Remove createWindow and add mustRunOnMainThread

graphics/opengl/src/main/java/de/staropensource/sosengine/graphics/opengl/OpenGlManagement.java

@@ -19,10 +19,7 @@
 
 package de.staropensource.sosengine.graphics.opengl;
 
-import de.staropensource.sosengine.base.types.vectors.Vec2i;
 import de.staropensource.sosengine.graphics.classes.ApiManagementClass;
-import de.staropensource.sosengine.graphics.opengl.classes.Window;
-import org.jetbrains.annotations.NotNull;
 
 /**
  * The OpenGL API management class.
@@ -37,9 +34,8 @@ public final class OpenGlManagement implements ApiManagementClass {
     public OpenGlManagement() {}
 
     /** {@inheritDoc} */
-    @NotNull
     @Override
-    public Window createWindow(String title, Vec2i size) {
-        return new Window(title, size);
+    public boolean mustRunOnMainThread() {
+        return true;
     }
 }

graphics/src/main/java/de/staropensource/sosengine/graphics/classes/ApiManagementClass.java

@@ -19,9 +19,6 @@
 
 package de.staropensource.sosengine.graphics.classes;
 
-import de.staropensource.sosengine.base.types.vectors.Vec2i;
-import org.jetbrains.annotations.NotNull;
-
 /**
  * The interface for Graphics API management classes.
  *
@@ -30,13 +27,10 @@ import org.jetbrains.annotations.NotNull;
 @SuppressWarnings({ "unused" })
 public interface ApiManagementClass {
     /**
-     * Creates a new {@link Window}.
+     * Returns if this Graphics API must be interacted with on the main thread.
      *
-     * @param title initial window title
-     * @param size initial window size
-     * @return new window
-     * @since v1-alpha0
+     * @return {@code true} if Graphics API must be interacted with on the main thread, {@code false} otherwise
+     * @since v1-alpha2
      */
-    @NotNull
-    Window createWindow(String title, Vec2i size);
+    boolean mustRunOnMainThread();
 }

testapp/src/main/java/de/staropensource/sosengine/testapp/Main.java

@@ -111,7 +111,6 @@ public class Main {
         ApiManagementClass management = api.getManagement();
 
         // Create window
-        management.createWindow("Test", new Vec2i(960, 540));
 
         // Sleep for five seconds
         Thread.sleep(5000);