Example usage for android.view View FOCUS_FORWARD

List of usage examples for android.view View FOCUS_FORWARD

Introduction

In this page you can find the example usage for android.view View FOCUS_FORWARD.

Prototype

int FOCUS_FORWARD

To view the source code for android.view View FOCUS_FORWARD.

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Document

Use with #focusSearch(int) .

Usage

From source file:com.hippo.widget.BothScrollView.java

/**
 * <p>// w w  w  . ja  v  a2 s . com
 * Finds the next focusable component that fits in the specified bounds.
 * </p>
 *
 * @param topFocus look for a candidate is the one at the top of the bounds
 *                 if topFocus is true, or at the bottom of the bounds if topFocus is
 *                 false
 * @param top      the top offset of the bounds in which a focusable must be
 *                 found
 * @param bottom   the bottom offset of the bounds in which a focusable must
 *                 be found
 * @return the next focusable component in the bounds or null if none can
 *         be found
 */
private View findFocusableViewInBoundsVertically(boolean topFocus, int top, int bottom) {

    List<View> focusables = getFocusables(View.FOCUS_FORWARD);
    View focusCandidate = null;

    /*
     * A fully contained focusable is one where its top is below the bound's
     * top, and its bottom is above the bound's bottom. A partially
     * contained focusable is one where some part of it is within the
     * bounds, but it also has some part that is not within bounds.  A fully contained
     * focusable is preferred to a partially contained focusable.
     */
    boolean foundFullyContainedFocusable = false;

    int count = focusables.size();
    for (int i = 0; i < count; i++) {
        View view = focusables.get(i);
        int viewTop = view.getTop();
        int viewBottom = view.getBottom();

        if (top < viewBottom && viewTop < bottom) {
            /*
             * the focusable is in the target area, it is a candidate for
             * focusing
             */

            final boolean viewIsFullyContained = (top < viewTop) && (viewBottom < bottom);

            if (focusCandidate == null) {
                /* No candidate, take this one */
                focusCandidate = view;
                foundFullyContainedFocusable = viewIsFullyContained;
            } else {
                final boolean viewIsCloserToBoundary = (topFocus && viewTop < focusCandidate.getTop())
                        || (!topFocus && viewBottom > focusCandidate.getBottom());

                if (foundFullyContainedFocusable) {
                    if (viewIsFullyContained && viewIsCloserToBoundary) {
                        /*
                         * We're dealing with only fully contained views, so
                         * it has to be closer to the boundary to beat our
                         * candidate
                         */
                        focusCandidate = view;
                    }
                } else {
                    if (viewIsFullyContained) {
                        /* Any fully contained view beats a partially contained view */
                        focusCandidate = view;
                        foundFullyContainedFocusable = true;
                    } else if (viewIsCloserToBoundary) {
                        /*
                         * Partially contained view beats another partially
                         * contained view if it's closer
                         */
                        focusCandidate = view;
                    }
                }
            }
        }
    }

    return focusCandidate;
}

From source file:com.peerless2012.twowaynestedscrollview.TwoWayNestedScrollView.java

/**
 * <p>//from   w  ww.  ja v  a  2  s .c  om
 * Finds the next focusable component that fits in the specified bounds.
 * </p>
 *
 * @param topFocus
 *            look for a candidate is the one at the top of the bounds if
 *            topFocus is true, or at the bottom of the bounds if topFocus
 *            is false
 * @param top
 *            the top offset of the bounds in which a focusable must be
 *            found
 * @param bottom
 *            the bottom offset of the bounds in which a focusable must be
 *            found
 * @return the next focusable component in the bounds or null if none can be
 *         found
 */
private View findFocusableViewInBounds(boolean topFocus, int top, int bottom) {

    List<View> focusables = getFocusables(View.FOCUS_FORWARD);
    View focusCandidate = null;

    /*
     * A fully contained focusable is one where its top is below the bound's
     * top, and its bottom is above the bound's bottom. A partially
     * contained focusable is one where some part of it is within the
     * bounds, but it also has some part that is not within bounds. A fully
     * contained focusable is preferred to a partially contained focusable.
     */
    boolean foundFullyContainedFocusable = false;

    int count = focusables.size();
    for (int i = 0; i < count; i++) {
        View view = focusables.get(i);
        int viewTop = view.getTop();
        int viewBottom = view.getBottom();

        if (top < viewBottom && viewTop < bottom) {
            /*
             * the focusable is in the target area, it is a candidate for
             * focusing
             */

            final boolean viewIsFullyContained = (top < viewTop) && (viewBottom < bottom);

            if (focusCandidate == null) {
                /* No candidate, take this one */
                focusCandidate = view;
                foundFullyContainedFocusable = viewIsFullyContained;
            } else {
                final boolean viewIsCloserToBoundary = (topFocus && viewTop < focusCandidate.getTop())
                        || (!topFocus && viewBottom > focusCandidate.getBottom());

                if (foundFullyContainedFocusable) {
                    if (viewIsFullyContained && viewIsCloserToBoundary) {
                        /*
                         * We're dealing with only fully contained views, so
                         * it has to be closer to the boundary to beat our
                         * candidate
                         */
                        focusCandidate = view;
                    }
                } else {
                    if (viewIsFullyContained) {
                        /*
                         * Any fully contained view beats a partially
                         * contained view
                         */
                        focusCandidate = view;
                        foundFullyContainedFocusable = true;
                    } else if (viewIsCloserToBoundary) {
                        /*
                         * Partially contained view beats another partially
                         * contained view if it's closer
                         */
                        focusCandidate = view;
                    }
                }
            }
        }
    }

    return focusCandidate;
}

From source file:com.my.infiniteviewpager.view.InfiniteViewPager.java

void populate(int newCurrentItem) {
    ItemInfo oldCurInfo = null;//from  w  ww  .  j a v  a2 s. c  o  m
    if (mCurItem != newCurrentItem) {
        oldCurInfo = infoForPosition(mCurItem);
        mCurItem = newCurrentItem;
    }

    if (mAdapter == null) {
        sortChildDrawingOrder();
        return;
    }

    // Bail now if we are waiting to populate.  This is to hold off
    // on creating views from the time the user releases their finger to
    // fling to a new position until we have finished the scroll to
    // that position, avoiding glitches from happening at that point.
    if (mPopulatePending) {
        if (DEBUG)
            Log.i(TAG, "populate is pending, skipping for now...");
        sortChildDrawingOrder();
        return;
    }

    // Also, don't populate until we are attached to a window.  This is to
    // avoid trying to populate before we have restored our view hierarchy
    // state and conflicting with what is restored.
    if (getWindowToken() == null) {
        return;
    }

    mAdapter.startUpdate(this);

    final int pageLimit = mOffscreenPageLimit;

    // Locate the currently focused item or add it if needed.
    int curIndex = -1;
    ItemInfo curItem = null;
    for (curIndex = 0; curIndex < mItems.size(); curIndex++) {
        final ItemInfo ii = mItems.get(curIndex);
        if (ii.position >= mCurItem) {
            if (ii.position == mCurItem)
                curItem = ii;
            break;
        }
    }

    if (curItem == null) {
        curItem = addNewItem(mCurItem, curIndex);
    }

    // Fill 3x the available width or up to the number of offscreen
    // pages requested to either side, whichever is larger.
    // If we have no current item we have no work to do.
    if (curItem != null) {
        float extraWidthLeft = 0.f;
        int itemIndex = curIndex - 1;
        ItemInfo ii = itemIndex >= 0 ? mItems.get(itemIndex) : null;
        final int clientWidth = getClientWidth();
        final float leftWidthNeeded = clientWidth <= 0 ? 0
                : 2.f - curItem.widthFactor + (float) getPaddingLeft() / (float) clientWidth;
        for (int pos = mCurItem - 1;; pos--) {
            if (extraWidthLeft >= leftWidthNeeded) {
                if (ii == null) {
                    break;
                }
                if (pos == ii.position && !ii.scrolling) {
                    mItems.remove(itemIndex);
                    mAdapter.destroyItem(this, pos, ii.object);
                    if (DEBUG) {
                        Log.i(TAG,
                                "populate() - destroyItem() with pos: " + pos + " view: " + ((View) ii.object));
                    }
                    itemIndex--;
                    curIndex--;
                    ii = itemIndex >= 0 ? mItems.get(itemIndex) : null;
                }
            } else if (ii != null && pos == ii.position) {
                extraWidthLeft += ii.widthFactor;
                itemIndex--;
                ii = itemIndex >= 0 ? mItems.get(itemIndex) : null;
            } else {
                ii = addNewItem(pos, itemIndex + 1);
                extraWidthLeft += ii.widthFactor;
                curIndex++;
                ii = itemIndex >= 0 ? mItems.get(itemIndex) : null;
            }
        }

        float extraWidthRight = curItem.widthFactor;
        itemIndex = curIndex + 1;
        if (extraWidthRight < 2.f) {
            ii = itemIndex < mItems.size() ? mItems.get(itemIndex) : null;
            final float rightWidthNeeded = clientWidth <= 0 ? 0
                    : (float) getPaddingRight() / (float) clientWidth + 2.f;
            for (int pos = mCurItem + 1;; pos++) {
                if (extraWidthRight >= rightWidthNeeded) {
                    if (ii == null) {
                        break;
                    }
                    if (pos == ii.position && !ii.scrolling) {
                        mItems.remove(itemIndex);
                        mAdapter.destroyItem(this, pos, ii.object);
                        if (DEBUG) {
                            Log.i(TAG, "populate() - destroyItem() with pos: " + pos + " view: "
                                    + ((View) ii.object));
                        }
                        ii = itemIndex < mItems.size() ? mItems.get(itemIndex) : null;
                    }
                } else if (ii != null && pos == ii.position) {
                    extraWidthRight += ii.widthFactor;
                    itemIndex++;
                    ii = itemIndex < mItems.size() ? mItems.get(itemIndex) : null;
                } else {
                    ii = addNewItem(pos, itemIndex);
                    itemIndex++;
                    extraWidthRight += ii.widthFactor;
                    ii = itemIndex < mItems.size() ? mItems.get(itemIndex) : null;
                }
            }
        }

        calculatePageOffsets(curItem, curIndex, oldCurInfo);
    }

    if (DEBUG) {
        Log.i(TAG, "Current page list:");
        for (int i = 0; i < mItems.size(); i++) {
            Log.i(TAG, "#" + i + ": page " + mItems.get(i).position);
        }
    }

    mAdapter.setPrimaryItem(this, mCurItem, curItem != null ? curItem.object : null);

    mAdapter.finishUpdate(this);

    // Check width measurement of current pages and drawing sort order.
    // Update LayoutParams as needed.
    final int childCount = getChildCount();
    for (int i = 0; i < childCount; i++) {
        final View child = getChildAt(i);
        final LayoutParams lp = (LayoutParams) child.getLayoutParams();
        lp.childIndex = i;
        if (!lp.isDecor && lp.widthFactor == 0.f) {
            // 0 means requery the adapter for this, it doesn't have a valid width.
            final ItemInfo ii = infoForChild(child);
            if (ii != null) {
                lp.widthFactor = ii.widthFactor;
                lp.position = ii.position;
            }
        }
    }
    sortChildDrawingOrder();

    if (hasFocus()) {
        View currentFocused = findFocus();
        ItemInfo ii = currentFocused != null ? infoForAnyChild(currentFocused) : null;
        if (ii == null || ii.position != mCurItem) {
            for (int i = 0; i < getChildCount(); i++) {
                View child = getChildAt(i);
                ii = infoForChild(child);
                if (ii != null && ii.position == mCurItem) {
                    if (child.requestFocus(View.FOCUS_FORWARD)) {
                        break;
                    }
                }
            }
        }
    }
}

From source file:com.example.eventtest.CustomViews.ViewPager.java

void populate(int newCurrentItem) {
    ItemInfo oldCurInfo = null;/*  www. j  a  va2  s .c om*/
    if (mCurItem != newCurrentItem) {
        oldCurInfo = infoForPosition(mCurItem);
        mCurItem = newCurrentItem;
    }

    if (mAdapter == null) {
        sortChildDrawingOrder();
        return;
    }

    // Bail now if we are waiting to populate.  This is to hold off
    // on creating views from the time the user releases their finger to
    // fling to a new position until we have finished the scroll to
    // that position, avoiding glitches from happening at that point.
    if (mPopulatePending) {
        if (DEBUG)
            Log.i(TAG, "populate is pending, skipping for now...");
        sortChildDrawingOrder();
        return;
    }

    // Also, don't populate until we are attached to a window.  This is to
    // avoid trying to populate before we have restored our view hierarchy
    // state and conflicting with what is restored.
    if (getWindowToken() == null) {
        return;
    }

    mAdapter.startUpdate(this);

    final int pageLimit = mOffscreenPageLimit;
    final int startPos = Math.max(0, mCurItem - pageLimit);
    final int N = mAdapter.getCount();
    final int endPos = Math.min(N - 1, mCurItem + pageLimit);

    if (N != mExpectedAdapterCount) {
        String resName;
        try {
            resName = getResources().getResourceName(getId());
        } catch (Resources.NotFoundException e) {
            resName = Integer.toHexString(getId());
        }
        throw new IllegalStateException("The application's PagerAdapter changed the adapter's"
                + " contents without calling PagerAdapter#notifyDataSetChanged!"
                + " Expected adapter item count: " + mExpectedAdapterCount + ", found: " + N + " Pager id: "
                + resName + " Pager class: " + getClass() + " Problematic adapter: " + mAdapter.getClass());
    }

    // Locate the currently focused item or add it if needed.
    int curIndex = -1;
    ItemInfo curItem = null;
    for (curIndex = 0; curIndex < mItems.size(); curIndex++) {
        final ItemInfo ii = mItems.get(curIndex);
        if (ii.position >= mCurItem) {
            if (ii.position == mCurItem)
                curItem = ii;
            break;
        }
    }

    if (curItem == null && N > 0) {
        curItem = addNewItem(mCurItem, curIndex);
    }

    // Fill 3x the available width or up to the number of offscreen
    // pages requested to either side, whichever is larger.
    // If we have no current item we have no work to do.
    if (curItem != null) {
        float extraWidthLeft = 0.f;
        int itemIndex = curIndex - 1;
        ItemInfo ii = itemIndex >= 0 ? mItems.get(itemIndex) : null;
        final int clientWidth = getClientWidth();
        final float leftWidthNeeded = clientWidth <= 0 ? 0
                : 2.f - curItem.widthFactor + (float) getPaddingLeft() / (float) clientWidth;
        for (int pos = mCurItem - 1; pos >= 0; pos--) {
            if (extraWidthLeft >= leftWidthNeeded && pos < startPos) {
                if (ii == null) {
                    break;
                }
                if (pos == ii.position && !ii.scrolling) {
                    mItems.remove(itemIndex);
                    mAdapter.destroyItem(this, pos, ii.object);
                    if (DEBUG) {
                        Log.i(TAG,
                                "populate() - destroyItem() with pos: " + pos + " view: " + ((View) ii.object));
                    }
                    itemIndex--;
                    curIndex--;
                    ii = itemIndex >= 0 ? mItems.get(itemIndex) : null;
                }
            } else if (ii != null && pos == ii.position) {
                extraWidthLeft += ii.widthFactor;
                itemIndex--;
                ii = itemIndex >= 0 ? mItems.get(itemIndex) : null;
            } else {
                ii = addNewItem(pos, itemIndex + 1);
                extraWidthLeft += ii.widthFactor;
                curIndex++;
                ii = itemIndex >= 0 ? mItems.get(itemIndex) : null;
            }
        }

        float extraWidthRight = curItem.widthFactor;
        itemIndex = curIndex + 1;
        if (extraWidthRight < 2.f) {
            ii = itemIndex < mItems.size() ? mItems.get(itemIndex) : null;
            final float rightWidthNeeded = clientWidth <= 0 ? 0
                    : (float) getPaddingRight() / (float) clientWidth + 2.f;
            for (int pos = mCurItem + 1; pos < N; pos++) {
                if (extraWidthRight >= rightWidthNeeded && pos > endPos) {
                    if (ii == null) {
                        break;
                    }
                    if (pos == ii.position && !ii.scrolling) {
                        mItems.remove(itemIndex);
                        mAdapter.destroyItem(this, pos, ii.object);
                        if (DEBUG) {
                            Log.i(TAG, "populate() - destroyItem() with pos: " + pos + " view: "
                                    + ((View) ii.object));
                        }
                        ii = itemIndex < mItems.size() ? mItems.get(itemIndex) : null;
                    }
                } else if (ii != null && pos == ii.position) {
                    extraWidthRight += ii.widthFactor;
                    itemIndex++;
                    ii = itemIndex < mItems.size() ? mItems.get(itemIndex) : null;
                } else {
                    ii = addNewItem(pos, itemIndex);
                    itemIndex++;
                    extraWidthRight += ii.widthFactor;
                    ii = itemIndex < mItems.size() ? mItems.get(itemIndex) : null;
                }
            }
        }

        calculatePageOffsets(curItem, curIndex, oldCurInfo);
    }

    if (DEBUG) {
        Log.i(TAG, "Current page list:");
        for (int i = 0; i < mItems.size(); i++) {
            Log.i(TAG, "#" + i + ": page " + mItems.get(i).position);
        }
    }

    mAdapter.setPrimaryItem(this, mCurItem, curItem != null ? curItem.object : null);

    mAdapter.finishUpdate(this);

    // Check width measurement of current pages and drawing sort order.
    // Update LayoutParams as needed.
    final int childCount = getChildCount();
    for (int i = 0; i < childCount; i++) {
        final View child = getChildAt(i);
        final LayoutParams lp = (LayoutParams) child.getLayoutParams();
        lp.childIndex = i;
        if (!lp.isDecor && lp.widthFactor == 0.f) {
            // 0 means requery the adapter for this, it doesn't have a valid width.
            final ItemInfo ii = infoForChild(child);
            if (ii != null) {
                lp.widthFactor = ii.widthFactor;
                lp.position = ii.position;
            }
        }
    }
    sortChildDrawingOrder();

    if (hasFocus()) {
        View currentFocused = findFocus();
        ItemInfo ii = currentFocused != null ? infoForAnyChild(currentFocused) : null;
        if (ii == null || ii.position != mCurItem) {
            for (int i = 0; i < getChildCount(); i++) {
                View child = getChildAt(i);
                ii = infoForChild(child);
                if (ii != null && ii.position == mCurItem) {
                    if (child.requestFocus(View.FOCUS_FORWARD)) {
                        break;
                    }
                }
            }
        }
    }
}

From source file:com.ifnoif.androidtestdemo.customview.VViewPager.java

void populate(int newCurrentItem) {
    ItemInfo oldCurInfo = null;//from  ww w  .j  a  va 2 s.  c  om
    if (mCurItem != newCurrentItem) {
        oldCurInfo = infoForPosition(mCurItem);
        mCurItem = newCurrentItem;
    }

    if (mAdapter == null) {
        sortChildDrawingOrder();
        return;
    }

    // Bail now if we are waiting to populate.  This is to hold off
    // on creating views from the time the user releases their finger to
    // fling to a new position until we have finished the scroll to
    // that position, avoiding glitches from happening at that point.
    if (mPopulatePending) {
        if (DEBUG)
            Log.i(TAG, "populate is pending, skipping for now...");
        sortChildDrawingOrder();
        return;
    }

    // Also, don't populate until we are attached to a window.  This is to
    // avoid trying to populate before we have restored our view hierarchy
    // state and conflicting with what is restored.
    if (getWindowToken() == null) {
        return;
    }

    mAdapter.startUpdate(this);

    final int pageLimit = mOffscreenPageLimit;
    final int startPos = Math.max(0, mCurItem - pageLimit);
    final int N = mAdapter.getCount();
    final int endPos = Math.min(N - 1, mCurItem + pageLimit);

    if (N != mExpectedAdapterCount) {
        String resName;
        try {
            resName = getResources().getResourceName(getId());
        } catch (Resources.NotFoundException e) {
            resName = Integer.toHexString(getId());
        }
        throw new IllegalStateException("The application's PagerAdapter changed the adapter's"
                + " contents without calling PagerAdapter#notifyDataSetChanged!"
                + " Expected adapter item count: " + mExpectedAdapterCount + ", found: " + N + " Pager id: "
                + resName + " Pager class: " + getClass() + " Problematic adapter: " + mAdapter.getClass());
    }

    // Locate the currently focused item or add it if needed.
    int curIndex = -1;
    ItemInfo curItem = null;
    for (curIndex = 0; curIndex < mItems.size(); curIndex++) {
        final ItemInfo ii = mItems.get(curIndex);
        if (ii.position >= mCurItem) {
            if (ii.position == mCurItem)
                curItem = ii;
            break;
        }
    }

    if (curItem == null && N > 0) {
        curItem = addNewItem(mCurItem, curIndex);
    }

    // Fill 3x the available width or up to the number of offscreen
    // pages requested to either side, whichever is larger.
    // If we have no current item we have no work to do.
    if (curItem != null) {
        float extraHeightTop = 0.f;
        int itemIndex = curIndex - 1;
        ItemInfo ii = itemIndex >= 0 ? mItems.get(itemIndex) : null;
        final int clientHeight = getClientHeight();
        final float topNeeded = clientHeight <= 0 ? 0
                : 2.f - curItem.heightFactor + (float) getPaddingTop() / (float) clientHeight;
        for (int pos = mCurItem - 1; pos >= 0; pos--) {
            if (extraHeightTop >= topNeeded && pos < startPos) {
                if (ii == null) {
                    break;
                }
                if (pos == ii.position && !ii.scrolling) {
                    mItems.remove(itemIndex);
                    mAdapter.destroyItem(this, pos, ii.object);
                    if (DEBUG) {
                        Log.i(TAG,
                                "populate() - destroyItem() with pos: " + pos + " view: " + ((View) ii.object));
                    }
                    itemIndex--;
                    curIndex--;
                    ii = itemIndex >= 0 ? mItems.get(itemIndex) : null;
                }
            } else if (ii != null && pos == ii.position) {
                extraHeightTop += ii.heightFactor;
                itemIndex--;
                ii = itemIndex >= 0 ? mItems.get(itemIndex) : null;
            } else {
                ii = addNewItem(pos, itemIndex + 1);
                extraHeightTop += ii.heightFactor;
                curIndex++;
                ii = itemIndex >= 0 ? mItems.get(itemIndex) : null;
            }
        }

        float extraHeightBottom = curItem.heightFactor;
        itemIndex = curIndex + 1;
        if (extraHeightBottom < 2.f) {
            ii = itemIndex < mItems.size() ? mItems.get(itemIndex) : null;
            final float bottomHeightNeeded = clientHeight <= 0 ? 0
                    : (float) getPaddingBottom() / (float) clientHeight + 2.f;
            for (int pos = mCurItem + 1; pos < N; pos++) {
                if (extraHeightBottom >= bottomHeightNeeded && pos > endPos) {
                    if (ii == null) {
                        break;
                    }
                    if (pos == ii.position && !ii.scrolling) {
                        mItems.remove(itemIndex);
                        mAdapter.destroyItem(this, pos, ii.object);
                        if (DEBUG) {
                            Log.i(TAG, "populate() - destroyItem() with pos: " + pos + " view: "
                                    + ((View) ii.object));
                        }
                        ii = itemIndex < mItems.size() ? mItems.get(itemIndex) : null;
                    }
                } else if (ii != null && pos == ii.position) {
                    extraHeightBottom += ii.heightFactor;
                    itemIndex++;
                    ii = itemIndex < mItems.size() ? mItems.get(itemIndex) : null;
                } else {
                    ii = addNewItem(pos, itemIndex);
                    itemIndex++;
                    extraHeightBottom += ii.heightFactor;
                    ii = itemIndex < mItems.size() ? mItems.get(itemIndex) : null;
                }
            }
        }

        calculatePageOffsets(curItem, curIndex, oldCurInfo);
    }

    if (DEBUG) {
        Log.i(TAG, "Current page list:");
        for (int i = 0; i < mItems.size(); i++) {
            Log.i(TAG, "#" + i + ": page " + mItems.get(i).position);
        }
    }

    mAdapter.setPrimaryItem(this, mCurItem, curItem != null ? curItem.object : null);

    mAdapter.finishUpdate(this);

    // Check width measurement of current pages and drawing sort order.
    // Update LayoutParams as needed.
    final int childCount = getChildCount();
    for (int i = 0; i < childCount; i++) {
        final View child = getChildAt(i);
        final LayoutParams lp = (LayoutParams) child.getLayoutParams();
        lp.childIndex = i;
        if (!lp.isDecor && lp.heightFactor == 0.f) {
            // 0 means requery the adapter for this, it doesn't have a valid width.
            final ItemInfo ii = infoForChild(child);
            if (ii != null) {
                lp.heightFactor = ii.heightFactor;
                lp.position = ii.position;
            }
        }
    }
    sortChildDrawingOrder();

    if (hasFocus()) {
        View currentFocused = findFocus();
        ItemInfo ii = currentFocused != null ? infoForAnyChild(currentFocused) : null;
        if (ii == null || ii.position != mCurItem) {
            for (int i = 0; i < getChildCount(); i++) {
                View child = getChildAt(i);
                ii = infoForChild(child);
                if (ii != null && ii.position == mCurItem) {
                    if (child.requestFocus(View.FOCUS_FORWARD)) {
                        break;
                    }
                }
            }
        }
    }
}

From source file:com.stay4it.framework.widgets.LoopViewPager1.java

void populate(int newCurrentItem) {
    ItemInfo oldCurInfo = null;//from   w w  w.  j  a v a 2 s . co  m
    if (mCurItem != newCurrentItem) {
        oldCurInfo = infoForPosition(mCurItem);
        mCurItem = newCurrentItem;
    }

    if (mAdapter == null) {
        sortChildDrawingOrder();
        return;
    }

    // Bail now if we are waiting to populate.  This is to hold off
    // on creating views from the time the user releases their finger to
    // fling to a new position until we have finished the scroll to
    // that position, avoiding glitches from happening at that point.
    if (mPopulatePending) {
        if (DEBUG)
            Log.i(TAG, "populate is pending, skipping for now...");
        sortChildDrawingOrder();
        return;
    }

    // Also, don't populate until we are attached to a window.  This is to
    // avoid trying to populate before we have restored our view hierarchy
    // state and conflicting with what is restored.
    if (getWindowToken() == null) {
        return;
    }

    mAdapter.startUpdate(this);

    final int pageLimit = mOffscreenPageLimit;
    //        final int startPos = Math.max(0, mCurItem - pageLimit);
    final int startPos = mCurItem - pageLimit;
    final int N = mAdapter.getCount();
    //        final int endPos = Math.min(N-1, mCurItem + pageLimit);
    final int endPos = mCurItem + pageLimit;

    if (N != mExpectedAdapterCount) {
        String resName;
        try {
            resName = getResources().getResourceName(getId());
        } catch (Resources.NotFoundException e) {
            resName = Integer.toHexString(getId());
        }
        throw new IllegalStateException("The application's PagerAdapter changed the adapter's"
                + " contents without calling PagerAdapter#notifyDataSetChanged!"
                + " Expected adapter item count: " + mExpectedAdapterCount + ", found: " + N + " Pager id: "
                + resName + " Pager class: " + getClass() + " Problematic adapter: " + mAdapter.getClass());
    }

    // Locate the currently focused item or add it if needed.
    int curIndex = -1;
    ItemInfo curItem = null;
    for (curIndex = 0; curIndex < mItems.size(); curIndex++) {
        final ItemInfo ii = mItems.get(curIndex);
        if (ii.position >= mCurItem) {
            if (ii.position == mCurItem)
                curItem = ii;
            break;
        }
    }

    if (curItem == null && N > 0) {
        curItem = addNewItem(mCurItem, curIndex);
    }

    // Fill 3x the available width or up to the number of offscreen
    // pages requested to either side, whichever is larger.
    // If we have no current item we have no work to do.
    if (curItem != null) {
        float extraWidthLeft = 0.f;
        int itemIndex = curIndex - 1;
        ItemInfo ii = itemIndex >= 0 ? mItems.get(itemIndex) : null;
        final int clientWidth = getClientWidth();
        final float leftWidthNeeded = clientWidth <= 0 ? 0
                : 2.f - curItem.widthFactor + (float) getPaddingLeft() / (float) clientWidth;
        for (int pos = mCurItem - 1; pos >= 0; pos--) {
            if (extraWidthLeft >= leftWidthNeeded && pos < startPos) {
                if (ii == null) {
                    break;
                }
                if (pos == ii.position && !ii.scrolling) {
                    mItems.remove(itemIndex);
                    mAdapter.destroyItem(this, pos, ii.object);
                    if (DEBUG) {
                        Log.i(TAG,
                                "populate() - destroyItem() with pos: " + pos + " view: " + ((View) ii.object));
                    }
                    itemIndex--;
                    curIndex--;
                    ii = itemIndex >= 0 ? mItems.get(itemIndex) : null;
                }
            } else if (ii != null && pos == ii.position) {
                extraWidthLeft += ii.widthFactor;
                itemIndex--;
                ii = itemIndex >= 0 ? mItems.get(itemIndex) : null;
            } else {
                ii = addNewItem(pos, itemIndex + 1);
                extraWidthLeft += ii.widthFactor;
                curIndex++;
                ii = itemIndex >= 0 ? mItems.get(itemIndex) : null;
            }
        }

        float extraWidthRight = curItem.widthFactor;
        itemIndex = curIndex + 1;
        if (extraWidthRight < 2.f) {
            ii = itemIndex < mItems.size() ? mItems.get(itemIndex) : null;
            final float rightWidthNeeded = clientWidth <= 0 ? 0
                    : (float) getPaddingRight() / (float) clientWidth + 2.f;
            for (int pos = mCurItem + 1; pos < N; pos++) {
                if (extraWidthRight >= rightWidthNeeded && pos > endPos) {
                    if (ii == null) {
                        break;
                    }
                    if (pos == ii.position && !ii.scrolling) {
                        mItems.remove(itemIndex);
                        mAdapter.destroyItem(this, pos, ii.object);
                        if (DEBUG) {
                            Log.i(TAG, "populate() - destroyItem() with pos: " + pos + " view: "
                                    + ((View) ii.object));
                        }
                        ii = itemIndex < mItems.size() ? mItems.get(itemIndex) : null;
                    }
                } else if (ii != null && pos == ii.position) {
                    extraWidthRight += ii.widthFactor;
                    itemIndex++;
                    ii = itemIndex < mItems.size() ? mItems.get(itemIndex) : null;
                } else {
                    ii = addNewItem(pos, itemIndex);
                    itemIndex++;
                    extraWidthRight += ii.widthFactor;
                    ii = itemIndex < mItems.size() ? mItems.get(itemIndex) : null;
                }
            }
        }

        calculatePageOffsets(curItem, curIndex, oldCurInfo);
    }

    if (DEBUG) {
        Log.i(TAG, "Current page list:");
        for (int i = 0; i < mItems.size(); i++) {
            Log.i(TAG, "#" + i + ": page " + mItems.get(i).position);
        }
    }

    mAdapter.setPrimaryItem(this, mCurItem, curItem != null ? curItem.object : null);

    mAdapter.finishUpdate(this);

    // Check width measurement of current pages and drawing sort order.
    // Update LayoutParams as needed.
    final int childCount = getChildCount();
    for (int i = 0; i < childCount; i++) {
        final View child = getChildAt(i);
        final LayoutParams lp = (LayoutParams) child.getLayoutParams();
        lp.childIndex = i;
        if (!lp.isDecor && lp.widthFactor == 0.f) {
            // 0 means requery the adapter for this, it doesn't have a valid width.
            final ItemInfo ii = infoForChild(child);
            if (ii != null) {
                lp.widthFactor = ii.widthFactor;
                lp.position = ii.position;
            }
        }
    }
    sortChildDrawingOrder();

    if (hasFocus()) {
        View currentFocused = findFocus();
        ItemInfo ii = currentFocused != null ? infoForAnyChild(currentFocused) : null;
        if (ii == null || ii.position != mCurItem) {
            for (int i = 0; i < getChildCount(); i++) {
                View child = getChildAt(i);
                ii = infoForChild(child);
                if (ii != null && ii.position == mCurItem) {
                    if (child.requestFocus(View.FOCUS_FORWARD)) {
                        break;
                    }
                }
            }
        }
    }
}

From source file:example.luojing.androidsourceanalysis.ViewPager.java

/**
 * ViewPager?/*from  w w w.  j a v a2 s  . c  om*/
 */
void populate(int newCurrentItem) {
    ItemInfo oldCurInfo = null;
    if (mCurItem != newCurrentItem) {
        oldCurInfo = infoForPosition(mCurItem);
        mCurItem = newCurrentItem;
    }

    if (mAdapter == null) {
        sortChildDrawingOrder();
        return;
    }

    // Bail now if we are waiting to populate.  This is to hold off
    // on creating views from the time the user releases their finger to
    // fling to a new position until we have finished the scroll to
    // that position, avoiding glitches from happening at that point.
    if (mPopulatePending) {
        if (DEBUG)
            Log.i(TAG, "populate is pending, skipping for now...");
        sortChildDrawingOrder();
        return;
    }

    // Also, don't populate until we are attached to a window.  This is to
    // avoid trying to populate before we have restored our view hierarchy
    // state and conflicting with what is restored.
    if (getWindowToken() == null) {
        return;
    }

    mAdapter.startUpdate(this);

    final int pageLimit = mOffscreenPageLimit;
    final int startPos = Math.max(0, mCurItem - pageLimit);
    final int N = mAdapter.getCount();
    final int endPos = Math.min(N - 1, mCurItem + pageLimit);

    if (N != mExpectedAdapterCount) {
        String resName;
        try {
            resName = getResources().getResourceName(getId());
        } catch (Resources.NotFoundException e) {
            resName = Integer.toHexString(getId());
        }
        throw new IllegalStateException("The application's PagerAdapter changed the adapter's"
                + " contents without calling PagerAdapter#notifyDataSetChanged!"
                + " Expected adapter item count: " + mExpectedAdapterCount + ", found: " + N + " Pager id: "
                + resName + " Pager class: " + getClass() + " Problematic adapter: " + mAdapter.getClass());
    }

    // Locate the currently focused item or add it if needed.
    int curIndex = -1;
    ItemInfo curItem = null;
    for (curIndex = 0; curIndex < mItems.size(); curIndex++) {
        final ItemInfo ii = mItems.get(curIndex);
        if (ii.position >= mCurItem) {
            if (ii.position == mCurItem)
                curItem = ii;
            break;
        }
    }

    if (curItem == null && N > 0) {
        curItem = addNewItem(mCurItem, curIndex);
    }

    // Fill 3x the available width or up to the number of offscreen
    // pages requested to either side, whichever is larger.
    // If we have no current item we have no work to do.
    if (curItem != null) {
        float extraWidthLeft = 0.f;
        int itemIndex = curIndex - 1;
        ItemInfo ii = itemIndex >= 0 ? mItems.get(itemIndex) : null;
        final int clientWidth = getClientWidth();
        final float leftWidthNeeded = clientWidth <= 0 ? 0
                : 2.f - curItem.widthFactor + (float) getPaddingLeft() / (float) clientWidth;
        for (int pos = mCurItem - 1; pos >= 0; pos--) {
            if (extraWidthLeft >= leftWidthNeeded && pos < startPos) {
                if (ii == null) {
                    break;
                }
                if (pos == ii.position && !ii.scrolling) {
                    mItems.remove(itemIndex);
                    mAdapter.destroyItem(this, pos, ii.object);
                    if (DEBUG) {
                        Log.i(TAG,
                                "populate() - destroyItem() with pos: " + pos + " view: " + ((View) ii.object));
                    }
                    itemIndex--;
                    curIndex--;
                    ii = itemIndex >= 0 ? mItems.get(itemIndex) : null;
                }
            } else if (ii != null && pos == ii.position) {
                extraWidthLeft += ii.widthFactor;
                itemIndex--;
                ii = itemIndex >= 0 ? mItems.get(itemIndex) : null;
            } else {
                ii = addNewItem(pos, itemIndex + 1);
                extraWidthLeft += ii.widthFactor;
                curIndex++;
                ii = itemIndex >= 0 ? mItems.get(itemIndex) : null;
            }
        }

        float extraWidthRight = curItem.widthFactor;
        itemIndex = curIndex + 1;
        if (extraWidthRight < 2.f) {
            ii = itemIndex < mItems.size() ? mItems.get(itemIndex) : null;
            final float rightWidthNeeded = clientWidth <= 0 ? 0
                    : (float) getPaddingRight() / (float) clientWidth + 2.f;
            for (int pos = mCurItem + 1; pos < N; pos++) {
                if (extraWidthRight >= rightWidthNeeded && pos > endPos) {
                    if (ii == null) {
                        break;
                    }
                    if (pos == ii.position && !ii.scrolling) {
                        mItems.remove(itemIndex);
                        mAdapter.destroyItem(this, pos, ii.object);
                        if (DEBUG) {
                            Log.i(TAG, "populate() - destroyItem() with pos: " + pos + " view: "
                                    + ((View) ii.object));
                        }
                        ii = itemIndex < mItems.size() ? mItems.get(itemIndex) : null;
                    }
                } else if (ii != null && pos == ii.position) {
                    extraWidthRight += ii.widthFactor;
                    itemIndex++;
                    ii = itemIndex < mItems.size() ? mItems.get(itemIndex) : null;
                } else {
                    ii = addNewItem(pos, itemIndex);
                    itemIndex++;
                    extraWidthRight += ii.widthFactor;
                    ii = itemIndex < mItems.size() ? mItems.get(itemIndex) : null;
                }
            }
        }

        calculatePageOffsets(curItem, curIndex, oldCurInfo);
    }

    if (DEBUG) {
        Log.i(TAG, "Current page list:");
        for (int i = 0; i < mItems.size(); i++) {
            Log.i(TAG, "#" + i + ": page " + mItems.get(i).position);
        }
    }

    mAdapter.setPrimaryItem(this, mCurItem, curItem != null ? curItem.object : null);

    mAdapter.finishUpdate(this);

    // Check width measurement of current pages and drawing sort order.
    // Update LayoutParams as needed.
    final int childCount = getChildCount();
    for (int i = 0; i < childCount; i++) {
        final View child = getChildAt(i);
        final LayoutParams lp = (LayoutParams) child.getLayoutParams();
        lp.childIndex = i;
        if (!lp.isDecor && lp.widthFactor == 0.f) {
            // 0 means requery the adapter for this, it doesn't have a valid width.
            final ItemInfo ii = infoForChild(child);
            if (ii != null) {
                lp.widthFactor = ii.widthFactor;
                lp.position = ii.position;
            }
        }
    }
    sortChildDrawingOrder();

    if (hasFocus()) {
        View currentFocused = findFocus();
        ItemInfo ii = currentFocused != null ? infoForAnyChild(currentFocused) : null;
        if (ii == null || ii.position != mCurItem) {
            for (int i = 0; i < getChildCount(); i++) {
                View child = getChildAt(i);
                ii = infoForChild(child);
                if (ii != null && ii.position == mCurItem) {
                    if (child.requestFocus(View.FOCUS_FORWARD)) {
                        break;
                    }
                }
            }
        }
    }
}

From source file:com.stay4it.framework.widgets.LoopViewPager3.java

void populate(int newCurrentItem) {
    ItemInfo oldCurInfo = null;/*from   w  ww.j a v  a2  s.  c om*/
    if (mCurItem != newCurrentItem) {
        oldCurInfo = infoForPosition(mCurItem);
        mCurItem = newCurrentItem;
    }

    if (mAdapter == null) {
        sortChildDrawingOrder();
        return;
    }

    // Bail now if we are waiting to populate.  This is to hold off
    // on creating views from the time the user releases their finger to
    // fling to a new position until we have finished the scroll to
    // that position, avoiding glitches from happening at that point.
    if (mPopulatePending) {
        if (DEBUG)
            Log.i(TAG, "populate is pending, skipping for now...");
        sortChildDrawingOrder();
        return;
    }

    // Also, don't populate until we are attached to a window.  This is to
    // avoid trying to populate before we have restored our view hierarchy
    // state and conflicting with what is restored.
    if (getWindowToken() == null) {
        return;
    }

    mAdapter.startUpdate(this);

    final int pageLimit = mOffscreenPageLimit;
    //        FIXME
    //        final int startPos = Math.max(0, mCurItem - pageLimit);
    final int startPos = mCurItem - pageLimit;
    final int N = mAdapter.getCount();
    //        FIXME
    //        final int endPos = Math.min(N-1, mCurItem + pageLimit);
    final int endPos = mCurItem + pageLimit;

    if (N != mExpectedAdapterCount) {
        String resName;
        try {
            resName = getResources().getResourceName(getId());
        } catch (Resources.NotFoundException e) {
            resName = Integer.toHexString(getId());
        }
        throw new IllegalStateException("The application's PagerAdapter changed the adapter's"
                + " contents without calling PagerAdapter#notifyDataSetChanged!"
                + " Expected adapter item count: " + mExpectedAdapterCount + ", found: " + N + " Pager id: "
                + resName + " Pager class: " + getClass() + " Problematic adapter: " + mAdapter.getClass());
    }

    // Locate the currently focused item or add it if needed.
    int curIndex = -1;
    ItemInfo curItem = null;
    for (curIndex = 0; curIndex < mItems.size(); curIndex++) {
        final ItemInfo ii = mItems.get(curIndex);
        L.e("populate: find item----" + ii.position + ", curItem" + mCurItem);
        //            if (ii.position >= mCurItem) {
        if (ii.position == mCurItem) {
            curItem = ii;
            break;
        }
        //            }
    }

    if (curItem == null && N > 0) {

        curItem = addNewItem(mCurItem, curIndex);
    }

    // Fill 3x the available width or up to the number of offscreen
    // pages requested to either side, whichever is larger.
    // If we have no current item we have no work to do.
    if (curItem != null) {
        float extraWidthLeft = 0.f;
        int itemIndex = curIndex - 1;
        final int realLeftPos = (mCurItem - 1 + N) % N;
        ItemInfo ii = null;
        for (int i = 0; i < mItems.size(); i++) {
            final ItemInfo temp = mItems.get(i);
            if (temp.position == realLeftPos) {
                ii = temp;
                L.e("populate: find left -" + realLeftPos);
                break;
            }
        }

        final int clientWidth = getClientWidth();
        final float leftWidthNeeded = clientWidth <= 0 ? 0
                : 2.f - curItem.widthFactor + (float) getPaddingLeft() / (float) clientWidth;
        for (int pos = mCurItem - 1; pos >= startPos; pos--) {
            //                FIXME
            //            for (int pos = mCurItem - 1; pos >= 0; pos--) {
            L.e("populate: fill left -" + pos);

            if (extraWidthLeft >= leftWidthNeeded && pos < startPos) {
                L.e("sssssss" + pos + "," + startPos);
                if (ii == null) {
                    break;
                }
                if (pos == ii.position && !ii.scrolling) {
                    mItems.remove(itemIndex);
                    mAdapter.destroyItem(this, pos, ii.object);
                    if (DEBUG) {
                        Log.i(TAG, "populate() - destroyItem() with pos left: " + pos + " view: "
                                + ((View) ii.object));
                    }
                    L.e("populate() - destroyItem() with pos: " + pos + " view: " + ((View) ii.object));
                    itemIndex--;
                    curIndex--;
                    ii = itemIndex >= 0 ? mItems.get(itemIndex) : null;
                }
            } else if (ii != null && (pos == ii.position || realLeftPos == ii.position)) {
                L.e("populate: fill left : ignore" + pos);
                extraWidthLeft += ii.widthFactor;
                itemIndex--;
                ii = itemIndex >= 0 ? mItems.get(itemIndex) : null;
            } else {
                L.e("populate: sss: sss" + pos);
                ii = addNewItem(pos, itemIndex + 1);
                extraWidthLeft += ii.widthFactor;
                curIndex++;
                ii = itemIndex >= 0 ? mItems.get(itemIndex) : null;
            }
        }

        float extraWidthRight = curItem.widthFactor;
        itemIndex = curIndex + 1;
        if (extraWidthRight < 2.f) {
            //                ii = itemIndex < mItems.size() ? mItems.get(itemIndex) : null;
            final int realRightPos = (mCurItem - 1 + N) % N;
            for (int i = 0; i < mItems.size(); i++) {
                final ItemInfo temp = mItems.get(i);
                if (temp.position == realLeftPos) {
                    ii = temp;
                    L.e("populate: find right -" + realLeftPos);
                    break;
                }
            }
            final float rightWidthNeeded = clientWidth <= 0 ? 0
                    : (float) getPaddingRight() / (float) clientWidth + 2.f;
            //                for (int pos = mCurItem + 1; pos < N; pos++) {
            for (int pos = mCurItem + 1; pos < endPos; pos++) {
                L.e("populate: fill right -" + pos);
                if (extraWidthRight >= rightWidthNeeded && pos > endPos) {
                    if (ii == null) {
                        break;
                    }
                    if (pos == ii.position && !ii.scrolling) {
                        mItems.remove(itemIndex);
                        mAdapter.destroyItem(this, pos, ii.object);
                        if (DEBUG) {
                            Log.i(TAG, "populate() - destroyItem() with pos: " + pos + " view: "
                                    + ((View) ii.object));
                        }
                        L.e("populate() - destroyItem() with pos right: " + pos + " view: "
                                + ((View) ii.object));
                        ii = itemIndex < mItems.size() ? mItems.get(itemIndex) : null;
                    }
                } else if (ii != null && (pos == ii.position || realRightPos == ii.position)) {
                    extraWidthRight += ii.widthFactor;
                    itemIndex++;
                    ii = itemIndex < mItems.size() ? mItems.get(itemIndex) : null;
                } else {
                    ii = addNewItem(pos, itemIndex);
                    itemIndex++;
                    extraWidthRight += ii.widthFactor;
                    ii = itemIndex < mItems.size() ? mItems.get(itemIndex) : null;
                }
            }
        }

        calculatePageOffsets(curItem, curIndex, oldCurInfo);
    }

    if (DEBUG) {
        Log.i(TAG, "Current page list:");
        for (int i = 0; i < mItems.size(); i++) {
            Log.i(TAG, "#" + i + ": page " + mItems.get(i).position);
        }
    }

    mAdapter.setPrimaryItem(this, mCurItem, curItem != null ? curItem.object : null);

    mAdapter.finishUpdate(this);

    // Check width measurement of current pages and drawing sort order.
    // Update LayoutParams as needed.
    final int childCount = getChildCount();
    for (int i = 0; i < childCount; i++) {
        final View child = getChildAt(i);
        final LayoutParams lp = (LayoutParams) child.getLayoutParams();
        lp.childIndex = i;
        if (!lp.isDecor && lp.widthFactor == 0.f) {
            // 0 means requery the adapter for this, it doesn't have a valid width.
            final ItemInfo ii = infoForChild(child);
            if (ii != null) {
                lp.widthFactor = ii.widthFactor;
                lp.position = ii.position;
            }
        }
    }
    sortChildDrawingOrder();

    if (hasFocus()) {
        View currentFocused = findFocus();
        ItemInfo ii = currentFocused != null ? infoForAnyChild(currentFocused) : null;
        if (ii == null || ii.position != mCurItem) {
            for (int i = 0; i < getChildCount(); i++) {
                View child = getChildAt(i);
                ii = infoForChild(child);
                if (ii != null && ii.position == mCurItem) {
                    if (child.requestFocus(View.FOCUS_FORWARD)) {
                        break;
                    }
                }
            }
        }
    }
}

From source file:com.av.remusic.widget.RoundViewPager.java

void populate(int newCurrentItem) {
    ItemInfo oldCurInfo = null;//  ww  w  .j  a v a2 s .  com
    if (mCurItem != newCurrentItem) {
        oldCurInfo = infoForPosition(mCurItem);
        mCurItem = newCurrentItem;
    }

    if (mAdapter == null) {
        sortChildDrawingOrder();
        return;
    }

    // Bail now if we are waiting to populate.  This is to hold off
    // on creating views from the time the user releases their finger to
    // fling to a new position until we have finished the scroll to
    // that position, avoiding glitches from happening at that point.
    if (mPopulatePending) {
        if (DEBUG)
            Log.i(TAG, "populate is pending, skipping for now...");
        sortChildDrawingOrder();
        return;
    }

    // Also, don't populate until we are attached to a window.  This is to
    // avoid trying to populate before we have restored our view hierarchy
    // state and conflicting with what is restored.
    if (getWindowToken() == null) {
        return;
    }

    mAdapter.startUpdate(this);

    final int pageLimit = mOffscreenPageLimit;
    final int startPos = Math.max(0, mCurItem - pageLimit);
    final int N = mAdapter.getCount();
    final int endPos = Math.min(N - 1, mCurItem + pageLimit);

    if (N != mExpectedAdapterCount) {
        String resName;
        try {
            resName = getResources().getResourceName(getId());
        } catch (Resources.NotFoundException e) {
            resName = Integer.toHexString(getId());
        }
        throw new IllegalStateException("The application's PagerAdapter changed the adapter's"
                + " contents without calling PagerAdapter#notifyDataSetChanged!"
                + " Expected adapter item count: " + mExpectedAdapterCount + ", found: " + N + " Pager id: "
                + resName + " Pager class: " + getClass() + " Problematic adapter: " + mAdapter.getClass());
    }

    // Locate the currently focused item or add it if needed.
    int curIndex = -1;
    ItemInfo curItem = null;
    for (curIndex = 0; curIndex < mItems.size(); curIndex++) {
        final ItemInfo ii = mItems.get(curIndex);
        if (ii.position >= mCurItem) {
            if (ii.position == mCurItem)
                curItem = ii;
            break;
        }
    }

    if (curItem == null && N > 0) {
        curItem = addNewItem(mCurItem, curIndex);
    }

    // Fill 3x the available width or up to the number of offscreen
    // pages requested to either side, whichever is larger.
    // If we have no currentPosition item we have no work to do.
    if (curItem != null) {
        float extraWidthLeft = 0.f;
        int itemIndex = curIndex - 1;
        ItemInfo ii = itemIndex >= 0 ? mItems.get(itemIndex) : null;
        final int clientWidth = getClientWidth();
        final float leftWidthNeeded = clientWidth <= 0 ? 0
                : 2.f - curItem.widthFactor + (float) getPaddingLeft() / (float) clientWidth;
        for (int pos = mCurItem - 1; pos >= 0; pos--) {
            if (extraWidthLeft >= leftWidthNeeded && pos < startPos) {
                if (ii == null) {
                    break;
                }
                if (pos == ii.position && !ii.scrolling) {
                    mItems.remove(itemIndex);
                    mAdapter.destroyItem(this, pos, ii.object);
                    if (DEBUG) {
                        Log.i(TAG,
                                "populate() - destroyItem() with pos: " + pos + " view: " + ((View) ii.object));
                    }
                    itemIndex--;
                    curIndex--;
                    ii = itemIndex >= 0 ? mItems.get(itemIndex) : null;
                }
            } else if (ii != null && pos == ii.position) {
                extraWidthLeft += ii.widthFactor;
                itemIndex--;
                ii = itemIndex >= 0 ? mItems.get(itemIndex) : null;
            } else {
                ii = addNewItem(pos, itemIndex + 1);
                extraWidthLeft += ii.widthFactor;
                curIndex++;
                ii = itemIndex >= 0 ? mItems.get(itemIndex) : null;
            }
        }

        float extraWidthRight = curItem.widthFactor;
        itemIndex = curIndex + 1;
        if (extraWidthRight < 2.f) {
            ii = itemIndex < mItems.size() ? mItems.get(itemIndex) : null;
            final float rightWidthNeeded = clientWidth <= 0 ? 0
                    : (float) getPaddingRight() / (float) clientWidth + 2.f;
            for (int pos = mCurItem + 1; pos < N; pos++) {
                if (extraWidthRight >= rightWidthNeeded && pos > endPos) {
                    if (ii == null) {
                        break;
                    }
                    if (pos == ii.position && !ii.scrolling) {
                        mItems.remove(itemIndex);
                        mAdapter.destroyItem(this, pos, ii.object);
                        if (DEBUG) {
                            Log.i(TAG, "populate() - destroyItem() with pos: " + pos + " view: "
                                    + ((View) ii.object));
                        }
                        ii = itemIndex < mItems.size() ? mItems.get(itemIndex) : null;
                    }
                } else if (ii != null && pos == ii.position) {
                    extraWidthRight += ii.widthFactor;
                    itemIndex++;
                    ii = itemIndex < mItems.size() ? mItems.get(itemIndex) : null;
                } else {
                    ii = addNewItem(pos, itemIndex);
                    itemIndex++;
                    extraWidthRight += ii.widthFactor;
                    ii = itemIndex < mItems.size() ? mItems.get(itemIndex) : null;
                }
            }
        }

        calculatePageOffsets(curItem, curIndex, oldCurInfo);
    }

    if (DEBUG) {
        Log.i(TAG, "Current page list:");
        for (int i = 0; i < mItems.size(); i++) {
            Log.i(TAG, "#" + i + ": page " + mItems.get(i).position);
        }
    }

    mAdapter.setPrimaryItem(this, mCurItem, curItem != null ? curItem.object : null);

    mAdapter.finishUpdate(this);

    // Check width measurement of currentPosition pages and drawing sort order.
    // Update LayoutParams as needed.
    final int childCount = getChildCount();
    for (int i = 0; i < childCount; i++) {
        final View child = getChildAt(i);
        final LayoutParams lp = (LayoutParams) child.getLayoutParams();
        lp.childIndex = i;
        if (!lp.isDecor && lp.widthFactor == 0.f) {
            // 0 means requery the adapter for this, it doesn't have a valid width.
            final ItemInfo ii = infoForChild(child);
            if (ii != null) {
                lp.widthFactor = ii.widthFactor;
                lp.position = ii.position;
            }
        }
    }
    sortChildDrawingOrder();

    if (hasFocus()) {
        View currentFocused = findFocus();
        ItemInfo ii = currentFocused != null ? infoForAnyChild(currentFocused) : null;
        if (ii == null || ii.position != mCurItem) {
            for (int i = 0; i < getChildCount(); i++) {
                View child = getChildAt(i);
                ii = infoForChild(child);
                if (ii != null && ii.position == mCurItem) {
                    if (child.requestFocus(View.FOCUS_FORWARD)) {
                        break;
                    }
                }
            }
        }
    }
}

From source file:com.example.sky.test.view.ViewPager.java

void populate(int newCurrentItem) {
    ItemInfo oldCurInfo = null;/*from w w w.  ja va2 s .  co  m*/
    if (mCurItem != newCurrentItem) {
        oldCurInfo = infoForPosition(mCurItem);
        mCurItem = newCurrentItem;
    }

    if (mAdapter == null) {
        sortChildDrawingOrder();
        return;
    }

    // Bail now if we are waiting to populate.  This is to hold off
    // on creating views from the time the user releases their finger to
    // fling to a new position until we have finished the scroll to
    // that position, avoiding glitches from happening at that point.
    if (mPopulatePending) {
        if (DEBUG)
            Log.i(TAG, "populate is pending, skipping for now...");
        sortChildDrawingOrder();
        return;
    }

    // Also, don't populate until we are attached to a window.  This is to
    // avoid trying to populate before we have restored our view hierarchy
    // state and conflicting with what is restored.
    if (getWindowToken() == null) {
        return;
    }

    mAdapter.startUpdate(this);

    final int pageLimit = mOffscreenPageLimit;
    final int startPos = Math.max(0, mCurItem - pageLimit);
    final int N = mAdapter.getCount();
    final int endPos = Math.min(N - 1, mCurItem + pageLimit);

    if (N != mExpectedAdapterCount) {
        String resName;
        try {
            resName = getResources().getResourceName(getId());
        } catch (Resources.NotFoundException e) {
            resName = Integer.toHexString(getId());
        }
        throw new IllegalStateException("The application's PagerAdapter changed the adapter's"
                + " contents without calling PagerAdapter#notifyDataSetChanged!"
                + " Expected adapter item count: " + mExpectedAdapterCount + ", found: " + N + " Pager id: "
                + resName + " Pager class: " + getClass() + " Problematic adapter: " + mAdapter.getClass());
    }

    // Locate the currently focused item or add it if needed.
    int curIndex = -1;
    ItemInfo curItem = null;
    for (curIndex = 0; curIndex < mItems.size(); curIndex++) {
        final ItemInfo ii = mItems.get(curIndex);
        if (ii.position >= mCurItem) {
            if (ii.position == mCurItem)
                curItem = ii;
            break;
        }
    }

    if (curItem == null && N > 0) {
        curItem = addNewItem(mCurItem, curIndex);
    }

    // Fill 3x the available width or up to the number of offscreen
    // pages requested to either side, whichever is larger.
    // If we have no current item we have no work to do.
    if (curItem != null) {
        float extraWidthLeft = 0.f;
        int itemIndex = curIndex - 1;
        ItemInfo ii = itemIndex >= 0 ? mItems.get(itemIndex) : null;
        final int clientWidth = getClientWidth();
        final float leftWidthNeeded = clientWidth <= 0 ? 0
                : 2.f - curItem.widthFactor + (float) getPaddingLeft() / (float) clientWidth;
        for (int pos = mCurItem - 1; pos >= 0; pos--) {
            if (extraWidthLeft >= leftWidthNeeded && pos < startPos) {
                if (ii == null) {
                    break;
                }
                if (pos == ii.position && !ii.scrolling) {
                    mItems.remove(itemIndex);
                    mAdapter.destroyItem(this, pos, ii.object);
                    if (DEBUG) {
                        Log.i(TAG,
                                "populate() - destroyItem() with pos: " + pos + " view: " + ((View) ii.object));
                    }
                    itemIndex--;
                    curIndex--;
                    ii = itemIndex >= 0 ? mItems.get(itemIndex) : null;
                }
            } else if (ii != null && pos == ii.position) {
                extraWidthLeft += ii.widthFactor;
                itemIndex--;
                ii = itemIndex >= 0 ? mItems.get(itemIndex) : null;
            } else {
                ii = addNewItem(pos, itemIndex + 1);
                extraWidthLeft += ii.widthFactor;
                curIndex++;
                ii = itemIndex >= 0 ? mItems.get(itemIndex) : null;
            }
        }

        float extraWidthRight = curItem.widthFactor;
        itemIndex = curIndex + 1;
        if (extraWidthRight < 2.f) {
            ii = itemIndex < mItems.size() ? mItems.get(itemIndex) : null;
            final float rightWidthNeeded = clientWidth <= 0 ? 0
                    : (float) getPaddingRight() / (float) clientWidth + 2.f;
            for (int pos = mCurItem + 1; pos < N; pos++) {
                if (extraWidthRight >= rightWidthNeeded && pos > endPos) {
                    if (ii == null) {
                        break;
                    }
                    if (pos == ii.position && !ii.scrolling) {
                        mItems.remove(itemIndex);
                        mAdapter.destroyItem(this, pos, ii.object);
                        if (DEBUG) {
                            Log.i(TAG, "populate() - destroyItem() with pos: " + pos + " view: "
                                    + ((View) ii.object));
                        }
                        ii = itemIndex < mItems.size() ? mItems.get(itemIndex) : null;
                    }
                } else if (ii != null && pos == ii.position) {
                    extraWidthRight += ii.widthFactor;
                    itemIndex++;
                    ii = itemIndex < mItems.size() ? mItems.get(itemIndex) : null;
                } else {
                    ii = addNewItem(pos, itemIndex);
                    itemIndex++;
                    extraWidthRight += ii.widthFactor;
                    ii = itemIndex < mItems.size() ? mItems.get(itemIndex) : null;
                }
            }
        }

        calculatePageOffsets(curItem, curIndex, oldCurInfo);
    }

    if (DEBUG) {
        Log.i(TAG, "Current page list:");
        for (int i = 0; i < mItems.size(); i++) {
            Log.i(TAG, "#" + i + ": page " + mItems.get(i).position);
        }
    }

    mAdapter.setPrimaryItem(this, mCurItem, curItem != null ? curItem.object : null);

    mAdapter.finishUpdate(this);

    // Check width measurement of current pages and drawing sort order.
    // Update LayoutParams as needed.
    final int childCount = getChildCount();
    for (int i = 0; i < childCount; i++) {
        final View child = getChildAt(i);
        final ViewPager.LayoutParams lp = (ViewPager.LayoutParams) child.getLayoutParams();
        lp.childIndex = i;
        if (!lp.isDecor && lp.widthFactor == 0.f) {
            // 0 means requery the adapter for this, it doesn't have a valid width.
            final ItemInfo ii = infoForChild(child);
            if (ii != null) {
                lp.widthFactor = ii.widthFactor;
                lp.position = ii.position;
            }
        }
    }
    sortChildDrawingOrder();

    if (hasFocus()) {
        View currentFocused = findFocus();
        ItemInfo ii = currentFocused != null ? infoForAnyChild(currentFocused) : null;
        if (ii == null || ii.position != mCurItem) {
            for (int i = 0; i < getChildCount(); i++) {
                View child = getChildAt(i);
                ii = infoForChild(child);
                if (ii != null && ii.position == mCurItem) {
                    if (child.requestFocus(View.FOCUS_FORWARD)) {
                        break;
                    }
                }
            }
        }
    }
}