Editable text fix (flutter#12249)

* enabling spellcheck for text editing

* Fixing errors in the input box, which arrises when the fontweight is null.

* Rollback the spellcheck change. Still not tested in safari mobile.

* Carrying the assignment of fontweight from index to EditingStyle constructor. This reduce # of null checks to one.

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

@@ -667,13 +667,11 @@ class HybridTextEditing {
     /// to its CSS equivalent value.
     /// Converts index of TextAlign to enum value.
     _editingStyle = _EditingStyle(
-      textDirection: ui.TextDirection.values[textDirectionIndex],
-      fontSize: style['fontSize'],
-      textAlign: ui.TextAlign.values[textAlignIndex],
-      fontFamily: style['fontFamily'],
-      fontWeight:
-          fontWeightIndexToCss(fontWeightIndex: style['fontWeightIndex']),
-    );
+        textDirection: ui.TextDirection.values[textDirectionIndex],
+        fontSize: style['fontSize'],
+        textAlign: ui.TextAlign.values[textAlignIndex],
+        fontFamily: style['fontFamily'],
+        fontWeightIndex: style['fontWeightIndex']);
   }
 
   /// Size and transform of the editable text on the page.
@@ -767,8 +765,10 @@ class _EditingStyle {
     @required this.fontSize,
     @required this.textAlign,
     @required this.fontFamily,
-    this.fontWeight,
-  });
+    @required fontWeightIndex,
+  }) : this.fontWeight = (fontWeightIndex != null)
+            ? fontWeightIndexToCss(fontWeightIndex: fontWeightIndex)
+            : 'normal';
 
   /// This information will be used for changing the style of the hidden input
   /// element, which will match it's size to the size of the editable widget.

lib/web_ui/test/text_editing_test.dart

@@ -472,22 +472,12 @@ void main() {
       textEditing.handleTextInput(codec.encodeMethodCall(setClient));
 
       final MethodCall setSizeAndTransform =
-          MethodCall('TextInput.setEditableSizeAndTransform', <String, dynamic>{
-        'width': 150,
-        'height': 50,
-        'transform':
-            Matrix4.translationValues(10.0, 20.0, 30.0).storage.toList()
-      });
+          configureSetSizeAndTransformMethodCall(150, 50,
+              Matrix4.translationValues(10.0, 20.0, 30.0).storage.toList());
       textEditing.handleTextInput(codec.encodeMethodCall(setSizeAndTransform));
 
-      const MethodCall setStyle =
-          MethodCall('TextInput.setStyle', <String, dynamic>{
-        'fontSize': 12,
-        'fontFamily': 'sans-serif',
-        'textAlignIndex': 4,
-        'fontWeightIndex': 4,
-        'textDirectionIndex': 1,
-      });
+      final MethodCall setStyle =
+          configureSetStyleMethodCall(12, 'sans-serif', 4, 4, 1);
       textEditing.handleTextInput(codec.encodeMethodCall(setStyle));
 
       const MethodCall setEditingState =
@@ -522,6 +512,52 @@ void main() {
       expect(spy.messages, isEmpty);
     });
 
+    test('input font set succesfully with null fontWeightIndex', () {
+      final MethodCall setClient = MethodCall(
+          'TextInput.setClient', <dynamic>[123, flutterSinglelineConfig]);
+      textEditing.handleTextInput(codec.encodeMethodCall(setClient));
+
+      final MethodCall setSizeAndTransform =
+          configureSetSizeAndTransformMethodCall(150, 50,
+              Matrix4.translationValues(10.0, 20.0, 30.0).storage.toList());
+      textEditing.handleTextInput(codec.encodeMethodCall(setSizeAndTransform));
+
+      final MethodCall setStyle = configureSetStyleMethodCall(
+          12, 'sans-serif', 4, null /* fontWeightIndex */, 1);
+      textEditing.handleTextInput(codec.encodeMethodCall(setStyle));
+
+      const MethodCall setEditingState =
+          MethodCall('TextInput.setEditingState', <String, dynamic>{
+        'text': 'abcd',
+        'selectionBase': 2,
+        'selectionExtent': 3,
+      });
+      textEditing.handleTextInput(codec.encodeMethodCall(setEditingState));
+
+      const MethodCall show = MethodCall('TextInput.show');
+      textEditing.handleTextInput(codec.encodeMethodCall(show));
+
+      final HtmlElement domElement = textEditing.editingElement.domElement;
+
+      checkInputEditingState(domElement, 'abcd', 2, 3);
+
+      // Check if the location and styling is correct.
+      expect(
+          domElement.getBoundingClientRect(),
+          Rectangle<double>.fromPoints(const Point<double>(10.0, 20.0),
+              const Point<double>(160.0, 70.0)));
+      expect(domElement.style.transform,
+          'matrix3d(1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 10, 20, 30, 1)');
+      expect(
+          textEditing.editingElement.domElement.style.font, '12px sans-serif');
+
+      const MethodCall clearClient = MethodCall('TextInput.clearClient');
+      textEditing.handleTextInput(codec.encodeMethodCall(clearClient));
+
+      // Confirm that [HybridTextEditing] didn't send any messages.
+      expect(spy.messages, isEmpty);
+    });
+
     test('Syncs the editing state back to Flutter', () {
       final MethodCall setClient = MethodCall(
           'TextInput.setClient', <dynamic>[123, flutterSinglelineConfig]);
@@ -642,6 +678,26 @@ void main() {
   });
 }
 
+MethodCall configureSetStyleMethodCall(int fontSize, String fontFamily,
+    int textAlignIndex, int fontWeightIndex, int textDirectionIndex) {
+  return MethodCall('TextInput.setStyle', <String, dynamic>{
+    'fontSize': fontSize,
+    'fontFamily': fontFamily,
+    'textAlignIndex': textAlignIndex,
+    'fontWeightIndex': fontWeightIndex,
+    'textDirectionIndex': textDirectionIndex,
+  });
+}
+
+MethodCall configureSetSizeAndTransformMethodCall(
+    int width, int height, List<double> transform) {
+  return MethodCall('TextInput.setEditableSizeAndTransform', <String, dynamic>{
+    'width': width,
+    'height': height,
+    'transform': transform
+  });
+}
+
 void checkInputEditingState(
     InputElement input, String text, int start, int end) {
   expect(document.activeElement, input);