misc [jewel] Add Modifier.resizeHostOnContentSizeChange

GitOrigin-RevId: a6dbd6ebf76d1284527e48809e8f8cb731c2869c

Author: dmyud

platform/jewel/ide-laf-bridge/api-dump-experimental.txt

@@ -13,6 +13,8 @@ f:org.jetbrains.jewel.bridge.JewelComposePanelWrapperKt
 - *bs:composeWithoutTheme$default(kotlin.jvm.functions.Function1,kotlin.jvm.functions.Function2,I,java.lang.Object):javax.swing.JComponent
 - *bs:composeWithoutTheme$default(Z,kotlin.jvm.functions.Function1,kotlin.jvm.functions.Function2,I,java.lang.Object):javax.swing.JComponent
 - *sf:getLocalComponent():androidx.compose.runtime.ProvidableCompositionLocal
+f:org.jetbrains.jewel.bridge.component.HostPopupResizeKt
+- *sf:resizeHostOnContentSizeChange(androidx.compose.ui.Modifier,kotlin.jvm.functions.Function0,kotlin.jvm.functions.Function1,androidx.compose.runtime.Composer,I,I):androidx.compose.ui.Modifier
 f:org.jetbrains.jewel.bridge.theme.IntUiBridgeTextKt
 - *sf:retrieveDefaultTextStyle(F):androidx.compose.ui.text.TextStyle
 f:org.jetbrains.jewel.bridge.theme.SwingBridgeThemeKt

platform/jewel/ide-laf-bridge/api-dump.txt

@@ -96,6 +96,7 @@ f:org.jetbrains.jewel.bridge.code.highlighting.CodeHighlighterFactory
 - f:createHighlighter():org.jetbrains.jewel.foundation.code.highlighting.CodeHighlighter
 f:org.jetbrains.jewel.bridge.code.highlighting.CodeHighlighterFactory$Companion
 - f:getInstance(com.intellij.openapi.project.Project):org.jetbrains.jewel.bridge.code.highlighting.CodeHighlighterFactory
+f:org.jetbrains.jewel.bridge.component.HostPopupResizeKt
 f:org.jetbrains.jewel.bridge.icon.IntelliJIconKeyKt
 - sf:fromPlatformIcon(org.jetbrains.jewel.ui.icon.IntelliJIconKey$Companion,javax.swing.Icon,java.lang.Class):org.jetbrains.jewel.ui.icon.IconKey
 - bs:fromPlatformIcon$default(org.jetbrains.jewel.ui.icon.IntelliJIconKey$Companion,javax.swing.Icon,java.lang.Class,I,java.lang.Object):org.jetbrains.jewel.ui.icon.IconKey

platform/jewel/ide-laf-bridge/src/main/kotlin/org/jetbrains/jewel/bridge/component/HostPopupResize.kt

@@ -0,0 +1,69 @@
+// Copyright 2000-2026 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license.
+package org.jetbrains.jewel.bridge.component
+
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.remember
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.layout.layout
+import androidx.compose.ui.unit.Constraints
+import com.intellij.openapi.ui.popup.JBPopup
+import com.intellij.ui.scale.JBUIScale
+import java.awt.Dimension
+import javax.swing.SwingUtilities
+import org.jetbrains.annotations.ApiStatus
+import org.jetbrains.jewel.foundation.ExperimentalJewelApi
+import org.jetbrains.jewel.foundation.LocalComponent
+
+/**
+ * Keeps the hosting `JewelComposePanel` and its [JBPopup] sized to fit the Compose content. To keep a dimension fixed,
+ * constrain it in the modifier chain (e.g. `.width(450.dp)`); unconstrained dimensions grow with the content.
+ *
+ * Example:
+ * ```kotlin
+ * Column(
+ *     modifier = Modifier
+ *         .resizeHostOnContentSizeChange(popup = { popupRef })
+ *         .width(450.dp)
+ * ) { ... }
+ * ```
+ *
+ * @param popup the popup hosting the panel; its `size` is kept in sync with the content. Invoked lazily so the modifier
+ *   can be created before the popup reference is assigned.
+ * @param onResize runs on the EDT after the resize is applied, e.g. for popup repositioning.
+ */
+@ApiStatus.Experimental
+@ExperimentalJewelApi
+@Composable
+public fun Modifier.resizeHostOnContentSizeChange(popup: () -> JBPopup?, onResize: (Dimension) -> Unit = {}): Modifier {
+    val host = LocalComponent.current
+    val lastDp = remember { intArrayOf(-1, -1) }
+    return this.layout { measurable, constraints ->
+        val relaxed =
+            constraints.copy(
+                minWidth = 0,
+                maxWidth = Constraints.Infinity,
+                minHeight = 0,
+                maxHeight = Constraints.Infinity,
+            )
+        val placeable = measurable.measure(relaxed)
+        val scale = JBUIScale.sysScale(host)
+        val widthDp = (placeable.width / scale).toInt()
+        val heightDp = (placeable.height / scale).toInt()
+        if (widthDp != lastDp[0] || heightDp != lastDp[1]) {
+            lastDp[0] = widthDp
+            lastDp[1] = heightDp
+            val newSize = Dimension(widthDp, heightDp)
+            SwingUtilities.invokeLater {
+                host.preferredSize = newSize
+                popup()?.size = newSize
+                onResize(newSize)
+            }
+        }
+        layout(
+            placeable.width.coerceIn(constraints.minWidth, constraints.maxWidth),
+            placeable.height.coerceIn(constraints.minHeight, constraints.maxHeight),
+        ) {
+            placeable.placeRelative(0, 0)
+        }
+    }
+}