private void updatePosition() {
mX.displace();
mY.displace();
PointF displacement = resetDisplacement();
if (FloatUtils.fuzzyEquals(displacement.x, 0.0f)
&& FloatUtils.fuzzyEquals(displacement.y, 0.0f)) {
return;
}
if (!mSubscroller.scrollBy(displacement)) {
synchronized (mTarget.getLock()) {
scrollBy(displacement.x, displacement.y);
}
}
}
@Override
public boolean onScale(SimpleScaleGestureDetector detector) {
if (GeckoApp.mAppContext == null || GeckoApp.mAppContext.mDOMFullScreen) return false;
if (mState != PanZoomState.PINCHING) return false;
float prevSpan = detector.getPreviousSpan();
if (FloatUtils.fuzzyEquals(prevSpan, 0.0f)) {
// let's eat this one to avoid setting the new zoom to infinity (bug 711453)
return true;
}
float spanRatio = detector.getCurrentSpan() / prevSpan;
/*
* Apply edge resistance if we're zoomed out smaller than the page size by scaling the zoom
* factor toward 1.0.
*/
float resistance = Math.min(mX.getEdgeResistance(true), mY.getEdgeResistance(true));
if (spanRatio > 1.0f) spanRatio = 1.0f + (spanRatio - 1.0f) * resistance;
else spanRatio = 1.0f - (1.0f - spanRatio) * resistance;
synchronized (mTarget.getLock()) {
float newZoomFactor = getMetrics().zoomFactor * spanRatio;
float minZoomFactor = 0.0f;
float maxZoomFactor = MAX_ZOOM;
ZoomConstraints constraints = mTarget.getZoomConstraints();
if (constraints.getMinZoom() > 0) minZoomFactor = constraints.getMinZoom();
if (constraints.getMaxZoom() > 0) maxZoomFactor = constraints.getMaxZoom();
if (newZoomFactor < minZoomFactor) {
// apply resistance when zooming past minZoomFactor,
// such that it asymptotically reaches minZoomFactor / 2.0
// but never exceeds that
final float rate = 0.5f; // controls how quickly we approach the limit
float excessZoom = minZoomFactor - newZoomFactor;
excessZoom = 1.0f - (float) Math.exp(-excessZoom * rate);
newZoomFactor = minZoomFactor * (1.0f - excessZoom / 2.0f);
}
if (newZoomFactor > maxZoomFactor) {
// apply resistance when zooming past maxZoomFactor,
// such that it asymptotically reaches maxZoomFactor + 1.0
// but never exceeds that
float excessZoom = newZoomFactor - maxZoomFactor;
excessZoom = 1.0f - (float) Math.exp(-excessZoom);
newZoomFactor = maxZoomFactor + excessZoom;
}
scrollBy(mLastZoomFocus.x - detector.getFocusX(), mLastZoomFocus.y - detector.getFocusY());
PointF focus = new PointF(detector.getFocusX(), detector.getFocusY());
scaleWithFocus(newZoomFactor, focus);
}
mLastZoomFocus.set(detector.getFocusX(), detector.getFocusY());
GeckoEvent event =
GeckoEvent.createNativeGestureEvent(
GeckoEvent.ACTION_MAGNIFY, mLastZoomFocus, getMetrics().zoomFactor);
GeckoAppShell.sendEventToGecko(event);
return true;
}