9.0 KiB
Desktop components
What is covered
In this tutorial, we will show you how to use desktop-specific components of Compose for Desktop such as scrollbars and tooltips.
Scrollbars
You can apply scrollbars to scrollable components. The scrollbar and scrollable components share a common state to synchronize with each other. For example, VerticalScrollbar
can be attached to Modifier.verticalScroll
, and LazyColumn
and HorizontalScrollbar
can be attached to Modifier.horizontalScroll
and LazyRow
.
import androidx.compose.foundation.HorizontalScrollbar
import androidx.compose.foundation.VerticalScrollbar
import androidx.compose.foundation.background
import androidx.compose.foundation.horizontalScroll
import androidx.compose.foundation.layout.Box
import androidx.compose.foundation.layout.Column
import androidx.compose.foundation.layout.Spacer
import androidx.compose.foundation.layout.fillMaxHeight
import androidx.compose.foundation.layout.fillMaxSize
import androidx.compose.foundation.layout.fillMaxWidth
import androidx.compose.foundation.layout.height
import androidx.compose.foundation.layout.padding
import androidx.compose.foundation.layout.width
import androidx.compose.foundation.rememberScrollState
import androidx.compose.foundation.rememberScrollbarAdapter
import androidx.compose.foundation.verticalScroll
import androidx.compose.material.Text
import androidx.compose.runtime.Composable
import androidx.compose.ui.Alignment
import androidx.compose.ui.Modifier
import androidx.compose.ui.graphics.Color
import androidx.compose.ui.unit.dp
import androidx.compose.ui.window.WindowState
import androidx.compose.ui.window.singleWindowApplication
fun main() = singleWindowApplication(
title = "Scrollbars",
state = WindowState(width = 250.dp, height = 400.dp)
) {
Box(
modifier = Modifier.fillMaxSize()
.background(color = Color(180, 180, 180))
.padding(10.dp)
) {
val stateVertical = rememberScrollState(0)
val stateHorizontal = rememberScrollState(0)
Box(
modifier = Modifier
.fillMaxSize()
.verticalScroll(stateVertical)
.padding(end = 12.dp, bottom = 12.dp)
.horizontalScroll(stateHorizontal)
) {
Column {
for (item in 0..30) {
TextBox("Item #$item")
if (item < 30) {
Spacer(modifier = Modifier.height(5.dp))
}
}
}
}
VerticalScrollbar(
modifier = Modifier.align(Alignment.CenterEnd)
.fillMaxHeight(),
adapter = rememberScrollbarAdapter(stateVertical)
)
HorizontalScrollbar(
modifier = Modifier.align(Alignment.BottomStart)
.fillMaxWidth()
.padding(end = 12.dp),
adapter = rememberScrollbarAdapter(stateHorizontal)
)
}
}
@Composable
fun TextBox(text: String = "Item") {
Box(
modifier = Modifier.height(32.dp)
.width(400.dp)
.background(color = Color(200, 0, 0, 20))
.padding(start = 10.dp),
contentAlignment = Alignment.CenterStart
) {
Text(text = text)
}
}
Scrollbars can be moved by dragging the bars and using the mouse wheel or the touchpad. Horizontal scrolling with the mouse wheel can be performed by side-clicking the wheel or by holding down Shift
.
![Scrollbars](/github/compose-jb/media/commit/c25f7c67ffe2f4f72512aa6fc48c5013214fb5e1/tutorials/Desktop_Components/scrollbars.gif)
Lazy scrollable components with Scrollbar
You can use scrollbars with lazy scrollable components, for example, LazyColumn
.
import androidx.compose.foundation.VerticalScrollbar
import androidx.compose.foundation.background
import androidx.compose.foundation.layout.Box
import androidx.compose.foundation.layout.Spacer
import androidx.compose.foundation.layout.fillMaxHeight
import androidx.compose.foundation.layout.fillMaxSize
import androidx.compose.foundation.layout.fillMaxWidth
import androidx.compose.foundation.layout.height
import androidx.compose.foundation.layout.padding
import androidx.compose.foundation.lazy.LazyColumn
import androidx.compose.foundation.lazy.rememberLazyListState
import androidx.compose.foundation.rememberScrollbarAdapter
import androidx.compose.material.Text
import androidx.compose.runtime.Composable
import androidx.compose.ui.Alignment
import androidx.compose.ui.Modifier
import androidx.compose.ui.graphics.Color
import androidx.compose.ui.unit.dp
import androidx.compose.ui.window.Window
import androidx.compose.ui.window.application
import androidx.compose.ui.window.rememberWindowState
fun main() = application {
Window(
onCloseRequest = ::exitApplication,
title = "Scrollbars",
state = rememberWindowState(width = 250.dp, height = 400.dp)
) {
LazyScrollable()
}
}
@Composable
fun LazyScrollable() {
Box(
modifier = Modifier.fillMaxSize()
.background(color = Color(180, 180, 180))
.padding(10.dp)
) {
val state = rememberLazyListState()
LazyColumn(Modifier.fillMaxSize().padding(end = 12.dp), state) {
items(1000) { x ->
TextBox("Item #$x")
Spacer(modifier = Modifier.height(5.dp))
}
}
VerticalScrollbar(
modifier = Modifier.align(Alignment.CenterEnd).fillMaxHeight(),
adapter = rememberScrollbarAdapter(
scrollState = state
)
)
}
}
@Composable
fun TextBox(text: String = "Item") {
Box(
modifier = Modifier.height(32.dp)
.fillMaxWidth()
.background(color = Color(0, 0, 0, 20))
.padding(start = 10.dp),
contentAlignment = Alignment.CenterStart
) {
Text(text = text)
}
}
![Lazy component](/github/compose-jb/media/commit/c25f7c67ffe2f4f72512aa6fc48c5013214fb5e1/tutorials/Desktop_Components/lazy_scrollbar.gif)
Tooltips
You can add tooltip to any components using TooltipArea
. TooltipArea
is similar to a Box
, but with the ability to show a tooltip.
The main arguments of the TooltipArea
function:
- tooltip - composable content representing tooltip
- tooltipPlacement - describes how to place tooltip. You can specify an anchor (the mouse cursor or the component), an offset and an alignment
- delay - time delay in milliseconds after which the tooltip will be shown (default is 500 ms)
import androidx.compose.foundation.ExperimentalFoundationApi
import androidx.compose.foundation.TooltipArea
import androidx.compose.foundation.TooltipPlacement
import androidx.compose.foundation.layout.Arrangement
import androidx.compose.foundation.layout.Column
import androidx.compose.foundation.layout.fillMaxSize
import androidx.compose.foundation.layout.padding
import androidx.compose.foundation.shape.RoundedCornerShape
import androidx.compose.material.Button
import androidx.compose.material.Surface
import androidx.compose.material.Text
import androidx.compose.ui.Alignment
import androidx.compose.ui.ExperimentalComposeUiApi
import androidx.compose.ui.Modifier
import androidx.compose.ui.draw.shadow
import androidx.compose.ui.graphics.Color
import androidx.compose.ui.unit.DpOffset
import androidx.compose.ui.unit.dp
import androidx.compose.ui.window.Window
import androidx.compose.ui.window.application
import androidx.compose.ui.window.rememberWindowState
@OptIn(ExperimentalComposeUiApi::class, ExperimentalFoundationApi::class)
fun main() = application {
Window(
onCloseRequest = ::exitApplication,
title = "Tooltip Example",
state = rememberWindowState(width = 300.dp, height = 300.dp)
) {
val buttons = listOf("Button A", "Button B", "Button C", "Button D", "Button E", "Button F")
Column(Modifier.fillMaxSize(), Arrangement.spacedBy(5.dp)) {
buttons.forEachIndexed { index, name ->
// wrap button in BoxWithTooltip
TooltipArea(
tooltip = {
// composable tooltip content
Surface(
modifier = Modifier.shadow(4.dp),
color = Color(255, 255, 210),
shape = RoundedCornerShape(4.dp)
) {
Text(
text = "Tooltip for ${name}",
modifier = Modifier.padding(10.dp)
)
}
},
modifier = Modifier.padding(start = 40.dp),
delayMillis = 600, // in milliseconds
tooltipPlacement = TooltipPlacement.CursorPoint(
alignment = Alignment.BottomEnd,
offset = if (index % 2 == 0) DpOffset(-16.dp, 0.dp) else DpOffset.Zero // tooltip offset
)
) {
Button(onClick = {}) { Text(text = name) }
}
}
}
}
}
![Tooltip](/github/compose-jb/media/commit/c25f7c67ffe2f4f72512aa6fc48c5013214fb5e1/tutorials/Desktop_Components/tooltips.gif)