Changing Count of ViewPager

Question

How do you unlock the ability to slide to a new page after clicking a button on a previous page?

Currently I have a PagerAdapter. The code below instantiates the item. Within the getCount(), a value of 3 is returned and thus 3 slides are made. I was wondering if there was a way to only have 3 views, but after clicking a button, unlock a 4th view that you can now slide to?

@Override
    public Object instantiateItem(final View collection, int position) {
        final LayoutInflater inflater = (LayoutInflater) TViewPager.this
                .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        TextView tv = new TextView(TViewPager.this);

//Describe the separate layouts of views
switch (position) {
        case 1:
            View v1 = inflater.inflate(R.layout.expander2, null, false);
                ((ViewPager) collection).addView(v1, 0);
                final Button button = (Button) findViewById(R.id.button_click_me);
                button.setOnClickListener(new View.OnClickListener() {
                     public void onClick(View v1) {
                         Toast.makeText(getBaseContext(), "+1", Toast.LENGTH_LONG).show();
                        //*Some code*//

                     }
                 });
                return v1;

Is there a way to change the:

public int getCount() {
        return 3; 
    }

Like a "setCount()" and then place it at the //* some code *// to increase the amount of slides?

Would adding

instantiateItem(collection,4);

work somewhere work?

Thanks,

score 6 · Accepted Answer · answered Feb 21 '12 at 06:51

Here's how I solved this problem. To clarify, how do you click a button and get more Pages that you can scroll into. I made:

private int NUM_VIEWS = 2;

public void setN(int N) {
    this.NUM_VIEWS = N;
}

and then I changed an important line.

@Override
public int getCount() {
    return NUM_VIEWS;
}

My clickListener is

button.setOnClickListener(new View.OnClickListener() {
    public void onClick(View v1) {
         myAdapter.setN(3);
         myPager.setCurrentItem(2);
        }
});

I added another case to facilitate the new item. Afterwards when I click the button, my pageadapter will expand to 3 views instead of 2 and the new case will be the new view.

score 2 · Answer 2 · answered Feb 21 '12 at 01:45

2

getCount by default returns the number of child views of your ViewPager. By doing pager.add(layout_item) you can add a new item to the pager (of course you have to inflate it somewhere first). getCount will automatically adjust.

answered Feb 21 '12 at 01:45

josephus

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so I tried adding: ((ViewPager) collection).addView(v1, 3); within the click listener but it hasnt worked. Can you give a bit more advice on how to do this? – d.mc2 Feb 21 '12 at 01:49
Did you do a `notifyDatasetChanged()` – Saad Farooq Feb 21 '12 at 02:05
I tried but it crashes. would I do ((ViewPager) collection).notifyDatasetChanged() all within the click listener. Also is it add or addview and on which object do these methods belong, collection's? – d.mc2 Feb 21 '12 at 02:19

Changing Count of ViewPager

2 Answers2

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