| /* |
| * Copyright 2020 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.ui.core.demos.gestures |
| |
| import androidx.compose.Composable |
| import androidx.compose.state |
| import androidx.ui.core.Modifier |
| import androidx.ui.core.gesture.longPressGestureFilter |
| import androidx.compose.foundation.Border |
| import androidx.compose.foundation.Box |
| import androidx.compose.foundation.ContentGravity |
| import androidx.compose.foundation.Text |
| import androidx.compose.ui.graphics.compositeOver |
| import androidx.compose.foundation.layout.Column |
| import androidx.compose.foundation.layout.fillMaxSize |
| import androidx.compose.foundation.layout.padding |
| import androidx.compose.ui.geometry.Offset |
| import androidx.ui.unit.dp |
| |
| /** |
| * Demonstration of how various press/tap gesture interact together in a nested fashion. |
| */ |
| @Composable |
| fun NestedLongPressDemo() { |
| Column { |
| Text( |
| "Demonstrates interaction between nested longPressGestureFitlers in an " + |
| "edge case that is nevertheless supported (normally regions will be separated" + |
| " by a pressIndicatorGestureFilter, but here they are not)." |
| ) |
| Text( |
| "This just demonstrates the interaction between directly nested " + |
| "longPressGestureFilters." |
| ) |
| LongPressableContainer(Modifier.fillMaxSize()) { |
| LongPressableContainer(Modifier.padding(48.dp).fillMaxSize()) { |
| LongPressableContainer(Modifier.padding(48.dp).fillMaxSize()) {} |
| } |
| } |
| } |
| } |
| |
| @Composable |
| private fun LongPressableContainer( |
| modifier: Modifier = Modifier, |
| children: @Composable () -> Unit |
| ) { |
| val defaultColor = DefaultBackgroundColor |
| val pressedColor = PressedColor |
| |
| val currentColor = state { defaultColor } |
| val pressed = state { false } |
| |
| val onLongPress: (Offset) -> Unit = { |
| currentColor.value = currentColor.value.next() |
| } |
| |
| val color = if (pressed.value) { |
| pressedColor.compositeOver(currentColor.value) |
| } else { |
| currentColor.value |
| } |
| |
| Box( |
| modifier.longPressGestureFilter(onLongPress), |
| backgroundColor = color, |
| gravity = ContentGravity.Center, |
| border = Border(2.dp, BorderColor), |
| children = children |
| ) |
| } |