Android/frameworks_base
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Merge "Fix misc. bugs in AbsListView smooth scrolling." into jb-dev

Browse Source
This commit is contained in:
Adam Powell
2012-05-07 17:10:42 -07:00
committed by Android (Google) Code Review
parent 401d93f0db e69370e168
commit 6392a3609c
1 changed files with 93 additions and 11 deletions
Download Patch File Download Diff File Expand all files Collapse all files

104
core/java/android/widget/AbsListView.java
View File

@@ -3985,7 +3985,7 @@ public abstract class AbsListView extends AdapterView<ListAdapter> implements Te
}
class PositionScroller implements Runnable {
private static final int SCROLL_DURATION = 400;
private static final int SCROLL_DURATION = 200;
private static final int MOVE_DOWN_POS = 1;
private static final int MOVE_UP_POS = 2;
@@ -4006,21 +4006,35 @@ public abstract class AbsListView extends AdapterView<ListAdapter> implements Te
mExtraScroll = ViewConfiguration.get(mContext).getScaledFadingEdgeLength();
}
void start(int position) {
void start(final int position) {
stop();
final int childCount = getChildCount();
if (childCount == 0) {
// Can't scroll without children.
if (mDataChanged) {
// But we might have something in a minute.
post(new Runnable() {
@Override public void run() {
start(position);
}
});
}
return;
}
final int firstPos = mFirstPosition;
final int lastPos = firstPos + getChildCount() - 1;
final int lastPos = firstPos + childCount - 1;
int viewTravelCount;
if (position <= firstPos) {
if (position < firstPos) {
viewTravelCount = firstPos - position + 1;
mMode = MOVE_UP_POS;
} else if (position >= lastPos) {
} else if (position > lastPos) {
viewTravelCount = position - lastPos + 1;
mMode = MOVE_DOWN_POS;
} else {
// Already on screen, nothing to do
scrollToVisible(position, INVALID_POSITION, SCROLL_DURATION);
return;
}
@@ -4036,7 +4050,7 @@ public abstract class AbsListView extends AdapterView<ListAdapter> implements Te
postOnAnimation(this);
}
void start(int position, int boundPosition) {
void start(final int position, final int boundPosition) {
stop();
if (boundPosition == INVALID_POSITION) {
@@ -4044,11 +4058,25 @@ public abstract class AbsListView extends AdapterView<ListAdapter> implements Te
return;
}
final int childCount = getChildCount();
if (childCount == 0) {
// Can't scroll without children.
if (mDataChanged) {
// But we might have something in a minute.
post(new Runnable() {
@Override public void run() {
start(position, boundPosition);
}
});
}
return;
}
final int firstPos = mFirstPosition;
final int lastPos = firstPos + getChildCount() - 1;
final int lastPos = firstPos + childCount - 1;
int viewTravelCount;
if (position <= firstPos) {
if (position < firstPos) {
final int boundPosFromLast = lastPos - boundPosition;
if (boundPosFromLast < 1) {
// Moving would shift our bound position off the screen. Abort.
@@ -4064,7 +4092,7 @@ public abstract class AbsListView extends AdapterView<ListAdapter> implements Te
viewTravelCount = posTravel;
mMode = MOVE_UP_POS;
}
} else if (position >= lastPos) {
} else if (position > lastPos) {
final int boundPosFromFirst = boundPosition - firstPos;
if (boundPosFromFirst < 1) {
// Moving would shift our bound position off the screen. Abort.
@@ -4081,7 +4109,7 @@ public abstract class AbsListView extends AdapterView<ListAdapter> implements Te
mMode = MOVE_DOWN_POS;
}
} else {
// Already on screen, nothing to do
scrollToVisible(position, boundPosition, SCROLL_DURATION);
return;
}
@@ -4137,6 +4165,60 @@ public abstract class AbsListView extends AdapterView<ListAdapter> implements Te
postOnAnimation(this);
}
/**
* Scroll such that targetPos is in the visible padded region without scrolling
* boundPos out of view. Assumes targetPos is onscreen.
*/
void scrollToVisible(int targetPos, int boundPos, int duration) {
final int firstPos = mFirstPosition;
final int childCount = getChildCount();
final int lastPos = firstPos + childCount - 1;
final int paddedTop = mListPadding.top;
final int paddedBottom = getHeight() - mListPadding.bottom;
if (targetPos < firstPos || targetPos > lastPos) {
Log.w(TAG, "scrollToVisible called with targetPos " + targetPos +
" not visible [" + firstPos + ", " + lastPos + "]");
}
if (boundPos < firstPos || boundPos > lastPos) {
// boundPos doesn't matter, it's already offscreen.
boundPos = INVALID_POSITION;
}
final View targetChild = getChildAt(targetPos - firstPos);
final int targetTop = targetChild.getTop();
final int targetBottom = targetChild.getBottom();
int scrollBy = 0;
if (targetBottom > paddedBottom) {
scrollBy = targetBottom - paddedBottom;
}
if (targetTop < paddedTop) {
scrollBy = targetTop - paddedTop;
}
if (scrollBy == 0) {
return;
}
if (boundPos >= 0) {
final View boundChild = getChildAt(boundPos - firstPos);
final int boundTop = boundChild.getTop();
final int boundBottom = boundChild.getBottom();
final int absScroll = Math.abs(scrollBy);
if (scrollBy < 0 && boundBottom + absScroll > paddedBottom) {
// Don't scroll the bound view off the bottom of the screen.
scrollBy = Math.max(0, boundBottom - paddedBottom);
} else if (scrollBy > 0 && boundTop - absScroll < paddedTop) {
// Don't scroll the bound view off the top of the screen.
scrollBy = Math.min(0, boundTop - paddedTop);
}
}
smoothScrollBy(scrollBy, duration);
}
void stop() {
removeCallbacks(this);
}