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KeyInputModifierKt

public final class KeyInputModifierKt


Summary

Public methods

static final @NonNull Modifier
onKeyEvent(
    @NonNull Modifier receiver,
    @NonNull Function1<@NonNull KeyEvent, @NonNull Boolean> onKeyEvent
)

Adding this modifier to the modifier parameter of a component will allow it to intercept hardware key events when it (or one of its children) is focused.

static final @NonNull Modifier
onPreviewKeyEvent(
    @NonNull Modifier receiver,
    @NonNull Function1<@NonNull KeyEvent, @NonNull Boolean> onPreviewKeyEvent
)

Adding this modifier to the modifier parameter of a component will allow it to intercept hardware key events when it (or one of its children) is focused.

Public methods

onKeyEvent

public static final @NonNull Modifier onKeyEvent(
    @NonNull Modifier receiver,
    @NonNull Function1<@NonNull KeyEvent, @NonNull Boolean> onKeyEvent
)

Adding this modifier to the modifier parameter of a component will allow it to intercept hardware key events when it (or one of its children) is focused.

import androidx.compose.foundation.focusable
import androidx.compose.foundation.layout.Box
import androidx.compose.ui.Modifier
import androidx.compose.ui.input.key.Key
import androidx.compose.ui.input.key.key
import androidx.compose.ui.input.key.onKeyEvent
import androidx.compose.ui.input.key.onPreviewKeyEvent

// When the inner Box is focused, and the user presses a key, the key goes down the hierarchy
// and then back up to the parent. At any stage you can stop the propagation by returning
// true to indicate that you consumed the event.
Box(
    Modifier
        .onPreviewKeyEvent { keyEvent1 -> false }
        .onKeyEvent { keyEvent4 -> false }
) {
    Box(
        Modifier
            .onPreviewKeyEvent { keyEvent2 -> false }
            .onKeyEvent { keyEvent3 -> false }
            .focusable()
    )
}
Parameters
@NonNull Function1<@NonNull KeyEvent, @NonNull Boolean> onKeyEvent

This callback is invoked when the user interacts with the hardware keyboard. While implementing this callback, return true to stop propagation of this event. If you return false, the key event will be sent to this onKeyEvent's parent.

onPreviewKeyEvent

public static final @NonNull Modifier onPreviewKeyEvent(
    @NonNull Modifier receiver,
    @NonNull Function1<@NonNull KeyEvent, @NonNull Boolean> onPreviewKeyEvent
)

Adding this modifier to the modifier parameter of a component will allow it to intercept hardware key events when it (or one of its children) is focused.

import androidx.compose.foundation.focusable
import androidx.compose.foundation.layout.Box
import androidx.compose.ui.Modifier
import androidx.compose.ui.input.key.Key
import androidx.compose.ui.input.key.key
import androidx.compose.ui.input.key.onKeyEvent
import androidx.compose.ui.input.key.onPreviewKeyEvent

// When the inner Box is focused, and the user presses a key, the key goes down the hierarchy
// and then back up to the parent. At any stage you can stop the propagation by returning
// true to indicate that you consumed the event.
Box(
    Modifier
        .onPreviewKeyEvent { keyEvent1 -> false }
        .onKeyEvent { keyEvent4 -> false }
) {
    Box(
        Modifier
            .onPreviewKeyEvent { keyEvent2 -> false }
            .onKeyEvent { keyEvent3 -> false }
            .focusable()
    )
}
Parameters
@NonNull Function1<@NonNull KeyEvent, @NonNull Boolean> onPreviewKeyEvent

This callback is invoked when the user interacts with the hardware keyboard. It gives ancestors of a focused component the chance to intercept a KeyEvent. Return true to stop propagation of this event. If you return false, the key event will be sent to this onPreviewKeyEvent's child. If none of the children consume the event, it will be sent back up to the root KeyInputModifierNode using the onKeyEvent callback.