Android: Add TextViews in Horizontal ScrollView and Check which texview is in Center?

Question

I need to add TextViews in Horizontal ScrollView and on scroll I have to check which textview is in the middle of the center if three textView are showing on the screen? Note: I have added horizontal scrollView and TextViews.Here is my code.

<HorizontalScrollView
    android:layout_width="fill_parent"
    android:layout_height="40dp"
    android:scrollbars="none" >

    <LinearLayout
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:background="@drawable/catagorybar"
        android:orientation="horizontal" >

        <TextView 
            android:id="@+id/textView1"
            android:layout_width="match_parent"
            android:layout_height="fill_parent"
            />
        <TextView 
            android:id="@+id/textView2"
            android:layout_width="match_parent"
            android:layout_height="fill_parent"
            />
        <TextView 
            android:id="@+id/textView3"
            android:layout_width="match_parent"
            android:layout_height="fill_parent"
            />
        <TextView 
            android:id="@+id/textView4"
            android:layout_width="match_parent"
            android:layout_height="fill_parent"
            />
        <TextView 
            android:id="@+id/textView5"
            android:layout_width="match_parent"
            android:layout_height="fill_parent"
            />
        <TextView 
            android:id="@+id/textView6"
            android:layout_width="match_parent"
            android:layout_height="fill_parent"
            />

    </LinearLayout>
</HorizontalScrollView>

you could do something like get visible item count and divide it by two to get the center view. which is general and it may depend on th possibilities of the library you were using. — Vigneshwaran Murugesan, Mar 02 '15 at 07:25
@SurenderKumar I need to create a title stripe with single screen, In which only three textviews will be displayed and on scroll it have to get data from server once a specific textView is in the middle. — Robin Royal, Mar 02 '15 at 07:32
@SurenderKumar I have added source code in my question, Please check. — Robin Royal, Mar 02 '15 at 07:35
can you use horizontal listview and set minimum item to 3 and when you scroll the next items will be loaded. — Surender Kumar, Mar 02 '15 at 07:45
@SurenderKumar I try this and than let you know. Thank you all — Robin Royal, Mar 02 '15 at 07:54

Xcihnegn · Answer 1 · 2015-03-02T09:05:06.910

Suggest you use Gallery - A view that shows items in a center-locked, horizontally scrolling list. and set your yourGallery:

yourGallery.setOnItemSelectedListener(new OnItemSelectedListener(){
    @Override
    public void onItemSelected(AdapterView<?> parent, View view,
                int position, long id) {
        //get focused/center view position here
});

Here is one sample available, but in the gallery adapter, in getView, you should inflate your custom view instead of just ImageView.

score 0 · Answer 2 · edited May 23 '17 at 11:43

You can get if the TextView partially/totally visible or not using the way described here:

Rect scrollBounds = new Rect();
scrollView.getHitRect(scrollBounds);
if (text.getLocalVisibleRect(scrollBounds)) {
    // Any portion of the TextView, even a single pixel, is within the visible window
} else {
    // NONE of the TextView is within the visible window
}

So, you have to get the HorizontalScrollView children and loop through it, then see what are the visible children and from that you can get the centered child:

    List<Integer> centered_textViews = new ArrayList<Integer>();
    TextView text;
    HorizontalScrollView scrollView = findViewById(R.id.your_hsv);
    Rect scrollBounds = new Rect();
    scrollView.getHitRect(scrollBounds);
    for (int i = 0; i < scrollView.getChildCount(); i++) {
        text = (TextView) scrollView.getChildAt(i);
        if (text.getLocalVisibleRect(scrollBounds))
            centered_textViews.add(i);
    }
    int centered_textview_index = (int) (centered_textViews.size() / 2);
    TextView centered_text = (TextView) (scrollView
            .getChildAt(centered_textViews.get(centered_textview_index)));

Android: Add TextViews in Horizontal ScrollView and Check which texview is in Center?

2 Answers2