refactor(editor): simplify expand/collapse label logic

Remove redundant state checks and simplify the logic for updating the expand/collapse label in the editor. The label now consistently shows "More lines" with a chevron down icon when the line count exceeds the threshold.

Author: phodal

core/src/main/kotlin/cc/unitmesh/devti/sketch/ui/code/CodeHighlightSketch.kt

@@ -116,14 +116,14 @@ open class CodeHighlightSketch(
             val normalizedText = StringUtil.convertLineSeparators(text)
             document?.replaceString(0, document.textLength, normalizedText)
 
-            document?.lineCount?.let {
-                if (it > editorLineThreshold) {
-                    editorFragment?.updateExpandCollapseLabel()
-                }
-                if (complete) {
-                    if (isDevIns && it > minDevinLineThreshold) {
-                        editorFragment?.resizeForNewThreshold(minDevinLineThreshold)
-                    }
+            val lineCount = document?.lineCount ?: 0
+            if (lineCount > editorLineThreshold) {
+                editorFragment?.updateExpandCollapseLabel()
+            }
+
+            if (complete) {
+                if (isDevIns) {
+                    editorFragment?.resizeForNewThreshold(minDevinLineThreshold)
                 }
             }
         }
@@ -223,7 +223,7 @@ open class CodeHighlightSketch(
 
                 try {
                     EditorFactory.getInstance().createViewer(document, project, EditorKind.PREVIEW) as EditorEx
-                } catch (e: Throwable){
+                } catch (e: Throwable) {
                     throw e
                 }
             }

core/src/main/kotlin/cc/unitmesh/devti/sketch/ui/code/EditorFragment.kt

@@ -104,14 +104,11 @@ class EditorFragment(var editor: EditorEx, private val editorLineThreshold: Int
     }
 
     fun resizeForNewThreshold(newThreshold: Int) {
-        setCollapsed(false)
-
         content.preferredSize = calculatePreferredSize(content.preferredSize, newThreshold)
 
-        val linesCount = editor.document.lineCount
-        expandCollapseTextLabel.isVisible = linesCount > editorLineThreshold
-        expandCollapseTextLabel.text = if (collapsed) "More lines" else ""
-        expandCollapseTextLabel.icon = if (collapsed) AllIcons.General.ChevronDown else AllIcons.General.ChevronUp
+        expandCollapseTextLabel.isVisible = true
+        expandCollapseTextLabel.text = "More lines"
+        expandCollapseTextLabel.icon = AllIcons.General.ChevronDown
 
         content.revalidate()
         content.repaint()