Develop Reference

Activate or de activate recyclerview items

I have a fragment which contains a recyclerview and a floating action button. In recyclerview, each row contains a radio button set as disabled by default. my requirement is I need to enable these radio buttons in every row upon floating action button click event. Is there any solution?
Thanks in advance..
OK... I got a solution.
here is my code.
fab.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
for (int i = 0; i <= adapter.getItemCount(); i++) {
View childVIew = recyclerView.getChildAt(i);
if (childVIew != null) {
RadioButton radioYes = childVIew.findViewById(R.id.radio_yes_my_health_info);
radioYes.setEnabled(true);
RadioButton radioNo = childVIew.findViewById(R.id.radio_no_my_health_info);
radioNo.setEnabled(true);
}
}
fab.setImageResource(R.drawable.ic_save_white_24dp);
recyclerView.getRecycledViewPool().setMaxRecycledViews(0, 0);
}
});
Now on FAB button click, all the radio buttons inside my recyclerview will be enabled and I can click to change the state of every radio button. But here I have got a problem. When I click FAB button, all the radio buttons inside the recyclerview will be activated but when I scroll the recyclerview all those radio buttons will be disabled or deactivated again. Please give me a solution for this.

You can have a flag in your adapter like
boolean isActivated = false;
public void setActivated(boolean activated) {
isActivated = activated;
}
and in your onBindViewHolder() method you can check for the flag and set the state of your flag accordingly.
In the OnClickListener of your FAB, call
adapter.setActivated(true);//true or false as per your requirement
adapter.notifyDataSetChanged();
This should work.

You can try looping through every view when you click the button, like so:
for (int i = 0; i < adapter.getItemCount(); i++) {
View view = recycler.getLayoutManager().findViewByPosition(i);
view.setSelected(true); //Select item
notifyItemChanged(i); //Notify item changed
}

How to disable BottomNavigationView click and Touch?

i want to implement behavior on certain condition the bottom view is unable to click, i want to make if bottom view item being click it does not navigate to that item but still stay at the current item

You can disable menu items if you want to disable bottom navigation view
private void enableBottomBar(boolean enable){
for (int i = 0; i < mBottomMenu.getMenu().size(); i++) {
mBottomMenu.getMenu().getItem(i).setEnabled(enable);
}
}

Kotlin style one-liner:
bottom_navigation.menu.forEach { it.isEnabled = false }

<android.support.design.widget.BottomNavigationView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:clickable="false"
android:contextClickable="false"/>
Try this code.it Disables the click.
Dynamicaly using Java pr Kotlin you can disable click.
bottomView.setEnabled(false);
bottomView.setFocusable(false);
bottomView.setFocusableInTouchMode(false);
bottomView.setClickable(false);
bottomView.setContextClickable(false);
bottomView.setOnClickListener(null);
setting onClick Listener to Null helps to Disable click events
bottomView.menu.forEach { it.isEnabled = false }

You can set the touch listeners of its subviews. Example using android-ktx:
bottomNav.children.forEach {
(it as? ViewGroup)?.children?.forEach {
it.setOnTouchListener { _, _ -> true } // or null to enable touch again
}
}

public class CustomBottomNavigationView extends BottomNavigationView {
...
#Override
public void setEnabled(boolean enabled) {
super.setEnabled(enabled);
ViewGroup menuView = (ViewGroup) getChildAt(0);
if (menuView != null) {
for (int i = 0; i < menuView.getChildCount(); i++) {
menuView.getChildAt(i).setEnabled(enabled);
}
}
}
}

You can do something like
bottomNavigation.menu.iterator().forEach { it.isEnabled = !error }

Android Code does not work / 2 questions

Hello can anybody tell me why this code give me error and crash my app?
This happens only when 'reset((View) child);' is added at the end
What I want to do is when I click a Button with onClick:reset, It will apply a kind of reset to only Images and textviews inside a LinearLayout which has more types of childrens
public void reset(View v) {
LinearLayout items = (LinearLayout) findViewById(R.id.itemsToSearch);
for (int i = 0; i < items.getChildCount(); i++)
{
Object child = items.getChildAt(i);
Context context = getApplicationContext();
CharSequence text = child.toString();
int duration = Toast.LENGTH_SHORT;
Toast toast = Toast.makeText(context, text, duration);
toast.show();
if (child instanceof ImageView)
{
((ImageView) child).setVisibility(View.INVISIBLE);
}
else if (child instanceof TextView)
{
((TextView) child).setTextColor(Color.parseColor("#98868A"));
}
else if(child instanceof ViewGroup)
{
reset((View) child);
}
}
}
and the other question is that my app works with FragmentPagerAdapter, How can I do for example if I click a Button in Frag#1 it will change a text inside Frag#3 which is currently not shown?, For me it always crash, As I see it is because Frag#3 or whatever other frag which is off screen is not yet loaded on screen and because of that it doesnt fint the specified ID
Thank You

Your reset method is broken. You are not using the view that is passed as an argument to the method, you are always searching for the same LinearLayout. Your code should look like this:
public void reset(ViewGroup viewGroup) {
final int childCount = viewGroup.getChildCount();
for (int i = 0; i < childCount; i++) {
View child = viewGroup.getChildAt(i);
if (child instanceof ImageView) {
((ImageView) child).setVisibility(View.INVISIBLE);
} else if (child instanceof TextView) {
((TextView) child).setTextColor(Color.parseColor("#98868A"));
} else if(child instanceof ViewGroup) {
// recursive call
reset((ViewGroup) child);
}
}
}
Regarding your other issue, only the current fragment and the ones to either side (within the offscreen page limit, which by default is 1) are actually loaded and in a state where you can manipulate their views. You will need to store some data somewhere and refer back to that data when the page you want (Fragment #3 in your example) is instantiated and you start loading data into it.

Method to get all EditTexts in a View

can anyone help me with coding a method to get all EditTexts in a view? I would like to implement the solution htafoya posted here:
How to hide soft keyboard on android after clicking outside EditText?
Unfortunately the getFields() method is missing and htafoya did not answer our request to share his getFields() method.

EDIT
MByD pointed me to an error, thus making my answer almost identical to that of blackbelt. I have edited mine to the correct approach.
You could do a for-each loop and then check if each view is of the type EditText:
ArrayList<EditText> myEditTextList = new ArrayList<EditText>();
for( int i = 0; i < myLayout.getChildCount(); i++ )
if( myLayout.getChildAt( i ) instanceof EditText )
myEditTextList.add( (EditText) myLayout.getChildAt( i ) );
You could also, instead of having a list of EditTexts, have a list of ID's and then just add the id of the child to the list: myIdList.add( child.getId() );
To access your layout you need to get a reference for it. This means you need to provide an ID for your layout in your XML:
<LinearLayout android:id="#+id/myLinearLayout" >
//Here is where your EditTexts would be declared
</LinearLayout>
Then when you inflate the layout in your activity you just make sure to save a reference to it:
LinearLayout myLinearLayout;
public void onCreate( Bundle savedInstanceState ) {
super( savedInstanceState );
setContentView( R.layout.myLayoutWithEditTexts );
...
myLinearLayout = (LinearLayout) findViewById( R.id.myLinearLayout );
}
You then have a reference to your the holder of your EditTexts within the activity.

Here's a method I wrote to recursively check all EditText children of a ViewGroup, handy for a long sign-up form I had to do and probably more maintainable.
private EditText traverseEditTexts(ViewGroup v)
{
EditText invalid = null;
for (int i = 0; i < v.getChildCount(); i++)
{
Object child = v.getChildAt(i);
if (child instanceof EditText)
{
EditText e = (EditText)child;
if(e.getText().length() == 0) // Whatever logic here to determine if valid.
{
return e; // Stops at first invalid one. But you could add this to a list.
}
}
else if(child instanceof ViewGroup)
{
invalid = traverseEditTexts((ViewGroup)child); // Recursive call.
if(invalid != null)
{
break;
}
}
}
return invalid;
}
private boolean validateFields()
{
EditText emptyText = traverseEditTexts(mainLayout);
if(emptyText != null)
{
Toast.makeText(this, "This field cannot be empty.", Toast.LENGTH_SHORT).show();
emptyText.requestFocus(); // Scrolls view to this field.
}
return emptyText == null;
}

You can do it by calling View#getFocusables, which will return an arraylist of all focusable views in a View.
Then you can either check if they are EditTexts, with (instanceof) or act on all of them.

This Methods walks recursively through all ViewGroups and collects their TextViews. I use this to assign a new Color to all TextViews (even those embedded in predefined Widgets like Switch etc that make use of TextViews)
private HashSet<TextView> getTextViews(ViewGroup root){
HashSet<TextView> views=new HashSet<>();
for(int i=0;i<root.getChildCount();i++){
View v=root.getChildAt(i);
if(v instanceof TextView){
views.add((TextView)v);
}else if(v instanceof ViewGroup){
views.addAll(getTextViews((ViewGroup)v));
}
}
return views;
}

Get all Edit Text in any type of layout.
public List<EditText> getAllEditTexts(ViewGroup layout){
List<EditText> views = new ArrayList<>();
for(int i =0; i< layout.getChildCount(); i++){
View v =layout.getChildAt(i);
if(v instanceof EditText){
views.add((EditText)v);
}
}
return views;
}

How to iterate through a view's elements

I have a view with radios, inputs and a button and when I click it, I want to check that all inputs contain information. How can I iterate through the view's elements in the activity and check if every textview meets the aforementioned requirement ? Thanks.

I've done something similar in some code I don't have with me at the moment, but from memory it should be something like this (assuming a parent view LinearLayout with an id of "layout"):
LinearLayout layout = (LinearLayout)findViewById(R.id.layout);
boolean success = formIsValid(layout);
public boolean formIsValid(LinearLayout layout) {
for (int i = 0; i < layout.getChildCount(); i++) {
View v = layout.getChildAt(i);
if (v instanceof EditText) {
//validate your EditText here
} else if (v instanceof RadioButton) {
//validate RadioButton
} //etc. If it fails anywhere, just return false.
}
return true;
}

To apply the method by kcoppock recursively, you can change it to this:
private void loopViews(ViewGroup view) {
for (int i = 0; i < view.getChildCount(); i++) {
View v = view.getChildAt(i);
if (v instanceof EditText) {
// Do something
} else if (v instanceof ViewGroup) {
this.loopViews((ViewGroup) v);
}
}
}

If you are writing in Kotlin, Android Jetpack's Kotlin extensions (KTX) provide extension functions for iterating over a ViewGroup's children.
myViewGroup.forEach { ... }
myViewGroup.forEachIndexed { index, view -> ... }
Just add the dependency to your app. Check the link above to get the most up-to-date version.
implementation "androidx.core:core-ktx:1.2.0"
These extensions contains hoards of useful functions otherwise chalked up as boilerplate. Worth checking out now to save time in the future!

Your onClickListener supplies the View v object; use View rV = v.getRootView() to position yourself on the form. Then use rV.findViewWithTag( ... ) or rV.findViewByID(R.id. ... ) to locate your form elements.