This is my code:
#Composable
fun GetPathList(context: Activity, path: String) {
val resultJson = remember { mutableStateListOf<RequestData.PathData>() }
var loadingPicController by remember { mutableStateOf(true) }
if (loadingPicController) {
Text("loading")
}
thread {
resultJson.addAll(RequestData().getPath(path))
loadingPicController = false // Loading End
}
LazyColumn(verticalArrangement = Arrangement.spacedBy(4.dp)) {
items(resultJson) { item ->
Surface(modifier = Modifier.clickable {
val intent = Intent(context, PathDetailsActivity::class.java)
intent.putExtra("folderName", item.name)
intent.putExtra("path", "$path/${item.name}")
context.startActivity(intent)
}) {
Row(
modifier = Modifier
.padding(start = 24.dp, top = 8.dp, bottom = 8.dp)
.fillMaxWidth(),
verticalAlignment = Alignment.CenterVertically
) {
Icon(painter = Icons.Document, contentDescription = "Files", modifier = Modifier.size(28.dp))
Column(modifier = Modifier.padding(start = 16.dp)) {
Text(item.name, fontWeight = FontWeight.Medium, fontSize = 14.sp)
Text(item.type, fontWeight = FontWeight.Light, fontSize = 12.sp)
}
}
}
}
}
}
The right result is here
However, With the code , After the loading finshing, the list was reloaded twice.
it should only load once.
But now after the loading animation is over it is loaded twice and the content is repeated twice
This is happening because every time your composable function is executed, a new thread is started and it's adding all the items again.
Basically the current flow is:
GetPathList is executed. The loadingPicController is true and a new thread is executed.
When the thread finishes, the loadingPicController flag is set to false, causing a recomposition (GetPathList is called again).
GetPathList is called again. The thread is triggered again, adding the items again. Since loadingPicController is false already, the recomposition didn't happen.
Items come with a key parameter that you can use to prevent any duplicates and also to ensure that if there is an update the right item is updated. in any case if this fails you can use list.distinct() to help clear out any duplicates
Related
I'm new to jetpack compose and I am just looking for a way to add and delete items from a lazyVerticalGrid using jetpack compose from a pop-up menu. Nothing complicated, just simple code to make me easily understand what I have to do
This is pretty easy as other LazyLists. You need to have a list that you can trigger recomposition after delete, add or update and use unique keys to not recompose your entire list and limit recomposition to a range of items.
val list = remember { mutableStateListOf<Snack>() }
You can remove or add inside you menu by changing this list
Adding, removing items or replacing any items with new one, to update you need to pass a new instance of object, will trigger recomposition
#Composable
private fun GridExample() {
val scrollState = rememberLazyListState()
val coroutineScope = rememberCoroutineScope()
val list = remember { mutableStateListOf<Snack>() }
Column {
LazyVerticalGrid(
contentPadding = PaddingValues(12.dp),
modifier = Modifier
.weight(1f)
.background(backgroundColor),
columns = GridCells.Fixed(3),
content = {
items(items = list,
key = { snack: Snack ->
snack.name
}) { snack: Snack ->
GridSnackCard(snack = snack)
}
}
)
Row(
modifier = Modifier.padding( 8.dp),
horizontalArrangement = Arrangement.SpaceEvenly
) {
Button(
modifier = Modifier.weight(1f),
onClick = {
if (list.size < snacks.size) {
list.add(snacks[list.size])
}
},
shape = RoundedCornerShape(8.dp)
) {
Text(text = "Add")
}
Spacer(modifier = Modifier.width(10.dp))
Button(
modifier = Modifier.weight(1f),
onClick = {
if (list.size > 0) {
list.removeLast()
}
},
shape = RoundedCornerShape(8.dp)
) {
Text(text = "Remove")
}
}
}
}
this started as a new compose project
with the following code the intent is to change the text to the picked time. The code is commented where the behavior occurs
class MainActivity : ComponentActivity() {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContent {
MyApplicationTestTheme {
// A surface container using the 'background' color from the theme
Surface(
modifier = Modifier.fillMaxSize(),
color = MaterialTheme.colors.background
) {
TimeCardButton(id = 1, symbol ="In", enabled=true,modifier = Modifier) { entry ->
Log.d("click", "$entry result")
}
}
}
}
}
}
data class TimeCardEntry(val id: Int = -1, var entry: String = "")
#Composable
fun TimeCardButton(
id: Int,
symbol: String,
enabled: Boolean = false,
modifier: Modifier,
onValueChange: (TimeCardEntry) -> Unit = {},
) {
// Value for storing time as a string
val timeState = remember {
mutableStateOf(TimeCardEntry(id, symbol))
}
val validState = remember {
timeState.value.entry.trim().isNotEmpty()
}
val mTime = remember { mutableStateOf(symbol) }
if (enabled) {
// Fetching local context
val mContext = LocalContext.current
// Declaring and initializing a calendar
val mCalendar = Calendar.getInstance()
val mHour = mCalendar[Calendar.HOUR_OF_DAY]
val mMinute = mCalendar[Calendar.MINUTE]
// Creating a TimePicker dialog
val mTimePickerDialog = TimePickerDialog(
mContext,
{ _, mHour: Int, mMinute: Int ->
timeState.value.entry = "$mHour:$mMinute"
mTime.value = "$mHour:$mMinute"
onValueChange(timeState.value)
}, mHour, mMinute, false
)
Box(
contentAlignment = Alignment.Center,
modifier = Modifier
.clip(CircleShape)
.then(modifier)
) {
TextButton(onClick = { mTimePickerDialog.show() }.also {
Log.d("click", "id $id clicked!") }) {
Column() {
// if I use just this it works [in changes to the time picked]
//Text(text = mTime.value)
// if i use both of these BOTH are set when the date picker is invoked
// if I just use the second one alone, the text never changes
Text(text = timeState.value.entry)
}
}
}
} else {
Box(
contentAlignment = Alignment.Center,
modifier = Modifier
.clip(CircleShape)
.then(modifier)
) {
Text(text = symbol, color =
MaterialTheme.colors.onBackground)
}
}
}
#Preview(showBackground = true)
#Composable
fun DefaultPreview() {
MyApplicationTestTheme {
}
}
First of all how to fix it:
Your problem basically is this. The easiest way to fix it would be to reassign the whole value of TimeState, not just entry by calling
timeState.value = timeState.value.copy(entry = "$mHour:$mMinute")
The reason it doesn't work with only the second one is that the change of a property doesn't trigger recomposition, even if the variable containing it is a mutableState. To fix (as outlined in the answers to the question linked above) this you either have to reassign the whole variable or make the parameter you want to observe observable (for example changing the String to State<String>)
PS: if you use by with mutableStateOf (i.e. val timeState = remember { mutableStateOf(TimeCardEntry(id, symbol)) }) you don't have to use .value every time. I find that a lot cleaner and more readable
I have dialog in compose:
#Composable
fun testgtt() {
val saveDialogState = remember { mutableStateOf(false) }
Button(onClick = { saveDialogState.value = true }, modifier = Modifier.testTag(PLACE_TAG)) {
Text(text = "helllow")
}
Dialog(onDismissRequest = { saveDialogState.value = false }) {
Text(text = "helllow",modifier = Modifier.testTag(BUTTON_TAG))
}
}
and want to test it:
#Test
fun das(){
composeTestRule.setContent {
TerTheme {
testgtt()
}
}
composeTestRule.onRoot(useUnmergedTree = true).printToLog("currentLabelExists")
composeTestRule.onNodeWithTag(PLACE_TAG).performClick()
composeTestRule.onNodeWithTag(BUTTON_TAG).assertIsDisplayed()
}
but I get this error:
java.lang.AssertionError: Failed: assertExists.
Reason: Expected exactly '1' node but found '2' nodes that satisfy: (isRoot)
Nodes found:
1) Node #1 at (l=0.0, t=0.0, r=206.0, b=126.0)px
Has 1 child
2) Node #78 at (l=0.0, t=0.0, r=116.0, b=49.0)px
Has 1 child
Inspite of the fact that I see the Dialog itself.
The reason for this error is the line: composeTestRule.onRoot(useUnmergedTree = true).printToLog("currentLabelExists")
onRoot expects a single node, but i suspect both the containing view and the dialog each return their own root (Speculation)
A possible workaround is to instead print both root trees using something like
composeTestRule.onAllNodes(isRoot()).printToLog("currentLabelExists")
use navigation component:
#Composable
fun de(){
val navController = rememberNavController()
Scaffold { innerPadding ->
NavHost(navController, "home", Modifier.padding(innerPadding)) {
composable("home") {
// This content fills the area provided to the NavHost
val saveDialogState = remember { mutableStateOf(true) }
Button(onClick = {
navController.navigate("detail_dialog")
}, modifier = Modifier.testTag(PLACE_TAG)) {
Text(text = "helllow")
}
}
dialog("detail_dialog") {
// This content will be automatically added to a Dialog() composable
// and appear above the HomeScreen or other composable destinations
Dialog(onDismissRequest = {navController.navigate("home")}) {
Card(
shape = RoundedCornerShape(10.dp),
modifier = Modifier
.fillMaxWidth()
.wrapContentHeight()
// .padding(horizontal = 16.dp)
.padding(vertical = 8.dp),
elevation = 8.dp
){
Text(text = "helllow", modifier = Modifier.testTag(BUTTON_TAG))
}
}
}
}
}
}
As #DanielO said you can use the isRoot() selector, see below. That however prints out the same message as before.
A possible workaround is to instead print both root trees using something like
composeTestRule.onAllNodes(isRoot()).printToLog("currentLabelExists")
You have to distinctivly select which root you are looking for. By using the selectors:
.get( index )
.onFirst()
.onLast()
When added it should look like this:
composeTestRule.onAllNodes(isRoot()).get(1).printToLog("T:")
composeTestRule.onAllNodes(isRoot()).onFirst().printToLog("T:")
composeTestRule.onAllNodes(isRoot()).onLast().printToLog("T:")
How can I slide in the keyboard?
I tried:
val keyboardController: SoftwareKeyboardController? = LocalSoftwareKeyboardController.current
keyboardController?.show()
But it does not work. What am I missing? Maybe some Manifest flags?
To show keyboard in Compose:
val showKeyboard = remember { mutableStateOf(true) }
val focusRequester = remember { FocusRequester() }
val keyboard = LocalSoftwareKeyboardController.current
OutlinedTextField(
modifier = Modifier
.fillMaxWidth()
.focusRequester(focusRequester),
value = value,
textStyle = MaterialTheme.typography.body2,
onValueChange = { onValueChange(it)},
label = { Text(label) }
)
// LaunchedEffect prevents endless focus request
LaunchedEffect(focusRequester) {
if (showKeyboard.equals(true)) {
focusRequester.requestFocus()
delay(100) // Make sure you have delay here
keyboard?.show()
}
}
Locked for 3 hours. There are disputes about this answer’s content being resolved at this time. It is not currently accepting new interactions.
What's the issue with the official method?
fun showSoftKeyboard(view: View) {
if (view.requestFocus()) {
val imm = getSystemService(Context.INPUT_METHOD_SERVICE) as InputMethodManager
imm.showSoftInput(view, InputMethodManager.SHOW_IMPLICIT)
}
}
Read more here.
This method works if you just use it like this:
showSoftKeyboard(AndroidView(context))
You could also try eliminating the parameter entirely by placing the AndroidView in the function's body instead.
#Composable
fun init() {
LazyColumn(Modifier.fillMaxSize()) {
for (i in 0..10) {
item { Box(Modifier.padding(15.dp)) { TextField("Hallo$i", modifier = Modifier.fillMaxWidth(), onValueChange = {}) } }
}
}
}
If i have something simple as this list with textfields
then the textfields will not let me scroll down the column.
Only works if i scroll down next to the textfields.
Tried also with readonly/disabled textfield.
is there a way to overcome this behaviour?
maybe a way to disable focus on textfield if scrolled?
I am using jetbrains-compose for desktop version (0.5.0-build245)
but can also be the same as in the jetpack-compose for android (did not try)
for the moment because i don't find any other solution i will use this workaround
using a invisible box above the text field and change the state accordingly
#Composable
fun init() {
LazyColumn(Modifier.fillMaxSize()) {
for (i in 0..10) {
item {
val isfocused = remember { mutableStateOf(false) }
val focusRequester = FocusRequester()
Box(Modifier.padding(15.dp)) {
TextField("Hallo$i", modifier = Modifier.fillMaxWidth().focusRequester(focusRequester).onFocusChanged {
isfocused.value = it.isFocused
}, onValueChange = {})
if (!isfocused.value)
Box(
modifier = Modifier
.matchParentSize()
.alpha(0f)
.clickable(onClick = {
isfocused.value = true
focusRequester.requestFocus()
}),
)
}
}
}
}
}