| /* |
| * 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.material.studies.rally |
| |
| import androidx.animation.LinearEasing |
| import androidx.animation.transitionDefinition |
| import androidx.animation.tween |
| import androidx.compose.Composable |
| import androidx.compose.remember |
| import androidx.ui.animation.ColorPropKey |
| import androidx.ui.animation.transition |
| import androidx.ui.core.Modifier |
| import androidx.compose.foundation.Text |
| import androidx.compose.foundation.selection.selectable |
| import androidx.ui.graphics.Color |
| import androidx.ui.graphics.vector.VectorAsset |
| import androidx.ui.layout.Row |
| import androidx.ui.layout.Spacer |
| import androidx.ui.layout.fillMaxWidth |
| import androidx.ui.layout.padding |
| import androidx.ui.layout.preferredHeight |
| import androidx.ui.layout.preferredWidth |
| import androidx.ui.material.MaterialTheme |
| import androidx.ui.material.Surface |
| import androidx.ui.material.ripple.RippleIndication |
| import androidx.ui.unit.dp |
| import java.util.Locale |
| |
| @Composable |
| fun RallyTopAppBar( |
| allScreens: List<RallyScreenState>, |
| onTabSelected: (RallyScreenState) -> Unit, |
| currentScreen: RallyScreenState |
| ) { |
| Surface(Modifier.preferredHeight(TabHeight).fillMaxWidth()) { |
| Row { |
| allScreens.forEachIndexed { index, screen -> |
| RallyTab( |
| text = screen.name.toUpperCase(Locale.getDefault()), |
| icon = screen.icon, |
| onSelected = { onTabSelected(screen) }, |
| selected = currentScreen.ordinal == index |
| ) |
| } |
| } |
| } |
| } |
| |
| @Composable |
| private fun RallyTab( |
| text: String, |
| icon: VectorAsset, |
| onSelected: () -> Unit, |
| selected: Boolean |
| ) { |
| TabTransition(selected = selected) { tabTintColor -> |
| Row( |
| modifier = Modifier |
| .padding(16.dp) |
| .preferredHeight(TabHeight) |
| .selectable( |
| selected = selected, |
| onClick = onSelected, |
| indication = RippleIndication(bounded = false) |
| ) |
| ) { |
| Icon(vectorImage = icon, tintColor = tabTintColor) |
| if (selected) { |
| Spacer(Modifier.preferredWidth(12.dp)) |
| Text(text, color = tabTintColor) |
| } |
| } |
| } |
| } |
| |
| @Composable |
| private fun TabTransition( |
| selected: Boolean, |
| children: @Composable (color: Color) -> Unit |
| ) { |
| val color = MaterialTheme.colors.onSurface |
| val transitionDefinition = remember { |
| transitionDefinition { |
| state(true) { |
| this[TabTintColorKey] = color |
| } |
| |
| state(false) { |
| this[TabTintColorKey] = color.copy(alpha = InactiveTabOpacity) |
| } |
| |
| transition(fromState = false, toState = true) { |
| TabTintColorKey using tween( |
| durationMillis = TabFadeInAnimationDuration, |
| delayMillis = TabFadeInAnimationDelay, |
| easing = LinearEasing |
| ) |
| } |
| |
| transition(fromState = true, toState = false) { |
| TabTintColorKey using tween( |
| durationMillis = TabFadeOutAnimationDuration, |
| delayMillis = TabFadeInAnimationDelay, |
| easing = LinearEasing |
| ) |
| } |
| } |
| } |
| val state = transition(transitionDefinition, selected) |
| children(state[TabTintColorKey]) |
| } |
| |
| private val TabTintColorKey = ColorPropKey() |
| private val TabHeight = 56.dp |
| private const val InactiveTabOpacity = 0.60f |
| |
| private const val TabFadeInAnimationDuration = 150 |
| private const val TabFadeInAnimationDelay = 100 |
| private const val TabFadeOutAnimationDuration = 100 |