/**
* @param startChild View closest to start of the list. (top or left)
* @param endChild View closest to end of the list (bottom or right)
*/
static int computeScrollOffset(
RecyclerView.State state,
OrientationHelper orientation,
View startChild,
View endChild,
RecyclerView.LayoutManager lm,
boolean smoothScrollbarEnabled,
boolean reverseLayout) {
if (lm.getChildCount() == 0
|| state.getItemCount() == 0
|| startChild == null
|| endChild == null) {
return 0;
}
final int minPosition = Math.min(lm.getPosition(startChild), lm.getPosition(endChild));
final int maxPosition = Math.max(lm.getPosition(startChild), lm.getPosition(endChild));
final int itemsBefore =
reverseLayout
? Math.max(0, state.getItemCount() - maxPosition - 1)
: Math.max(0, minPosition - 1);
if (!smoothScrollbarEnabled) {
return itemsBefore;
}
final int laidOutArea =
Math.abs(orientation.getDecoratedEnd(endChild) - orientation.getDecoratedStart(startChild));
final int itemRange = Math.abs(lm.getPosition(startChild) - lm.getPosition(endChild)) + 1;
final float avgSizePerRow = (float) laidOutArea / itemRange;
return Math.round(
itemsBefore * avgSizePerRow
+ (orientation.getStartAfterPadding() - orientation.getDecoratedStart(startChild)));
}
@Override
public void onRestoreInstanceState(Parcelable state) {
super.onRestoreInstanceState(state);
if (state instanceof LayoutManagerSavedState) {
mUuid = ((LayoutManagerSavedState) state).mUuid;
}
}
@Override
public void onAdapterChanged(RecyclerView.Adapter oldAdapter, RecyclerView.Adapter newAdapter) {
super.onAdapterChanged(oldAdapter, newAdapter);
mPrevAdapter = oldAdapter;
mNextAdapter = newAdapter;
mAdapterChangedCount++;
}
/**
* @param startChild View closest to start of the list. (top or left)
* @param endChild View closest to end of the list (bottom or right)
*/
static int computeScrollExtent(
RecyclerView.State state,
OrientationHelper orientation,
View startChild,
View endChild,
RecyclerView.LayoutManager lm,
boolean smoothScrollbarEnabled) {
if (lm.getChildCount() == 0
|| state.getItemCount() == 0
|| startChild == null
|| endChild == null) {
return 0;
}
if (!smoothScrollbarEnabled) {
return Math.abs(lm.getPosition(startChild) - lm.getPosition(endChild)) + 1;
}
final int extend =
orientation.getDecoratedEnd(endChild) - orientation.getDecoratedStart(startChild);
return Math.min(orientation.getTotalSpace(), extend);
}
/**
* @param startChild View closest to start of the list. (top or left)
* @param endChild View closest to end of the list (bottom or right)
*/
static int computeScrollRange(
RecyclerView.State state,
OrientationHelper orientation,
View startChild,
View endChild,
RecyclerView.LayoutManager lm,
boolean smoothScrollbarEnabled) {
if (lm.getChildCount() == 0
|| state.getItemCount() == 0
|| startChild == null
|| endChild == null) {
return 0;
}
if (!smoothScrollbarEnabled) {
return state.getItemCount();
}
// smooth scrollbar enabled. try to estimate better.
final int laidOutArea =
orientation.getDecoratedEnd(endChild) - orientation.getDecoratedStart(startChild);
final int laidOutRange = Math.abs(lm.getPosition(startChild) - lm.getPosition(endChild)) + 1;
// estimate a size for full list.
return (int) ((float) laidOutArea / laidOutRange * state.getItemCount());
}
static int computeScrollExtent(
RecyclerView.State paramState,
OrientationHelper paramOrientationHelper,
View paramView1,
View paramView2,
RecyclerView.LayoutManager paramLayoutManager,
boolean paramBoolean) {
if ((paramLayoutManager.getChildCount() == 0)
|| (paramState.getItemCount() == 0)
|| (paramView1 == null)
|| (paramView2 == null)) {
return 0;
}
if (!paramBoolean) {
return Math.abs(
paramLayoutManager.getPosition(paramView1)
- paramLayoutManager.getPosition(paramView2))
+ 1;
}
int i = paramOrientationHelper.getDecoratedEnd(paramView2);
int j = paramOrientationHelper.getDecoratedStart(paramView1);
return Math.min(paramOrientationHelper.getTotalSpace(), i - j);
}
@Override
protected int getHorizontalGravity(RecyclerView.LayoutManager layoutManager) {
boolean rtl = layoutManager.getLayoutDirection() == ViewCompat.LAYOUT_DIRECTION_RTL;
if (mConfig.mOrientation == VERTICAL) {
if (rtl) {
return Gravity.RIGHT;
}
return Gravity.LEFT;
}
boolean end = mConfig.mReverseLayout ^ mConfig.mStackFromEnd;
if (rtl ^ end) {
return Gravity.RIGHT;
}
return Gravity.LEFT;
}
static int computeScrollRange(
RecyclerView.State paramState,
OrientationHelper paramOrientationHelper,
View paramView1,
View paramView2,
RecyclerView.LayoutManager paramLayoutManager,
boolean paramBoolean) {
if ((paramLayoutManager.getChildCount() == 0)
|| (paramState.getItemCount() == 0)
|| (paramView1 == null)
|| (paramView2 == null)) {
return 0;
}
if (!paramBoolean) {
return paramState.getItemCount();
}
int i = paramOrientationHelper.getDecoratedEnd(paramView2);
int j = paramOrientationHelper.getDecoratedStart(paramView1);
int k =
Math.abs(
paramLayoutManager.getPosition(paramView1)
- paramLayoutManager.getPosition(paramView2));
return (int) ((i - j) / (k + 1) * paramState.getItemCount());
}
static int computeScrollOffset(
RecyclerView.State paramState,
OrientationHelper paramOrientationHelper,
View paramView1,
View paramView2,
RecyclerView.LayoutManager paramLayoutManager,
boolean paramBoolean1,
boolean paramBoolean2) {
int i = 0;
int j = i;
if (paramLayoutManager.getChildCount() != 0) {
j = i;
if (paramState.getItemCount() != 0) {
j = i;
if (paramView1 != null) {
if (paramView2 != null) {
break label45;
}
j = i;
}
}
}
return j;
label45:
i =
Math.min(
paramLayoutManager.getPosition(paramView1), paramLayoutManager.getPosition(paramView2));
j =
Math.max(
paramLayoutManager.getPosition(paramView1), paramLayoutManager.getPosition(paramView2));
if (paramBoolean2) {}
for (i = Math.max(0, paramState.getItemCount() - j - 1); ; i = Math.max(0, i)) {
j = i;
if (!paramBoolean1) {
break;
}
j =
Math.abs(
paramOrientationHelper.getDecoratedEnd(paramView2)
- paramOrientationHelper.getDecoratedStart(paramView1));
int k =
Math.abs(
paramLayoutManager.getPosition(paramView1)
- paramLayoutManager.getPosition(paramView2));
float f = j / (k + 1);
return Math.round(
i * f
+ (paramOrientationHelper.getStartAfterPadding()
- paramOrientationHelper.getDecoratedStart(paramView1)));
}
}