com.sun.glass.ui.monocle.NearbyPointsTouchFilter Maven / Gradle / Ivy
/*
* Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
package com.sun.glass.ui.monocle;
/**
* This TouchFilter merges together points that are closer together than a
* certain threshold.
*/
final class NearbyPointsTouchFilter implements TouchFilter {
private final int radius = TouchInput.getInstance()
.getTouchRadius();
@Override
public int getPriority() {
return PRIORITY_PRE_ID;
}
@Override
public boolean filter(TouchState state) {
// keep merging points until the closest points are further part than
// radius
while (mergeClosestPoints(state)) {
}
return false;
}
private boolean mergeClosestPoints(TouchState state) {
int pointIndex1 = -1, pointIndex2 = -1;
int closestDistanceSquared = Integer.MAX_VALUE;
for (int i = 0; i < state.getPointCount(); i++) {
for (int j = i + 1; j < state.getPointCount(); j++) {
TouchState.Point p1 = state.getPoint(i);
TouchState.Point p2 = state.getPoint(j);
int dx = p1.x - p2.x;
int dy = p1.y - p2.y;
int distanceSquared = dx * dx + dy * dy;
if (distanceSquared < closestDistanceSquared) {
closestDistanceSquared = distanceSquared;
pointIndex1 = i;
pointIndex2 = j;
}
}
}
if (closestDistanceSquared < radius * radius) {
TouchState.Point p1 = state.getPoint(pointIndex1);
TouchState.Point p2 = state.getPoint(pointIndex2);
p1.x = (p1.x + p2.x) / 2;
p1.y = (p1.y + p2.y) / 2;
state.removePointForID(p2.id);
return true;
} else {
return false;
}
}
@Override
public boolean flush(TouchState state) {
return false;
}
@Override
public boolean equals(Object o) {
return o instanceof NearbyPointsTouchFilter;
}
@Override
public int hashCode() {
return 0;
}
@Override
public String toString() {
return "NearbyPoints";
}
}