Implement maxDeltaX/Y for android.

Author: kmagiera

android/lib/src/main/java/com/swmansion/gesturehandler/PanGestureHandler.java

@@ -6,6 +6,7 @@
 public class PanGestureHandler extends GestureHandler<PanGestureHandler> {
 
   private static float MIN_VALUE_IGNORE = Float.MAX_VALUE;
+  private static float MAX_VALUE_IGNORE = Float.MIN_VALUE;
 
   private static float DEFAULT_MIN_DISTANCE = 10.0f;
   private static int DEFAULT_MIN_POINTERS = 1;
@@ -15,6 +16,8 @@ public class PanGestureHandler extends GestureHandler<PanGestureHandler> {
   private float mMinOffsetY = MIN_VALUE_IGNORE;
   private float mMinDeltaX = MIN_VALUE_IGNORE;
   private float mMinDeltaY = MIN_VALUE_IGNORE;
+  private float mMaxDeltaX = MAX_VALUE_IGNORE;
+  private float mMaxDeltaY = MAX_VALUE_IGNORE;
   private float mMinDistSq = DEFAULT_MIN_DISTANCE * DEFAULT_MIN_DISTANCE;
   private float mMinVelocityX = MIN_VALUE_IGNORE;
   private float mMinVelocityY = MIN_VALUE_IGNORE;
@@ -100,6 +103,16 @@ public PanGestureHandler setMinDy(float deltaY) {
     return this;
   }
 
+  public PanGestureHandler setMaxDx(float deltaX) {
+    mMaxDeltaX = deltaX;
+    return this;
+  }
+
+  public PanGestureHandler setMaxDy(float deltaY) {
+    mMaxDeltaY = deltaY;
+    return this;
+  }
+
   public PanGestureHandler setMinOffsetX(float offsetX) {
     mMinOffsetX = offsetX;
     return this;
@@ -192,6 +205,20 @@ private boolean shouldActivate() {
     return false;
   }
 
+  private boolean shouldFail() {
+    float dx = mLastX - mStartX + mOffsetX;
+    if (mMaxDeltaX != MAX_VALUE_IGNORE && Math.abs(dx) > mMaxDeltaX) {
+      return true;
+    }
+
+    float dy = mLastY - mStartY + mOffsetY;
+    if (mMaxDeltaY != MAX_VALUE_IGNORE && Math.abs(dy) > mMaxDeltaY) {
+      return true;
+    }
+
+    return false;
+  }
+
   @Override
   protected void onHandle(MotionEvent event) {
     int state = getState();
@@ -241,7 +268,9 @@ protected void onHandle(MotionEvent event) {
         fail();
       }
     } else if (state == STATE_BEGAN) {
-      if (shouldActivate()) {
+      if (shouldFail()) {
+        fail();
+      } else if (shouldActivate()) {
         // reset starting point
         mStartX = mLastX;
         mStartY = mLastY;

android/src/main/java/com/swmansion/gesturehandler/react/RNGestureHandlerModule.java

@@ -49,6 +49,8 @@ public class RNGestureHandlerModule extends ReactContextBaseJavaModule {
   private static final String KEY_LONG_PRESS_MIN_DURATION_MS = "minDurationMs";
   private static final String KEY_PAN_MIN_DELTA_X = "minDeltaX";
   private static final String KEY_PAN_MIN_DELTA_Y = "minDeltaY";
+  private static final String KEY_PAN_MAX_DELTA_X = "maxDeltaX";
+  private static final String KEY_PAN_MAX_DELTA_Y = "maxDeltaY";
   private static final String KEY_PAN_MIN_OFFSET_X = "minOffsetX";
   private static final String KEY_PAN_MIN_OFFSET_Y = "minOffsetY";
   private static final String KEY_PAN_MIN_DIST = "minDist";
@@ -200,6 +202,12 @@ public void configure(PanGestureHandler handler, ReadableMap config) {
       if (config.hasKey(KEY_PAN_MIN_DELTA_Y)) {
         handler.setMinDy(PixelUtil.toPixelFromDIP(config.getDouble(KEY_PAN_MIN_DELTA_Y)));
       }
+      if (config.hasKey(KEY_PAN_MAX_DELTA_X)) {
+        handler.setMaxDx(PixelUtil.toPixelFromDIP(config.getDouble(KEY_PAN_MAX_DELTA_X)));
+      }
+      if (config.hasKey(KEY_PAN_MAX_DELTA_Y)) {
+        handler.setMaxDy(PixelUtil.toPixelFromDIP(config.getDouble(KEY_PAN_MAX_DELTA_Y)));
+      }
       if (config.hasKey(KEY_PAN_MIN_OFFSET_X)) {
         handler.setMinOffsetX(PixelUtil.toPixelFromDIP(config.getDouble(KEY_PAN_MIN_OFFSET_X)));
       }
@@ -226,7 +234,7 @@ public void configure(PanGestureHandler handler, ReadableMap config) {
         handler.setMinPointers(config.getInt(KEY_PAN_MIN_POINTERS));
       }
       if (config.hasKey(KEY_PAN_MAX_POINTERS)) {
-        handler.setMinPointers(config.getInt(KEY_PAN_MAX_POINTERS));
+        handler.setMaxPointers(config.getInt(KEY_PAN_MAX_POINTERS));
       }
       if (config.hasKey(KEY_PAN_AVG_TOUCHES)) {
         handler.setAverageTouches(config.getBoolean(KEY_PAN_AVG_TOUCHES));