Update

Author: xtyxtyx

lib/src/terminal_view.dart

@@ -45,6 +45,7 @@ class TerminalView extends StatefulWidget {
     this.alwaysShowCursor = false,
     this.deleteDetection = false,
     this.shortcuts,
+    this.onKey,
     this.readOnly = false,
     this.hardwareKeyboardOnly = false,
     this.simulateScroll = true,
@@ -126,6 +127,10 @@ class TerminalView extends StatefulWidget {
   /// of the terminal If not provided, [defaultTerminalShortcuts] will be used.
   final Map<ShortcutActivator, Intent>? shortcuts;
 
+  /// Keyboard event handler of the terminal. This has higher priority than
+  /// [shortcuts] and input handler of the terminal.
+  final FocusOnKeyCallback? onKey;
+
   /// True if no input should send to the terminal.
   final bool readOnly;
 
@@ -268,7 +273,7 @@ class TerminalViewState extends State<TerminalView> {
             widget.terminal.keyInput(TerminalKey.enter);
           }
         },
-        onKey: _onKeyEvent,
+        onKey: _handleKeyEvent,
         readOnly: widget.readOnly,
         child: child,
       );
@@ -280,7 +285,7 @@ class TerminalViewState extends State<TerminalView> {
         autofocus: widget.autofocus,
         onInsert: _onInsert,
         onComposing: _onComposing,
-        onKey: _onKeyEvent,
+        onKey: _handleKeyEvent,
       );
     }
 
@@ -388,7 +393,12 @@ class TerminalViewState extends State<TerminalView> {
     setState(() => _composingText = text);
   }
 
-  KeyEventResult _onKeyEvent(FocusNode focusNode, RawKeyEvent event) {
+  KeyEventResult _handleKeyEvent(FocusNode focusNode, RawKeyEvent event) {
+    final resultOverride = widget.onKey?.call(focusNode, event);
+    if (resultOverride != null && resultOverride != KeyEventResult.ignored) {
+      return resultOverride;
+    }
+
     // ignore: invalid_use_of_protected_member
     final shortcutResult = _shortcutManager.handleKeypress(
       focusNode.context!,

lib/suggestion.dart

@@ -0,0 +1,199 @@
+import 'dart:math';
+
+import 'package:flutter/foundation.dart';
+import 'package:flutter/rendering.dart';
+import 'package:flutter/widgets.dart';
+
+/// Controls the location of the suggestion popup of [SuggestionPortal].
+class SuggestionPortalController extends OverlayPortalController {
+  final _cursorRect = ValueNotifier<Rect>(Rect.zero);
+
+  /// Updates the location of the suggestion popup to [rect]. If the popup is
+  /// not showing, it will be shown after this call.
+  void update(Rect rect) {
+    _cursorRect.value = rect;
+    if (!isShowing) show();
+  }
+}
+
+/// A convenience widget to place a suggestion popup around the cursor specified
+/// by [SuggestionPortalController].
+class SuggestionPortal extends StatefulWidget {
+  const SuggestionPortal({
+    super.key,
+    required this.controller,
+    required this.overlayBuilder,
+    required this.child,
+    this.padding = const EdgeInsets.all(8),
+    this.cursorMargin = const EdgeInsets.all(4),
+  });
+
+  final SuggestionPortalController controller;
+
+  final WidgetBuilder overlayBuilder;
+
+  /// The minimum space between [child] and the screen edge.
+  final EdgeInsets padding;
+
+  /// The minimum space between [child] and the cursor. Currently, only top and
+  /// bottom are used.
+  final EdgeInsets cursorMargin;
+
+  final Widget child;
+
+  @override
+  State<SuggestionPortal> createState() => _SuggestionPortalState();
+}
+
+class _SuggestionPortalState extends State<SuggestionPortal> {
+  @override
+  Widget build(BuildContext context) {
+    return OverlayPortal.targetsRootOverlay(
+      controller: widget.controller,
+      overlayChildBuilder: (context) {
+        return SuggestionLayout(
+          cursorRect: widget.controller._cursorRect,
+          padding: widget.padding,
+          cursorMargin: widget.cursorMargin,
+          child: widget.overlayBuilder(context),
+        );
+      },
+      child: widget.child,
+    );
+  }
+}
+
+/// A widget that places [child] around [cursorRect].
+class SuggestionLayout extends SingleChildRenderObjectWidget {
+  SuggestionLayout({
+    super.child,
+    required this.cursorRect,
+    required this.padding,
+    required this.cursorMargin,
+  });
+
+  /// The location of the cursor relative to the top left corner of this widget.
+  final ValueListenable<Rect> cursorRect;
+
+  /// The minimum space between [child] and the edge of this widget.
+  final EdgeInsets padding;
+
+  /// The minimum space between [child] and the cursor. Currently, only top and
+  /// bottom are used.
+  final EdgeInsets cursorMargin;
+
+  @override
+  RenderObject createRenderObject(BuildContext context) {
+    return RenderCompletionLayout(
+      null,
+      cursorRect: cursorRect,
+      padding: padding,
+      cursorMargin: cursorMargin,
+    );
+  }
+
+  @override
+  void updateRenderObject(
+    BuildContext context,
+    covariant RenderCompletionLayout renderObject,
+  ) {
+    renderObject.cursorRect = cursorRect;
+    renderObject.padding = padding;
+    renderObject.cursorMargin = cursorMargin;
+  }
+}
+
+class RenderCompletionLayout extends RenderShiftedBox {
+  RenderCompletionLayout(
+    super.child, {
+    required ValueListenable<Rect> cursorRect,
+    required EdgeInsets padding,
+    required EdgeInsets cursorMargin,
+  })  : _cursorRect = cursorRect,
+        _padding = padding,
+        _cursorPadding = cursorMargin;
+
+  ValueListenable<Rect> _cursorRect;
+  ValueListenable<Rect> get cursorRect => _cursorRect;
+  set cursorRect(ValueListenable<Rect> value) {
+    if (_cursorRect == value) return;
+    _cursorRect.removeListener(markNeedsLayout);
+    _cursorRect = value;
+    _cursorRect.addListener(markNeedsLayout);
+    markNeedsLayout();
+  }
+
+  EdgeInsets _padding;
+  EdgeInsets get padding => _padding;
+  set padding(EdgeInsets value) {
+    if (_padding == value) return;
+    _padding = value;
+    markNeedsLayout();
+  }
+
+  EdgeInsets _cursorPadding;
+  EdgeInsets get cursorMargin => _cursorPadding;
+  set cursorMargin(EdgeInsets value) {
+    if (_cursorPadding == value) return;
+    _cursorPadding = value;
+    markNeedsLayout();
+  }
+
+  @override
+  void attach(covariant PipelineOwner owner) {
+    cursorRect.addListener(markNeedsLayout);
+    super.attach(owner);
+  }
+
+  @override
+  void detach() {
+    cursorRect.removeListener(markNeedsLayout);
+    super.detach();
+  }
+
+  @override
+  void performLayout() {
+    final child = this.child;
+
+    if (child == null) {
+      size = constraints.smallest;
+      return;
+    }
+
+    size = constraints.biggest;
+
+    // space available for the completion overlay above the cursor
+    final spaceAbove = cursorRect.value.top - padding.top - cursorMargin.top;
+
+    // space available for the completion overlay below the cursor
+    final spaceBelow = size.height -
+        cursorRect.value.bottom -
+        padding.bottom -
+        cursorMargin.bottom;
+
+    final childConstraints = BoxConstraints(
+      minWidth: 0,
+      maxWidth: size.width - padding.horizontal,
+      minHeight: 0,
+      maxHeight: max(spaceAbove, spaceBelow),
+    );
+
+    child.layout(childConstraints, parentUsesSize: true);
+
+    // Whether the completion overlay can be placed above the cursor.
+    final fitsBelow = spaceBelow >= child.size.height;
+
+    final childParentData = child.parentData as BoxParentData;
+    childParentData.offset = Offset(
+      min(
+        size.width - padding.right - child.size.width,
+        cursorRect.value.left,
+      ),
+      // Showing the completion overlay below the cursor is preferred, unless
+      // there's insufficient space for it.
+      fitsBelow
+          ? cursorRect.value.bottom + cursorMargin.bottom
+          : cursorRect.value.top - cursorMargin.top - child.size.height,
+    );
+  }
+}