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Merge "Tweaks for ScaleGestureDetector" into nyc-dev

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This commit is contained in:
Adam Powell
2016-04-04 23:05:58 +00:00
committed by Android (Google) Code Review
parent fe3442d366 c6df18f5fa
commit 13af9845d4
1 changed files with 2 additions and 86 deletions
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88
core/java/android/view/ScaleGestureDetector.java
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@@ -145,13 +145,6 @@ public class ScaleGestureDetector {
private int mSpanSlop;
private int mMinSpan;
// Bounds for recently seen values
private float mTouchUpper;
private float mTouchLower;
private float mTouchHistoryLastAccepted;
private int mTouchHistoryDirection;
private long mTouchHistoryLastAcceptedTime;
private int mTouchMinMajor;
private final Handler mHandler;
private float mAnchoredScaleStartX;
@@ -207,8 +200,6 @@ public class ScaleGestureDetector {
mSpanSlop = ViewConfiguration.get(context).getScaledTouchSlop() * 2;
final Resources res = context.getResources();
mTouchMinMajor = res.getDimensionPixelSize(
com.android.internal.R.dimen.config_minScalingTouchMajor);
mMinSpan = res.getDimensionPixelSize(com.android.internal.R.dimen.config_minScalingSpan);
mHandler = handler;
// Quick scale is enabled by default after JB_MR2
@@ -222,77 +213,6 @@ public class ScaleGestureDetector {
}
}
/**
* The touchMajor/touchMinor elements of a MotionEvent can flutter/jitter on
* some hardware/driver combos. Smooth it out to get kinder, gentler behavior.
* @param ev MotionEvent to add to the ongoing history
*/
private void addTouchHistory(MotionEvent ev) {
final long currentTime = SystemClock.uptimeMillis();
final int count = ev.getPointerCount();
boolean accept = currentTime - mTouchHistoryLastAcceptedTime >= TOUCH_STABILIZE_TIME;
float total = 0;
int sampleCount = 0;
for (int i = 0; i < count; i++) {
final boolean hasLastAccepted = !Float.isNaN(mTouchHistoryLastAccepted);
final int historySize = ev.getHistorySize();
final int pointerSampleCount = historySize + 1;
for (int h = 0; h < pointerSampleCount; h++) {
float major;
if (h < historySize) {
major = ev.getHistoricalTouchMajor(i, h);
} else {
major = ev.getTouchMajor(i);
}
if (major < mTouchMinMajor) major = mTouchMinMajor;
total += major;
if (Float.isNaN(mTouchUpper) || major > mTouchUpper) {
mTouchUpper = major;
}
if (Float.isNaN(mTouchLower) || major < mTouchLower) {
mTouchLower = major;
}
if (hasLastAccepted) {
final int directionSig = (int) Math.signum(major - mTouchHistoryLastAccepted);
if (directionSig != mTouchHistoryDirection ||
(directionSig == 0 && mTouchHistoryDirection == 0)) {
mTouchHistoryDirection = directionSig;
final long time = h < historySize ? ev.getHistoricalEventTime(h)
: ev.getEventTime();
mTouchHistoryLastAcceptedTime = time;
accept = false;
}
}
}
sampleCount += pointerSampleCount;
}
final float avg = total / sampleCount;
if (accept) {
float newAccepted = (mTouchUpper + mTouchLower + avg) / 3;
mTouchUpper = (mTouchUpper + newAccepted) / 2;
mTouchLower = (mTouchLower + newAccepted) / 2;
mTouchHistoryLastAccepted = newAccepted;
mTouchHistoryDirection = 0;
mTouchHistoryLastAcceptedTime = ev.getEventTime();
}
}
/**
* Clear all touch history tracking. Useful in ACTION_CANCEL or ACTION_UP.
* @see #addTouchHistory(MotionEvent)
*/
private void clearTouchHistory() {
mTouchUpper = Float.NaN;
mTouchLower = Float.NaN;
mTouchHistoryLastAccepted = Float.NaN;
mTouchHistoryDirection = 0;
mTouchHistoryLastAcceptedTime = 0;
}
/**
* Accepts MotionEvents and dispatches events to a {@link OnScaleGestureListener}
* when appropriate.
@@ -344,7 +264,6 @@ public class ScaleGestureDetector {
}
if (streamComplete) {
clearTouchHistory();
return true;
}
}
@@ -391,17 +310,14 @@ public class ScaleGestureDetector {
focusY = sumY / div;
}
addTouchHistory(event);
// Determine average deviation from focal point
float devSumX = 0, devSumY = 0;
for (int i = 0; i < count; i++) {
if (skipIndex == i) continue;
// Convert the resulting diameter into a radius.
final float touchSize = mTouchHistoryLastAccepted / 2;
devSumX += Math.abs(event.getX(i) - focusX) + touchSize;
devSumY += Math.abs(event.getY(i) - focusY) + touchSize;
devSumX += Math.abs(event.getX(i) - focusX);
devSumY += Math.abs(event.getY(i) - focusY);
}
final float devX = devSumX / div;
final float devY = devSumY / div;