I'm trying to programmatically click on an item of a recyclerView. I'm using:
recyclerView.findViewHolderForAdapterPosition(index).itemView.performClick();
This perfectly works when the index is of a visible item. If the item is not visible (at the last position of the recyclerview, for istance), an Exception is thrown.
What can I do?
I just had a similar question with yours.And I had solve it! Here is what I did.
xxx.mRecyclerView.postDelayed(new Runnable() {
#Override
public void run() {
xx.mRecyclerView.scrollToPosition(position);
}
},300);
xxx.mRecyclerView.postDelayed(new Runnable() {
#Override
public void run() {
xxx.mRecyclerView.findViewHolderForAdapterPosition(position).itemView.performClick();
}
},400);
}
You can scroll to the specific item, then perform click.
Because the doc say
If the item at the given position is not laid out, it will not create a new one.
But I know the adapter has the data, so scroll to it first, and findViewHolderForAdapterPositionwill not be null.
One more thing, I do not know how you use the RecyclerView. In my application, I use it in a fragment, and I don not know why we should delay it scroll and perform click. (Maybe it is because of the life circle?).But this really works.
You could call onClick directly, assuming that view manages its own click listener.
View view = recyclerView.findViewHolderForAdapterPosition(index).itemView;
view.onClick(view);
If the click listener is located somewhere else, you just need to get a reference to the object with the onClick method and call it with the correct view as a parameter.
try this for kotlin and viewBinding
viewBinding.catList.post {
val view = viewBinding.catList.findViewHolderForAdapterPosition(0)?.itemView?.findViewById<CheckBox>(R.id.catButton)
view?.callOnClick()
}
Related
Okay, I'm just trying to handle the second click on a CardView.
For example, Now when I click on the CardView, It will change background color for the CardView. Also, it should change the image in the ImageView.
If I understand your question: you wanna ask how to prevent from multiple click/tap on a view, if yes then you can handle it by adding following method into your Utility class
public static void avoidMultipleTapping(View view) {
view.setEnabled(false);
final Handler handler = new Handler();
handler.postDelayed(() -> view.setEnabled(true), 1000);
}
if you want to say something else you can comment below over my answer.
I wanted to know if its possible to have two onclick methods for one buttton..Im trying to have a button that can open a new activity and send a id token to the server for firebase purposes, if possible how do i go about it on android studio
I think you are getting the underlying concept wrong.
Buttons react to clicks.
The "ActionListener" that gets triggered on that click ... can do whatever it wants. There is nothing (conceptually) that prevents you in your code to just trigger various things. Of course, you have to understand what you are doing (things like: not blocking the UI thread for too long; or how to kick of things in background threads, and so on).
No. There is only one onClick method for a Button. But you can still perform two different purposes by one button.
I am using a button to hide and show a linear layout. The code is given below :
final int[] count = {2};
//here startTopics is the button....
startTopics.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if(count[0] %2==0)
{
topicLin.setVisibility(View.VISIBLE);
count[0]++;
}
else
{
topicLin.setVisibility(View.GONE);
//here topicLin is the linear layout
count[0]++;
}
}
});
It is one button and so you should apply only one onClick listener which performs the buttons job.
In your onClick-method you can just call another (private) method if you want to do multiple things without sacrificing code management.
button.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
sendTokenToServer();
// Include your code to open the activity here or outsource it again into another private method
}
});
And your method to send the token to the server:
private void sendTokenToServer() {
// Your code here.
}
I am trying to create a calculator. I am working in the latest Android Studio. Like in calculators, all new tokes(numbers, operators) should be shown in the right and if the field is larger than the display, it should scroll to the latest token. I have already browsed and found a way to do the same.
The code for the same is:
private void scrollRight() {
horizontalScrollView = (HorizontalScrollView) findViewById(R.id.horizontalScrollView);
ViewTreeObserver viewTreeObserver = horizontalScrollView.getViewTreeObserver();
viewTreeObserver.addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
#Override
public void onGlobalLayout() {
horizontalScrollView.getViewTreeObserver().removeOnGlobalLayoutListener(this);
horizontalScrollView.scrollTo(entry.getWidth(), 0);
}
});
}
scrollRight is called by a onClick event which checks if a token is entered and calls this.
Everything is working perfectly, i.e. on every new token the scroll bar is scrolling to the end. But if I try to scroll to the beginning manually, it no longer works. After this every time a new token is pressed, the scroll bar first moves to the end and then back to the beginning.
The only option that remains is to restart the program. I tried debugging the OnGlobalLayout function but the debugger loses all frames while stepping out from the function, so it is difficult to know what exactly is making the scroll bar go to the beginning.
GIF to show the problem:
Please Help!
Try
horizontalScrollView.post(new Runnable() {
#Override
public void run() {
horizontalScrollView.fullScroll(View.FOCUS_RIGHT);
}
});
And call findViewById only once in onCreate.
I have problem in listening user interaction of the spinner when item selected.
I know the below listener work perfect
spinner.setOnItemSelectedListener(this);
#Override
public void onItemSelected(AdapterView<?> parentView, View selectedItemView, int position, long id) {
// your code here
}
#Override
public void onNothingSelected(AdapterView<?> parentView) {
// your code here
}
but In my application scenario I will change the spinner value through program,that time also it fire the onitemselected event.but I need this event should fired only when user interaction happened on the spinner
Note:I am not talking on initial spinner value selected item.
Please Let me know how can I accomplish this
Thanks in advance,
Naveenkumar.R
tempListener = spinner.getOnItemSelectedListener();
spinner.setOnItemSelectedListener(null);
//change the spinner value...
spinner.setOnItemSelectedListener(tempListener)
More elegantly, you could subclass the Spinner class, and create 'disableOnItemSelectedListener()' and 'enableOnItemSelectedListener()' methods, which do the same as the code above.
Undesired calls to onItemSelected can be avoided using a simple technique I describe in the following link. This way, you can yourself setSelection anytime without a worry. Check the accepted answer to this question:
Undesired onItemSelected calls
I might be on the wrong track here, and should be thinking events/publish-subscriber, if so, please enlighten me.
I have an android project running, where I have a layout which acts as an on-screen menu. Implemented in several activities/"parent-views" with the use of '< include>'. Working nicely.
Now, some of the functionality is general and global. Like I have an "add"-button, which does something, that it should always do. Then I'd like the possibility to customize what it does in addition to this, based on the activity where the action originated.
I have seperated menulogic in a simple java class, with the constructor taking an activity as a parameter. From here, I can attach clicklisteners to the buttons in the menu fine, and do stuff on click.
What I'd like is something like:
private void addBtn(String text, String path) {
LinearLayout ll = (LinearLayout) parentActivity.findViewById(R.id.dynamicButtonLayout);
Button newButton = new Button(parentActivity);
newButton.setText(text);
newButton.setTag(path);
newButton.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
try {
//Do Stuff.
fireDoneHandlingButtonClick();
} catch (Exception e) {
}
}
});
}
And then have a way of handling this method in the parent activity. Should I be thinking of events, or should I be thinking of a way to add a method as an argument to the addBtn method from the activity, which can be fired from inside the click-listener?
Look at How To Implement Your Own Listener in Android or Fire and Forget Messages (events) in Android