Inspector: Show source file of components and jump there in IntelliJ

api/Elementa.api

@@ -1158,6 +1158,8 @@ public final class gg/essential/elementa/components/inspector/Inspector : gg/ess
 }
 
 public final class gg/essential/elementa/components/inspector/Inspector$Companion {
+	public final fun registerComponentFactory (Ljava/lang/Class;Ljava/lang/String;)V
+	public static synthetic fun registerComponentFactory$default (Lgg/essential/elementa/components/inspector/Inspector$Companion;Ljava/lang/Class;Ljava/lang/String;ILjava/lang/Object;)V
 }
 
 public final class gg/essential/elementa/components/inspector/InspectorNode : gg/essential/elementa/components/TreeNode {

src/main/kotlin/gg/essential/elementa/UIComponent.kt

@@ -6,6 +6,7 @@ import gg.essential.elementa.components.UIBlock
 import gg.essential.elementa.components.UIContainer
 import gg.essential.elementa.components.UpdateFunc
 import gg.essential.elementa.components.Window
+import gg.essential.elementa.components.inspector.Inspector
 import gg.essential.elementa.constraints.*
 import gg.essential.elementa.constraints.animation.*
 import gg.essential.elementa.dsl.animate
@@ -1310,6 +1311,25 @@ abstract class UIComponent : Observable(), ReferenceHolder {
     }
     //endregion
 
+    //region Source code location
+    internal val source: Array<StackTraceElement>? = if (elementaDev) Throwable().stackTrace else null
+
+    internal val filteredSource: List<StackTraceElement>?
+        get() = source?.filterNot { it.lineNumber == 1 }
+
+    internal val primarySource: StackTraceElement?
+        get() {
+            val className = javaClass.name
+            return (source ?: return null)
+                .asSequence()
+                .dropWhile { it.methodName == "<init>" && it.className != className } // super class constructors
+                .dropWhile { it.methodName == "<init>" && it.className == className } // constructors
+                .filterNot { it.lineNumber == 1 } // ignore synthetic methods
+                .dropWhile { frame -> Inspector.factoryMethods.any { (c, m) -> c == frame.className && (m == null || m == frame.methodName) } }
+                .firstOrNull()
+        }
+    //endregion
+
     /**
      * Field animation API
      */

src/main/kotlin/gg/essential/elementa/components/UIImage.kt

@@ -2,6 +2,7 @@ package gg.essential.elementa.components
 
 import gg.essential.elementa.UIComponent
 import gg.essential.elementa.components.image.*
+import gg.essential.elementa.components.inspector.Inspector
 import gg.essential.elementa.utils.ResourceCache
 import gg.essential.elementa.utils.drawTexture
 import gg.essential.universal.UGraphics
@@ -127,6 +128,10 @@ open class UIImage @JvmOverloads constructor(
 
         val defaultResourceCache = ResourceCache(50)
 
+        init {
+            Inspector.registerComponentFactory(Companion::class.java)
+        }
+
         @JvmStatic
         fun ofFile(file: File): UIImage {
             return UIImage(CompletableFuture.supplyAsync { ImageIO.read(file) })

src/main/kotlin/gg/essential/elementa/components/inspector/Inspector.kt

@@ -10,11 +10,15 @@ import gg.essential.elementa.effects.ScissorEffect
 import gg.essential.elementa.utils.ObservableAddEvent
 import gg.essential.elementa.utils.ObservableClearEvent
 import gg.essential.elementa.utils.ObservableRemoveEvent
+import gg.essential.elementa.utils.devPropSet
 import gg.essential.elementa.utils.elementaDebug
 import gg.essential.universal.UGraphics
 import gg.essential.universal.UMatrixStack
 import org.lwjgl.opengl.GL11
 import java.awt.Color
+import java.io.FileNotFoundException
+import java.net.ConnectException
+import java.net.URL
 import java.text.NumberFormat
 
 class Inspector @JvmOverloads constructor(
@@ -201,6 +205,59 @@ class Inspector @JvmOverloads constructor(
             infoBlockScroller childOf container
         }
         selectedNode = node
+        if (node != null) {
+            val source = node.targetComponent.primarySource
+            if (source != null) {
+                node.selectedSourceIndex = node.targetComponent.filteredSource!!.indexOf(source)
+                openSourceFile(source)
+            }
+        }
+    }
+
+    init {
+        // Workaround for ScrollComponent.actualContent breaking scroll event propagation
+        var recursive = false
+        onMouseScroll { event ->
+            if (recursive) return@onMouseScroll
+            recursive = true
+            treeBlock.mouseScroll(event.delta)
+            recursive = false
+        }
+    }
+
+    internal fun scrollSource(node: InspectorNode, up: Boolean) {
+        val elements = node.targetComponent.filteredSource ?: return
+        var index = node.selectedSourceIndex
+        index = (index + if (up) 1 else -1).coerceIn(elements.indices)
+        node.selectedSourceIndex = index
+        openSourceFile(elements[index])
+    }
+
+    private fun openSourceFile(frame: StackTraceElement) {
+        val folder = frame.className.substringBeforeLast(".").replace(".", "/")
+        val file = folder + "/" + frame.fileName
+        val line = frame.lineNumber
+        try {
+            // For docs see https://www.develar.org/idea-rest-api/#api-Platform-file
+            // For impl see https://github.com/JetBrains/intellij-community/blob/d9b508478de6d3b5d2e765738d561ead77c97824/plugins/remote-control/src/org/jetbrains/ide/OpenFileHttpService.kt
+            val url = URL("$INTELLIJ_REST_API/api/file?file=$file&line=$line&focused=false")
+            val conn = url.openConnection()
+            // IntelliJ uses Origin/Referrer to determine whether to trust a given request (a JavaScript snippet in your
+            // browser could try to request this page too after all!), so we use localhost which is trusted by default.
+            // See https://github.com/JetBrains/intellij-community/blob/d9b508478de6d3b5d2e765738d561ead77c97824/platform/built-in-server/src/org/jetbrains/ide/RestService.kt#L272
+            // We can't use Origin because Java considers that a restricted header and will just ignore it.
+            conn.setRequestProperty("Referer", "http://localhost")
+            conn.connect()
+            conn.inputStream.skip(Long.MAX_VALUE)
+        } catch (ignored: ConnectException) {
+        } catch (e: FileNotFoundException) { // HTTP 404
+            if (!hintedIntelliJSupport) {
+                hintedIntelliJSupport = true
+                println("IntelliJ detected! Install JetBrain's `IDE Remote Control` plugin to automatically jump to the source of the selected component.")
+            }
+        } catch (e: Exception) {
+            e.printStackTrace()
+        }
     }
 
     private fun getClickSelectTarget(mouseX: Float, mouseY: Float): UIComponent? {
@@ -283,5 +340,22 @@ class Inspector @JvmOverloads constructor(
 
     companion object {
         internal val percentFormat: NumberFormat = NumberFormat.getPercentInstance()
+
+        private val INTELLIJ_REST_API = System.getProperty("elementa.intellij_rest_api", "http://localhost:63342")
+        private var hintedIntelliJSupport = false
+
+        internal val factoryMethods: MutableList<Pair<String, String?>> = mutableListOf()
+
+        fun registerComponentFactory(cls: Class<*>?, method: String? = null) {
+            if (!devPropSet) return
+            factoryMethods.add(Pair(cls?.name ?: callerClassName(), method))
+        }
+
+        private fun callerClassName(): String =
+            Throwable().stackTrace.asSequence()
+                .filterNot { it.methodName.endsWith("\$default") } // synthetic Kotlin defaults method
+                .drop(2) // this method + caller of this method
+                .first()
+                .className
     }
 }

src/main/kotlin/gg/essential/elementa/components/inspector/InspectorNode.kt

@@ -11,31 +11,35 @@ import gg.essential.elementa.dsl.toConstraint
 import gg.essential.elementa.dsl.childOf
 import gg.essential.elementa.dsl.constrain
 import gg.essential.elementa.dsl.pixels
+import gg.essential.universal.UKeyboard
+import gg.essential.universal.UMatrixStack
 import java.awt.Color
 
 class InspectorNode(private val inspector: Inspector, val targetComponent: UIComponent) : TreeNode() {
     private val componentClassName = targetComponent.javaClass.simpleName.ifEmpty { "UnknownType" }
     private val componentDisplayName = targetComponent.componentName.let { if (it == componentClassName) it else "$componentClassName: $it" }
-    private var wasHidden = false
+
+    private var selectedSource = targetComponent.primarySource
+    internal var selectedSourceIndex: Int = targetComponent.filteredSource?.indexOf(selectedSource) ?: 0
+        set(value) {
+            field = value
+            selectedSource = targetComponent.filteredSource?.get(value)
+        }
 
     private val component: UIComponent = object : UIBlock(Color(0, 0, 0, 0)) {
         private val text = UIText(componentDisplayName).constrain {
             width = TextAspectConstraint()
         } childOf this
 
-        override fun animationFrame() {
-            super.animationFrame()
+        override fun draw(matrixStack: UMatrixStack) {
+            super.draw(matrixStack)
 
             val isCurrentlyHidden = targetComponent.parent != targetComponent && !targetComponent.parent.children.contains(
                 targetComponent
             )
-            if (isCurrentlyHidden && !wasHidden) {
-                wasHidden = true
-                text.setText("§r$componentDisplayName §7§o(Hidden)")
-            } else if (!isCurrentlyHidden && wasHidden) {
-                wasHidden = false
-                text.setText(componentDisplayName)
-            }
+            val file = selectedSource?.let { " §7${it.fileName ?: it.className.substringAfterLast(".")}:${it.lineNumber}" } ?: ""
+            val hidden = if (isCurrentlyHidden) " §7§o(Hidden)" else ""
+            text.setText("§r$componentDisplayName$file$hidden")
         }
     }.constrain {
         x = SiblingConstraint()
@@ -45,6 +49,10 @@ class InspectorNode(private val inspector: Inspector, val targetComponent: UICom
     }.onMouseClick { event ->
         event.stopImmediatePropagation()
         toggleSelection()
+    }.onMouseScroll { event ->
+        if (!UKeyboard.isShiftKeyDown()) return@onMouseScroll
+        event.stopImmediatePropagation()
+        inspector.scrollSource(this@InspectorNode, event.delta > 0)
     }
 
     internal fun toggleSelection() {

src/main/kotlin/gg/essential/elementa/utils/ResourceCache.kt

@@ -3,6 +3,7 @@ package gg.essential.elementa.utils
 import gg.essential.elementa.components.UIImage
 import gg.essential.elementa.components.image.CacheableImage
 import gg.essential.elementa.components.image.MSDFComponent
+import gg.essential.elementa.components.inspector.Inspector
 import java.awt.image.BufferedImage
 import java.util.concurrent.CompletableFuture
 import java.util.concurrent.ConcurrentHashMap
@@ -44,4 +45,10 @@ class ResourceCache(val size: Int = 50) {
             cachedImage.supply(it)
         }
     }
+
+    private companion object {
+        init {
+            Inspector.registerComponentFactory(ResourceCache::class.java)
+        }
+    }
 }