Parse an android XML layout file using XmlPullParser

Question

This question has been asked a lot in different situations, but for over a day I can't find an answer that fixes my error.

I have an xml file called activity_single_touch.xml inside res/layout folder. This file is used to add views like buttons, but I also want to be able to edit it "live" (the user can draw on screen).

Following android guide, I tried using XmlPullParser in my main java code like so:

public class SingleTouchActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        // setContentView(R.layout.activity_single_touch);
        XmlPullParser parser = getResources().getXml(R.xml.activity_single_touch);
        AttributeSet attributes = Xml.asAttributeSet(parser);
        setContentView(new SingleTouchEventView(this, attributes));
    }

    public class SingleTouchEventView extends View {
        ...
    }
}

The rest of the code uses OnDraw and OnTouchEvent to draw a path according to user movement, and then invalidate.

The error I am getting at the moment is "cannot resolve symbol 'xml'". How can I fix this?

p.s: Things I have tried (and have failed): Using

XmlPullParser parser =getResources().getXml(R.layout.activity_single_touch);

and getting "expected xml element" error,

I've read over

this guide
these answeres
these as well
use of streams
use of context
moving the xml file to a different folder(could not move it)
this guide

and of course searching google and some more stackOverflow questions and answers.

K Neeraj Lal · Accepted Answer · 2016-09-20T10:33:11.963

1

You can use getLayout method to open the layout file and parse it. This is how you can parse it manually.

Try this,

try {
    XmlResourceParser parser = getResources().getLayout(R.layout.activity_single_touch);
    int event = parser.getEventType();
    do{
        String tagName = parser.getName();
        if(event == XmlPullParser.START_TAG){
            Log.e("TagName", tagName);
        }
        event = parser.next();
    } while (event != XmlPullParser.END_DOCUMENT);
} catch (XmlPullParserException e) {
    e.printStackTrace();
} catch (Exception e){
    e.printStackTrace();
}

Usage in your code,

public class SingleTouchActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        try {
            XmlResourceParser parser = getResources().getLayout(R.layout.activity_single_touch);
            AttributeSet attributes = Xml.asAttributeSet(parser);
            setContentView(new SingleTouchEventView(this, attributes));
        } catch (XmlPullParserException e) {
            e.printStackTrace();
        } catch (Exception e){
            e.printStackTrace();
        }
    }

    public class SingleTouchEventView extends View {

    }
}

edited Sep 20 '16 at 10:33

answered Sep 18 '16 at 16:01

K Neeraj Lal

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I'm not sure how you want me to use this - I tried changing this line: XmlPullParser parser = getResources().getXml(R.xml.activity_single_touch); to the block of code you gave me and it didn't work. I also tried switching this line to: XmlResourceParser parser = getResources().getLayout(R.layout.activity_single_touch); and it didn't work. What am I doing wrong? – yo1122 Sep 19 '16 at 16:21
What do you mean by it doesn't work? Is the `TagName` not being printed? – K Neeraj Lal Sep 20 '16 at 05:50
First of all - it tells me on this line: AttributeSet attributes = Xml.asAttributeSet(parser); "cannot resolve symbol 'parser'". I thought it's a problem with the scope, so I changed the first few lines of your code to: XmlResourceParser parser ; try { parser = getResources().getLayout(R.layout.activity_main); ... But then it says "variable 'parser' might not have been initialized". What else should I do? Btw - just to make sure I'm using this code in the right place, this is all in the OnCreate method instead of the line quoted in the above comment. – yo1122 Sep 20 '16 at 09:57
I do in my code, and I asked few times if you mean that I just change that one line of my code into this block you gave me and keep the rest, otherwise I don't know how to use this block. Otherwise how do I use this parser? How do I implement it so that the ui includes both the SingleTouchEventView from the java file, and different views from the xml file? – yo1122 Sep 20 '16 at 10:22
compiled with no errors, but I can't see the button from my xml view.. only a blank screen I can draw on (SingleTouchEventView). Maybe I need to add something to the xml code? I'll add the first few lines to my question – yo1122 Sep 20 '16 at 12:11
It's not letting me. I'll try here: – yo1122 Sep 20 '16 at 12:19

Parse an android XML layout file using XmlPullParser

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