Fix initially disabling input methods.

[m-sasha]

We currently try to disable input methods in ComposeSceneMediator.init, but this doesn't work because it's too early. The call enableInputMethods is ignored unless the component actually has focus.

This PR moves the call enableInputMethods(false) into a focus-gained listener after focus is requested for the content component.

Note that it doesn't seem to be possible to fix this for SwingSkiaLayerComponent (i.e. when using ComposePanel) because the focus there is not requested explicitly by us (but by the system, when the window becomes active).

Fixes https://youtrack.jetbrains.com/issue/CMP-3839

Note that this only fixes the issue for JBR (JetBrains Runtime). For some reason Corretto keeps showing the input method toolbar even when enableInputMethods is called correctly. It behaves the same in pure Swing. For example, this code correctly disables the toolbar on JBR, but not on Corretto:

    JFrame().apply {
        size = Dimension(800, 600)
        defaultCloseOperation = WindowConstants.EXIT_ON_CLOSE
        isVisible = true
        SwingUtilities.invokeLater {
            focusOwner?.enableInputMethods(false)
        }
    }

Testing

Tested manually on

    singleWindowApplication { }

using Pinyin - Simplified input method on macOS.

This should be tested by QA

Release Notes

Fixes - Desktop

• [macOS] Fix showing the input method toolbar before any text field becomes focused (on JBR only; other runtimes continue to be buggy).