android - Disable ScrollView Programmatically?

Question

I would like to enable ScrollView and disable it by a Button Click.
Disable means like if the ScrollView wasn't there, and enable it returns the ScrollView.

I want that because I have a gallery with text images, and on a button click the screen orientation changes, so in Landscape the text becomes bigger. And I want the ScrollView so the image does not stretch itself and the text becomes unreadable.

scrollview.Enabled=false / setVisibility(false) doesn't make anything.

xml:

<ScrollView 
android:id="@+id/QuranGalleryScrollView" 
android:layout_height="fill_parent" 
android:layout_width="fill_parent">
<Gallery android:id="@+id/Gallery" 
android:layout_width="fill_parent" 
android:layout_height="fill_parent"
android:scrollbars="horizontal"></Gallery>
</ScrollView>

I can't use Visibility (gone) since that would also hide the Gallery, what I want is to hide the effect of the ScrollView. When there is ScrollView, the images in Gallery become scrollable and do not fit in the screen so you have to scroll to see the whole image. I don't want to disable/enable that on a button click.

I tried this:

((ScrollView)findViewById(R.id.QuranGalleryScrollView)).setOnTouchListener(null);
                        ((ScrollView)findViewById(R.id.QuranGalleryScrollView)).setHorizontalScrollBarEnabled(false);
                        ((ScrollView)findViewById(R.id.QuranGalleryScrollView)).setVerticalScrollBarEnabled(false);
                        ((ScrollView)findViewById(R.id.QuranGalleryScrollView)).setEnabled(false);

But still the images in the Gallery are scrollable and not fit the screen. What's the solution to this?

Answer 1

Several points to begin with:

1. You cannot disable the scrolling of a ScrollView. You would need to extend to ScrollView and override the onTouchEvent method to return false when some condition is matched.
2. The Gallery component scrolls horizontally regardless of whether it is in a ScrollView or not - a ScrollView provides only vertical scrolling (you need a HorizontalScrollView for horizontal scrolling)
3. You seem to say you have a problem with the image stretching itself -- this has nothing to do with the ScrollView, you can change how an ImageView scales with the android:scaleType property (XML) or the setScaleType method - for instance ScaleType.CENTER will not stretch your image and will center it at it's original size

You could modify ScrollView as follows to disable scrolling

class LockableScrollView extends ScrollView {

    ...

    // true if we can scroll (not locked)
    // false if we cannot scroll (locked)
    private boolean mScrollable = true;

    public void setScrollingEnabled(boolean enabled) {
        mScrollable = enabled;
    }

    public boolean isScrollable() {
        return mScrollable;
    }

    @Override
    public boolean onTouchEvent(MotionEvent ev) {
        switch (ev.getAction()) {
            case MotionEvent.ACTION_DOWN:
                // if we can scroll pass the event to the superclass
                return mScrollable && super.onTouchEvent(ev);
            default:
                return super.onTouchEvent(ev);
        }
    }

    @Override
    public boolean onInterceptTouchEvent(MotionEvent ev) {
        // Don't do anything with intercepted touch events if
        // we are not scrollable
        return mScrollable && super.onInterceptTouchEvent(ev);
    }

}

You would then use

<com.mypackagename.LockableScrollView 
    android:id="@+id/QuranGalleryScrollView" 
    android:layout_height="fill_parent" 
    android:layout_width="fill_parent">

    <Gallery android:id="@+id/Gallery" 
        android:layout_width="fill_parent" 
        android:layout_height="fill_parent"
        android:scrollbars="horizontal">
    </Gallery>

</com.mypackagename.LockableScrollView>

in your XML file (just changed the ScrollView to your special LockableScrollView).

Then call

((LockableScrollView)findViewById(R.id.QuranGalleryScrollView)).setScrollingEnabled(false);

to disable scrolling of the view.

I think that you have more than just the issue of disabling scrolling though to achieve your desired result (the gallery will remain scrollable with the above code for instance) - I'd recommend doing some more research on each of the three components (Gallery, ScrollView, ImageView) to see what properties each one has and how it behaves.