Change video engine resize callback API to encapsulate JNA

src/main/java/uk/co/caprica/vlcj/player/embedded/videosurface/VideoEngineVideoSurface.java

@@ -39,6 +39,7 @@
 import uk.co.caprica.vlcj.player.base.MediaPlayer;
 import uk.co.caprica.vlcj.player.embedded.videosurface.videoengine.VideoEngine;
 import uk.co.caprica.vlcj.player.embedded.videosurface.videoengine.VideoEngineCallback;
+import uk.co.caprica.vlcj.player.embedded.videosurface.videoengine.VideoEngineResizeCallbackHandler;
 
 import static uk.co.caprica.vlcj.binding.lib.LibVlc.libvlc_video_set_output_callbacks;
 
@@ -68,6 +69,11 @@ public final class VideoEngineVideoSurface extends VideoSurface {
     private final libvlc_video_makeCurrent_cb makeCurrent = new MakeCurrentCallback();
     private final libvlc_video_getProcAddress_cb getProcAddress = new GetProcAddressCallback();
 
+    /**
+     * Handler to bridge the native video engine resize callback.
+     */
+    private VideoEngineResizeCallbackHandler resizeCallbackHandler;
+
     /**
      * Create a video surface.
      *
@@ -116,7 +122,8 @@ public void cleanup(Pointer opaque) {
     private final class SetResizeCallback implements libvlc_video_output_set_resize_cb {
         @Override
         public void setResizeCallback(Pointer opaque, ReportSizeChanged report_size_change, Pointer report_opaque) {
-            callback.onSetResizeCallback(opaque, report_size_change, report_opaque);
+            VideoEngineVideoSurface.this.resizeCallbackHandler = new VideoEngineResizeCallbackHandler(opaque, report_opaque, report_size_change);
+            callback.onSetResizeCallback(resizeCallbackHandler);
         }
     }
 

src/main/java/uk/co/caprica/vlcj/player/embedded/videosurface/videoengine/VideoEngineCallback.java

@@ -20,7 +20,6 @@
 package uk.co.caprica.vlcj.player.embedded.videosurface.videoengine;
 
 import com.sun.jna.Pointer;
-import uk.co.caprica.vlcj.binding.internal.ReportSizeChanged;
 import uk.co.caprica.vlcj.binding.internal.libvlc_video_output_cfg_t;
 import uk.co.caprica.vlcj.binding.internal.libvlc_video_render_cfg_t;
 import uk.co.caprica.vlcj.binding.internal.libvlc_video_setup_device_cfg_t;
@@ -54,11 +53,9 @@ public interface VideoEngineCallback {
      * The resize callback must be invoked by the application when the size of the video display surface changes (e.g.
      * due to a window resize event).
      *
-     * @param opaque opaque data pointer
-     * @param report_size_change  callback
-     * @param report_opaque opaque data pointer for the callback
+     * @param resizeCallback resize callback
      */
-    void onSetResizeCallback(Pointer opaque, ReportSizeChanged report_size_change, Pointer report_opaque);
+    void onSetResizeCallback(VideoEngineResizeCallback resizeCallback);
 
     /**
      * Update the video output with new dimensions.

src/main/java/uk/co/caprica/vlcj/player/embedded/videosurface/videoengine/VideoEngineCallbackAdapter.java

@@ -20,7 +20,6 @@
 package uk.co.caprica.vlcj.player.embedded.videosurface.videoengine;
 
 import com.sun.jna.Pointer;
-import uk.co.caprica.vlcj.binding.internal.ReportSizeChanged;
 import uk.co.caprica.vlcj.binding.internal.libvlc_video_output_cfg_t;
 import uk.co.caprica.vlcj.binding.internal.libvlc_video_render_cfg_t;
 import uk.co.caprica.vlcj.binding.internal.libvlc_video_setup_device_cfg_t;
@@ -43,7 +42,7 @@ public void onCleanup(Pointer opaque) {
     }
 
     @Override
-    public void onSetResizeCallback(Pointer opaque, ReportSizeChanged report_size_change, Pointer report_opaque) {
+    public void onSetResizeCallback(VideoEngineResizeCallback resizeCallback) {
     }
 
     @Override

src/main/java/uk/co/caprica/vlcj/player/embedded/videosurface/videoengine/VideoEngineResizeCallback.java

@@ -0,0 +1,34 @@
+/*
+ * This file is part of VLCJ.
+ *
+ * VLCJ is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * VLCJ is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with VLCJ.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Copyright 2009-2022 Caprica Software Limited.
+ */
+
+package uk.co.caprica.vlcj.player.embedded.videosurface.videoengine;
+
+/**
+ * Specification for a component that informs the video engine when the size of the hosted video window changes.
+ */
+public interface VideoEngineResizeCallback {
+
+    /**
+     * Set the new window size.
+     *
+     * @param width new width
+     * @param height new height
+     */
+    void setSize(int width, int height);
+}

src/main/java/uk/co/caprica/vlcj/player/embedded/videosurface/videoengine/VideoEngineResizeCallbackHandler.java

@@ -0,0 +1,66 @@
+/*
+ * This file is part of VLCJ.
+ *
+ * VLCJ is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * VLCJ is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with VLCJ.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Copyright 2009-2022 Caprica Software Limited.
+ */
+
+package uk.co.caprica.vlcj.player.embedded.videosurface.videoengine;
+
+import com.sun.jna.Pointer;
+import uk.co.caprica.vlcj.binding.internal.ReportSizeChanged;
+
+/**
+ * Handler component that bridges a vlcj application with the native video engine resize callback.
+ */
+public final class VideoEngineResizeCallbackHandler implements VideoEngineResizeCallback {
+
+    /**
+     * Opaque pointer associated with the callbacks.
+     */
+    private final Pointer opaque;
+
+    /**
+     * Opaque pointer for the native report size changed callback.
+     * <p>
+     * This pointer <strong>must</strong> be passed with the native callback method.
+     */
+    private final Pointer reportOpaque;
+
+    /**
+     * Native callback.
+     */
+    private final ReportSizeChanged reportSizeChanged;
+
+    /**
+     * Create a resize callback handler.
+     *
+     * @param opaque opaque pointer associated with the callbacks
+     * @param reportOpaque opaque pointer for the native report size changed callback
+     * @param reportSizeChanged native callback
+     */
+    public VideoEngineResizeCallbackHandler(Pointer opaque, Pointer reportOpaque, ReportSizeChanged reportSizeChanged) {
+        this.opaque = opaque;
+        this.reportOpaque = reportOpaque;
+        this.reportSizeChanged = reportSizeChanged;
+    }
+
+    @Override
+    public void setSize(int width, int height) {
+        if (reportSizeChanged != null) {
+            reportSizeChanged.reportSizeChanged(reportOpaque, width, height);
+        }
+    }
+}