🐛 Fix Windows COM apartment handling for file dialogs

.gitignore

@@ -17,6 +17,7 @@ captures
 !*.xcworkspace/contents.xcworkspacedata
 **/xcshareddata/WorkspaceSettings.xcsettings
 node_modules/
+.scratch/
 
 #So we don't accidentally commit our private keys
 *.gpg

filekit-dialogs/src/jvmMain/kotlin/io/github/vinceglb/filekit/dialogs/platform/windows/WindowsDialogExecutor.kt

@@ -0,0 +1,60 @@
+package io.github.vinceglb.filekit.dialogs.platform.windows
+
+import com.sun.jna.platform.win32.Ole32
+import kotlinx.coroutines.asCoroutineDispatcher
+import kotlinx.coroutines.withContext
+import java.util.concurrent.Executors
+
+internal interface WindowsComRuntime {
+    fun initializeSta(): Int
+
+    fun uninitialize()
+}
+
+internal object JnaWindowsComRuntime : WindowsComRuntime {
+    override fun initializeSta(): Int = Ole32.INSTANCE
+        .CoInitializeEx(
+            null,
+            Ole32.COINIT_APARTMENTTHREADED or Ole32.COINIT_DISABLE_OLE1DDE,
+        ).toInt()
+
+    override fun uninitialize() {
+        Ole32.INSTANCE.CoUninitialize()
+    }
+}
+
+internal class WindowsDialogExecutor(
+    private val comRuntime: WindowsComRuntime,
+) : AutoCloseable {
+    private val dispatcher = Executors
+        .newSingleThreadExecutor { runnable ->
+            Thread(runnable, THREAD_NAME).apply {
+                isDaemon = true
+            }
+        }.asCoroutineDispatcher()
+
+    suspend fun <T> execute(block: () -> T): T = withContext(dispatcher) {
+        val initializationResult = comRuntime.initializeSta()
+        if (initializationResult != S_OK && initializationResult != S_FALSE) {
+            throw RuntimeException(
+                "CoInitializeEx failed with HRESULT 0x${initializationResult.toUInt().toString(16)}",
+            )
+        }
+
+        try {
+            block()
+        } finally {
+            comRuntime.uninitialize()
+        }
+    }
+
+    override fun close() {
+        dispatcher.close()
+    }
+
+    private companion object {
+        const val THREAD_NAME = "FileKit-Windows-Dialog"
+        const val S_OK = 0
+        const val S_FALSE = 1
+    }
+}

filekit-dialogs/src/jvmMain/kotlin/io/github/vinceglb/filekit/dialogs/platform/windows/WindowsFilePicker.kt

@@ -2,11 +2,9 @@ package io.github.vinceglb.filekit.dialogs.platform.windows
 
 import com.sun.jna.Native
 import com.sun.jna.WString
-import com.sun.jna.platform.win32.COM.COMUtils
 import com.sun.jna.platform.win32.COM.COMUtils.FAILED
 import com.sun.jna.platform.win32.Guid
 import com.sun.jna.platform.win32.Ole32
-import com.sun.jna.platform.win32.Ole32.COINIT_APARTMENTTHREADED
 import com.sun.jna.platform.win32.WTypes
 import com.sun.jna.platform.win32.Win32Exception
 import com.sun.jna.platform.win32.WinDef
@@ -35,12 +33,12 @@ import io.github.vinceglb.filekit.dialogs.platform.windows.jna.ShellItem
 import io.github.vinceglb.filekit.dialogs.platform.windows.jna.ShellItemArray
 import io.github.vinceglb.filekit.dialogs.platform.windows.util.GuidFixed
 import io.github.vinceglb.filekit.path
-import kotlinx.coroutines.Dispatchers
-import kotlinx.coroutines.withContext
 import java.awt.Window
 import java.io.File
 
-internal class WindowsFilePicker : PlatformFilePicker {
+internal class WindowsFilePicker(
+    private val dialogExecutor: WindowsDialogExecutor = WindowsDialogExecutor(JnaWindowsComRuntime),
+) : PlatformFilePicker {
     override suspend fun openFilePicker(
         fileExtensions: Set<String>?,
         directory: PlatformFile?,
@@ -152,12 +150,9 @@ internal class WindowsFilePicker : PlatformFilePicker {
     private suspend fun <FD : FileDialog, T> useFileDialog(
         type: FileDialogType<FD>,
         block: (FD) -> T,
-    ): T = withContext(Dispatchers.IO) {
+    ): T = dialogExecutor.execute {
         var fileDialog: FD? = null
         try {
-            // Initialize COM
-            initCom()
-
             // Create FileOpenDialog
             val pbrFileDialog = PointerByReference()
             fileDialog = Ole32.INSTANCE
@@ -174,7 +169,6 @@ internal class WindowsFilePicker : PlatformFilePicker {
             block(fileDialog)
         } finally {
             fileDialog?.Release()
-            Ole32.INSTANCE.CoUninitialize()
         }
     }
 
@@ -199,19 +193,6 @@ internal class WindowsFilePicker : PlatformFilePicker {
         }
     }
 
-    private fun initCom() {
-        Ole32.INSTANCE
-            .CoInitializeEx(
-                null,
-                COINIT_APARTMENTTHREADED or Ole32.COINIT_DISABLE_OLE1DDE,
-            ).verify("CoInitializeEx failed")
-
-        val isInit = COMUtils.comIsInitialized()
-        if (!isInit) {
-            throw RuntimeException("COM initialization failed")
-        }
-    }
-
     private fun FileDialog.setDefaultPath(defaultPath: PlatformFile) {
         val pbrFolder = PointerByReference()
         val resultFolder = Shell32.INSTANCE.SHCreateItemFromParsingName(

filekit-dialogs/src/jvmTest/kotlin/io/github/vinceglb/filekit/dialogs/platform/windows/WindowsDialogExecutorIntegrationTest.kt

@@ -0,0 +1,75 @@
+package io.github.vinceglb.filekit.dialogs.platform.windows
+
+import com.sun.jna.platform.win32.Ole32
+import com.sun.jna.platform.win32.WTypes
+import com.sun.jna.ptr.PointerByReference
+import io.github.vinceglb.filekit.dialogs.platform.windows.jna.FileOpenDialog
+import io.github.vinceglb.filekit.dialogs.platform.windows.jna.IFileOpenDialog
+import io.github.vinceglb.filekit.utils.Platform
+import io.github.vinceglb.filekit.utils.PlatformUtil
+import kotlinx.coroutines.asCoroutineDispatcher
+import kotlinx.coroutines.runBlocking
+import kotlinx.coroutines.withContext
+import java.util.concurrent.Executors
+import kotlin.test.Test
+import kotlin.test.assertEquals
+import kotlin.test.assertNotEquals
+import kotlin.test.assertNotNull
+
+@Suppress("ktlint:standard:function-naming", "FunctionName")
+class WindowsDialogExecutorIntegrationTest {
+    @Test
+    fun WindowsDialogExecutor_executeFromMtaCaller_createsFileDialogOnOwnedStaThread() = runBlocking {
+        if (PlatformUtil.current != Platform.Windows) return@runBlocking
+
+        val callerDispatcher = Executors.newSingleThreadExecutor().asCoroutineDispatcher()
+        try {
+            withContext(callerDispatcher) {
+                val callerThread = Thread.currentThread()
+                val callerInitialization = Ole32.INSTANCE
+                    .CoInitializeEx(null, Ole32.COINIT_MULTITHREADED)
+                    .toInt()
+                assertEquals(S_OK, callerInitialization)
+
+                try {
+                    val dialogExecutor = WindowsDialogExecutor(JnaWindowsComRuntime)
+                    try {
+                        val dialogThread = dialogExecutor.execute {
+                            val dialogPointer = PointerByReference()
+                            val creationResult = Ole32.INSTANCE
+                                .CoCreateInstance(
+                                    IFileOpenDialog.CLSID_FILEOPENDIALOG,
+                                    null,
+                                    WTypes.CLSCTX_ALL,
+                                    IFileOpenDialog.IID_IFILEOPENDIALOG,
+                                    dialogPointer,
+                                ).toInt()
+
+                            assertEquals(S_OK, creationResult)
+                            val pointer = assertNotNull(dialogPointer.value)
+                            val fileDialog = FileOpenDialog(pointer)
+                            try {
+                                Thread.currentThread()
+                            } finally {
+                                fileDialog.Release()
+                            }
+                        }
+
+                        assertNotEquals(callerThread, dialogThread)
+                        assertEquals("FileKit-Windows-Dialog", dialogThread.name)
+                    } finally {
+                        dialogExecutor.close()
+                    }
+                } finally {
+                    Ole32.INSTANCE.CoUninitialize()
+                }
+            }
+        } finally {
+            callerDispatcher.close()
+        }
+    }
+
+    private companion object {
+        const val S_OK = 0
+    }
+}