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Better touch handling for doubletap scale.

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This commit is contained in:
GaidamakUA 2016-01-21 14:43:12 +02:00
parent 66175e3ce8
commit 266c085fbd
1 changed files with 48 additions and 23 deletions
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55
OsmAnd/src/net/osmand/plus/views/DoubleTapScaleDetector.java
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@ -13,21 +13,26 @@ import org.apache.commons.logging.Log;
public class DoubleTapScaleDetector {
private static final Log LOG = PlatformUtil.getLog(DoubleTapScaleDetector.class);
private static final int DOUBLE_TAPPING_DELTA = ViewConfiguration.getTapTimeout() + 100;
private static final int DOUBLE_TAP_TIMEOUT = ViewConfiguration.getDoubleTapTimeout();
private static final int DOUBLE_TAP_MIN_TIME = 40;
private static final int DP_PER_1X = 200;
private final DoubleTapZoomListener listener;
protected final Context ctx;
private long startTime = 0;
private boolean isDoubleTapping = false;
private float startX;
private float startY;
private float scale;
private MotionEvent firstDown;
private MotionEvent firstUp;
private int mDoubleTapSlopSquare;
public DoubleTapScaleDetector(Context ctx, DoubleTapZoomListener listener) {
this.ctx = ctx;
this.listener = listener;
final ViewConfiguration configuration = ViewConfiguration.get(ctx);
int doubleTapSlop = configuration.getScaledTouchSlop();
mDoubleTapSlopSquare = doubleTapSlop * doubleTapSlop;
}
public boolean onTouchEvent(MotionEvent event) {
@ -41,26 +46,28 @@ public class DoubleTapScaleDetector {
listener.onZoomEnded(scale, 0);
return true;
} else {
startTime = currentTime;
return true;
firstUp = MotionEvent.obtain(event);
}
} else if (event.getAction() == MotionEvent.ACTION_DOWN && !isDoubleTapping
&& currentTime - startTime < DOUBLE_TAPPING_DELTA) {
} else {
if (event.getAction() == MotionEvent.ACTION_DOWN && !isDoubleTapping) {
if (isConsideredDoubleTap(firstDown, firstUp, event)) {
isDoubleTapping = true;
startX = event.getX();
startY = event.getY();
listener.onGestureInit(startX, startY, startX, startY);
listener.onZoomStarted(new PointF(startX, startY));
float x = event.getX();
float y = event.getY();
listener.onGestureInit(x, y, x, y);
listener.onZoomStarted(new PointF(x, y));
return true;
} else {
firstDown = MotionEvent.obtain(event);
}
} else if (event.getAction() == MotionEvent.ACTION_MOVE) {
if (isDoubleTapping) {
float delta = convertPxToDp((int) (startY - event.getY()));
float delta = convertPxToDp((int) (firstDown.getY() - event.getY()));
float scaleDelta = delta / DP_PER_1X;
scale = 1 - scaleDelta;
listener.onZoomingOrRotating(scale, 0);
return true;
} else {
return false;
}
}
}
return false;
@ -74,6 +81,24 @@ public class DoubleTapScaleDetector {
return Math.round(px / (Resources.getSystem().getDisplayMetrics().xdpi / DisplayMetrics.DENSITY_DEFAULT));
}
private final boolean isConsideredDoubleTap(MotionEvent firstDown,
MotionEvent firstUp,
MotionEvent secondDown) {
if (firstDown == null || firstUp == null || secondDown == null) {
return false;
}
final long deltaTime = secondDown.getEventTime() - firstUp.getEventTime();
if (deltaTime > DOUBLE_TAP_TIMEOUT || deltaTime < DOUBLE_TAP_MIN_TIME) {
return false;
}
int deltaX = (int) firstDown.getX() - (int) secondDown.getX();
int deltaY = (int) firstDown.getY() - (int) secondDown.getY();
int squared = deltaX * deltaX + deltaY * deltaY;
boolean toReturn = squared < mDoubleTapSlopSquare;
return toReturn;
}
public interface DoubleTapZoomListener {
public void onZoomStarted(PointF centerPoint);