Working Example

RallyActivity.kt

/*
 * 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.material.studies.rally

import android.app.Activity
import android.os.Bundle
import androidx.compose.Composable
import androidx.compose.composer
import androidx.compose.Model
import androidx.compose.memo
import androidx.compose.state
import androidx.compose.unaryPlus
import androidx.ui.core.Text
import androidx.ui.core.dp
import androidx.ui.core.setContent
import androidx.ui.foundation.VerticalScroller
import androidx.ui.input.EditorModel
import androidx.ui.layout.Column
import androidx.ui.layout.FlexSize
import androidx.ui.layout.HeightSpacer
import androidx.ui.layout.MainAxisAlignment
import androidx.ui.layout.Padding
import androidx.ui.layout.Row
import androidx.ui.material.Button
import androidx.ui.material.Checkbox
import androidx.ui.material.studies.Scaffold
import androidx.ui.material.themeTextStyle

/**
 * This Activity recreates the Rally Material Study from
 * https://material.io/design/material-studies/rally.html
 */
class RallyActivity : Activity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContent {
            RallyApp()
        }
    }

    @Composable
    fun RallyApp() {
        RallyTheme {
            Scaffold(appBar = { RallyAppBar() }) {
                TaskList()
            }
        }
    }

    @Composable
    fun RallyAppBar() {
        // TODO: Transform to tabs
        Row {
            // Icon()
            Text(text = "Overview", style = +themeTextStyle{ h4 })
            // TODO: Other items
        }
    }
}

@Model
class TodoList(var counter: Int = 0, var todoList: MutableList<TaskModel>)

@Composable
fun TaskList() {
    val count = +memo { TodoList(0, mutableListOf()) }
    VerticalScroller {
        Column(crossAxisSize = FlexSize.Max) {
            Button(text = "Add", onClick = {
                count.counter++
                count.todoList.add(TaskModel(false, "1"))
            })

            count.todoList.sortedBy {
                it.isDone
            }.forEach {
                Task(it)
            }
        }
    }
}

@Composable
fun Task(taskModel: TaskModel) {
    Row(mainAxisAlignment = MainAxisAlignment.SpaceEvenly, mainAxisSize = FlexSize.Max) {
        Checkbox(taskModel.isDone, onCheckedChange = { taskModel.isDone = it })
        Text(text = taskModel.description)
    }
}

@Model
data class TaskModel(var isDone: Boolean, val description: String)