MapController returns null if no intersection is found

tangrams · Jul 12, 2016 · a70362b · a70362b
1 parent 89a2991
commit a70362b
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Showing 2 changed files with 14 additions and 9 deletions.
diff --git a/android/tangram/jni/jniExports.cpp b/android/tangram/jni/jniExports.cpp
@@ -56,16 +56,18 @@ extern "C" {
         return Tangram::getTilt();
     }
 
-    JNIEXPORT void JNICALL Java_com_mapzen_tangram_MapController_nativeScreenPositionToLngLat(JNIEnv* jniEnv, jobject obj, jdoubleArray coordinates) {
+    JNIEXPORT jboolean JNICALL Java_com_mapzen_tangram_MapController_nativeScreenPositionToLngLat(JNIEnv* jniEnv, jobject obj, jdoubleArray coordinates) {
         jdouble* arr = jniEnv->GetDoubleArrayElements(coordinates, NULL);
-        Tangram::screenPositionToLngLat(arr[0], arr[1], &arr[0], &arr[1]);
+        bool ret = Tangram::screenPositionToLngLat(arr[0], arr[1], &arr[0], &arr[1]);
         jniEnv->ReleaseDoubleArrayElements(coordinates, arr, 0);
+        return ret;
     }
 
-    JNIEXPORT void JNICALL Java_com_mapzen_tangram_MapController_nativeLngLatToScreenPosition(JNIEnv* jniEnv, jobject obj, jdoubleArray coordinates) {
+    JNIEXPORT jboolean JNICALL Java_com_mapzen_tangram_MapController_nativeLngLatToScreenPosition(JNIEnv* jniEnv, jobject obj, jdoubleArray coordinates) {
         jdouble* arr = jniEnv->GetDoubleArrayElements(coordinates, NULL);
-        Tangram::lngLatToScreenPosition(arr[0], arr[1], &arr[0], &arr[1]);
+        bool ret = Tangram::lngLatToScreenPosition(arr[0], arr[1], &arr[0], &arr[1]);
         jniEnv->ReleaseDoubleArrayElements(coordinates, arr, 0);
+        return ret;
     }
 
     JNIEXPORT void JNICALL Java_com_mapzen_tangram_MapController_nativeInit(JNIEnv* jniEnv, jobject obj, jobject tangramInstance, jobject assetManager, jstring stylePath) {

diff --git a/android/tangram/src/com/mapzen/tangram/MapController.java b/android/tangram/src/com/mapzen/tangram/MapController.java
@@ -379,12 +379,15 @@ public CameraType getCameraType() {
     /**
      * Find the geographic coordinates corresponding to the given position on screen
      * @param screenPosition Position in pixels from the top-left corner of the map area
-     * @return LngLat corresponding to the given point
+     * @return LngLat corresponding to the given point, or null if the screen position
+     * does not intersect a geographic location.
      */
     public LngLat screenPositionToLngLat(PointF screenPosition) {
         double[] tmp = { screenPosition.x, screenPosition.y };
-        nativeScreenPositionToLngLat(tmp);
-        return new LngLat(tmp[0], tmp[1]);
+        if (nativeScreenPositionToLngLat(tmp)) {
+            return new LngLat(tmp[0], tmp[1]);
+        }
+        return null;
     }
 
     /**
@@ -681,8 +684,8 @@ public void useCachedGlState(boolean use) {
     private synchronized native void nativeSetTilt(float radians);
     private synchronized native void nativeSetTiltEased(float radians, float seconds, int ease);
     private synchronized native float nativeGetTilt();
-    private synchronized native void nativeScreenPositionToLngLat(double[] coordinates);
-    private synchronized native void nativeLngLatToScreenPosition(double[] coordinates);
+    private synchronized native boolean nativeScreenPositionToLngLat(double[] coordinates);
+    private synchronized native boolean nativeLngLatToScreenPosition(double[] coordinates);
     private synchronized native void nativeSetPixelScale(float scale);
     private synchronized native void nativeSetCameraType(int type);
     private synchronized native int nativeGetCameraType();