Pause framebuffer updates when app is in background

app/src/main/cpp/native-vnc.cpp

@@ -412,7 +412,16 @@ extern "C"
 JNIEXPORT jboolean JNICALL
 Java_com_gaurav_avnc_vnc_VncClient_nativeRefreshFrameBuffer(JNIEnv *env, jobject thiz, jlong clientPtr) {
     auto client = (rfbClient *) clientPtr;
-    return (jboolean) SendFramebufferUpdateRequest(client, 0, 0, client->width, client->height, FALSE);
+    return (jboolean) SendFramebufferUpdateRequest(client, 0, 0, client->width, client->height, TRUE);
+}
+
+extern "C"
+JNIEXPORT void JNICALL
+Java_com_gaurav_avnc_vnc_VncClient_nativeSetAutomaticFramebufferUpdates(JNIEnv *env, jobject thiz, jlong client_ptr,
+                                                                        jboolean enabled) {
+    auto client = ((rfbClient *) client_ptr);
+    client->automaticUpdateRequests = enabled ? TRUE : FALSE;
+    if (enabled) SendIncrementalFramebufferUpdateRequest(client);
 }
 
 extern "C"

app/src/main/java/com/gaurav/avnc/ui/vnc/VncActivity.kt

@@ -121,12 +121,14 @@ class VncActivity : AppCompatActivity() {
     override fun onStart() {
         super.onStart()
         binding.frameView.onResume()
+        viewModel.resumeFrameBufferUpdates()
     }
 
     override fun onStop() {
         super.onStop()
         virtualKeys.releaseMetaKeys()
         binding.frameView.onPause()
+        viewModel.pauseFrameBufferUpdates()
     }
 
     override fun onSaveInstanceState(outState: Bundle) {

app/src/main/java/com/gaurav/avnc/viewmodel/VncViewModel.kt

@@ -343,6 +343,14 @@ class VncViewModel(val profile: ServerProfile, app: Application) : BaseViewModel
         }
     }
 
+    fun pauseFrameBufferUpdates() {
+        client.setAutomaticFrameBufferUpdates(false)
+    }
+
+    fun resumeFrameBufferUpdates() {
+        client.setAutomaticFrameBufferUpdates(true)
+    }
+
     /**************************************************************************
      * [VncClient.Observer] Implementation
      **************************************************************************/

app/src/main/java/com/gaurav/avnc/vnc/VncClient.kt

@@ -99,6 +99,11 @@ class VncClient(private val observer: Observer) {
     @Volatile
     var ignorePointerMovesByServer = false
 
+
+    @Volatile
+    private var autoFBRequestsQueued = true
+    private var autoFBRequests = autoFBRequestsQueued
+
     /**
      * Setup different properties for this client.
      *
@@ -134,6 +139,11 @@ class VncClient(private val observer: Observer) {
             connected = false
             throw IOException(nativeGetLastErrorStr())
         }
+
+        if (autoFBRequests != autoFBRequestsQueued) {
+            autoFBRequests = autoFBRequestsQueued
+            nativeSetAutomaticFramebufferUpdates(nativePtr, autoFBRequests)
+        }
     }
 
     /**
@@ -198,9 +208,19 @@ class VncClient(private val observer: Observer) {
     }
 
     /**
-     * Sends a request for full frame buffer update to remote server.
+     * Sends frame buffer update request to remote server.
      */
-    fun refreshFrameBuffer() = nativeRefreshFrameBuffer(nativePtr)
+    fun refreshFrameBuffer() = ifConnected {
+        nativeRefreshFrameBuffer(nativePtr)
+    }
+
+    /**
+     * Controls whether framebuffer update requests are sent automatically.
+     * It takes effect after the next call to [processServerMessage].
+     */
+    fun setAutomaticFrameBufferUpdates(enabled: Boolean) = ifConnected {
+        autoFBRequestsQueued = enabled
+    }
 
     /**
      * Puts framebuffer contents in currently active OpenGL texture.
@@ -242,6 +262,7 @@ class VncClient(private val observer: Observer) {
     private external fun nativeSendCutText(clientPtr: Long, bytes: ByteArray, isUTF8: Boolean): Boolean
     private external fun nativeSetDesktopSize(clientPtr: Long, width: Int, height: Int): Boolean
     private external fun nativeRefreshFrameBuffer(clientPtr: Long): Boolean
+    private external fun nativeSetAutomaticFramebufferUpdates(clientPtr: Long, enabled: Boolean)
     private external fun nativeGetDesktopName(clientPtr: Long): String
     private external fun nativeGetWidth(clientPtr: Long): Int
     private external fun nativeGetHeight(clientPtr: Long): Int