Implement scrolling

poorly documented, but who reads the documentation anyways?

Author: Geolykt

src/main/java/de/geolykt/starloader/api/NullUtils.java

@@ -22,7 +22,7 @@ public final class NullUtils {
      * @param object The object to wrap
      * @return The newly created optional
      */
-    public static @NotNull <T> Optional<@NotNull T> asOptional(@Nullable T object) {
+    public static @NotNull <T> Optional<T> asOptional(@Nullable T object) {
         if (object == null) {
             return emptyOptional();
         }

src/main/java/de/geolykt/starloader/api/gui/Drawing.java

@@ -161,7 +161,7 @@ public static float drawText(@NotNull String message, float x, float y, @NotNull
      * @param y         The Y-position to draw on; it is not known which corner it corresponds to. Caution is advised
      * @param width     The width of the rectangle.
      * @param height    The height of the rectangle.
-     * @param camera    The camera to use. It transforms x/y-positions as well as width and height of the drawn rectangle.
+     * @param camera    The camera to use. It transforms x/y-positions of the drawn rectangle. <b>Width and height are unaffected</b>
      * @param fillColor The GDX color to fill it with.
      * @since 1.5.0
      */

src/main/java/de/geolykt/starloader/api/gui/DrawingImpl.java

@@ -123,7 +123,7 @@ public default float drawText(@NotNull String message, float x, float y, @NotNul
      * @param y         The Y-position to draw on; it is not known which corner it corresponds to. Caution is advised
      * @param width     The width of the rectangle.
      * @param height    The height of the rectangle.
-     * @param camera    The camera to use. It transforms x/y-positions as well as width and height of the drawn rectangle.
+     * @param camera    The camera to use. It transforms x/y-positions of the drawn rectangle. <b>Width and height are unaffected</b>
      * @param fillColor The GDX color to fill it with.
      * @since 1.5.0
      */

src/main/java/de/geolykt/starloader/api/gui/screen/ReactiveComponent.java

@@ -10,42 +10,56 @@
  */
 public interface ReactiveComponent extends ScreenComponent {
 
+    // Formerly, the screenY was inverted to the rendering y position. For some arbitrary reason this is no longer the case.
+
+    /**
+     * Called when the user clicks on the component.
+     * The documentation of screenX, screenY, componentX and componentY is done as intended. The future me should not come to the idea
+     * that the documentation was wrong. However the variable names might be misleading...
+     *
+     * @param screenX    The Y-position of the mouse relative to this component. Bound between {@link ScreenComponent#getWidth()} and {@code 0}
+     * @param screenY    The Y-position of the mouse relative to this component. Bound between {@link ScreenComponent#getHeight()} and {@code 0}
+     * @param componentX The X-position of the component relative to the screen. Use for drawing operations only.
+     * @param componentY The Y-position of the component relative to the screen. Use for drawing operations only.
+     * @param camera     The camera supplied for drawing operations.
+     */
+    public void onClick(int screenX, int screenY, int componentX, int componentY, @NotNull Camera camera);
+
     /**
      * Called when the mouse moves over the component.
      *
-     * @param screenX The Y-position of the mouse relative to this component. Bound between {@link ScreenComponent#getWidth()} and {@code 0}
-     * @param screenY The Y-position of the mouse relative to this component. Bound between {@link ScreenComponent#getHeight()} and {@code 0}
+     * @param screenX    The Y-position of the mouse relative to this component. Bound between {@link ScreenComponent#getWidth()} and {@code 0}
+     * @param screenY    The Y-position of the mouse relative to this component. Bound between {@link ScreenComponent#getHeight()} and {@code 0}
      * @param componentX The X-position of the component relative to the screen. Use for drawing operations only.
      * @param componentY The Y-position of the component relative to the screen. Use for drawing operations only.
-     * @param camera The camera supplied for drawing operations.
+     * @param camera     The camera supplied for drawing operations.
      * @deprecated Not yet implemented
      */
     @Deprecated(forRemoval = false, since = "1.5.0")
     public void onHover(int screenX, int screenY, int componentX, int componentY, @NotNull Camera camera);
 
     /**
-     * Called when the user clicks on the component.
-     * The documentation of screenX, screenY, componentX and componentY is done as intended. The future me should not come to the idea
-     * that the documentation was wrong. However the variable names might be misleading ...
-     *
-     * <p>screenY will be inverted compared to the rendering y's. You might want to do component.getHeight() - screenY to obtain a more usable height.
+     * Unknown use but could be helpful to have. Mirrors the behaviour of {@link GestureListener#longPress(float, float)}.
      *
-     * @param screenX The Y-position of the mouse relative to this component. Bound between {@link ScreenComponent#getWidth()} and {@code 0}
-     * @param screenY The Y-position of the mouse relative to this component. Bound between {@link ScreenComponent#getHeight()} and {@code 0}
+     * @param screenX    The Y-position of the mouse relative to this component. Bound between {@link ScreenComponent#getWidth()} and {@code 0}
+     * @param screenY    The Y-position of the mouse relative to this component. Bound between {@link ScreenComponent#getHeight()} and {@code 0}
      * @param componentX The X-position of the component relative to the screen. Use for drawing operations only.
      * @param componentY The Y-position of the component relative to the screen. Use for drawing operations only.
-     * @param camera The camera supplied for drawing operations.
+     * @param camera     The camera supplied for drawing operations.
      */
-    public void onClick(int screenX, int screenY, int componentX, int componentY, @NotNull Camera camera);
+    public void onLongClick(int screenX, int screenY, int componentX, int componentY, @NotNull Camera camera);
 
     /**
-     * Unknown use but could be helpful to have. Mirrors the behaviour of {@link GestureListener#longPress(float, float)}.
+     * Called when the user scrolls while being on this component.
+     * The documentation of screenX, screenY, componentX and componentY is done as intended. The future me should not come to the idea
+     * that the documentation was wrong. However the variable names might be misleading...
      *
-     * @param screenX The Y-position of the mouse relative to this component. Bound between {@link ScreenComponent#getWidth()} and {@code 0}
-     * @param screenY The Y-position of the mouse relative to this component. Bound between {@link ScreenComponent#getHeight()} and {@code 0}
+     * @param screenX    The Y-position of the mouse relative to this component. Bound between {@link ScreenComponent#getWidth()} and {@code 0}
+     * @param screenY    The Y-position of the mouse relative to this component. Bound between {@link ScreenComponent#getHeight()} and {@code 0}
      * @param componentX The X-position of the component relative to the screen. Use for drawing operations only.
      * @param componentY The Y-position of the component relative to the screen. Use for drawing operations only.
-     * @param camera The camera supplied for drawing operations.
+     * @param camera     The camera supplied for drawing operations.
+     * @param amount     The amount that was scrolled. Either {@code -1} or {@code 1}.
      */
-    public void onLongClick(int screenX, int screenY, int componentX, int componentY, @NotNull Camera camera);
+    public void onScroll(int screenX, int screenY, int componentX, int componentY, @NotNull Camera camera, int amount);
 }

src/main/java/de/geolykt/starloader/impl/gui/SLAbstractWidget.java

@@ -6,6 +6,7 @@
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
+import com.badlogic.gdx.InputProcessor;
 import com.badlogic.gdx.graphics.Camera;
 import com.badlogic.gdx.input.GestureDetector.GestureListener;
 
@@ -41,6 +42,12 @@ public void a(double x, double y) {
         tap(x, getHeight() - y, false);
     }
 
+    @Override
+    public void a(float unknown, float amount, float x, float y) {
+        super.a(unknown, amount, x, y);
+        scroll((int) x, (int) y, (int) amount / -40);
+    }
+
     @Override
     public void b(double x, double y) {
         super.b(x, y);
@@ -152,6 +159,21 @@ protected final void renderChildren() {
         this.z();
     }
 
+    /**
+     * Listener method for when the user chooses to scroll while having the mouse on this widget.
+     * Corresponds to {@link InputProcessor#scrolled(int)}.
+     *
+     * @param x      The X-position of the mouse at this time
+     * @param y      The Y-position of the mouse at this time
+     * @param amount The amount that should be scrolled. Either {@code -1} or {@code 1}.
+     * @return True when the game should not be zoomed. False when the zoom of the main board should not be blocked.
+     * @since 1.5.0
+     */
+    protected boolean scroll(int x, int y, int amount) {
+        // Stub
+        return true;
+    }
+
     /**
      * Sets the title that should be used for the {@link #drawHeader()} operation.
      * The title itself will be rendered in white color.

src/main/java/de/geolykt/starloader/impl/gui/SLScreenWidget.java

@@ -15,6 +15,7 @@
 import com.badlogic.gdx.math.Vector2;
 
 import de.geolykt.starloader.api.NullUtils;
+import de.geolykt.starloader.api.gui.Drawing;
 import de.geolykt.starloader.api.gui.screen.ComponentSupplier;
 import de.geolykt.starloader.api.gui.screen.LineWrappingInfo;
 import de.geolykt.starloader.api.gui.screen.ReactiveComponent;
@@ -264,9 +265,43 @@ protected void renderSLChildComponents() {
             Map.Entry<Vector2, ScreenComponent> componentEntry = populator.next();
             Vector2 pos = componentEntry.getKey();
             ScreenComponent component = componentEntry.getValue();
-            int width = component.renderAt((int) pos.x, (int) pos.y, c); // TODO originally the render operation had offsets, but not anymore. Explore why this may have been dumb to remove. (#getInnerWidth does not make any sense anymore dummy.)
-            componentPositioningMeta.add(new ScreenComponentPositioningMeta(pos, width, component.getHeight(), component));
+            try {
+                int width = component.renderAt((int) pos.x, (int) pos.y, c); // TODO originally the render operation had offsets, but not anymore. Explore why this may have been dumb to remove. (#getInnerWidth does not make any sense anymore dummy.)
+                componentPositioningMeta.add(new ScreenComponentPositioningMeta(pos, width, component.getHeight(), component));
+            } catch (Exception e) {
+                // Throwing an exception here would cause serious UI issues
+                e.printStackTrace();
+                Drawing.toast("Unable to draw a screen component. Review the log for details!");
+            }
+        }
+    }
+
+    @Override
+    protected boolean scroll(int x, int y, int amount) {
+        Camera c = NullUtils.requireNotNull(getCamera());
+        double actualY = lastRenderHeight - y - 25.0D;
+
+        for (ScreenComponentPositioningMeta posMeta : this.componentPositioningMeta) {
+            if (!(posMeta.component instanceof ReactiveComponent)) {
+                continue;
+            }
+            ReactiveComponent component = (ReactiveComponent) posMeta.component;
+            Vector2 pos = posMeta.pos;
+            System.out.println("x >= pos.x && x <= pos.x + posMeta.width = " + (x >= pos.x && x <= pos.x + posMeta.width));
+            System.out.println("pos.y <= actualY = " + (pos.y <= actualY));
+            System.out.println("(pos.y + posMeta.height) >= actualY = " + ((pos.y + posMeta.height) >= actualY));
+            if ((x >= pos.x && x <= pos.x + posMeta.width)
+                    && (pos.y <= actualY && (pos.y + posMeta.height) >= actualY)) {
+                component.onScroll((int) (x - pos.x), (int) (posMeta.height - (actualY - pos.y)), (int) pos.x, (int) pos.y, c, amount);
+            }
         }
+
+        return true;
+    }
+
+    @Override
+    public void setCamera(@NotNull Camera camera) {
+        throw new UnsupportedOperationException("This method call is not permitted.");
     }
 
     @Override
@@ -289,9 +324,4 @@ protected void tap(double x, double y, boolean isLongTap) {
             }
         }
     }
-
-    @Override
-    public void setCamera(@NotNull Camera camera) {
-        throw new UnsupportedOperationException("This method call is not permitted.");
-    }
 }

src/main/java/de/geolykt/starloader/impl/gui/SimpleScreenChildList.java

@@ -13,7 +13,11 @@
 /**
  * A collection class that sets the parent screen of all the components. Note: in order for this to work the component
  * must implement {@link SLScreenComponent}.
+ *
+ * @deprecated The only functionality of this class depends on {@link SLScreenComponent}, which has been deprecated
+ * for removal
  */
+@Deprecated(forRemoval = true, since = "1.5.0")
 public class SimpleScreenChildList extends LinkedList<@NotNull ScreenComponent> {
 
     /**