If the new fling is much slower (less than 1/5 of (3c19d990) · Commits · e / os / android_frameworks_base

core/java/android/webkit/WebView.java

+9 −2

Original line number	Diff line number	Diff line
		@@ -398,6 +398,10 @@ public class WebView extends AbsoluteLayout
		private float mLastVelX;
		private float mLastVelY;

		// only trigger accelerated fling if the new velocity is at least
		// MINIMUM_VELOCITY_RATIO_FOR_ACCELERATION times of the previous velocity
		private static final float MINIMUM_VELOCITY_RATIO_FOR_ACCELERATION = 0.2f;

		/**
		* Touch mode
		*/
		@@ -5512,13 +5516,16 @@ public class WebView extends AbsoluteLayout
		return;
		}
		float currentVelocity = mScroller.getCurrVelocity();
		if (mLastVelocity > 0 && currentVelocity > 0) {
		float velocity = (float) Math.hypot(vx, vy);
		if (mLastVelocity > 0 && currentVelocity > 0 && velocity
		> mLastVelocity * MINIMUM_VELOCITY_RATIO_FOR_ACCELERATION) {
		float deltaR = (float) (Math.abs(Math.atan2(mLastVelY, mLastVelX)
		- Math.atan2(vy, vx)));
		final float circle = (float) (Math.PI) * 2.0f;
		if (deltaR > circle * 0.9f \|\| deltaR < circle * 0.1f) {
		vx += currentVelocity * mLastVelX / mLastVelocity;
		vy += currentVelocity * mLastVelY / mLastVelocity;
		velocity = (float) Math.hypot(vx, vy);
		if (DebugFlags.WEB_VIEW) {
		Log.v(LOGTAG, "doFling vx= " + vx + " vy=" + vy);
		}
		@@ -5534,7 +5541,7 @@ public class WebView extends AbsoluteLayout
		}
		mLastVelX = vx;
		mLastVelY = vy;
		mLastVelocity = (float) Math.hypot(vx, vy);
		mLastVelocity = velocity;

		mScroller.fling(mScrollX, mScrollY, -vx, -vy, 0, maxX, 0, maxY);
		// TODO: duration is calculated based on velocity, if the range is