Example usage for android.support.v4.widget ListViewAutoScrollHelper ListViewAutoScrollHelper

Introduction

In this page you can find the example usage for android.support.v4.widget ListViewAutoScrollHelper ListViewAutoScrollHelper.

Prototype

public ListViewAutoScrollHelper(ListView listView) 

Source Link

Usage

From source file:android.support.v7.widget.DropDownListView.java

/**
 * Handles forwarded events.//  w  w w  . j ava  2 s . co m
 *
 * @param activePointerId id of the pointer that activated forwarding
 * @return whether the event was handled
 */
public boolean onForwardedEvent(MotionEvent event, int activePointerId) {
    boolean handledEvent = true;
    boolean clearPressedItem = false;

    final int actionMasked = MotionEventCompat.getActionMasked(event);
    switch (actionMasked) {
    case MotionEvent.ACTION_CANCEL:
        handledEvent = false;
        break;
    case MotionEvent.ACTION_UP:
        handledEvent = false;
        // $FALL-THROUGH$
    case MotionEvent.ACTION_MOVE:
        final int activeIndex = event.findPointerIndex(activePointerId);
        if (activeIndex < 0) {
            handledEvent = false;
            break;
        }

        final int x = (int) event.getX(activeIndex);
        final int y = (int) event.getY(activeIndex);
        final int position = pointToPosition(x, y);
        if (position == INVALID_POSITION) {
            clearPressedItem = true;
            break;
        }

        final View child = getChildAt(position - getFirstVisiblePosition());
        setPressedItem(child, position, x, y);
        handledEvent = true;

        if (actionMasked == MotionEvent.ACTION_UP) {
            clickPressedItem(child, position);
        }
        break;
    }

    // Failure to handle the event cancels forwarding.
    if (!handledEvent || clearPressedItem) {
        clearPressedItem();
    }

    // Manage automatic scrolling.
    if (handledEvent) {
        if (mScrollHelper == null) {
            mScrollHelper = new ListViewAutoScrollHelper(this);
        }
        mScrollHelper.setEnabled(true);
        mScrollHelper.onTouch(this, event);
    } else if (mScrollHelper != null) {
        mScrollHelper.setEnabled(false);
    }

    return handledEvent;
}

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