Web: add support for TextInputType.none (flutter/engine#26573)

engine/src/flutter/lib/web_ui/lib/src/engine/text_editing/input_type.dart

@@ -25,12 +25,17 @@ abstract class EngineInputType {
         return url;
       case 'TextInputType.multiline':
         return multiline;
+      case 'TextInputType.none':
+        return none;
       case 'TextInputType.text':
       default:
         return text;
     }
   }
 
+  /// No text input.
+  static const NoTextInputType none = NoTextInputType();
+
   /// Single-line text input type.
   static const TextInputType text = TextInputType();
 
@@ -76,12 +81,21 @@ abstract class EngineInputType {
     // Only apply `inputmode` in mobile browsers so that the right virtual
     // keyboard shows up.
     if (operatingSystem == OperatingSystem.iOs ||
-        operatingSystem == OperatingSystem.android) {
+        operatingSystem == OperatingSystem.android ||
+        inputmodeAttribute == EngineInputType.none.inputmodeAttribute) {
       domElement.setAttribute('inputmode', inputmodeAttribute!);
     }
   }
 }
 
+/// No text input.
+class NoTextInputType extends EngineInputType {
+  const NoTextInputType();
+
+  @override
+  final String inputmodeAttribute = 'none';
+}
+
 /// Single-line text input type.
 class TextInputType extends EngineInputType {
   const TextInputType();

engine/src/flutter/lib/web_ui/lib/src/engine/text_editing/text_editing.dart

@@ -860,6 +860,10 @@ abstract class DefaultTextEditingStrategy implements TextEditingStrategy {
       activeDomElement.setAttribute('type', 'password');
     }
 
+    if (config.inputType == EngineInputType.none) {
+      activeDomElement.setAttribute('inputmode', 'none');
+    }
+
     config.autofill?.applyToDomElement(activeDomElement, focusedElement: true);
 
     final String autocorrectValue = config.autocorrect ? 'on' : 'off';

engine/src/flutter/lib/web_ui/test/text_editing_test.dart

@@ -1580,6 +1580,9 @@ void testMain() {
       showKeyboard(inputType: 'url');
       expect(getEditingInputMode(), 'url');
 
+      showKeyboard(inputType: 'none');
+      expect(getEditingInputMode(), 'none');
+
       hideKeyboard();
     });
 
@@ -1612,6 +1615,9 @@ void testMain() {
         showKeyboard(inputType: 'url');
         expect(getEditingInputMode(), 'url');
 
+        showKeyboard(inputType: 'none');
+        expect(getEditingInputMode(), 'none');
+
         hideKeyboard();
       }
     });