Add Map::pause/resume

Fixed bug after switching apps

android/java/lib/src/main/java/com/mapbox/mapboxgl/lib/MapView.java

@@ -373,6 +373,7 @@ public class MapView extends SurfaceView {
         }
 
         mNativeMapView.initializeDisplay();
+        mNativeMapView.initializeContext();
     }
 
     // Called when we need to save instance state
@@ -392,6 +393,7 @@ public class MapView extends SurfaceView {
     // Must be called from Activity onDestroy
     public void onDestroy() {
         Log.v(TAG, "onDestroy");
+        mNativeMapView.terminateContext();
         mNativeMapView.terminateDisplay();
     }
 
@@ -399,21 +401,22 @@ public class MapView extends SurfaceView {
     // Must be called from Activity onStart
     public void onStart() {
         Log.v(TAG, "onStart");
-        mNativeMapView.initializeContext();
+        mNativeMapView.pause();
+        mNativeMapView.start();
     }
 
     // Called when we need to terminate the GL context
     // Must be called from Activity onPause
     public void onStop() {
         Log.v(TAG, "onStop");
-        mNativeMapView.terminateContext();
+        mNativeMapView.stop();
     }
 
     // Called when we need to stop the render thread
     // Must be called from Activity onPause
     public void onPause() {
         Log.v(TAG, "onPause");
-        mNativeMapView.stop();
+        mNativeMapView.pause();
     }
 
     // Called when we need to start the render thread
@@ -421,7 +424,7 @@ public class MapView extends SurfaceView {
 
     public void onResume() {
         Log.v(TAG, "onResume");
-        mNativeMapView.start();
+        mNativeMapView.resume();
     }
 
     // This class handles SurfaceHolder callbacks
@@ -464,6 +467,8 @@ public class MapView extends SurfaceView {
         }
     }
 
+    // TODO examine how GLSurvaceView hadles attach/detach from window
+
     // Called when view is no longer connected
     @Override
     protected void onDetachedFromWindow() {

android/java/lib/src/main/java/com/mapbox/mapboxgl/lib/NativeMapView.java

@@ -80,6 +80,14 @@ class NativeMapView {
         nativeStop(mNativeMapViewPtr);
     }
 
+    public void pause() {
+        nativePause(mNativeMapViewPtr);
+    }
+
+    public void resume() {
+        nativeResume(mNativeMapViewPtr);
+    }
+
     public void run() {
         nativeRun(mNativeMapViewPtr);
     }
@@ -420,6 +428,10 @@ class NativeMapView {
 
     private native void nativeStop(long nativeMapViewPtr);
 
+    private native void nativePause(long nativeMapViewPtr);
+
+    private native void nativeResume(long nativeMapViewPtr);
+
     private native void nativeRun(long nativeMapViewPtr);
 
     private native void nativeRerender(long nativeMapViewPtr);