com.sun.javafx.tk.quantum.ScrollGestureRecognizer Maven / Gradle / Ivy
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package com.sun.javafx.tk.quantum;
import com.sun.glass.events.KeyEvent;
import com.sun.glass.events.TouchEvent;
import java.security.AccessController;
import java.security.PrivilegedAction;
import java.util.HashMap;
import java.util.Map;
import javafx.util.Duration;
import javafx.scene.input.ScrollEvent;
import javafx.animation.Interpolator;
import javafx.animation.KeyFrame;
import javafx.animation.KeyValue;
import javafx.animation.Timeline;
import javafx.beans.property.DoubleProperty;
import javafx.beans.property.SimpleDoubleProperty;
class ScrollGestureRecognizer implements GestureRecognizer {
// gesture will be activated if |scroll amount| > SCROLL_THRESHOLD
private static double SCROLL_THRESHOLD = 10; //in pixels
private static boolean SCROLL_INERTIA_ENABLED = true;
private static double MAX_INITIAL_VELOCITY = 1000;
private static double SCROLL_INERTIA_MILLIS = 1500;
static {
@SuppressWarnings("removal")
var dummy = AccessController.doPrivileged((PrivilegedAction) () -> {
String s = System.getProperty("com.sun.javafx.gestures.scroll.threshold");
if (s != null) {
SCROLL_THRESHOLD = Double.valueOf(s);
}
s = System.getProperty("com.sun.javafx.gestures.scroll.inertia");
if (s != null) {
SCROLL_INERTIA_ENABLED = Boolean.valueOf(s);
}
return null;
});
}
private ViewScene scene;
private ScrollRecognitionState state = ScrollRecognitionState.IDLE;
private Timeline inertiaTimeline = new Timeline();
private DoubleProperty inertiaScrollVelocity = new SimpleDoubleProperty();
private double initialInertiaScrollVelocity = 0;
private double scrollStartTime = 0;
private double lastTouchEventTime = 0;
private Map trackers = new HashMap<>();
private int modifiers;
private boolean direct;
private int currentTouchCount = 0;
private int lastTouchCount;
private boolean touchPointsSetChanged;
private boolean touchPointsPressed;
private double centerX, centerY;
private double centerAbsX, centerAbsY;
private double lastCenterAbsX, lastCenterAbsY;
private double deltaX, deltaY;
private double totalDeltaX, totalDeltaY;
private double factorX, factorY;
double inertiaLastTime = 0;
ScrollGestureRecognizer(final ViewScene scene) {
this.scene = scene;
inertiaScrollVelocity.addListener(valueModel -> {
double currentTime = inertiaTimeline.getCurrentTime().toSeconds();
double timePassed = currentTime - inertiaLastTime;
inertiaLastTime = currentTime;
double scrollVectorSize = timePassed * inertiaScrollVelocity.get();
deltaX = scrollVectorSize * factorX;
totalDeltaX += deltaX;
deltaY = scrollVectorSize * factorY;
totalDeltaY += deltaY;
//send inertia scroll event
sendScrollEvent(true, centerAbsX, centerAbsY, currentTouchCount);
});
}
@Override
public void notifyBeginTouchEvent(long time, int modifiers, boolean isDirect,
int touchEventCount) {
params(modifiers, isDirect);
touchPointsSetChanged = false;
touchPointsPressed = false;
}
@Override
public void notifyNextTouchEvent(long time, int type, long touchId,
int x, int y, int xAbs, int yAbs) {
switch(type) {
case TouchEvent.TOUCH_PRESSED:
touchPointsSetChanged = true;
touchPointsPressed = true;
touchPressed(touchId, time, x, y, xAbs, yAbs);
break;
case TouchEvent.TOUCH_STILL:
break;
case TouchEvent.TOUCH_MOVED:
touchMoved(touchId, time, x, y, xAbs, yAbs);
break;
case TouchEvent.TOUCH_RELEASED:
touchPointsSetChanged = true;
touchReleased(touchId, time, x, y, xAbs, yAbs);
break;
default:
throw new RuntimeException("Error in Scroll gesture recognition: "
+ "unknown touch state: " + state);
}
}
private void calculateCenter() {
if (currentTouchCount <= 0) {
throw new RuntimeException("Error in Scroll gesture recognition: "
+ "touch count is zero!");
}
double totalX = 0.0;
double totalY = 0.0;
double totalAbsX = 0.0;
double totalAbsY = 0.0;
for (TouchPointTracker tracker : trackers.values()) {
totalX += tracker.getX();
totalY += tracker.getY();
totalAbsX += tracker.getAbsX();
totalAbsY += tracker.getAbsY();
}
centerX = totalX / currentTouchCount;
centerY = totalY / currentTouchCount;
centerAbsX = totalAbsX / currentTouchCount;
centerAbsY = totalAbsY / currentTouchCount;
}
@Override
public void notifyEndTouchEvent(long time) {
lastTouchEventTime = time;
if (currentTouchCount != trackers.size()) {
throw new RuntimeException("Error in Scroll gesture recognition: "
+ "touch count is wrong: " + currentTouchCount);
}
if (currentTouchCount < 1) {
if (state == ScrollRecognitionState.ACTIVE) {
sendScrollFinishedEvent(lastCenterAbsX, lastCenterAbsY, lastTouchCount);
if (SCROLL_INERTIA_ENABLED) {
double timeFromLastScroll = ((double)time - scrollStartTime) / 1000000;
if (timeFromLastScroll < 300) {
state = ScrollRecognitionState.INERTIA;
// activate inertia
inertiaLastTime = 0;
if (initialInertiaScrollVelocity > MAX_INITIAL_VELOCITY)
initialInertiaScrollVelocity = MAX_INITIAL_VELOCITY;
inertiaTimeline.getKeyFrames().setAll(
new KeyFrame(
Duration.millis(0),
new KeyValue(inertiaScrollVelocity, initialInertiaScrollVelocity, Interpolator.LINEAR)),
new KeyFrame(
Duration.millis(SCROLL_INERTIA_MILLIS * Math.abs(initialInertiaScrollVelocity) / MAX_INITIAL_VELOCITY),
event -> {
//stop inertia
reset();
},
new KeyValue(inertiaScrollVelocity, 0, Interpolator.LINEAR))
);
inertiaTimeline.playFromStart();
} else {
reset();
}
} else {
reset();
}
}
} else {
// currentTouchCount >= 1
calculateCenter();
if (touchPointsPressed && state == ScrollRecognitionState.INERTIA) {
//Stop inertia
inertiaTimeline.stop();
reset();
}
if (touchPointsSetChanged) {
if (state == ScrollRecognitionState.IDLE) {
state = ScrollRecognitionState.TRACKING;
}
if (state == ScrollRecognitionState.ACTIVE) {
//finish previous gesture
sendScrollFinishedEvent(lastCenterAbsX, lastCenterAbsY, lastTouchCount);
totalDeltaX = 0.0;
totalDeltaY = 0.0;
//start previous gesture
sendScrollStartedEvent(centerAbsX, centerAbsY, currentTouchCount);
}
lastTouchCount = currentTouchCount;
lastCenterAbsX = centerAbsX;
lastCenterAbsY = centerAbsY;
} else {
//state should be either TRACKING or ACTIVE
deltaX = centerAbsX - lastCenterAbsX;
deltaY = centerAbsY - lastCenterAbsY;
if (state == ScrollRecognitionState.TRACKING) {
if ( Math.abs(deltaX) > SCROLL_THRESHOLD || Math.abs(deltaY) > SCROLL_THRESHOLD) {
state = ScrollRecognitionState.ACTIVE;
sendScrollStartedEvent(centerAbsX, centerAbsY, currentTouchCount);
}
}
if (state == ScrollRecognitionState.ACTIVE) {
totalDeltaX += deltaX;
totalDeltaY += deltaY;
sendScrollEvent(false, centerAbsX, centerAbsY, currentTouchCount);
double timePassed = ((double)time - scrollStartTime) / 1000000000;
if (timePassed > 1e-4) {
//capture radius (pytaguras) or init to variables x,y ???
double scrollMagnitude = Math.sqrt(deltaX * deltaX + deltaY * deltaY);
factorX = deltaX / scrollMagnitude;
factorY = deltaY / scrollMagnitude;
initialInertiaScrollVelocity = scrollMagnitude / timePassed;
scrollStartTime = time;
}
lastCenterAbsX = centerAbsX;
lastCenterAbsY = centerAbsY;
}
}
}
}
@SuppressWarnings("removal")
private void sendScrollStartedEvent(double xAbs, double yAbs, int touchCount) {
AccessController.doPrivileged((PrivilegedAction) () -> {
if (scene.sceneListener != null) {
scene.sceneListener.scrollEvent(ScrollEvent.SCROLL_STARTED,
0, 0,
0, 0,
1 /*xMultiplier*/, 1 /*yMultiplier*/,
touchCount,
0 /*scrollTextX*/, 0 /*scrollTextY*/,
0 /*defaultTextX*/, 0 /*defaultTextY*/,
centerX, centerY, xAbs, yAbs,
(modifiers & KeyEvent.MODIFIER_SHIFT) != 0,
(modifiers & KeyEvent.MODIFIER_CONTROL) != 0,
(modifiers & KeyEvent.MODIFIER_ALT) != 0,
(modifiers & KeyEvent.MODIFIER_WINDOWS) != 0,
direct, false /*inertia*/);
}
return null;
}, scene.getAccessControlContext());
}
@SuppressWarnings("removal")
private void sendScrollEvent(boolean isInertia, double xAbs, double yAbs, int touchCount) {
AccessController.doPrivileged((PrivilegedAction) () -> {
if (scene.sceneListener != null) {
scene.sceneListener.scrollEvent(ScrollEvent.SCROLL,
deltaX, deltaY,
totalDeltaX, totalDeltaY,
1 /*xMultiplier*/, 1 /*yMultiplier*/,
touchCount,
0 /*scrollTextX*/, 0 /*scrollTextY*/,
0 /*defaultTextX*/, 0 /*defaultTextY*/,
centerX, centerY, xAbs, yAbs,
(modifiers & KeyEvent.MODIFIER_SHIFT) != 0,
(modifiers & KeyEvent.MODIFIER_CONTROL) != 0,
(modifiers & KeyEvent.MODIFIER_ALT) != 0,
(modifiers & KeyEvent.MODIFIER_WINDOWS) != 0,
direct, isInertia);
}
return null;
}, scene.getAccessControlContext());
}
@SuppressWarnings("removal")
private void sendScrollFinishedEvent(double xAbs, double yAbs, int touchCount) {
AccessController.doPrivileged((PrivilegedAction) () -> {
if (scene.sceneListener != null) {
scene.sceneListener.scrollEvent(ScrollEvent.SCROLL_FINISHED,
0, 0,
totalDeltaX, totalDeltaY,
1 /*xMultiplier*/, 1 /*yMultiplier*/,
touchCount,
0 /*scrollTextX*/, 0 /*scrollTextY*/,
0 /*defaultTextX*/, 0 /*defaultTextY*/,
centerX, centerY, xAbs, yAbs,
(modifiers & KeyEvent.MODIFIER_SHIFT) != 0,
(modifiers & KeyEvent.MODIFIER_CONTROL) != 0,
(modifiers & KeyEvent.MODIFIER_ALT) != 0,
(modifiers & KeyEvent.MODIFIER_WINDOWS) != 0,
direct, false /*inertia*/);
}
return null;
}, scene.getAccessControlContext());
}
public void params(int modifiers, boolean direct) {
this.modifiers = modifiers;
this.direct = direct;
}
public void touchPressed(long id, long nanos, int x, int y, int xAbs, int yAbs) {
currentTouchCount++;
TouchPointTracker tracker = new TouchPointTracker();
tracker.update(nanos, x, y, xAbs, yAbs);
trackers.put(id, tracker);
}
public void touchReleased(long id, long nanos, int x, int y, int xAbs, int yAbs) {
if (state != ScrollRecognitionState.FAILURE) {
TouchPointTracker tracker = trackers.get(id);
if (tracker == null) {
// we don't know this ID, something went completely wrong
state = ScrollRecognitionState.FAILURE;
throw new RuntimeException("Error in Scroll gesture "
+ "recognition: released unknown touch point");
}
trackers.remove(id);
}
currentTouchCount--;
}
public void touchMoved(long id, long nanos, int x, int y, int xAbs, int yAbs) {
if (state == ScrollRecognitionState.FAILURE) {
return;
}
TouchPointTracker tracker = trackers.get(id);
if (tracker == null) {
// we don't know this ID, something went completely wrong
state = ScrollRecognitionState.FAILURE;
throw new RuntimeException("Error in scroll gesture "
+ "recognition: reported unknown touch point");
}
tracker.update(nanos, x, y, xAbs, yAbs);
}
void reset() {
state = ScrollRecognitionState.IDLE;
totalDeltaX = 0.0;
totalDeltaY = 0.0;
}
private static class TouchPointTracker {
double x, y;
double absX, absY;
public void update(long nanos, double x, double y, double absX, double absY) {
this.x = x;
this.y = y;
this.absX = absX;
this.absY = absY;
}
public double getX() {
return x;
}
public double getY() {
return y;
}
public double getAbsX() {
return absX;
}
public double getAbsY() {
return absY;
}
}
private enum ScrollRecognitionState {
IDLE, // no touch points available
TRACKING, // 1+ touch points, center position is tracked
ACTIVE, // threshold accepted, gesture is started
INERTIA, // inertia is active
FAILURE
}
}