Note: this class is deprecated

This article illustrate how to prevent the page navigation (horizontal scroll) while the page is zoomed with the rendering mode set as double page.
Here you can find a class that extends PDFViewDual class, it also supports RTOL:

@Deprecated
public class PDFViewDualExt extends PDFViewDual {

    protected boolean isRTL = false;

    Context context;

    public PDFViewDualExt(Context context, boolean isRTL) {
        super(context);
        this.context = context;
        this.isRTL = isRTL;
    }


    @Override
    protected boolean motionNormal(MotionEvent event) {
        super.motionNormal(event);
        try {
            switch (event.getActionMasked()) {
                case MotionEvent.ACTION_MOVE:
                    if (m_status == STA_MOVING) {
                        int x = m_scroller.getFinalX();
                        if (x + m_w > m_docw) x = m_docw - m_w;
                        if (vGetScale() > vGetMinScale()) {
                            try {
                                if (Global.def_view == 6 && m_w > m_h && isLandscape()) { //dual page
                                    if (isRTL) {
                                        if ((m_pageno - 2 >= 0) && (m_pageno - 2 < m_pages.length) && x + m_w > m_pages[m_pageno - 2].m_x)
                                            x = m_pages[m_pageno - 2].m_x - m_w;
                                        if (m_pageno >= 0 && x <= (m_pages[m_pageno + 1].m_x + m_pages[m_pageno + 1].m_w))
                                            x = (m_pages[m_pageno + 1].m_x + m_pages[m_pageno + 1].m_w);
                                    } else {
                                        if ((m_pageno + 2 < m_pages.length) && x + m_w > m_pages[m_pageno + 2].m_x)
                                            x = m_pages[m_pageno + 2].m_x - m_w;
                                        if (m_pageno > 0 && x <= (m_pages[m_pageno - 1].m_x + m_pages[m_pageno - 1].m_w))
                                            x = (m_pages[m_pageno - 1].m_x + m_pages[m_pageno - 1].m_w);
                                    }
                                } else { //single page
                                    if (isRTL) {
                                        if ((m_pageno - 1) >= 0 && (m_pageno - 1 < m_pages.length) && x + m_w > m_pages[m_pageno - 1].m_x)
                                            x = m_pages[m_pageno - 1].m_x - m_w;
                                        if (m_pageno >= 0 && x <= (m_pages[m_pageno + 1].m_x + m_pages[m_pageno + 1].m_w))
                                            x = (m_pages[m_pageno + 1].m_x + m_pages[m_pageno + 1].m_w);
                                    } else {
                                        if ((m_pageno + 1 < m_pages.length) && x + m_w > m_pages[m_pageno + 1].m_x)
                                            x = m_pages[m_pageno + 1].m_x - m_w;
                                        if (m_pageno > 0 && x <= (m_pages[m_pageno - 1].m_x + m_pages[m_pageno - 1].m_w))
                                            x = (m_pages[m_pageno - 1].m_x + m_pages[m_pageno - 1].m_w);
                                    }
                                }
                            } catch (Exception e) {
                                e.printStackTrace();
                            }
                        }
                        if (x < 0) x = 0;
                        m_scroller.setFinalX(x);
                        if (m_listener != null) m_listener.OnPDFInvalidate(false);
                    }
                    break;
                case MotionEvent.ACTION_UP:
                case MotionEvent.ACTION_CANCEL:
                    if (m_status == STA_MOVING) {
                        int x = m_scroller.getFinalX();
                        if (x + m_w > m_docw) x = m_docw - m_w;

                        if (vGetScale() > vGetMinScale()) {
                            try {
                                if (Global.def_view == 6 && m_w > m_h && isLandscape()) { //dual page
                                    if (isRTL) {
                                        if ((m_pageno - 2 >= 0) && (m_pageno - 2 < m_pages.length) && x + m_w > m_pages[m_pageno - 2].m_x)
                                            x = m_pages[m_pageno - 2].m_x - m_w;
                                        if (m_pageno >= 0 && x <= (m_pages[m_pageno + 1].m_x + m_pages[m_pageno + 1].m_w))
                                            x = (m_pages[m_pageno + 1].m_x + m_pages[m_pageno + 1].m_w);
                                    } else {
                                        if ((m_pageno + 2 < m_pages.length) && x + m_w > m_pages[m_pageno + 2].m_x)
                                            x = m_pages[m_pageno + 2].m_x - m_w;
                                        if (m_pageno > 0 && x <= (m_pages[m_pageno - 1].m_x + m_pages[m_pageno - 1].m_w))
                                            x = (m_pages[m_pageno - 1].m_x + m_pages[m_pageno - 1].m_w);
                                    }
                                } else { //single page
                                    if (isRTL) {
                                        if ((m_pageno - 1 >= 0) && (m_pageno - 1 < m_pages.length) && x + m_w > m_pages[m_pageno - 1].m_x)
                                            x = m_pages[m_pageno - 1].m_x - m_w;
                                        if (m_pageno >= 0 && x <= (m_pages[m_pageno + 1].m_x + m_pages[m_pageno + 1].m_w))
                                            x = (m_pages[m_pageno + 1].m_x + m_pages[m_pageno + 1].m_w);
                                    } else {
                                        if ((m_pageno + 1 < m_pages.length) && x + m_w > m_pages[m_pageno + 1].m_x)
                                            x = m_pages[m_pageno + 1].m_x - m_w;
                                        if (m_pageno > 0 && x <= (m_pages[m_pageno - 1].m_x + m_pages[m_pageno - 1].m_w))
                                            x = (m_pages[m_pageno - 1].m_x + m_pages[m_pageno - 1].m_w);
                                    }
                                }
                            } catch (Exception e) {
                                e.printStackTrace();
                            }
                        }
                        if (x < 0) x = 0;
                        m_scroller.setFinalX(x);
                        m_status = STA_NONE;
                        vOnMoveEnd(x, m_scroller.getFinalY());
                        if (m_listener != null) m_listener.OnPDFInvalidate(false);
                    }
                    break;
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        return true;
    }

    public boolean isLandscape() {
        return context.getResources().getConfiguration().orientation == Configuration.ORIENTATION_LANDSCAPE;
    }

    @Override
    protected boolean vOnFling(float dx, float dy, float velocityX, float velocityY) {
        if (vGetScale() > vGetMinScale()) return true;
        return super.vOnFling(dx, dy, velocityX, velocityY);
    }

/**
     * This override is to prevent scroller from stopping between two pages while searching
     */
    @Override
    protected void vFindGoto() {
        if (m_pages == null) return;
        int pg = m_finder.find_get_page();
        if (pg < 0 || pg >= m_doc.GetPageCount()) return;
        float pos[] = m_finder.find_get_pos();
        if (pos == null) return;
        pos[0] = m_pages[pg].ToDIBX(pos[0]) + m_pages[pg].GetX();
        pos[1] = m_pages[pg].ToDIBY(pos[1]) + m_pages[pg].GetY();
        pos[2] = m_pages[pg].ToDIBX(pos[2]) + m_pages[pg].GetX();
        pos[3] = m_pages[pg].ToDIBY(pos[3]) + m_pages[pg].GetY();
        float x = m_scroller.getCurrX();
        float y = m_scroller.getCurrY();
        if (x > pos[0] - m_w / 8) x = pos[0] - m_w / 8;
        if (x < pos[2] - m_w * 7 / 8) x = pos[2] - m_w * 7 / 8;
        if (y > pos[1] - m_h / 8) y = pos[1] - m_h / 8;
        if (y < pos[3] - m_h * 7 / 8) y = pos[3] - m_h * 7 / 8;
        if (x > m_docw - m_w) x = m_docw - m_w;
        if (x < 0) x = 0;
        if (y > m_doch - m_h) y = m_doch - m_h;
        if (y < 0) y = 0;
        m_scroller.forceFinished(true);
        m_scroller.setFinalX((int) x);
        m_scroller.setFinalY((int) y);
        if (m_listener != null) m_listener.OnPDFInvalidate(false);
        /*center page after search*/

        if (vGetScale() <= vGetMinScale()) {

            vCenterPage(pg);
        }
    }
}