up/down handler for CellSelection

Moves the caret to the next/previous line.

Author: slisson

editor-runtime/src/commonMain/kotlin/org/modelix/editor/CaretSelection.kt

@@ -1,8 +1,5 @@
 package org.modelix.editor
 
-import kotlinx.html.TagConsumer
-import kotlinx.html.classes
-import kotlinx.html.div
 import kotlin.math.max
 import kotlin.math.min
 
@@ -78,15 +75,13 @@ class CaretSelection(val layoutable: LayoutableCell, val start: Int, val end: In
                 }
             }
             KnownKeys.ArrowDown -> {
-                createNextPreviousLineSelection(true, desiredXPosition ?: getAbsoluteX())
-                    ?.let { editor.changeSelection(it) }
+                selectNextPreviousLine(true)
             }
             KnownKeys.ArrowUp -> {
                 if (event.modifiers.meta) {
                     layoutable.cell.let { editor.changeSelection(CellSelection(it, true, this)) }
                 } else {
-                    createNextPreviousLineSelection(false, desiredXPosition ?: getAbsoluteX())
-                        ?.let { editor.changeSelection(it) }
+                    selectNextPreviousLine(false)
                 }
             }
             KnownKeys.Tab -> {
@@ -147,6 +142,11 @@ class CaretSelection(val layoutable: LayoutableCell, val start: Int, val end: In
         return true
     }
 
+    fun selectNextPreviousLine(next: Boolean) {
+        createNextPreviousLineSelection(next, desiredXPosition ?: getAbsoluteX())
+            ?.let { getEditor()?.changeSelection(it) }
+    }
+
     private fun processTypedText(typedText: String, editor: EditorComponent) {
         val oldText = layoutable.cell.getSelectableText() ?: ""
         val range = min(start, end) until max(start, end)

editor-runtime/src/commonMain/kotlin/org/modelix/editor/CellSelection.kt

@@ -34,11 +34,15 @@ data class CellSelection(val cell: Cell, val directionLeft: Boolean, val previou
                 if (event.modifiers.meta) {
                     cell.ancestors().firstOrNull { it.getProperty(CommonCellProperties.selectable) }
                         ?.let { editor.changeSelection(CellSelection(it, directionLeft, this)) }
+                } else {
+                    unwrapCaretSelection()?.selectNextPreviousLine(false)
                 }
             }
             KnownKeys.ArrowDown -> {
                 if (event.modifiers == Modifiers.META && previousSelection != null) {
                     editor.changeSelection(previousSelection)
+                } else {
+                    unwrapCaretSelection()?.selectNextPreviousLine(true)
                 }
             }
             KnownKeys.ArrowLeft, KnownKeys.ArrowRight -> {
@@ -51,8 +55,7 @@ data class CellSelection(val cell: Cell, val directionLeft: Boolean, val previou
                         previousSelection?.let { editor.changeSelection(it) }
                     }
                 } else {
-                    val caretSelection = generateSequence<Selection>(this) { (it as? CellSelection)?.previousSelection }
-                        .lastOrNull() as? CaretSelection
+                    val caretSelection = unwrapCaretSelection()
                     if (caretSelection != null) {
                         editor.changeSelection(CaretSelection(caretSelection.layoutable, caretSelection.start))
                     } else {
@@ -73,6 +76,11 @@ data class CellSelection(val cell: Cell, val directionLeft: Boolean, val previou
         return true
     }
 
+    private fun unwrapCaretSelection(): CaretSelection? {
+        return generateSequence<Selection>(this) { (it as? CellSelection)?.previousSelection }
+            .lastOrNull() as? CaretSelection
+    }
+
     fun getLayoutables(): List<Layoutable> {
         val editor = getEditor() ?: return emptyList()
         val rootText = editor.getRootCell().layout