| /* |
| * Copyright 2019 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.Alignment |
| import androidx.ui.core.DensityAmbient |
| import androidx.ui.core.Modifier |
| import androidx.ui.core.gesture.longPressDragGestureFilter |
| import androidx.ui.core.gesture.LongPressDragObserver |
| import androidx.compose.foundation.Box |
| import androidx.compose.foundation.Text |
| import androidx.compose.foundation.layout.Column |
| import androidx.compose.foundation.layout.fillMaxSize |
| import androidx.compose.foundation.layout.offset |
| import androidx.compose.foundation.layout.preferredSize |
| import androidx.compose.foundation.layout.wrapContentSize |
| import androidx.compose.ui.geometry.Offset |
| import androidx.ui.unit.dp |
| |
| /** |
| * Simple [longPressDragGestureFilter] demo. |
| */ |
| @Composable |
| fun LongPressDragGestureFilterDemo() { |
| |
| val offset = state { Offset.Zero } |
| val color = state { Grey } |
| |
| val longPressDragObserver = |
| object : LongPressDragObserver { |
| |
| override fun onLongPress(pxPosition: Offset) { |
| color.value = Red |
| } |
| |
| override fun onDragStart() { |
| super.onDragStart() |
| color.value = Blue |
| } |
| |
| override fun onDrag(dragDistance: Offset): Offset { |
| offset.value += dragDistance |
| return dragDistance |
| } |
| |
| override fun onStop(velocity: Offset) { |
| color.value = Grey |
| } |
| } |
| |
| val (offsetX, offsetY) = |
| with(DensityAmbient.current) { offset.value.x.toDp() to offset.value.y.toDp() } |
| |
| Column { |
| Text("Demonstrates dragging that only begins once a long press has occurred!") |
| Text("Dragging only occurs once you have long pressed on the box.") |
| Box( |
| Modifier.offset(offsetX, offsetY) |
| .fillMaxSize() |
| .wrapContentSize(Alignment.Center) |
| .preferredSize(192.dp) |
| .longPressDragGestureFilter(longPressDragObserver), |
| backgroundColor = color.value |
| ) |
| } |
| } |