I have a simple increment app. When you press on the button the number goes up. However i also made the number change to red once it's higher then 5.
I was able to get the number to save on rotation however the colour resets back to normal.
I'm not sure how i can also save the colour. Any ideas on how i can do this?
// number starts at 0
var num = 0
class MainActivity : AppCompatActivity() {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
val textView = findViewById<TextView>(R.id.textView)
val add = findViewById<Button>(R.id.button)
add.setOnClickListener {
++num
if(num > 5) {
textView.setTextColor(Color.parseColor("#FF0000"))
}
textView.setText(num.toString())
}
}
override fun onSaveInstanceState(outState: Bundle) {
super.onSaveInstanceState(outState)
outState.putInt("int", num)
}
override fun onRestoreInstanceState(savedInstanceState: Bundle) {
super.onRestoreInstanceState(savedInstanceState)
if(savedInstanceState != null) {
num = savedInstanceState.getInt("int")
textView.setText(num.toString())
}
}
}
update this method onRestoreInstanceState
override fun onRestoreInstanceState(savedInstanceState: Bundle) {
super.onRestoreInstanceState(savedInstanceState)
if(savedInstanceState != null) {
num = savedInstanceState.getInt("int")
if(num > 5){
textView.setTextColor(Color.parseColor("#FF0000"))
}
textView.setText(num.toString())
}
}
Related
When the basictextfield is at bottom of view and is focused, the basictextfield is moving to the center of screen. How can I stop that? If I remove imePadding(), only half of textfield is visible.
#AndroidEntryPoint
class MainActivity : ComponentActivity() {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
WindowCompat.setDecorFitsSystemWindows(window, false)
setContent {
var a by remember {
mutableStateOf("")
}
Box(
modifier = Modifier
.fillMaxSize()
.imePadding()
) {
BasicTextField(
value = a, onValueChange = { a = it }, modifier = Modifier.align(
Alignment.BottomCenter
)
)
}
}
}
}
Why does navigation composable call twice? If I set a breakpoint on the Text I will get two stops when the app runs. Thank you for your answers.
class MainActivity : ComponentActivity() {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContent {
val navController = rememberNavController()
var i: Int = 0
NavHost(navController = navController, startDestination = "s1") {
composable("s1") {
i++
Text("$i")
}
}
}
}
}
I have made an app that uses an API to make a request and then shows the results in a RecyclerView.
I was following a tutorial and in it they used a differCallback and a liveData so the lists updates and such. However whenever the user makes a second search, the recyclerView should only show the new results but the previous results don't dissapear and the new results just appear below the previous search.
I have debugged it for quite some time now but I don't seem to understand where the list is made and where sure it be updated (or in this case cleared).
I tried using .clear() for the diff (Asynclistdiffer), creating a new list in the onBindViewHolder and then clearing that list every time the "search" is called but without any luck. As im still a beginner I don't have a clue on where or what is happening, all your helo will be greatly appreciated
this is my adapter:
class RecipePreviewAdapter : RecyclerView.Adapter<RecipePreviewAdapter.RecipePreviewViewHolder>() {
inner class RecipePreviewViewHolder(itemView: View) : RecyclerView.ViewHolder(itemView)
private val differCallback = object : DiffUtil.ItemCallback<Recipe>() {
override fun areItemsTheSame(oldItem: Recipe, newItem: Recipe): Boolean {
return oldItem.sourceUrl == newItem.sourceUrl
}
override fun areContentsTheSame(oldItem: Recipe, newItem: Recipe): Boolean {
return oldItem == newItem
}
}
val differ = AsyncListDiffer(this, differCallback)
lateinit var recipeList: MutableList<Recipe>
var isRecipeListInitialized = false
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): RecipePreviewViewHolder {
return RecipePreviewViewHolder(
LayoutInflater.from(parent.context).inflate(
R.layout.item_recipe_preview,
parent,
false
)
)
}
override fun onBindViewHolder(holder: RecipePreviewViewHolder, position: Int) {
recipeList = differ.currentList.toMutableList()
isRecipeListInitialized = true
// Log.d(TAG, recipeList.toString())
val recipe = recipeList[position]
holder.itemView.apply {
Glide.with(this).load(recipe.image).into(ivRecipeImagePreview)
tvRecipeTitlePreview.text = recipe.title
tvTimeToMakeTVPreview.text = "${recipe.readyInMinutes} minutes"
tvSummaryPreview.text = Jsoup.parse(recipe.summary).text()
setOnClickListener {
onItemClickListener?.let { it(recipe) }
}
}
}
override fun getItemCount(): Int {
return differ.currentList.size
}
And this is where I call it:
class SearchRecipeFragment : Fragment(R.layout.fragment_search_recipe) {
lateinit var viewModel: RecipeViewModel
lateinit var recipeAdapter: RecipePreviewAdapter
val TAG = "SearchRecipeFragment"
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
super.onViewCreated(view, savedInstanceState)
viewModel = (activity as RecipesActivity).viewModel
setupRecyclerView()
recipeAdapter.setOnItemClickListener {
val bundle = Bundle().apply {
putSerializable("recipe", it)
}
findNavController().navigate(
R.id.action_searchRecipeFragment_to_recipeFragment,
bundle
)
}
etSearch.setOnKeyListener(View.OnKeyListener { _, keyCode, event ->
if (keyCode == KeyEvent.KEYCODE_ENTER && event.action == KeyEvent.ACTION_DOWN) {
if (etSearch.text.toString().isNotEmpty()) {
viewModel.searchRecipe(etSearch.text.toString())
}
return#OnKeyListener true
}
false
})
viewModel.searchRecipeLiveData.observe(viewLifecycleOwner, Observer { response ->
when (response) {
is Resource.Success -> {
hideProgressBar()
response.data?.let { recipeResponse ->
recipeAdapter.differ.submitList(recipeResponse.results.toList())
}
}
is Resource.Error -> {
hideProgressBar()
response.message?.let { message ->
Log.e(TAG, "An error occurred: $message")
Toast.makeText(activity, "An error occurred: $message", Toast.LENGTH_LONG)
.show()
}
}
is Resource.Loading -> {
showProgressBar()
}
}
})
}
Ans this is the part of the ViewModel that I'm not really sure what it does
private fun handleSearchRecipeResponse(response: Response<SearchRecipeResponse>): Resource<SearchRecipeResponse> {
if (response.isSuccessful) {
response.body()?.let { resultResponse ->
searchRecipesPage++
if (searchRecipesResponse == null) {
searchRecipesResponse = resultResponse
} else {
val oldRecipes = searchRecipesResponse?.results
val newRecipes = resultResponse.results
oldRecipes?.addAll(newRecipes)
}
return Resource.Success(searchRecipesResponse ?: resultResponse)
}
}
return Resource.Error(response.message())
}
too late but it is because of "searchRecipesResponse". You have to set it to "null" and reset searchRecipesPage to 1 for each new search in etSearch.setOnKeyListener().
In my adapter of a ViewPager I have the position. What I want to do is add 1 to the position by pressing a Button in the activity but I cannot access the position from the activity. How can I do it?
Adapter:
class MyAdapter(var context: Context,private var myList: List<MyModel>) : PagerAdapter() {
override fun getCount(): Int {
return myList.size
}
override fun isViewFromObject(view: View, `object`: Any): Boolean {
return view == `object`
}
override fun destroyItem(container: ViewGroup, position: Int, `object`: Any) {
container.removeView(`object` as View?)
}
override fun instantiateItem(container: ViewGroup, position: Int): Any {
var view: View = LayoutInflater.from(context).inflate(R.layout.layout_item,container,false)
var img: ImageView = view.findViewById(R.id.imgView)
val listPos= myList[position]
container.addView(view)
return view
}
}
Activity:
class MyActivity : AppCompatActivity() {
private var myAdapter: MyAdapter? = null
private val myList = ArrayList<MyModel>()
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.my_activity_layout)
myAdapter = MyAdapter(this,myList)
myViewPager.adapter = myAdapter
myList.add("Name",R.drawable.img1)
myList.add("Name2",R.drawable.img2)
myList.add("Name3",R.drawable.img3)
myButtonPlus.setOnClickListener{
//Here I want to +1 the position for every click
}
myButtonMinus.setOnClickListener{
//Here I want to -1 the position for every click
}
}
}
If you want to increase and decrease your ViewPager position you should use the setCurrentItem function.
Try to change your code like this:
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.my_activity_layout)
myAdapter = MyAdapter(this,myList)
myViewPager.adapter = myAdapter
myList.add("Name",R.drawable.img1)
myList.add("Name2",R.drawable.img2)
myList.add("Name3",R.drawable.img3)
myButtonPlus.setOnClickListener{
//Here I want to +1 the position for every click
val currentPage = myAdapter?.currentItem ?: 0
val maxPage = myAdapter?.childCount ?: 0
if (currentPage < maxPage) {
myAdapter?.currentItem = currentPage + 1
}
}
myButtonMinus.setOnClickListener{
//Here I want to -1 the position for every click
val currentPage = myAdapter?.currentItem ?: 0
if (currentPage > 0) {
myAdapter?.currentItem = currentPage - 1
}
}
}
I'm a Beginner in Kotlin and I want a way to display Interstitial Ad every time I click on the button tvName, but on the contrary, the app crashes whenever I click on the button. I searched for the solution for a long time.
Here's MainActivity
import ...
#Suppress("UNREACHABLE_CODE")
class MainActivity : AppCompatActivity() {
lateinit var mAdView : AdView
var adapter:ChaptersAdapter?=null
var listOfChapters= ArrayList<Chapters>()
#SuppressLint("WrongViewCast")
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
MobileAds.initialize(this) {}
mAdView = findViewById(R.id.adView)
val adRequest = AdRequest.Builder().build()
mAdView.loadAd(adRequest)
loadChapters()
adapter = ChaptersAdapter(listOfChapters, this)
lvchapters.adapter = adapter
MobileAds.initialize(this,
"ca-app-pub-3940256099942544~3347511713")
mInterstitialAd = InterstitialAd(this)
mInterstitialAd.adUnitId = "ca-app-pub-3940256099942544/1033173712"
mInterstitialAd.loadAd(AdRequest.Builder().build())
}
fun loadChapters(){
listOfChapters.add(Chapters(" Chapter 1 ", applicationContext.assets.open("Chapter0.txt").bufferedReader().use {
it.readText()
}
))
listOfChapters.add(Chapters(" Chapter 2 ", applicationContext.assets.open("Chapter1.txt").bufferedReader().use {
it.readText()
}
))
}
class ChaptersAdapter: BaseAdapter {
var context:Context?=null
var listOfChaptersLocal= ArrayList<Chapters>()
constructor(listOfChapters:ArrayList<Chapters>,context:Context){
listOfChaptersLocal=listOfChapters
this.context=context
}
override fun getView(p0: Int, p1: View?, p2: ViewGroup?): View {
val chapters= listOfChaptersLocal[p0]
var inflator= context!!.getSystemService(Context.LAYOUT_INFLATER_SERVICE) as LayoutInflater
val chaptersView=inflator.inflate(R.layout.list_chapters,null)
chaptersView.tvName.text= chapters.name!!
chaptersView.**tvName.setOnClickListener** {
// **i want to show the Ads in this time frame** but like this example it didn't work
if (mInterstitialAd.isLoaded) {
mInterstitialAd.show()
} else {
Log.d("TAG", "The interstitial wasn't loaded yet.")
}
val intent =Intent(context,ChapterDetails::class.java)
intent.putExtra("name",chapters.name!!)
intent.putExtra("des",chapters.des!!)
context!!.startActivity(intent)
}
return chaptersView
}
override fun getItem(p0: Int): Any {
return listOfChaptersLocal[p0]
}
override fun getItemId(p0: Int): Long {
return p0.toLong()
}
override fun getCount(): Int {
return listOfChaptersLocal.size
}
}
}