Cleaning up scrollbar logic to properly calculate stable extents.
- Removing old logic which assumed that views were the same size,
especially now we can have variable dividers, etc.
- Simplifying old scroll position logic.
- Removing unnecessary prediction icon layout (same as normal icon)
Bug: 30023608
Change-Id: I39e1126fa586a76a9bdd3ff38cd6e360ac3021e6
diff --git a/src/com/android/launcher3/BaseRecyclerView.java b/src/com/android/launcher3/BaseRecyclerView.java
index 4cb050e..8bd5eba 100644
--- a/src/com/android/launcher3/BaseRecyclerView.java
+++ b/src/com/android/launcher3/BaseRecyclerView.java
@@ -41,21 +41,6 @@
@Thunk int mDy = 0;
private float mDeltaThreshold;
- /**
- * The current scroll state of the recycler view. We use this in onUpdateScrollbar()
- * and scrollToPositionAtProgress() to determine the scroll position of the recycler view so
- * that we can calculate what the scroll bar looks like, and where to jump to from the fast
- * scroller.
- */
- public static class ScrollPositionState {
- // The index of the first visible row
- public int rowIndex;
- // The offset of the first visible row
- public int rowTopOffset;
- // The adapter position of the first visible item
- public int itemPos;
- }
-
protected BaseRecyclerViewFastScrollBar mScrollbar;
private int mDownX;
@@ -199,11 +184,7 @@
* Returns the available scroll height:
* AvailableScrollHeight = Total height of the all items - last page height
*/
- protected int getAvailableScrollHeight(int rowCount) {
- int totalHeight = getPaddingTop() + getTop(rowCount) + getPaddingBottom();
- int availableScrollHeight = totalHeight - getVisibleHeight();
- return availableScrollHeight;
- }
+ protected abstract int getAvailableScrollHeight();
/**
* Returns the available scroll bar height:
@@ -247,15 +228,12 @@
* this by mapping the available scroll area of the recycler view to the available space for the
* scroll bar.
*
- * @param scrollPosState the current scroll position
- * @param rowCount the number of rows, used to calculate the total scroll height (assumes that
- * all rows are the same height)
+ * @param scrollY the current scroll y
*/
- protected void synchronizeScrollBarThumbOffsetToViewScroll(ScrollPositionState scrollPosState,
- int rowCount) {
+ protected void synchronizeScrollBarThumbOffsetToViewScroll(int scrollY,
+ int availableScrollHeight) {
// Only show the scrollbar if there is height to be scrolled
int availableScrollBarHeight = getAvailableScrollBarHeight();
- int availableScrollHeight = getAvailableScrollHeight(rowCount);
if (availableScrollHeight <= 0) {
mScrollbar.setThumbOffset(-1, -1);
return;
@@ -264,7 +242,6 @@
// Calculate the current scroll position, the scrollY of the recycler view accounts for the
// view padding, while the scrollBarY is drawn right up to the background padding (ignoring
// padding)
- int scrollY = Math.max(0, getScrollTop(scrollPosState));
int scrollBarY = mBackgroundPadding.top +
(int) (((float) scrollY / availableScrollHeight) * availableScrollBarHeight);
@@ -291,20 +268,7 @@
*
* @return the scroll top of this recycler view.
*/
- protected int getScrollTop(ScrollPositionState scrollPosState) {
- return getPaddingTop() + getTop(scrollPosState.rowIndex) -
- scrollPosState.rowTopOffset;
- }
-
- /**
- * Returns information about the item that the recycler view is currently scrolled to.
- */
- protected abstract void getCurScrollState(ScrollPositionState stateOut, int viewTypeMask);
-
- /**
- * Returns the top (or y position) of the row at the specified index.
- */
- protected abstract int getTop(int rowIndex);
+ protected abstract int getCurrentScrollY();
/**
* Maps the touch (from 0..1) to the adapter position that should be visible.