Develop Reference

how to assign a condition to an imageView by using if else?

I tried to show a random imageView out of 2(one,two) with this
binding.imageView.setImageResource(oneandtwo[random.nextInt(oneandtwo.size)]) it works fine
and
i wanted to increase score when i clicked on imageView
but score increases independent to that, sometimes increases when i clicked on imageView2 and sometimes imageView, i want to increase score when i only clicked on imageView. i couldnt figure out. Thanks in advance.
var score = 0
val oneandtwo: IntArray = intArrayOf(
R.drawable.ic_baseline_looks_one_24,
R.drawable.ic_baseline_looks_two_24
)
binding.imageView.setOnClickListener{
val random = Random
binding.imageView.setImageResource(oneandtwo[random.nextInt(oneandtwo.size)])
if (oneandtwo[random.nextInt(oneandtwo.size)]==(R.drawable.ic_baseline_looks_one_24)){
score++
binding.textView.text = score.toString()
}
}

The number you gave in the image and the number you checked in the if block may not match and will not give the result you want. If you change code like this. Probably your problem will be solved.
binding.imageView.setOnClickListener{
val random = Random().nextInt(oneandtwo.size)
binding.imageView.setImageResource(oneandtwo[random])
if (oneandtwo[random]==(R.drawable.ic_baseline_looks_one_24)){
score++
binding.textView.text = score.toString()
}
}

What you are doing is checking the resourceId of the newly generated image, not the one you just clicked. That's why it not giving the result you want ,i.e, increment on the click of imageView and not on click of imageView2. Try below code. it should work
var score = 0
val oneandtwo: IntArray = intArrayOf(R.drawable.ic_baseline_looks_one_24,R.drawable.ic_baseline_looks_two_24)
/*Initalize the initial image and tag either here or in xml file*/
val random = Random().nextInt(oneandtwo.size)
binding.imageView.setImageResource(oneandtwo[random])
binding.imageView.Tag = oneandtwo[random]
binding.imageView.setOnClickListener{
val imageTag = binding.imageView.Tag
if (imageTag == (R.drawable.ic_baseline_looks_one_24)) {
score++
binding.textView.text = score.toString()
}
val random = Random().nextInt(oneandtwo.size)
binding.imageView.setImageResource(oneandtwo[random])
binding.imageView.Tag = oneandtwo[random]
}

You've got two problems that both the answers cover - if clicking a particular image is meant to give you points, you have to check the image before you change it. And if you're using random items, you need to pick one and keep a reference to it. This:
binding.imageView.setImageResource(oneandtwo[random.nextInt(oneandtwo.size)])
if (oneandtwo[random.nextInt(oneandtwo.size)]==(R.drawable.ic_baseline_looks_one_24))
picks two completely independent numbers which may not match - and they're supposed to be referencing the same item, right? Get your random thing once, use it twice
RahulK's answer should work but here's another way you could do it, with an explicit listener object so you can throw a state variable in there:
binding.imageView.setOnClickListener(object : View.OnClickListener {
// keep track of whether the current image adds to the score when clicked
var givesPoints = false
override fun onClick(view: View) {
// first, we just got clicked, so add to the score if appropriate
if (givesPoints) score++
// you can just call random() on a collection to get a random element from it
val resId = oneAndTwo.random()
// set the image - might be better to do (view as ImageView).setImageResource
// so it sets it on -whatever was clicked- so it's easier to reuse
binding.imageView.setImageResource(resId)
// now set whether this new image gives points or not
givesPoints = resId == R.drawable.ic_baseline_looks_one_24
}
})
So this way, every time you set a new image, the listener knows whether to give points for it next time it's clicked
I don't know how you have this set up, you're only initialising things when the image is clicked so if you need to set them up beforehand (so you can have an image displayed that you an click for points) you probably want everything in a separate function you can call when clicked and during setup:
/** Assigns a random picture to this ImageView - returns true if it's a point-scoring pic */
fun assignRandomPic(imageView: Imageview): Boolean {
val resId = oneAndTwo.random()
imageView.setImageResource(resId)
return resId == R.drawable.ic_baseline_looks_one_24
}
// set an initial image, storing whether it scores points
val scoreMe = assignRandomPic(binding.imageView)
binding.imageView.setOnClickListener(object : View.OnClickListener {
// initialise this as appropriate for the image we just set up
var givesPoints = scoreMe
override fun onClick(view: View) {
if (givesPoints) score++
// set a new pic and store its point-scoring state
givesPoints = assignRandomPic(view as ImageView)
}
})
or you could just do var givesPoints = assignRandomPic(binding.imageView) and init the image inside the click listener, whatever feels better

Is DrawableCompat.setTint() lazy?

I am designing an app that has 3 button in main activity, and several buttons in a fragment. I want to change the color of a button in the fragment, depending on which button of main activity is toggled.
color1.setOnClickListener {
brush_chosen = 1
color1.setBackgroundColor(R.color.black)
color2.setBackgroundColor(0x00000000)
color3.setBackgroundColor(0x00000000)
if (frag_num == 8 ){
frag_8p.set_frag_value(frag_num,brush_chosen)
}
}
The function set_frag_value is :
fun set_frag_value(frag_num:Int,brush:Int) : Int
{
brush_chosen=brush
return brush
}
This change the value of brush_chosen. Then I made a function :
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
super.onViewCreated(view, savedInstanceState)
ib0.setOnClickListener { view ->
Log.d("brush_color","Brush of 0 : "+brush_chosen)
if (brush_chosen==1)
{
Log.d("brush_color","Brush Confirm : "+brush_chosen)
DrawableCompat.setTint(ib0.drawable, ContextCompat.getColor(requireContext(),R.color.rndcolor1))
}
else if (brush_chosen==2)
{
Log.d("brush_color","Brush Confirm : "+brush_chosen)
DrawableCompat.setTint(ib0.drawable, ContextCompat.getColor(requireContext(),R.color.purple_500))
}
else if (brush_chosen==3)
{
Log.d("brush_color","Brush Confirm : "+brush_chosen)
DrawableCompat.setTint(ib0.drawable, ContextCompat.getColor(requireContext(),R.color.teal_200))
}
Log.d("brush_color","End of onclicklistener ")
}
}
I checked the log and theoretically this code should work correctly. However, I found that the button color did not change properly, even I checked my app prints all log correctly. For example, when I clicked button color1 in main activity, variable brush_chosen becomes 1 and the first button in fragment I clicked changes its color. But the second button I clicked does not change its color.
Is there any problem on my code using DrawableCompat ??

Android does some Drawable state caching under the hood. You might need to call mutate() on the Drawable you want to tint and then set the new Drawable in order for the tint to show up properly.

Simulating a button press with another button press

I currently want to have a button that when I press it another button flashes as if it has been pressed at the same time and activates the function of the other button. My current code is as such:
fun onTwo(view: View) {
button1.callOnClick()
button1.isPressed = true
}
However the issue I am facing is that it freezes button1 as if it is pressed until it is pressed again. Anyone have a solution for this?

You could add listener in one of the button to check for clicks and then use that event to trigger click event in another button, like this:
val button1 = findViewById(R.id.btn1ID) as Button
button1.setOnClickListener {
val button2 = findViewById(R.id.btn2ID) as Button
button2.performClick()
}
Replace R.id.btn1ID and R.id.btn2ID with their respective id(a).
Reference: performClick()
You could also create a utility function to use it without making redundant variables like this:
#Suppress("UNCHECKED_CAST")
fun Activity.findButtonById(#IdRes res : Int) : Button =
findViewById(res) as Button
// and then in your create method of activity:
findButtonById(R.id.btn1ID).setOnClickListener {
findButtonById(R.id.btn2ID).performClick()
}

Try performClick() method like below:
fun onTwo(view: View)
{
button1.performClick()
}

I ended up fixing this issue using coroutines in the end as such:
fun onTwo(view: View){
GlobalScope.async{
delay(100)
button1.isPressed = false
GlobalScope.cancel()
}
button1.setPressed(true)
button1.performClick()
}

Bottom OnClickListener always unresolved

I have a simple button in my recyclerview, when clicked the first time it should make the text editable, when clicked the second time, it should confirm the change. The problem I'm having is that I have the two onClickListeners set up, but they refer to each other, and the bottom one can always resolve the top one, but the top one can't resolve the bottom one.
Recyclerview: bindIngredient
fun bindIngredient(ingredient: ListIngredientsQuery.Item, clickListener: RecyclerViewClickListener) {
val ocl1 = View.OnClickListener{
//Text Editable
view.ingEditText.setText(view.ingNameTV.text.toString())
view.ingNameTV.visibility = View.GONE
view.ingEditText.visibility = View.VISIBLE
view.ingEditButton.text = "Confirm"
view.ingEditButton.setOnClickListener(ocl2)
}
var ocl2 = View.OnClickListener {
//Text Not Editable
view.ingNameTV.text = view.ingEditText.text
view.ingEditText.visibility = View.GONE
view.ingNameTV.visibility = View.VISIBLE
view.ingEditButton.setOnClickListener(ocl1)
clickListener.onConfirmSelect(ingredient)
}
this.ingredient = ingredient
view.ingNameTV.text = ingredient.name()
view.ingEditButton.setOnClickListener(ocl1)
view.veganSpinner.setSelection(Vegan.valueOf(ingredient.vegan().toString()).ordinal, false)
view.gfSpinner.setSelection(GlutenFree.valueOf(ingredient.glutenfree().toString()).ordinal, false)
}
In this example the line
view.ingEditButton.setOnClickListener(ocl2)
errors because ocl2 is unresolved. If I switch the order of the two onClickListeners being declared and initialized, the line
view.ingEditButton.setOnClickListener(ocl1)
errors because ocl1 is resolved. I take this to mean that it won't look further down to find what it needs, it'll only rely on objects that have already been initialized.
Is there a way to fix this? Is there a better way to do this? I'm tempted to just put two buttons in the same spot, give them each their own onclicklistener and swap their visibility, but this seems like a waste of resources.

You need to declare your objects before you use them.
fun bindIngredient(ingredient: ListIngredientsQuery.Item, clickListener: RecyclerViewClickListener) {
val ocl1: View.OnClickListener
val ocl2: View.OnClickListener
ocl1 = View.OnClickListener{
//Text Editable
view.ingEditText.setText(view.ingNameTV.text.toString())
view.ingNameTV.visibility = View.GONE
view.ingEditText.visibility = View.VISIBLE
view.ingEditButton.text = "Confirm"
view.ingEditButton.setOnClickListener(ocl2)
}
ocl2 = View.OnClickListener {
//Text Not Editable
view.ingNameTV.text = view.ingEditText.text
view.ingEditText.visibility = View.GONE
view.ingNameTV.visibility = View.VISIBLE
view.ingEditButton.setOnClickListener(ocl1)
clickListener.onConfirmSelect(ingredient)
}
this.ingredient = ingredient
view.ingNameTV.text = ingredient.name()
view.ingEditButton.setOnClickListener(ocl1)
view.veganSpinner.setSelection(Vegan.valueOf(ingredient.vegan().toString()).ordinal, false)
view.gfSpinner.setSelection(GlutenFree.valueOf(ingredient.glutenfree().toString()).ordinal, false)
}
However, it would be better if you just used one OnClickListener. You can simply save which state you are in, and when the button is clicked, you just check which state you are in, perform your action, and then change the state. This way you don't have to worry about switching your listeners, which can get messy.

First visible item in recycler view chagnes rest of the list

I have list of users with circle foreground on their avatar. If user is online circle is green, otherwise it is red. The problem is, whole list is red (for example) until I scroll under the user which is supposed to be green.
After that when I scroll back upwards whole list has green circles until I reach offline user which will change whole list back to red.
My bind function looks like this:
fun bind(userInfo: UserInfo) {
val foreground = ContextCompat.getDrawable(itemView.context, R.drawable.ic_online)
foreground?.colorFilter = PorterDuffColorFilter(ContextCompat.getColor(
itemView.context, when {
userInfo.status == Status.OFFLINE -> R.color.offline_red
else -> R.color.colorAccent
}), PorterDuff.Mode.SRC_ATOP)
itemView.profilePictureImageView.foreground = foreground
val options = RequestOptions()
options.placeholder(R.drawable.ic_default_avatar)
options.circleCrop()
Glide.with(itemView.context)
.load("http://scdb.abradio.cz/uploads/interprets/r/radek-rettegy.jpg")
.apply(options)
.into(itemView.profilePictureImageView)
}

You need to call mutate on the drawable otherwise you're changing the shared instance:
val foreground = ContextCompat.getDrawable(itemView.context, R.drawable.ic_online)
.mutate()