TextFieldFocusModifier.android.kt
/*
* Copyright 2022 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package androidx.compose.foundation.text
import android.view.InputDevice.SOURCE_DPAD
import android.view.KeyEvent.KEYCODE_DPAD_CENTER
import android.view.KeyEvent.KEYCODE_DPAD_DOWN
import android.view.KeyEvent.KEYCODE_DPAD_LEFT
import android.view.KeyEvent.KEYCODE_DPAD_RIGHT
import android.view.KeyEvent.KEYCODE_DPAD_UP
import androidx.compose.ui.Modifier
import androidx.compose.ui.focus.FocusDirection.Companion.Down
import androidx.compose.ui.focus.FocusDirection.Companion.Left
import androidx.compose.ui.focus.FocusDirection.Companion.Right
import androidx.compose.ui.focus.FocusDirection.Companion.Up
import androidx.compose.ui.focus.FocusManager
import androidx.compose.ui.input.key.KeyEvent
import androidx.compose.ui.input.key.KeyEventType.Companion.KeyDown
import androidx.compose.ui.input.key.key
import androidx.compose.ui.input.key.nativeKeyCode
import androidx.compose.ui.input.key.onPreviewKeyEvent
import androidx.compose.ui.input.key.type
/**
* TextField consumes the D-pad keys, due to which we can't move focus once a TextField is focused.
* To prevent this, this modifier can be used to intercept D-pad key events before they are sent to
* the TextField. It intercepts and handles the directional (Up, Down, Left, Right & Center) D-pad
* key presses, to move the focus between TextField and other focusable items on the screen.
*
* NOTE: Key events from non-dpad sources or virtual keyboards are ignored.
*/
internal actual fun Modifier.interceptDPadAndMoveFocus(
state: TextFieldState,
focusManager: FocusManager
): Modifier {
return this
.onPreviewKeyEvent { keyEvent ->
val device = keyEvent.nativeKeyEvent.device
when {
device == null -> false
// Ignore key events from non-dpad sources
!device.supportsSource(SOURCE_DPAD) -> false
// Ignore key events from virtual keyboards
device.isVirtual -> false
// Ignore key release events
keyEvent.type != KeyDown -> false
keyEvent.isKeyCode(KEYCODE_DPAD_UP) -> focusManager.moveFocus(Up)
keyEvent.isKeyCode(KEYCODE_DPAD_DOWN) -> focusManager.moveFocus(Down)
keyEvent.isKeyCode(KEYCODE_DPAD_LEFT) -> focusManager.moveFocus(Left)
keyEvent.isKeyCode(KEYCODE_DPAD_RIGHT) -> focusManager.moveFocus(Right)
keyEvent.isKeyCode(KEYCODE_DPAD_CENTER) -> {
// Enable keyboard on center key press
state.inputSession?.showSoftwareKeyboard()
true
}
else -> false
}
}
}
private fun KeyEvent.isKeyCode(keyCode: Int): Boolean =
this.key.nativeKeyCode == keyCode