Fix Input methods on JBR, disable input methods when we lose focus

1. Fixes JetBrains/compose-multiplatform#2628
2. Doesn't show input methods popup if there is no focused TextField (only on Windows for now, on macOs, Swing seems has a bug: JetBrains/compose-multiplatform#3839)

## Testing
Tested manually on Windows/macOs/Linux, OpenJDK/JBR, Accessibility enabled/disabled

Author: igordmn

compose/ui/ui/src/desktopMain/kotlin/androidx/compose/ui/awt/ComposeBridge.desktop.kt

@@ -54,6 +54,11 @@ import org.jetbrains.skiko.*
  * Provides a base implementation for integrating a Compose scene with AWT/Swing.
  * It allows setting Compose content by [setContent], this content should be drawn on [component].
  *
+ * This bridge contain 2 components that should be added to the view hirarachy:
+ * [component] the main visible Swing component, on which Compose will be shown
+ * [invisibleComponent] service component used to bypass Swing issues:
+ * - for forcing refocus on input methods change
+ *
  * Inheritors should call [attachComposeToComponent], so events that came to [component] will be transferred to [ComposeScene]
  */
 internal abstract class ComposeBridge(
@@ -66,7 +71,10 @@ internal abstract class ComposeBridge(
         mainOwnerProvider = { scene.mainOwner }
     )
 
+    private val _invisibleComponent = InvisibleComponent()
+
     abstract val component: JComponent
+    val invisibleComponent: Component get() = _invisibleComponent
 
     abstract val renderApi: GraphicsApi
 
@@ -86,16 +94,30 @@ internal abstract class ComposeBridge(
 
     private var window: Window? = null
 
+    private fun refocus() {
+        if (component.isFocusOwner) {
+            _invisibleComponent.requestFocusTemporary()
+            component.requestFocus()
+        }
+    }
+
     private val platformComponent: PlatformComponent = object : PlatformComponent {
         override fun enableInput(inputMethodRequests: InputMethodRequests) {
             currentInputMethodRequests = inputMethodRequests
             component.enableInputMethods(true)
-            val focusGainedEvent = FocusEvent(focusComponentDelegate, FocusEvent.FOCUS_GAINED)
-            component.inputContext.dispatchEvent(focusGainedEvent)
+            // Without resetting the focus, Swing won't update the status (doesn't show/hide popup)
+            // enableInputMethods is design to used per-Swing component level at init stage,
+            // not dynamically
+            refocus()
         }
 
         override fun disableInput() {
             currentInputMethodRequests = null
+            component.enableInputMethods(false)
+            // Without resetting the focus, Swing won't update the status (doesn't show/hide popup)
+            // enableInputMethods is design to used per-Swing component level at init stage,
+            // not dynamically
+            refocus()
         }
 
         override val locationOnScreen: Point
@@ -181,6 +203,7 @@ internal abstract class ComposeBridge(
 
     @OptIn(ExperimentalComposeUiApi::class)
     protected fun attachComposeToComponent() {
+        component.enableInputMethods(false)
         component.addInputMethodListener(object : InputMethodListener {
             override fun caretPositionChanged(event: InputMethodEvent?) {
                 if (isDisposed) return
@@ -393,6 +416,12 @@ internal abstract class ComposeBridge(
             override val touchSlop: Float get() = with(platformComponent.density) { 18.dp.toPx() }
         }
     }
+
+    private class InvisibleComponent : Component() {
+        fun requestFocusTemporary(): Boolean {
+            return super.requestFocus(true)
+        }
+    }
 }
 
 private fun ComposeScene.onMouseEvent(

compose/ui/ui/src/desktopMain/kotlin/androidx/compose/ui/awt/ComposePanel.desktop.kt

@@ -113,6 +113,7 @@ class ComposePanel @ExperimentalComposeUiApi constructor(
         if (bridge != null) {
             bridge!!.dispose()
             super.remove(bridge!!.component)
+            super.remove(bridge!!.invisibleComponent)
             bridge = null
         }
     }
@@ -187,6 +188,7 @@ class ComposePanel @ExperimentalComposeUiApi constructor(
         if (bridge == null) {
             bridge = createComposeBridge()
             initContent()
+            super.add(bridge!!.invisibleComponent, Integer.valueOf(1))
             super.add(bridge!!.component, Integer.valueOf(1))
         }
     }

compose/ui/ui/src/desktopMain/kotlin/androidx/compose/ui/awt/ComposeWindowDelegate.desktop.kt

@@ -93,11 +93,13 @@ internal class ComposeWindowDelegate(
 
         init {
             layout = null
+            super.add(bridge.invisibleComponent, 1)
             super.add(bridge.component, 1)
         }
 
         fun dispose() {
             super.remove(bridge.component)
+            super.remove(bridge.invisibleComponent)
         }
     }