feature #511 Add scroll state.

Author: toastkidjp

editor/src/main/java/jp/toastkid/editor/view/EditorTabViewModel.kt

@@ -46,6 +46,8 @@ class EditorTabViewModel {
 
     private val lineCount = mutableIntStateOf(0)
 
+    private val verticalScrollState = ScrollState(0)
+
     private val lineNumberScrollState = ScrollState(0)
 
     private val focusRequester = FocusRequester()
@@ -105,6 +107,8 @@ class EditorTabViewModel {
         lineNumbers.value = list
     }
 
+    fun verticalScrollState() = verticalScrollState
+
     fun lineNumberScrollState() = lineNumberScrollState
 
     fun onClickLineNumber(it: Int) {