Android webview : erkennen Blättern

Ich eine Lösung gefunden, die für mich arbeiten, ich check den Quellcode der Klasse WebView in 2.3 API und finden, wie es mit einer 2.1-API. Vielleicht kann die Arbeit mit älteren API:

public class CustomWebView extends WebView {

    private float oldX;

    //indicate if horizontal scrollbar can't go more to the left
    private boolean overScrollLeft = false;

    //indicate if horizontal scrollbar can't go more to the right
    private boolean overScrollRight = false;

    //indicate if horizontal scrollbar can't go more to the left OR right
    private boolean isScrolling = false;

    public CustomWebView(Context context) {
        super(context);
        //TODO Auto-generated constructor stub
    }


    public CustomWebView(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
        //TODO Auto-generated constructor stub
    }



    public CustomWebView(Context context, AttributeSet attrs) {
        super(context, attrs);
        //TODO Auto-generated constructor stub
    }

    @Override
    public boolean onTouchEvent(MotionEvent event) {
        //width of the vertical scrollbar
        int scrollBarWidth = getVerticalScrollbarWidth();

        //width of the view depending of you set in the layout
        int viewWidth = computeHorizontalScrollExtent();

        //width of the webpage depending of the zoom
        int innerWidth = computeHorizontalScrollRange();

        //position of the left side of the horizontal scrollbar
        int scrollBarLeftPos = computeHorizontalScrollOffset();

        //position of the right side of the horizontal scrollbar, the width of scroll is the width of view minus the width of vertical scrollbar
        int scrollBarRightPos = scrollBarLeftPos + viewWidth - scrollBarWidth;

        //if left pos of scroll bar is 0 left over scrolling is true
        if(scrollBarLeftPos == 0) {
            overScrollLeft = true;
        } else {
            overScrollLeft = false;
        }

        //if right pos of scroll bar is superior to webpage width: right over scrolling is true
        if(scrollBarRightPos >= innerWidth) {
            overScrollRight = true;
        } else {
            overScrollRight = false;
        }

        switch (event.getAction()) {
        case MotionEvent.ACTION_DOWN: //when user touch the screen
            //if scrollbar is the most left or right
            if(overScrollLeft || overScrollRight) {
                isScrolling = false;
            } else {
                isScrolling = true;
            }
            oldX = event.getX();
            break;

        case MotionEvent.ACTION_UP: //when user stop to touch the screen
            //if scrollbar can't go more to the left OR right 
            //this allow to force the user to do another gesture when he reach a side
            if(!isScrolling) {
                if(event.getX() > oldX && overScrollLeft) {
                    //left action
                }

                if(event.getX() < oldX && overScrollRight) {
                    //right actio
                }
            }

            break;
        default:
            break;
        }
        return super.onTouchEvent(event);
    }

}

Ich denke, das wird dieses problem lösen:

int horizontalOffset = computeHorizontalScrollOffset();
int contentWidth = (int) Math.floor(getContentWidth() * getScale());
int viewportWidth = getWidth();

//1 just for random error
boolean reachRightEnd = ((horizontalOffset +  viewportWidth) >= (contentWidth - 1));
boolean reachLeftEnd = (horizontalOffset == 0);