How do you find a View from a parent activity using findViewByID from a Listener

Question

I have a custom View in a parent activity that calls...

getContext().startActivity(intent);

...in it's onClickListener. In this new Activity, there is a button callback where I need to call a method in the parent activity's custom View. The same custom View that started the Activity. I tried doing it like so:

 ((CustomView) ((LinearLayout) view.getRootView().findViewById(R.id.linear_layout_amp_row))
                    .getChildAt(col)).function();

I have tried to set the parent activity as a global variable in the new Activity, but the parent is null. I tried setting it in onCreate and onAttachToWindow. I've also tried getParent and using view. I did not see a way to pass the View through the bundle.

How do you go about getting a view from a parent activity?

*parent activity as a global variable*: don't do it! About your question: why should you get a view in the parent activity? — Gabriele Mariotti, Jul 19 '20 at 16:35
The activity that contains the custom View that called getContext().startActivity(intent); — John Glen, Jul 19 '20 at 19:01
Don't try to make any changes to a user interface other than in the foreground Activity. Pass a simple data type to a background Activity that will result in the view change when that Activity comes to the foreground. — codebod, Jul 19 '20 at 20:17
how do you pass a simple data type to a background Activity? — John Glen, Jul 19 '20 at 21:15
Using some form of data storage or by using `startActivityForResult`, for example. — codebod, Jul 19 '20 at 21:22

score 0 · Answer 1 · answered Jul 19 '20 at 16:35

0

You don't need to do that bro if you are extending your parent activity just because you are inheriting properties of a parent class then you can also have access to its member variables.

answered Jul 19 '20 at 16:35

Azhar Ansari

46
3

I'm not extending. I have an activity that contains a custom View. This custom view opens a new Activity. This new Activity needs to call a function contained in the custom View. – John Glen Jul 19 '20 at 19:03
Oh, do you mean the new Activity should extend the parent Activity? How would that work? Both activities have their own layout and variables. I only need access to the function in the parent activity. – John Glen Jul 19 '20 at 19:05

score 0 · Answer 2 · answered Jul 19 '20 at 16:39

0

if you are required to call methods of fragment or activity then you can do that is this way.

Calling fragments methods from activity Calling a Fragment method from a parent Activity

Calling activity methods from fragment ((YourActivityClassName)getActivity()).yourPublicMethod();

answered Jul 19 '20 at 16:39

Azhar Ansari

46
3

I only see getCallingActivity() – John Glen Jul 19 '20 at 19:11

How do you find a View from a parent activity using findViewByID from a Listener

2 Answers2