jme3-lwjgl3: add a WindowSizeListener (#1711)

* Added a WindowSizeListener for lwjgl3 which can be registered in LwjglWindow and refactored GlfwMouseInput to use this listener instead of directly registering a callback on GLFW as GLFW does not support multiple callbacks.

* Javadoc improvement & code cleanup.

* Added license to WindowSizeListener class.

* Improve javadoc & expand imports.

jme3-lwjgl3/src/main/java/com/jme3/input/lwjgl/GlfwMouseInput.java

@@ -37,6 +37,7 @@ import com.jme3.input.RawInputListener;
 import com.jme3.input.event.MouseButtonEvent;
 import com.jme3.input.event.MouseMotionEvent;
 import com.jme3.system.lwjgl.LwjglWindow;
+import com.jme3.system.lwjgl.WindowSizeListener;
 import com.jme3.util.BufferUtils;
 import java.nio.ByteBuffer;
 import java.nio.IntBuffer;
@@ -114,6 +115,7 @@ public class GlfwMouseInput implements MouseInput {
 
     private final LwjglWindow context;
 
+    private WindowSizeListener windowSizeListener;
     private RawInputListener listener;
 
     private IntBuffer currentCursorDelays;
@@ -236,12 +238,9 @@ public class GlfwMouseInput implements MouseInput {
             }
         });
 
-        glfwSetWindowSizeCallback(window, new GLFWWindowSizeCallback() {
-            @Override
-            public void invoke(final long window, final int width, final int height) {
-                currentHeight = height;
-            }
-        });
+        context.registerWindowSizeListener(windowSizeListener = ((width, height) -> {
+            currentHeight = height;
+        }));
     }
 
     private void initCurrentMousePosition(long window) {
@@ -335,6 +334,7 @@ public class GlfwMouseInput implements MouseInput {
         cursorPosCallback.close();
         scrollCallback.close();
         mouseButtonCallback.close();
+        context.removeWindowSizeListener(windowSizeListener);
     }
 
     @Override

jme3-lwjgl3/src/main/java/com/jme3/system/lwjgl/LwjglWindow.java

@@ -45,19 +45,25 @@ import com.jme3.system.JmeContext;
 import com.jme3.system.JmeSystem;
 import com.jme3.system.NanoTimer;
 import com.jme3.util.BufferUtils;
-import java.awt.*;
+import com.jme3.util.SafeArrayList;
+import org.lwjgl.Version;
+import org.lwjgl.glfw.GLFWErrorCallback;
+import org.lwjgl.glfw.GLFWFramebufferSizeCallback;
+import org.lwjgl.glfw.GLFWImage;
+import org.lwjgl.glfw.GLFWVidMode;
+import org.lwjgl.glfw.GLFWWindowFocusCallback;
+import org.lwjgl.glfw.GLFWWindowSizeCallback;
+import org.lwjgl.system.Platform;
+
+import java.awt.Graphics2D;
 import java.awt.image.BufferedImage;
 import java.nio.ByteBuffer;
-import java.nio.IntBuffer;
 import java.util.EnumSet;
 import java.util.HashMap;
 import java.util.Map;
 import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.logging.Level;
 import java.util.logging.Logger;
-import org.lwjgl.Version;
-import org.lwjgl.glfw.*;
-import org.lwjgl.system.Platform;
 
 import static org.lwjgl.glfw.GLFW.*;
 import static org.lwjgl.opengl.GL11.GL_FALSE;
@@ -126,6 +132,7 @@ public abstract class LwjglWindow extends LwjglContext implements Runnable {
     protected final AtomicBoolean needRestart = new AtomicBoolean(false);
 
     private final JmeContext.Type type;
+    private final SafeArrayList<WindowSizeListener> windowSizeListeners = new SafeArrayList<>(WindowSizeListener.class);
 
     private GLFWErrorCallback errorCallback;
     private GLFWWindowSizeCallback windowSizeCallback;
@@ -150,6 +157,24 @@ public abstract class LwjglWindow extends LwjglContext implements Runnable {
         this.type = type;
     }
 
+    /**
+     * Registers the specified listener to get notified when window size changes.
+     *
+     * @param listener The WindowSizeListener to register.
+     */
+    public void registerWindowSizeListener(WindowSizeListener listener) {
+        windowSizeListeners.add(listener);
+    }
+
+    /**
+     * Removes the specified listener from the listeners list.
+     *
+     * @param listener The WindowSizeListener to remove.
+     */
+    public void removeWindowSizeListener(WindowSizeListener listener) {
+        windowSizeListeners.remove(listener);
+    }
+
     /**
      * @return Type.Display or Type.Canvas
      */
@@ -313,6 +338,11 @@ public abstract class LwjglWindow extends LwjglContext implements Runnable {
                 // This is the window size, never to passed to any pixel based stuff!
                 // https://www.glfw.org/docs/latest/window_guide.html#window_size
                 onWindowSizeChanged(width, height);
+
+                // Notify listeners
+                for (WindowSizeListener listener : windowSizeListeners.getArray()) {
+                    listener.onWindowSizeChanged(width, height);
+                }
             }
         });
 
@@ -321,14 +351,6 @@ public abstract class LwjglWindow extends LwjglContext implements Runnable {
 
             @Override
             public void invoke(final long window, final int width, final int height) {
-
-                // The window size might be also changed, but the window size callback might not trigger
-                // Maybe a bug in graphics drivers or LWJGL 3...? So make sure we emulate the original JME behavior here
-                IntBuffer windowWidth = BufferUtils.createIntBuffer(1);
-                IntBuffer windowHeight = BufferUtils.createIntBuffer(1);
-                glfwGetWindowSize(window, windowWidth, windowHeight);
-                onWindowSizeChanged(windowWidth.get(), windowHeight.get());
-
                 // https://www.glfw.org/docs/latest/window_guide.html#window_fbsize
                 listener.reshape(width, height);
             }

jme3-lwjgl3/src/main/java/com/jme3/system/lwjgl/WindowSizeListener.java

@@ -0,0 +1,54 @@
+/*
+ * Copyright (c) 2009-2021 jMonkeyEngine
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ * * Redistributions of source code must retain the above copyright
+ *   notice, this list of conditions and the following disclaimer.
+ *
+ * * Redistributions in binary form must reproduce the above copyright
+ *   notice, this list of conditions and the following disclaimer in the
+ *   documentation and/or other materials provided with the distribution.
+ *
+ * * Neither the name of 'jMonkeyEngine' nor the names of its contributors
+ *   may be used to endorse or promote products derived from this software
+ *   without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+ * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+package com.jme3.system.lwjgl;
+
+/**
+ * Listen to window size changes. Note, GLFW does not support registering multiple callbacks
+ * in {@link org.lwjgl.glfw.GLFW#glfwSetWindowSizeCallback(long, org.lwjgl.glfw.GLFWWindowSizeCallbackI)},
+ * registering a new one will remove the previous one. Using this interface one can register
+ * multiple listeners.
+ *
+ * @author Ali-RS
+ */
+public interface WindowSizeListener {
+
+    /**
+     * When registered by {@link LwjglWindow#registerWindowSizeListener(WindowSizeListener)},
+     * it gets invoked on each glfw window size callback to notify the listener about changes
+     * in the window size.
+     *
+     * @param width the new window width.
+     * @param height the new window height.
+     */
+    public void onWindowSizeChanged(final int width, final int height);
+
+}