/**
* Sets the current item. Does nothing when index is wrong.
*
* @param index the item index
* @param animated the animation flag
*/
public void setCurrentItem(int index, boolean animated) {
if (adapter == null || adapter.getItemsCount() == 0) {
return; // throw?
}
if (index < 0 || index >= adapter.getItemsCount()) {
if (isCyclic) {
while (index < 0) {
index += adapter.getItemsCount();
}
index %= adapter.getItemsCount();
} else {
return; // throw?
}
}
if (index != currentItem) {
if (animated) {
scroll(index - currentItem, SCROLLING_DURATION);
} else {
invalidateLayouts();
int old = currentItem;
currentItem = index;
notifyChangingListeners(old, currentItem);
invalidate();
}
}
}
/**
* Returns text item by index
*
* @param index the item index
* @return the item or null
*/
private String getTextItem(int index) {
if (adapter == null || adapter.getItemsCount() == 0) {
return null;
}
int count = adapter.getItemsCount();
if ((index < 0 || index >= count) && !isCyclic) {
return null;
} else {
while (index < 0) {
index = count + index;
}
}
index %= count;
return adapter.getItem(index);
}
public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {
lastScrollY = currentItem * getItemHeight() + scrollingOffset;
int maxY = isCyclic ? 0x7FFFFFFF : adapter.getItemsCount() * getItemHeight();
int minY = isCyclic ? -maxY : 0;
scroller.fling(0, lastScrollY, 0, (int) -velocityY / 2, 0, 0, minY, maxY);
setNextMessage(MESSAGE_SCROLL);
return true;
}
/**
* Returns the max item length that can be present
*
* @return the max length
*/
private int getMaxTextLength() {
WheelAdapter adapter = getAdapter();
if (adapter == null) {
return 0;
}
int adapterLength = adapter.getMaximumLength();
if (adapterLength > 0) {
return adapterLength;
}
String maxText = null;
int addItems = visibleItems / 2;
for (int i = Math.max(currentItem - addItems, 0);
i < Math.min(currentItem + visibleItems, adapter.getItemsCount());
i++) {
String text = adapter.getItem(i);
if (text != null && (maxText == null || maxText.length() < text.length())) {
maxText = text;
}
}
return maxText != null ? maxText.length() : 0;
}
/** Justifies wheel */
private void justify() {
if (adapter == null) {
return;
}
lastScrollY = 0;
int offset = scrollingOffset;
int itemHeight = getItemHeight();
boolean needToIncrease = offset > 0 ? currentItem < adapter.getItemsCount() : currentItem > 0;
if ((isCyclic || needToIncrease) && Math.abs((float) offset) > (float) itemHeight / 2) {
if (offset < 0) offset += itemHeight + MIN_DELTA_FOR_SCROLLING;
else offset -= itemHeight + MIN_DELTA_FOR_SCROLLING;
}
if (Math.abs(offset) > MIN_DELTA_FOR_SCROLLING) {
scroller.startScroll(0, 0, 0, offset, SCROLLING_DURATION);
setNextMessage(MESSAGE_JUSTIFY);
} else {
finishScrolling();
}
}
/**
* Scrolls the wheel
*
* @param delta the scrolling value
*/
private void doScroll(int delta) {
scrollingOffset += delta;
int count = scrollingOffset / getItemHeight();
int pos = currentItem - count;
if (isCyclic && adapter.getItemsCount() > 0) {
// fix position by rotating
while (pos < 0) {
pos += adapter.getItemsCount();
}
pos %= adapter.getItemsCount();
} else if (isScrollingPerformed) {
//
if (pos < 0) {
count = currentItem;
pos = 0;
} else if (pos >= adapter.getItemsCount()) {
count = currentItem - adapter.getItemsCount() + 1;
pos = adapter.getItemsCount() - 1;
}
} else {
// fix position
pos = Math.max(pos, 0);
pos = Math.min(pos, adapter.getItemsCount() - 1);
}
int offset = scrollingOffset;
if (pos != currentItem) {
setCurrentItem(pos, false);
} else {
invalidate();
}
// update offset
scrollingOffset = offset - count * getItemHeight();
if (scrollingOffset > getHeight()) {
scrollingOffset = scrollingOffset % getHeight() + getHeight();
}
}
@Override
protected CharSequence getItemText(int index) {
return adapter.getItem(index);
}
@Override
public int getItemsCount() {
return adapter.getItemsCount();
}
