });
 
   factory QuillEditor.basic({
@@ -148,6 +154,7 @@ class QuillEditor extends StatefulWidget {
         autoFocus: true,
         readOnly: readOnly,
         expands: false,
+        scrollBottomInset: 0,
         padding: EdgeInsets.zero);
   }
 
@@ -155,6 +162,7 @@ class QuillEditor extends StatefulWidget {
   final FocusNode focusNode;
   final ScrollController scrollController;
   final bool scrollable;
+  final double scrollBottomInset;
   final EdgeInsetsGeometry padding;
   final bool autoFocus;
   final bool? showCursor;
@@ -249,6 +257,7 @@ class _QuillEditorState extends State<QuillEditor>
           widget.focusNode,
           widget.scrollController,
           widget.scrollable,
+          widget.scrollBottomInset,
           widget.padding,
           widget.readOnly,
           widget.placeholder,
@@ -282,11 +291,6 @@ class _QuillEditorState extends State<QuillEditor>
           widget.keyboardAppearance,
           widget.enableInteractiveSelection,
           widget.scrollPhysics,
-          widget.onTapDown,
-          widget.onTapUp,
-          widget.onSingleLongTapStart,
-          widget.onSingleLongTapMoveUpdate,
-          widget.onSingleLongTapEnd,
           widget.embedBuilder),
     );
   }
@@ -569,6 +573,7 @@ class RenderEditor extends RenderEditableContainerBox
   RenderEditor(
     List<RenderEditableBox>? children,
     TextDirection textDirection,
+    double scrollBottomInset,
     EdgeInsetsGeometry padding,
     this.document,
     this.selection,
@@ -581,6 +586,7 @@ class RenderEditor extends RenderEditableContainerBox
           children,
           document.root,
           textDirection,
+          scrollBottomInset,
           padding,
         );
 
@@ -639,6 +645,14 @@ class RenderEditor extends RenderEditableContainerBox
     markNeedsPaint();
   }
 
+  void setScrollBottomInset(double value) {
+    if (scrollBottomInset == value) {
+      return;
+    }
+    scrollBottomInset = value;
+    markNeedsPaint();
+  }
+
   @override
   List<TextSelectionPoint> getEndpointsForSelection(
       TextSelection textSelection) {
@@ -911,8 +925,9 @@ class RenderEditor extends RenderEditableContainerBox
         child.preferredLineHeight(TextPosition(
             offset: selection.extentOffset - child.getContainer().offset)) -
         kMargin +
-        offsetInViewport;
-    final caretBottom = endpoint.point.dy + kMargin + offsetInViewport;
+        offsetInViewport +
+        scrollBottomInset;
+    final caretBottom = endpoint.point.dy + kMargin + offsetInViewport + scrollBottomInset;
     double? dy;
     if (caretTop < scrollOffset) {
       dy = caretTop;
@@ -939,6 +954,7 @@ class RenderEditableContainerBox extends RenderBox
     List<RenderEditableBox>? children,
     this._container,
     this.textDirection,
+    this.scrollBottomInset,
     this._padding,
   ) : assert(_padding.isNonNegative) {
     addAll(children);
@@ -947,6 +963,7 @@ class RenderEditableContainerBox extends RenderBox
   container_node.Container _container;
   TextDirection textDirection;
   EdgeInsetsGeometry _padding;
+  double scrollBottomInset;
   EdgeInsets? _resolvedPadding;
 
   container_node.Container getContainer() {

lib/widgets/raw_editor.dart

@@ -34,6 +34,7 @@ class RawEditor extends StatefulWidget {
     this.focusNode,
     this.scrollController,
     this.scrollable,
+    this.scrollBottomInset,
     this.padding,
     this.readOnly,
     this.placeholder,
@@ -65,6 +66,7 @@ class RawEditor extends StatefulWidget {
   final FocusNode focusNode;
   final ScrollController scrollController;
   final bool scrollable;
+  final double scrollBottomInset;
   final EdgeInsetsGeometry padding;
   final bool readOnly;
   final String? placeholder;
@@ -527,6 +529,7 @@ class RawEditorState extends EditorState
           startHandleLayerLink: _startHandleLayerLink,
           endHandleLayerLink: _endHandleLayerLink,
           onSelectionChanged: _handleSelectionChanged,
+          scrollBottomInset: widget.scrollBottomInset,
           padding: widget.padding,
           children: _buildChildren(_doc, context),
         ),
@@ -588,6 +591,7 @@ class RawEditorState extends EditorState
         final editableTextBlock = EditableTextBlock(
             node,
             _textDirection,
+            widget.scrollBottomInset,
             _getVerticalSpacingForBlock(node, _styles),
             widget.controller.selection,
             widget.selectionColor,
@@ -1137,6 +1141,7 @@ class _Editor extends MultiChildRenderObjectWidget {
     required this.startHandleLayerLink,
     required this.endHandleLayerLink,
     required this.onSelectionChanged,
+    required this.scrollBottomInset,
     this.padding = EdgeInsets.zero,
   }) : super(key: key, children: children);
 
@@ -1147,6 +1152,7 @@ class _Editor extends MultiChildRenderObjectWidget {
   final LayerLink startHandleLayerLink;
   final LayerLink endHandleLayerLink;
   final TextSelectionChangedHandler onSelectionChanged;
+  final double scrollBottomInset;
   final EdgeInsetsGeometry padding;
 
   @override
@@ -1154,6 +1160,7 @@ class _Editor extends MultiChildRenderObjectWidget {
     return RenderEditor(
       null,
       textDirection,
+      scrollBottomInset,
       padding,
       document,
       selection,
@@ -1177,6 +1184,7 @@ class _Editor extends MultiChildRenderObjectWidget {
       ..setStartHandleLayerLink(startHandleLayerLink)
       ..setEndHandleLayerLink(endHandleLayerLink)
       ..onSelectionChanged = onSelectionChanged
+      ..setScrollBottomInset(scrollBottomInset)
       ..setPadding(padding);
   }
 }

lib/widgets/text_block.dart

@@ -50,6 +50,7 @@ class EditableTextBlock extends StatelessWidget {
   const EditableTextBlock(
     this.block,
     this.textDirection,
+    this.scrollBottomInset,
     this.verticalSpacing,
     this.textSelection,
     this.color,
@@ -64,6 +65,7 @@ class EditableTextBlock extends StatelessWidget {
 
   final Block block;
   final TextDirection textDirection;
+  final double scrollBottomInset;
   final Tuple2 verticalSpacing;
   final TextSelection textSelection;
   final Color color;
@@ -84,6 +86,7 @@ class EditableTextBlock extends StatelessWidget {
         block,
         textDirection,
         verticalSpacing as Tuple2<double, double>,
+        scrollBottomInset,
         _getDecorationForBlock(block, defaultStyles) ?? const BoxDecoration(),
         contentPadding,
         _buildChildren(context, indentLevelCounts));
@@ -256,6 +259,7 @@ class RenderEditableTextBlock extends RenderEditableContainerBox
     required Block block,
     required TextDirection textDirection,
     required EdgeInsetsGeometry padding,
+    required double scrollBottomInset,
     required Decoration decoration,
     List<RenderEditableBox>? children,
     ImageConfiguration configuration = ImageConfiguration.empty,
@@ -268,6 +272,7 @@ class RenderEditableTextBlock extends RenderEditableContainerBox
           children,
           block,
           textDirection,
+          scrollBottomInset,
           padding.add(contentPadding),
         );
 
@@ -512,14 +517,16 @@ class _EditableBlock extends MultiChildRenderObjectWidget {
     this.block,
     this.textDirection,
     this.padding,
+    this.scrollBottomInset,
     this.decoration,
     this.contentPadding,
-    List<Widget> children,
+    List<Widget> children
   ) : super(children: children);
 
   final Block block;
   final TextDirection textDirection;
   final Tuple2<double, double> padding;
+  final double scrollBottomInset;
   final Decoration decoration;
   final EdgeInsets? contentPadding;
 
@@ -534,6 +541,7 @@ class _EditableBlock extends MultiChildRenderObjectWidget {
       block: block,
       textDirection: textDirection,
       padding: _padding,
+      scrollBottomInset: scrollBottomInset,
       decoration: decoration,
       contentPadding: _contentPadding,
     );
@@ -545,6 +553,7 @@ class _EditableBlock extends MultiChildRenderObjectWidget {
     renderObject
       ..setContainer(block)
       ..textDirection = textDirection
+      ..scrollBottomInset = scrollBottomInset
       ..setPadding(_padding)
       ..decoration = decoration
       ..contentPadding = _contentPadding;