merge any strings in a composed line

Author: brachy84

src/main/java/com/cleanroommc/modularui/api/drawable/IHoverable.java

@@ -7,10 +7,15 @@
 import org.jetbrains.annotations.ApiStatus;
 import org.jetbrains.annotations.Nullable;
 
+/**
+ * This marks an {@link IDrawable} as hoverable in a {@link com.cleanroommc.modularui.drawable.text.RichText RichText}. This should not be
+ * extended in most cases instead obtain an instance by calling {@link IIcon#asHoverable()}.
+ */
+@ApiStatus.NonExtendable
 public interface IHoverable extends IIcon {
 
     /**
-     * Called every frame this hoverable is hovered inside a {@link com.cleanroommc.modularui.drawable.text.RichText}.
+     * Called every frame this hoverable is hovered inside a {@link com.cleanroommc.modularui.drawable.text.RichText RichText}.
      */
     default void onHover() {}
 
@@ -19,7 +24,13 @@ default RichTooltip getTooltip() {
         return null;
     }
 
+    /**
+     * An internal function to set the current rendered position. This is used to detect if this element is under the mouse.
+     */
     void setRenderedAt(int x, int y);
 
+    /**
+     * @return the last area this drawable was drawn at.
+     */
     Area getRenderedArea();
 }

src/main/java/com/cleanroommc/modularui/drawable/text/RichTextCompiler.java

@@ -182,9 +182,10 @@ private void newLine() {
 
     private void addLineElement(Object o) {
         if (o instanceof String s2) {
-            if (this.currentLine.size() == 1 && this.currentLine.get(0) instanceof String s1) {
-                // if there is already one string in the line, merge them
-                this.currentLine.set(0, s1 + s2);
+            int s = this.currentLine.size();
+            if (s > 0 && this.currentLine.get(s - 1) instanceof String s1) {
+                // if the last element in the line is a string, merge them
+                this.currentLine.set(s - 1, s1 + s2);
                 return;
             }
             if (this.currentLine.isEmpty()) {

src/main/java/com/cleanroommc/modularui/test/TestGuis.java

@@ -49,7 +49,7 @@ public class TestGuis extends CustomModularScreen {
 
     @Override
     public @NotNull ModularPanel buildUI(ModularGuiContext context) {
-        return buildListUi(context);
+        return buildRichTextUI(context);
     }
 
     public @NotNull ModularPanel buildAnimationUI(ModularGuiContext context) {