Add keyboard control (WIP)

commonUI/src/commonMain/kotlin/ch/dissem/yaep/ui/common/App.kt

@@ -1,5 +1,6 @@
 package ch.dissem.yaep.ui.common
 
+import SelectionManager
 import androidx.compose.foundation.layout.Box
 import androidx.compose.material3.Text
 import androidx.compose.runtime.Composable
@@ -15,6 +16,7 @@ import androidx.compose.ui.unit.Dp
 import androidx.compose.ui.unit.TextUnit
 import androidx.compose.ui.unit.TextUnitType
 import ch.dissem.yaep.domain.Game
+import focus
 import ch.dissem.yaep.domain.HorizontalClue
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.Dispatchers
@@ -25,6 +27,7 @@ import kotlin.time.ExperimentalTime
 @OptIn(ExperimentalTime::class)
 fun App(
     modifier: Modifier = Modifier,
+    selectionManager: SelectionManager,
     selectDirectly: Boolean,
     spacing: Dp,
     game: Game,
@@ -56,6 +59,8 @@ fun App(
             modifier = Modifier.blurOnFinished(isSolved),
             grid = {
                 PuzzleGrid(
+                    modifier = Modifier
+                        .focus(remember { selectionManager.add() }),
                     grid = game.grid,
                     spacing = spacing,
                     selectDirectly = selectDirectly,
@@ -66,9 +71,12 @@ fun App(
                 )
             },
             horizontalClues = {
+                val horizontalClueSelection = remember { selectionManager.add() }
                 for (clue in horizontalClues) {
                     HorizontalClue(
-                        modifier = Modifier.forClue(clue, spacing),
+                        modifier = Modifier
+                            .focus(horizontalClueSelection)
+                            .forClue(clue, spacing),
                         spacing = spacing,
                         clue = clue.clue,
                         isClueViolated = clue.isViolated
@@ -76,9 +84,12 @@ fun App(
                 }
             },
             verticalClues = {
+                val verticalClueSelection = remember { selectionManager.add() }
                 for (clue in verticalClues) {
                     VerticalClue(
-                        modifier = Modifier.forClue(clue, spacing),
+                        modifier = Modifier
+                            .focus(verticalClueSelection)
+                            .forClue(clue, spacing),
                         spacing = spacing,
                         clue = clue.clue,
                         isClueViolated = clue.isViolated

commonUI/src/commonMain/kotlin/ch/dissem/yaep/ui/common/widget status.kt

@@ -1,39 +1,118 @@
 import androidx.compose.foundation.border
 import androidx.compose.material3.MaterialTheme
 import androidx.compose.runtime.Composable
+import androidx.compose.runtime.collectAsState
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.graphics.RectangleShape
+import androidx.compose.ui.input.key.Key
+import androidx.compose.ui.input.key.KeyEvent
+import androidx.compose.ui.input.key.KeyEventType
+import androidx.compose.ui.input.key.isShiftPressed
+import androidx.compose.ui.input.key.key
+import androidx.compose.ui.input.key.type
 import androidx.compose.ui.unit.dp
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.combine
+import kotlin.IllegalStateException
 
-class StatusManager {
+class SelectionManager(
-    lateinit var focused: StatusHolder
+    val keyNext: Key,
-        private set
+    val keyPrevious: Key? = null
+) {
+    var isActiveFlow = MutableStateFlow<Boolean>(false)
+    var isActive: Boolean
+        get() = isActiveFlow.value
+        set(value) {
+            isActiveFlow.value = value
+        }
+
+    var focusedFlow = MutableStateFlow<Focusable?>(null)
+
+    var focused: Focusable?
+        get() = focusedFlow.value
+        set(value) {
+            focusedFlow.value = value
+        }
+
+    val last: Focusable
+        get() = focused?.previous ?: throw IllegalStateException("not initialized")
+
+    val child: SelectionManager?
+        get() = focused?.child
 
     fun focusNext() {
-        focused = focused.next
+        focused = focused?.next
     }
 
     fun focusPrevious() {
-        focused = focused.previous
+        focused = focused?.previous
+    }
+
+    fun add(): Focusable {
+        val new = Focusable(this)
+        if (focused != null) {
+            new.next = focused!!
+        } else {
+            focused = new
+        }
+        return new
+    }
+
+    fun onKeyEvent(event: KeyEvent): Boolean {
+        if (event.type != KeyEventType.KeyUp) return false
+
+        if (event.key == keyNext) {
+            if (keyPrevious == null && event.isShiftPressed) {
+                focusPrevious()
+            } else {
+                focusNext()
+            }
+        } else if (event.key == keyPrevious) {
+            focusPrevious()
+        } else {
+            return child?.onKeyEvent(event) == true
+        }
+        return true
     }
 }
 
-class StatusHolder(private val manager: StatusManager) {
+class Focusable(
-    val hasFocus: Boolean
+    manager: SelectionManager,
-        get() = manager.focused == this
+) {
-    var isSelected: Boolean = false
+    val hasFocus: Flow<Boolean> =
+        combine(manager.isActiveFlow, manager.focusedFlow) { isActive, focused ->
+            isActive && focused == this
+        }
 
-    var previous: StatusHolder = this
+    var previous: Focusable = this
         private set
-    var next: StatusHolder = this
+
+    private var _next: Focusable = this
+    var next: Focusable
+        get() = _next
         set(value) {
-            field = value
+            previous = value.previous
+            previous._next = this
             value.previous = this
+            _next = value
+        }
+
+    var child: SelectionManager? = null
+        private set
+
+    fun createChild(
+        keyNext: Key,
+        keyPrevious: Key? = null
+    ): SelectionManager {
+        child = SelectionManager(keyNext, keyPrevious)
+        child!!.isActive = false
+        return child!!
     }
 }
 
 @Composable
-fun Modifier.status(holder: StatusHolder): Modifier = if (holder.hasFocus) {
+fun Modifier.focus(holder: Focusable): Modifier = if (holder.hasFocus.collectAsState(false).value) {
     border(
         width = 2.dp,
         color = MaterialTheme.colorScheme.primary,

desktop/src/main/kotlin/ch/dissem/yaep/ui/desktop/desktop window.kt

@@ -1,5 +1,6 @@
 package ch.dissem.yaep.ui.desktop
 
+import SelectionManager
 import androidx.compose.foundation.Image
 import androidx.compose.foundation.layout.PaddingValues
 import androidx.compose.foundation.layout.Spacer
@@ -16,6 +17,8 @@ import androidx.compose.material3.Text
 import androidx.compose.material3.TopAppBar
 import androidx.compose.runtime.Composable
 import androidx.compose.ui.Modifier
+import androidx.compose.ui.draw.scale
+import androidx.compose.ui.input.key.onKeyEvent
 import androidx.compose.ui.unit.dp
 import androidx.compose.ui.window.WindowPlacement
 import androidx.compose.ui.window.WindowScope
@@ -40,11 +43,13 @@ import yaep.desktop.generated.resources.Res as DRes
 @Composable
 fun WindowScope.DesktopWindow(
     useDarkMode: Boolean,
+    selectionManager: SelectionManager,
     topBar: @Composable () -> Unit,
     content: @Composable (PaddingValues) -> Unit
 ) {
     AppTheme(darkTheme = useDarkMode) {
         Scaffold(
+            modifier = Modifier.onKeyEvent { event -> selectionManager.onKeyEvent(event) },
             topBar = {
                 WindowDraggableArea {
                     topBar()

desktop/src/main/kotlin/ch/dissem/yaep/ui/desktop/main.kt

@@ -6,6 +6,7 @@ import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.remember
 import androidx.compose.runtime.setValue
 import androidx.compose.ui.Modifier
+import androidx.compose.ui.input.key.Key
 import androidx.compose.ui.text.font.FontFamily
 import androidx.compose.ui.text.font.FontStyle
 import androidx.compose.ui.text.font.FontWeight
@@ -47,10 +48,12 @@ fun main(): Unit = application {
         state = windowState,
         icon = painterResource(DRes.drawable.ic_launcher)
     ) {
+        val selectionManager = remember { SelectionManager(Key.Tab).apply { isActive = true } }
         var useDarkMode by remember { mutableStateOf(true) }
         var resetCluesBeacon by remember { mutableStateOf(Any()) }
         DesktopWindow(
             useDarkMode = useDarkMode,
+            selectionManager = selectionManager,
             topBar = {
                 AppBar(
                     useDarkMode = useDarkMode,
@@ -67,6 +70,7 @@ fun main(): Unit = application {
         ) {
             App(
                 modifier = Modifier.padding(it),
+                selectionManager = selectionManager,
                 spacing = 8.dp,
                 selectDirectly = true,
                 game = game,