WIP - Refactored add header and remove character logic

Author: cp-megh-l

editor/src/main/java/com/canopas/editor/ui/data/QuillTextManager.kt

@@ -266,21 +266,14 @@ class QuillTextManager(quillSpan: QuillSpan) {
         val fromIndex = selection.min
         val toIndex = if (selection.collapsed) fromIndex else selection.max
 
-        val startIndex: Int = max(0, text.lastIndexOf("\n", fromIndex - 1))
-        var endIndex: Int = text.indexOf("\n", toIndex)
-
-        if (endIndex == -1) endIndex = text.length - 1
-        val selectedParts =
-            quillTextSpans.filter { endIndex >= it.to && startIndex <= it.from && it.style.any { it.isHeaderStyle() } }
-
-        quillTextSpans.removeAll(selectedParts)
-        quillTextSpans.add(
-            QuillTextSpan(
-                from = startIndex,
-                to = endIndex,
-                style = listOf(style)
-            )
-        )
+        val currentSpan = quillTextSpans.find {
+            it.from <= fromIndex && it.to >= toIndex
+        }
+        val index = quillTextSpans.indexOf(currentSpan)
+        quillTextSpans[index] =
+            currentSpan?.copy(style = currentSpan.style.filterNot { it.isHeaderStyle() } + listOf(
+                style
+            )) ?: return
         updateText()
     }
 
@@ -308,7 +301,9 @@ class QuillTextManager(quillSpan: QuillSpan) {
             part.from < endIndex && part.to >= startIndex
         }
 
-        quillTextSpans.removeAll(selectedParts.filter { it.style.any { it.isHeaderStyle() } })
+        quillTextSpans.removeAll(selectedParts.filter {
+            it.style.size == 1 && it.style.first().isHeaderStyle()
+        })
     }
 
     private fun removeStylesFromSelectedPart(