TextFieldGestureModifiers.kt

/*
 * Copyright 2021 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 androidx.compose.foundation.focusable
import androidx.compose.foundation.gestures.awaitFirstDown
import androidx.compose.foundation.gestures.drag
import androidx.compose.foundation.gestures.forEachGesture
import androidx.compose.foundation.interaction.MutableInteractionSource
import androidx.compose.ui.Modifier
import androidx.compose.ui.focus.FocusRequester
import androidx.compose.ui.focus.FocusState
import androidx.compose.ui.focus.focusRequester
import androidx.compose.ui.focus.onFocusChanged
import androidx.compose.ui.input.pointer.PointerInputScope
import androidx.compose.ui.input.pointer.consumeAllChanges
import androidx.compose.ui.input.pointer.consumeDownChange
import androidx.compose.ui.input.pointer.pointerInput
import androidx.compose.ui.input.pointer.positionChange

// Touch selection
internal fun Modifier.longPressDragGestureFilter(
    observer: TextDragObserver,
    enabled: Boolean
) = if (enabled) {
    this.pointerInput(observer) { detectDragGesturesAfterLongPressWithObserver(observer) }
} else {
    this
}

// Focus modifiers
internal fun Modifier.textFieldFocusModifier(
    enabled: Boolean,
    focusRequester: FocusRequester,
    interactionSource: MutableInteractionSource?,
    onFocusChanged: (FocusState) -> Unit
) = this
    .focusRequester(focusRequester)
    .onFocusChanged(onFocusChanged)
    .focusable(interactionSource = interactionSource, enabled = enabled)

// Mouse
internal fun Modifier.mouseDragGestureFilter(dragObserver: TextDragObserver, enabled: Boolean) =
    if (enabled) {
        this.pointerInput(dragObserver) {
            forEachGesture {
                awaitPointerEventScope {
                    val down = awaitFirstDown(requireUnconsumed = false)
                    down.consumeDownChange()
                    dragObserver.onStart(down.position)
                    drag(down.id) { event ->
                        dragObserver.onDrag(event.positionChange())
                        event.consumeAllChanges()
                    }
                    // specifically don't call observer.onStop/onCancel for mouse case
                }
            }
        }
    } else {
        this
    }

internal fun Modifier.mouseDragGestureDetector(
    detector: suspend PointerInputScope.() -> Unit,
    enabled: Boolean
) = if (enabled) Modifier.pointerInput(Unit, detector) else this