void addMarker(int index, PageMarkerResources marker, boolean allowAnimations) {
index = Math.max(0, Math.min(index, mMarkers.size()));
PageIndicatorMarker m =
(PageIndicatorMarker) mLayoutInflater.inflate(R.layout.page_indicator_marker, this, false);
m.setMarkerDrawables(marker.activeId, marker.inactiveId);
mMarkers.add(index, m);
offsetWindowCenterTo(mActiveMarkerIndex, allowAnimations);
}
void offsetWindowCenterTo(int activeIndex, boolean allowAnimations) {
if (activeIndex < 0) {
new Throwable().printStackTrace();
}
int windowSize = Math.min(mMarkers.size(), mMaxWindowSize);
int hWindowSize = (int) windowSize / 2;
float hfWindowSize = windowSize / 2f;
int windowStart = Math.max(0, activeIndex - hWindowSize);
int windowEnd = Math.min(mMarkers.size(), windowStart + mMaxWindowSize);
windowStart = windowEnd - Math.min(mMarkers.size(), windowSize);
int windowMid = windowStart + (windowEnd - windowStart) / 2;
boolean windowAtStart = (windowStart == 0);
boolean windowAtEnd = (windowEnd == mMarkers.size());
boolean windowMoved = (mWindowRange[0] != windowStart) || (mWindowRange[1] != windowEnd);
if (!allowAnimations) {
disableLayoutTransitions();
}
// Remove all the previous children that are no longer in the window
for (int i = getChildCount() - 1; i >= 0; --i) {
PageIndicatorMarker marker = (PageIndicatorMarker) getChildAt(i);
int markerIndex = mMarkers.indexOf(marker);
if (markerIndex < windowStart || markerIndex >= windowEnd) {
removeView(marker);
}
}
// Add all the new children that belong in the window
for (int i = 0; i < mMarkers.size(); ++i) {
PageIndicatorMarker marker = (PageIndicatorMarker) mMarkers.get(i);
if (windowStart <= i && i < windowEnd) {
if (indexOfChild(marker) < 0) {
addView(marker, i - windowStart);
}
if (i == activeIndex) {
marker.activate(windowMoved);
} else {
marker.inactivate(windowMoved);
}
} else {
marker.inactivate(true);
}
if (MODULATE_ALPHA_ENABLED) {
// Update the marker's alpha
float alpha = 1f;
if (mMarkers.size() > windowSize) {
if ((windowAtStart && i > hWindowSize)
|| (windowAtEnd && i < (mMarkers.size() - hWindowSize))
|| (!windowAtStart && !windowAtEnd)) {
alpha = 1f - Math.abs((i - windowMid) / hfWindowSize);
}
}
marker.animate().alpha(alpha).setDuration(500).start();
}
}
if (!allowAnimations) {
enableLayoutTransitions();
}
mWindowRange[0] = windowStart;
mWindowRange[1] = windowEnd;
}
void updateMarker(int index, PageMarkerResources marker) {
PageIndicatorMarker m = mMarkers.get(index);
m.setMarkerDrawables(marker.activeId, marker.inactiveId);
}
