Introduce DataProvider support (#110)

* Introduce DataProvider support

* Code style

* Code style

* Fix detektTest issue with Unit type

(cherry picked from commit 8c9f591)

ide-laf-bridge/src/main/kotlin/org/jetbrains/jewel/bridge/actionSystem/DataProviderElement.kt

@@ -0,0 +1,24 @@
+package org.jetbrains.jewel.bridge.actionSystem
+
+import androidx.compose.ui.node.ModifierNodeElement
+
+internal class DataProviderElement(val dataProvider: (dataId: String) -> Any?) : ModifierNodeElement<DataProviderNode>() {
+
+    override fun create(): DataProviderNode = DataProviderNode(dataProvider)
+
+    override fun update(node: DataProviderNode) {
+        node.dataProvider = dataProvider
+        node.updateParent()
+    }
+
+    override fun equals(other: Any?): Boolean {
+        if (this === other) return true
+        if (javaClass != other?.javaClass) return false
+
+        other as DataProviderElement
+
+        return dataProvider == other.dataProvider
+    }
+
+    override fun hashCode(): Int = dataProvider.hashCode()
+}

ide-laf-bridge/src/main/kotlin/org/jetbrains/jewel/bridge/actionSystem/DataProviderNode.kt

@@ -0,0 +1,58 @@
+package org.jetbrains.jewel.bridge.actionSystem
+
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.focus.FocusEventModifierNode
+import androidx.compose.ui.focus.FocusState
+import androidx.compose.ui.modifier.ModifierLocalMap
+import androidx.compose.ui.modifier.ModifierLocalModifierNode
+import androidx.compose.ui.modifier.modifierLocalMapOf
+import androidx.compose.ui.modifier.modifierLocalOf
+
+/**
+ * Holder for parent node of current [DataProviderNode].
+ * So, each [DataProviderNode] provides itself and read parent node.
+ * It allows building tree of [DataProviderNode] and traverse it later on.
+ *
+ * @see ModifierLocalModifierNode
+ */
+private val LocalDataProviderNode = modifierLocalOf<DataProviderNode?> {
+    null
+}
+
+internal class DataProviderNode(var dataProvider: (dataId: String) -> Any?) :
+    Modifier.Node(),
+    ModifierLocalModifierNode,
+    FocusEventModifierNode {
+
+    // TODO: should we use state here and in parent with children for thread safety? Will it trigger recompositions?
+    var hasFocus = false
+
+    var parent: DataProviderNode? = null
+
+    private val _children = mutableSetOf<DataProviderNode>()
+    val children: Set<DataProviderNode> = _children
+
+    override val providedValues: ModifierLocalMap = modifierLocalMapOf(LocalDataProviderNode to this)
+
+    override fun onAttach() {
+        val oldParent = parent
+        parent = LocalDataProviderNode.current
+        if (parent !== oldParent) {
+            oldParent?._children?.remove(this)
+            parent?._children?.add(this)
+        }
+    }
+
+    override fun onDetach() {
+        parent?._children?.remove(this)
+        parent = null
+    }
+
+    override fun onFocusEvent(focusState: FocusState) {
+        hasFocus = focusState.hasFocus
+    }
+
+    fun updateParent() {
+        parent = LocalDataProviderNode.current
+    }
+}

ide-laf-bridge/src/main/kotlin/org/jetbrains/jewel/bridge/actionSystem/ProvideData.kt

@@ -0,0 +1,111 @@
+package org.jetbrains.jewel.bridge.actionSystem
+
+import androidx.compose.foundation.focusable
+import androidx.compose.foundation.layout.Box
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.DisposableEffect
+import androidx.compose.runtime.remember
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.focus.FocusEventModifierNode
+import androidx.compose.ui.node.ModifierNodeElement
+import com.intellij.ide.DataManager
+import com.intellij.openapi.actionSystem.DataContext
+import com.intellij.openapi.actionSystem.DataProvider
+import org.jetbrains.annotations.VisibleForTesting
+import javax.swing.JComponent
+
+/**
+ * Layout composable that create the bridge between [Modifier.provideData] used inside [content] and
+ * [component]. So, IntelliJ's [DataManager] can use [component] as [DataProvider].
+ *
+ * When IntelliJ requests [getData] from [component] Compose will traverse [DataProviderNode] hierarchy
+ * and collect it according [DataProvider] rules (see javadoc).
+ */
+// TODO: choose better naming?
+@Suppress("unused", "FunctionName")
+@Composable
+fun ComponentDataProviderBridge(
+    component: JComponent,
+    modifier: Modifier = Modifier,
+    content: @Composable () -> Unit,
+) {
+    val rootDataProviderModifier = remember { RootDataProviderModifier() }
+
+    Box(modifier = Modifier.then(rootDataProviderModifier).then(modifier)) {
+        content()
+    }
+
+    DisposableEffect(component) {
+        DataManager.registerDataProvider(component, rootDataProviderModifier.dataProvider)
+
+        onDispose {
+            DataManager.removeDataProvider(component)
+        }
+    }
+}
+
+/**
+ * Configure component to provide data for IntelliJ Actions system.
+ *
+ * Use this modifier to provide context related data that can be used by
+ * IntelliJ Actions functionality such as Search Everywhere, Action Popups etc.
+ *
+ * Important note: modifiers order is important, so be careful with order of [focusable] and [provideData]
+ * (see [FocusEventModifierNode]).
+ *
+ * @see DataProvider
+ * @see DataContext
+ * @see ComponentDataProviderBridge
+ */
+@Suppress("unused")
+fun Modifier.provideData(dataProvider: (dataId: String) -> Any?) = this.then(
+    DataProviderElement(dataProvider),
+)
+
+@VisibleForTesting
+internal class RootDataProviderModifier : ModifierNodeElement<DataProviderNode>() {
+
+    private val rootNode = DataProviderNode { null }
+
+    val dataProvider: (String) -> Any? = {
+        rootNode.getData(it)
+    }
+
+    override fun create() = rootNode
+
+    override fun update(node: DataProviderNode) {
+        // do nothing
+    }
+
+    override fun hashCode(): Int = rootNode.hashCode()
+
+    override fun equals(other: Any?) = other === this
+}
+
+private fun DataProviderNode.getData(dataId: String): Any? {
+    val focusedNode = this.traverseDownToFocused() ?: return null
+    return focusedNode.collectData(dataId)
+}
+
+private fun DataProviderNode.collectData(dataId: String): Any? {
+    var currentNode: DataProviderNode? = this
+    while (currentNode != null) {
+        val data = currentNode.dataProvider(dataId)
+        if (data != null) {
+            return data
+        }
+        currentNode = currentNode.parent
+    }
+
+    return null
+}
+
+private fun DataProviderNode.traverseDownToFocused(): DataProviderNode? {
+    for (child in children) {
+        if (child.hasFocus) {
+            return child.traverseDownToFocused()
+        }
+    }
+
+    return this.takeIf { hasFocus }
+}

ide-laf-bridge/src/test/kotlin/org/jetbrains/jewel/bridge/actionSystem/ProvideDataTest.kt

@@ -0,0 +1,115 @@
+package org.jetbrains.jewel.bridge.actionSystem
+
+import androidx.compose.foundation.focusable
+import androidx.compose.foundation.layout.Box
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.focus.FocusDirection
+import androidx.compose.ui.focus.FocusManager
+import androidx.compose.ui.platform.LocalFocusManager
+import androidx.compose.ui.platform.testTag
+import androidx.compose.ui.test.assertIsFocused
+import androidx.compose.ui.test.junit4.createComposeRule
+import androidx.compose.ui.test.onNodeWithTag
+import kotlinx.coroutines.runBlocking
+import org.junit.Assert.assertEquals
+import org.junit.Rule
+import org.junit.Test
+
+class ProvideDataTest {
+
+    @JvmField
+    @Rule
+    val rule = createComposeRule()
+
+    @Test
+    fun `one component`() {
+        runBlocking {
+            val rootDataProviderModifier = RootDataProviderModifier()
+            var focusManager: FocusManager? = null
+            rule.setContent {
+                focusManager = LocalFocusManager.current
+                Box(
+                    modifier = Modifier
+                        .then(rootDataProviderModifier)
+                        .testTag("provider")
+                        .provideData {
+                            when (it) {
+                                "data" -> "ok"
+                                else -> null
+                            }
+                        }
+                        .focusable(),
+                )
+            }
+            rule.awaitIdle()
+            focusManager!!.moveFocus(FocusDirection.Next)
+            rule.awaitIdle()
+
+            rule.onNodeWithTag("provider").assertIsFocused()
+
+            assertEquals("ok", rootDataProviderModifier.dataProvider("data"))
+            assertEquals(null, rootDataProviderModifier.dataProvider("another_data"))
+        }
+    }
+
+    @Test
+    fun `component hierarchy`() {
+        runBlocking {
+            val rootDataProviderModifier = RootDataProviderModifier()
+            var focusManager: FocusManager? = null
+            rule.setContent {
+                focusManager = LocalFocusManager.current
+                Box(
+                    modifier = Modifier
+                        .then(rootDataProviderModifier)
+                        .testTag("root_provider")
+                        .provideData {
+                            when (it) {
+                                "isRoot" -> "yes"
+                                else -> null
+                            }
+                        }
+                        .focusable(),
+                ) {
+                    Box(modifier = Modifier.testTag("non_data_provider").focusable()) {
+                        Box(
+                            modifier = Modifier
+                                .testTag("data_provider_item")
+                                .provideData {
+                                    when (it) {
+                                        "data" -> "ok"
+                                        else -> null
+                                    }
+                                }.focusable(),
+                        )
+                    }
+                }
+            }
+
+            rule.awaitIdle()
+            focusManager!!.moveFocus(FocusDirection.Next)
+            rule.awaitIdle()
+
+            rule.onNodeWithTag("root_provider").assertIsFocused()
+            assertEquals("yes", rootDataProviderModifier.dataProvider("isRoot"))
+            assertEquals(null, rootDataProviderModifier.dataProvider("data"))
+
+            focusManager!!.moveFocus(FocusDirection.Next)
+            rule.awaitIdle()
+
+            rule.onNodeWithTag("non_data_provider").assertIsFocused()
+            // non_data_provider still should provide isRoot == true because it should be taken from root
+            // but shouldn't provide "data" yet
+            assertEquals("yes", rootDataProviderModifier.dataProvider("isRoot"))
+            assertEquals(null, rootDataProviderModifier.dataProvider("data"))
+
+            focusManager!!.moveFocus(FocusDirection.Next)
+            rule.awaitIdle()
+
+            rule.onNodeWithTag("data_provider_item").assertIsFocused()
+
+            assertEquals("yes", rootDataProviderModifier.dataProvider("isRoot"))
+            assertEquals("ok", rootDataProviderModifier.dataProvider("data"))
+        }
+    }
+}