default color, Document.fromDelta, fix isItCut null check (#123)

* default color, Document.fromDelta, fix isItCut null check

* fix merge conflict

lib/models/documents/document.dart

@@ -43,6 +43,10 @@ class Document {
     _loadDocument(_delta);
   }
 
+  Document.fromDelta(Delta delta) : _delta = delta {
+    _loadDocument(delta);
+  }
+
   Delta insert(int index, Object? data) {
     assert(index >= 0);
     assert(data is String || data is Embeddable);

lib/widgets/default_styles.dart

@@ -52,6 +52,7 @@ class DefaultStyles {
   final TextStyle? sizeLarge; // 'large'
   final TextStyle? sizeHuge; // 'huge'
   final TextStyle? link;
+  final Color? color;
   final DefaultTextBlockStyle? placeHolder;
   final DefaultTextBlockStyle? lists;
   final DefaultTextBlockStyle? quote;
@@ -69,6 +70,7 @@ class DefaultStyles {
       this.underline,
       this.strikeThrough,
       this.link,
+      this.color,
       this.placeHolder,
       this.lists,
       this.quote,
@@ -197,6 +199,7 @@ class DefaultStyles {
         underline: other.underline ?? underline,
         strikeThrough: other.strikeThrough ?? strikeThrough,
         link: other.link ?? link,
+        color: other.color ?? color,
         placeHolder: other.placeHolder ?? placeHolder,
         lists: other.lists ?? lists,
         quote: other.quote ?? quote,

lib/widgets/raw_editor.dart

@@ -1087,8 +1087,10 @@ class RawEditorState extends EditorState
   }
 
   Future<bool> __isItCut(TextEditingValue value) async {
-    final ClipboardData data = await (Clipboard.getData(Clipboard.kTextPlain)
-        as FutureOr<ClipboardData>);
+    ClipboardData? data = await Clipboard.getData(Clipboard.kTextPlain);
+    if (data == null) {
+      return false;
+    }
     return textEditingValue.text.length - value.text.length ==
         data.text!.length;
   }

lib/widgets/text_line.dart

@@ -165,8 +165,13 @@ class TextLine extends StatelessWidget {
 
     Attribute? color = textNode.style.attributes[Attribute.color.key];
     if (color != null && color.value != null) {
-      final textColor = stringToColor(color.value);
-      res = res.merge(TextStyle(color: textColor));
+      var textColor = defaultStyles.color;
+      if (color.value is String) {
+        textColor = stringToColor(color.value);
+      }
+      if (textColor != null) {
+        res = res.merge(TextStyle(color: textColor));
+      }
     }
 
     Attribute? background = textNode.style.attributes[Attribute.background.key];