ComposePanel. Focus moves to child after focusing/unfocusing the main window

[igordmn]

Compose 1.6.20-dev1663

1. Run

   
   import androidx.compose.foundation.border
   import androidx.compose.foundation.layout.Box
   import androidx.compose.foundation.layout.padding
   import androidx.compose.material.TextField
   import androidx.compose.runtime.getValue
   import androidx.compose.runtime.mutableStateOf
   import androidx.compose.runtime.remember
   import androidx.compose.runtime.setValue
   import androidx.compose.ui.Modifier
   import androidx.compose.ui.awt.ComposePanel
   import androidx.compose.ui.focus.focusTarget
   import androidx.compose.ui.focus.onFocusChanged
   import androidx.compose.ui.graphics.Color
   import androidx.compose.ui.unit.dp
   import java.awt.Dimension
   import javax.swing.JFrame
   import javax.swing.SwingUtilities

fun main() = SwingUtilities.invokeLater { val panel = ComposePanel() panel.setContent { var isFocused by remember { mutableStateOf(false) } Box(Modifier .onFocusChanged { isFocused = it.isFocused } .focusTarget() .border(1.dp, if (isFocused) Color.Red else Color.Transparent) .padding(8.dp) ) { TextField("", {}, singleLine = true) } }

val frame = JFrame()
frame.contentPane.add(panel)
frame.size = Dimension(500, 500)
frame.isVisible = true

}

2. Focus the box
![image](https://github.com/JetBrains/compose-multiplatform/assets/5963351/8c1b51a7-ed4c-497f-8025-967a94328853)
3. Deactivate/Activate the window
4. See that focus moved to the textfield
![image](https://github.com/JetBrains/compose-multiplatform/assets/5963351/47d75b1c-305a-432c-9f9b-9a2f4c55ba36)

This happens, because Swing calls `focusGained` with `FocusEvent.Cause.ACTIVATION` when activating the main window, and Enter moves the focus to the child

Regression after https://github.com/JetBrains/compose-multiplatform-core/pull/1352

[igordmn]

Will be fixed in integration branch

[m-sasha]

I guess the fix will be to focus the first focusable element instead of "Enter"?

[igordmn]

The fix will be to skip requesting focus if it is already in focus. It is the only way to behave when we activate/deactivate window.

[m-sasha]

I couldn't immediately find a way to check if something is already focused. When "nothing" is focused, the root node has the focus.

[okushnikov]

Please check the following ticket on YouTrack for follow-ups to this issue. GitHub issues will be closed in the coming weeks.