aixan/lawnchair
1
0
Fork 0
mirror of https://github.com/LawnchairLauncher/lawnchair.git synced 2026-03-03 01:16:49 +00:00
Code Issues Packages Projects Releases Wiki Activity

Merge "Bug 2639807 - Add smarter smoothing to home screen touch scrolling." into froyo

Browse Source
This commit is contained in:
Adam Powell
2010-05-04 15:17:11 -07:00
committed by Android (Google) Code Review
parent fad1fb5ed4 fe8e279dbc
commit 68b4182d77
1 changed files with 39 additions and 38 deletions
Download Patch File Download Diff File Expand all files Collapse all files

77
src/com/android/launcher2/Workspace.java
View File

@@ -109,7 +109,6 @@ public class Workspace extends ViewGroup implements DropTarget, DragSource, Drag
private boolean mAllowLongPress = true;
private int mTouchSlop;
private int mPagingTouchSlop;
private int mMaximumVelocity;
private static final int INVALID_POINTER = -1;
@@ -119,9 +118,11 @@ public class Workspace extends ViewGroup implements DropTarget, DragSource, Drag
private Drawable mPreviousIndicator;
private Drawable mNextIndicator;
// Touch scrolling history for smoothing
private float[] mLastX = new float[6];
private int mLastCount = 0;
private static final float NANOTIME_DIV = 1000000000.0f;
private static final float SMOOTHING_SPEED = 0.75f;
private static final float SMOOTHING_CONSTANT = (float) (0.016 / Math.log(SMOOTHING_SPEED));
private float mSmoothingTime;
private float mTouchX;
private WorkspaceOvershootInterpolator mScrollInterpolator;
@@ -196,7 +197,6 @@ public class Workspace extends ViewGroup implements DropTarget, DragSource, Drag
final ViewConfiguration configuration = ViewConfiguration.get(getContext());
mTouchSlop = configuration.getScaledTouchSlop();
mPagingTouchSlop = configuration.getScaledPagingTouchSlop();
mMaximumVelocity = configuration.getScaledMaximumFlingVelocity();
}
@@ -430,10 +430,18 @@ public class Workspace extends ViewGroup implements DropTarget, DragSource, Drag
}
}
@Override
public void scrollTo(int x, int y) {
super.scrollTo(x, y);
mTouchX = x;
mSmoothingTime = System.nanoTime() / NANOTIME_DIV;
}
@Override
public void computeScroll() {
if (mScroller.computeScrollOffset()) {
mScrollX = mScroller.getCurrX();
mTouchX = mScrollX = mScroller.getCurrX();
mSmoothingTime = System.nanoTime() / NANOTIME_DIV;
mScrollY = mScroller.getCurrY();
updateWallpaperOffset();
postInvalidate();
@@ -444,6 +452,18 @@ public class Workspace extends ViewGroup implements DropTarget, DragSource, Drag
Launcher.setScreen(mCurrentScreen);
mNextScreen = INVALID_SCREEN;
clearChildrenCache();
} else if (mTouchState == TOUCH_STATE_SCROLLING) {
final float now = System.nanoTime() / NANOTIME_DIV;
final float e = (float) Math.exp((now - mSmoothingTime) / SMOOTHING_CONSTANT);
final float dx = mTouchX - mScrollX;
mScrollX += dx * e;
mSmoothingTime = now;
// Keep generating points as long as we're more than 1px away from the target
if (dx > 1.f || dx < -1.f) {
updateWallpaperOffset();
postInvalidate();
}
}
}
@@ -656,16 +676,17 @@ public class Workspace extends ViewGroup implements DropTarget, DragSource, Drag
final int yDiff = (int) Math.abs(y - mLastMotionY);
final int touchSlop = mTouchSlop;
boolean xPaged = xDiff > mPagingTouchSlop;
boolean xMoved = xDiff > touchSlop;
boolean yMoved = yDiff > touchSlop;
if (xMoved || yMoved) {
if (xPaged) {
if (xMoved) {
// Scroll if the user moved far enough along the X axis
mTouchState = TOUCH_STATE_SCROLLING;
mLastMotionX = x;
mTouchX = mScrollX;
mSmoothingTime = System.nanoTime() / NANOTIME_DIV;
enableChildrenCache(mCurrentScreen - 1, mCurrentScreen + 1);
}
// Either way, cancel any pending longpress
@@ -755,7 +776,6 @@ public class Workspace extends ViewGroup implements DropTarget, DragSource, Drag
if (mVelocityTracker != null) {
mVelocityTracker.clear();
}
resetFilter();
}
}
@@ -813,25 +833,6 @@ public class Workspace extends ViewGroup implements DropTarget, DragSource, Drag
layout.setChildrenDrawnWithCacheEnabled(false);
}
}
private float filterX(float x) {
final float[] lastX = mLastX;
final int len = lastX.length;
final int lastCount = Math.min(len, mLastCount + 1);
float sum = x;
for (int i = 1; i < lastCount; i++) {
sum += lastX[i] = lastX[i - 1];
}
lastX[0] = x;
mLastCount = lastCount;
return sum / lastCount;
}
private void resetFilter() {
mLastCount = 0;
}
@Override
public boolean onTouchEvent(MotionEvent ev) {
@@ -876,21 +877,23 @@ public class Workspace extends ViewGroup implements DropTarget, DragSource, Drag
if (mTouchState == TOUCH_STATE_SCROLLING) {
// Scroll to follow the motion event
final int pointerIndex = ev.findPointerIndex(mActivePointerId);
final float x = filterX(ev.getX(pointerIndex));
final float x = ev.getX(pointerIndex);
final float deltaX = mLastMotionX - x;
mLastMotionX = x;
if (deltaX < 0) {
if (mScrollX > 0) {
scrollBy(Math.round(Math.max(-mScrollX, deltaX)), 0);
updateWallpaperOffset();
if (mTouchX > 0) {
mTouchX += Math.max(-mTouchX, deltaX);
mSmoothingTime = System.nanoTime() / NANOTIME_DIV;
invalidate();
}
} else if (deltaX > 0) {
final int availableToScroll = getChildAt(getChildCount() - 1).getRight() -
mScrollX - getWidth();
final float availableToScroll = getChildAt(getChildCount() - 1).getRight() -
mTouchX - getWidth();
if (availableToScroll > 0) {
scrollBy(Math.round(Math.min(availableToScroll, deltaX)), 0);
updateWallpaperOffset();
mTouchX += Math.min(availableToScroll, deltaX);
mSmoothingTime = System.nanoTime() / NANOTIME_DIV;
invalidate();
}
} else {
awakenScrollBars();
@@ -927,7 +930,6 @@ public class Workspace extends ViewGroup implements DropTarget, DragSource, Drag
mVelocityTracker.recycle();
mVelocityTracker = null;
}
resetFilter();
}
mTouchState = TOUCH_STATE_REST;
mActivePointerId = INVALID_POINTER;
@@ -935,7 +937,6 @@ public class Workspace extends ViewGroup implements DropTarget, DragSource, Drag
case MotionEvent.ACTION_CANCEL:
mTouchState = TOUCH_STATE_REST;
mActivePointerId = INVALID_POINTER;
resetFilter();
break;
case MotionEvent.ACTION_POINTER_UP:
onSecondaryPointerUp(ev);