left/right handlers for CellSelection

Author: slisson

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

@@ -47,7 +47,7 @@ class CaretSelection(val layoutable: LayoutableCell, val start: Int, val end: In
                     if (previous != null) {
                         if (event.modifiers.shift) {
                             val commonAncestor = layoutable.cell.commonAncestor(previous.cell)
-                            editor.changeSelection(CellSelection(commonAncestor, this))
+                            editor.changeSelection(CellSelection(commonAncestor, true, this))
                         } else {
                             editor.changeSelection(CaretSelection(previous, previous.cell.getMaxCaretPos()))
                         }
@@ -68,7 +68,7 @@ class CaretSelection(val layoutable: LayoutableCell, val start: Int, val end: In
                     if (next != null) {
                         if (event.modifiers.shift) {
                             val commonAncestor = layoutable.cell.commonAncestor(next.cell)
-                            editor.changeSelection(CellSelection(commonAncestor, this))
+                            editor.changeSelection(CellSelection(commonAncestor, false, this))
                         } else {
                             editor.changeSelection(CaretSelection(next, 0))
                         }
@@ -81,7 +81,7 @@ class CaretSelection(val layoutable: LayoutableCell, val start: Int, val end: In
             }
             KnownKeys.ArrowUp -> {
                 if (event.modifiers.meta) {
-                    layoutable.cell.let { editor.changeSelection(CellSelection(it, this)) }
+                    layoutable.cell.let { editor.changeSelection(CellSelection(it, true, this)) }
                 } else {
                     createNextPreviousLineSelection(false, desiredXPosition ?: getAbsoluteX())
                         ?.let { editor.changeSelection(it) }

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

@@ -51,3 +51,4 @@ object CommonCellProperties {
 }
 
 fun Cell.isTabTarget() = getProperty(CommonCellProperties.tabTarget)
+fun Cell.isSelectable() = getProperty(CommonCellProperties.selectable)

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

@@ -13,7 +13,7 @@
  */
 package org.modelix.editor
 
-data class CellSelection(val cell: Cell, val downSelection: Selection?): Selection() {
+data class CellSelection(val cell: Cell, val directionLeft: Boolean, val previousSelection: Selection?): Selection() {
     fun getEditor(): EditorComponent? = cell.editorComponent
 
     override fun isValid(): Boolean {
@@ -23,7 +23,7 @@ data class CellSelection(val cell: Cell, val downSelection: Selection?): Selecti
     override fun update(editor: EditorComponent): Selection? {
         return cell.data.cellReferences.asSequence()
             .flatMap { editor.resolveCell(it) }
-            .map { CellSelection(it, downSelection?.update(editor)) }
+            .map { CellSelection(it, directionLeft, previousSelection?.update(editor)) }
             .firstOrNull()
     }
 
@@ -33,12 +33,38 @@ data class CellSelection(val cell: Cell, val downSelection: Selection?): Selecti
             KnownKeys.ArrowUp -> {
                 if (event.modifiers.meta) {
                     cell.ancestors().firstOrNull { it.getProperty(CommonCellProperties.selectable) }
-                        ?.let { editor.changeSelection(CellSelection(it, this)) }
+                        ?.let { editor.changeSelection(CellSelection(it, directionLeft, this)) }
                 }
             }
             KnownKeys.ArrowDown -> {
-                if (event.modifiers.meta && downSelection != null) {
-                    editor.changeSelection(downSelection)
+                if (event.modifiers == Modifiers.META && previousSelection != null) {
+                    editor.changeSelection(previousSelection)
+                }
+            }
+            KnownKeys.ArrowLeft, KnownKeys.ArrowRight -> {
+                if (event.modifiers == Modifiers.SHIFT) {
+                    val isLeft = event.knownKey == KnownKeys.ArrowLeft
+                    if (isLeft == directionLeft) {
+                        cell.ancestors().firstOrNull { it.isSelectable() }
+                            ?.let { editor.changeSelection(CellSelection(it, directionLeft, this)) }
+                    } else {
+                        previousSelection?.let { editor.changeSelection(it) }
+                    }
+                } else {
+                    val caretSelection = generateSequence<Selection>(this) { (it as? CellSelection)?.previousSelection }
+                        .lastOrNull() as? CaretSelection
+                    if (caretSelection != null) {
+                        editor.changeSelection(CaretSelection(caretSelection.layoutable, caretSelection.start))
+                    } else {
+                        val tabTargets = cell.descendantsAndSelf().filter { it.isTabTarget() }
+                        if (event.knownKey == KnownKeys.ArrowLeft) {
+                            tabTargets.firstOrNull()?.layoutable()
+                                ?.let { editor.changeSelection(CaretSelection(it, 0)) }
+                        } else {
+                            tabTargets.lastOrNull()?.layoutable()
+                                ?.let { editor.changeSelection(CaretSelection(it, it.cell.getSelectableText()?.length ?: 0)) }
+                        }
+                    }
                 }
             }
             else -> {}