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how i can handle webview.canGoBack() on adapter?

I have an Tab activity with cards with url on them as i click on card it will open an webview with given url my problem is that how can i call webview.canGoBack() on my adapter.
after i click on card this window will open help me to handle canGoback() on adapter.

Technically it should be doable BUT this is absolutely not the place for that logic. If you for any reason really need to have WebView in a ListView or RecyclerView, then It'd be cleaner to put it into i.e. Fragment and then let your parent activity notify that fragment on its onBackPressed(). But again, to make it all clean, I'd consider using observer pattern i.e. with EventBus where Activity emits and Fragment listens.

Is it possible to go to a specific page of a viewpager from other activity?

I'm not so good at Android but I'm working on my project. So please forgive my ignorance.
I'm making a set of similar items with need prefenrences setting, so I made them preference fragments for each, and put those preference fragments in a viewpager, for easier use. I want to go to fragment No.1 if I clicked item No.1, then maybe fragment No.3 if I clicked on item No.3. Simply put, I want the items can link to its own preference fragment in the viewpager. The items are in MainActivity, the viewpager is in its own activity and this viewpager activity would not start as the app starts unless an item was clicked.
I learnt that viewPager.setCurrentItem(position); should be used when I want to get to a specific page of a viewpager. But my items are in MainActivity, not inside the viewpager activity. I set the viewpager as static, and put viewPager.setCurrentItem(position); inside onClick method in MainActivity, but when I click a item, the app crashes. It shows error: java.lang.NullPointerException. The app had worked fine before I dicided to link those items to their own settings, and now I really have no idea...
Could you please tell me whether it is possible to get to a specific page of a viewpager from other activity? If it is possible, how to do? Thank you so much!
Renew:
I tried to mess with the code, I changed the adapter of the viewpager into protected static MyAdapter adapter;. There was no crash then, but I always went to the first page of the viewpager, whichever item I clicked...

I think you need to pass the data to the activity.
When you call the ViewPager in the MainActivity, set a parameter.
Intent intent = new Intent(getBaseContext(), ViewPagerActivity.class);
intent.putExtra("EXTRA_PAGE", (String) position);
startActivity(intent);
Then in the start of the View Pager Activity, get the object and change the currentItem.
Bundle extras = getIntent().getExtras();
if (extras != null) {
String value = extras.getString("EXTRA_PAGE");
int position= Integer.parseInt(value );
viewPager.setCurrentItem(position);
}

Android can only have 1 visible activity at the same time, so i think it's impossible in your way.
Another approach will be the use of Fragment, but it depends on your app design and structure.
You can check more about Fragments here (Android documentation).
Hope it helps ;)
Best Regards

Updating edittext from fragment

I currently have the following situation:
1) The "main view" which contains the EditText I'm trying to update. (Let's call it mainView)
2) A fragment that is opened whenever I click in a button that is contained in the "main view", the
fragment receives mainView as parameter.
3) An OnClickListener which is set to a button that is contained by the fragment. This listener receives the fragment as parameter.
Basically what I need to do is, each time I click on the button that triggers the listener, I need to update the editText, however it doesn't seem to be working. I believe it has something to do with "notifying" the view, but I haven't been able to get it working no matter what I try. After I update the text I close the fragment and
Basically the code is the following:
public void onClick(View v){
String newMessageContent = "hello world";
fragment1.mainView.editText1.setText(newMessageContent);
FragmentManager manager = this.fragment1.getActivity().getFragmentManager();
manager.beginTransaction().replace(R.id.container,this.fragment1.mainView.getPlaceHolderFragment()).commit();
}
Please note that I have simplified the problem a little bit and changed the name of the fragment/views in order for you guys to understand better. The text "hello world" is actually dynamic, and depends no another parameter that is received by the OnClickListener.
After I click the fragment does get replaced, so I know the onClickListener is working correctly, however I believe there's something wrong with the way the data change is being notified.
I've already looked at many SO questions, however none of them have helped me to achieve what I need.
Any help is appreciated, thanks.

I suggest implementing an interface, say, IUpdateFromFragment with method, say, onUpdate(String message), then let activity implement that interface and inside the fragment just call something like ((IUpdateFromFragment)this.getActivity()).onUpdate(newMessageContent);

I realized the problem was that each time I replaced the fargment via the fragmentManager, the method setActivityView was being called again, which replaced the EditText content.
In order to avoid this, I manually removed the fragment (instead of replacing it), doing the following:
FragmentManager manager = this.selectTemplateFragment.getActivity().getFragmentManager();
manager.beginTransaction().remove(this.selectTemplateFragment).commit();

Update the fragment via transaction, then within the fragment1 class OnViewCreated, you can do mainView.editText1.setText("whatever");
The way you're doing this now, I'm surprised isn't throwing an exception since the view isn't inflated yet.

Fragment with a ListView calling another Fragment

I have an Fragment with a ListView from where i want to call another Fragment. In my BaseAdapter i want to register an onClick and open a new Fragment where i use a ViewPager.
Is here Broadcastreciver/sender the right way to go? or can i just call the new Fragment in the onClick method?
If Broadcastreciver ist the way to go, i would appreciate it if you could help me with the Code. I have never used a Broadcastreciver before. What comes in the onClick method and what needs to be done in my mainActivity.
Thanks

How to prevent calling onCreateView when back button pressed in fragment in android

In my application, I have tabbar functionality. In one tab i am displaying server data in lisview, and on clicking on that detail page for that list item will be open in new fragment.
But when I press back button from that detail page, every time oncreateview called of previous page, so every time listview created and new fetches new server data. So how to prevent such and just display previous state when back button press?

I know it has been too long to give this answer but what i am guessing is you are replacing your fragment with other one. I mean to say is you are using
ft.replace(R.id.realTabContent, fragment);
to move to other fragment which is you are using in your onItemClick so simple solution is use
ft.add(R.id.realTabContent, fragment);
instead of replacing your fragment.
Understand the difference between replace and add. This will solve your problem.
Replace : it will replace the original fragment and re-create the view when you come back
Add : it will just add a new fragment to stack.
Hope this will help someone who is facing the same problem...

I don't think prevent calling onCreateView is a good idea, beside if the function is not called, there will be exception, so NO, you shouldn't. Instead of doing that, I suggest you move your "listview created and new fetches new server data" into another place where you can call explicitly (when you want, where you want, onCreate() is a good place), don't put it in onCreateView(). Hope this helps.

You should cache your data objects apart from view variables as their references needs to be updated if you are fetching any data from server and don't want to make a call again then use branching to branch out that code.
Create an init() method where you do all initialization and server calls and logically branch out call to init() method whenever you don't want to call init().