From 6751472a55b2cc7d1aade08e253259b44e1ffbe2 Mon Sep 17 00:00:00 2001
From: li3317 <li3317@purdue.edu>
Date: Tue, 13 Jul 2021 23:19:43 +0800
Subject: [PATCH] fix clear format button

---
 lib/src/models/documents/document.dart        |  8 +++--
 lib/src/models/documents/nodes/line.dart      | 33 +++++++++++++++++++
 lib/src/widgets/controller.dart               |  8 ++++-
 .../widgets/toolbar/clear_format_button.dart  |  2 +-
 4 files changed, 47 insertions(+), 4 deletions(-)

diff --git a/lib/src/models/documents/document.dart b/lib/src/models/documents/document.dart
index 346da93b..010df462 100644
--- a/lib/src/models/documents/document.dart
+++ b/lib/src/models/documents/document.dart
@@ -119,9 +119,13 @@ class Document {
     return delta;
   }
 
-  Style collectStyle(int index, int len) {
+  Style collectStyle(int index, int len, bool collectAll) {
     final res = queryChild(index);
-    return (res.node as Line).collectStyle(res.offset, len);
+    if (collectAll) {
+      return (res.node as Line).collectAllStyle(res.offset, len);
+    } else {
+      return (res.node as Line).collectStyle(res.offset, len);
+    }
   }
 
   ChildQuery queryChild(int offset) {
diff --git a/lib/src/models/documents/nodes/line.dart b/lib/src/models/documents/nodes/line.dart
index fabfad4d..a67a17da 100644
--- a/lib/src/models/documents/nodes/line.dart
+++ b/lib/src/models/documents/nodes/line.dart
@@ -368,4 +368,37 @@ class Line extends Container<Leaf?> {
 
     return result;
   }
+
+  /// Returns all style for any character within the specified text range.
+  Style collectAllStyle(int offset, int len) {
+    final local = math.min(length - offset, len);
+    var result = Style();
+
+    final data = queryChild(offset, true);
+    var node = data.node as Leaf?;
+    if (node != null) {
+      result = result.mergeAll(node.style);
+      var pos = node.length - data.offset;
+      while (!node!.isLast && pos < local) {
+        node = node.next as Leaf?;
+        result = result.mergeAll(node!.style);
+        pos += node.length;
+      }
+    }
+
+    result = result.mergeAll(style);
+    if (parent is Block) {
+      final block = parent as Block;
+      result = result.mergeAll(block.style);
+    }
+
+    final remaining = len - local;
+    if (remaining > 0) {
+      final rest = nextLine!.collectAllStyle(0, remaining);
+      result = result.mergeAll(rest);
+    }
+
+    return result;
+  }
+
 }
diff --git a/lib/src/widgets/controller.dart b/lib/src/widgets/controller.dart
index 7de1a122..9e2e01b0 100644
--- a/lib/src/widgets/controller.dart
+++ b/lib/src/widgets/controller.dart
@@ -57,7 +57,13 @@ class QuillController extends ChangeNotifier {
 
   Style getSelectionStyle() {
     return document
-        .collectStyle(selection.start, selection.end - selection.start)
+        .collectStyle(selection.start, selection.end - selection.start, false)
+        .mergeAll(toggledStyle);
+  }
+
+  Style getAllSelectionStyle() {
+    return document
+        .collectStyle(selection.start, selection.end - selection.start, true)
         .mergeAll(toggledStyle);
   }
 
diff --git a/lib/src/widgets/toolbar/clear_format_button.dart b/lib/src/widgets/toolbar/clear_format_button.dart
index d55c21df..ee049b41 100644
--- a/lib/src/widgets/toolbar/clear_format_button.dart
+++ b/lib/src/widgets/toolbar/clear_format_button.dart
@@ -34,7 +34,7 @@ class _ClearFormatButtonState extends State<ClearFormatButton> {
         fillColor: fillColor,
         onPressed: () {
           for (final k
-              in widget.controller.getSelectionStyle().attributes.values) {
+              in widget.controller.getAllSelectionStyle().attributes.values) {
             widget.controller.formatSelection(Attribute.clone(k, null));
           }
         });