Rename classes to Selectors.

Split single and multiple item selectors for easier implementation.
Update proper locales.

src/main/java/world/bentobox/challenges/panel/util/ChallengeSelector.java

@@ -0,0 +1,221 @@
+package world.bentobox.challenges.panel.util;
+
+
+import java.util.ArrayList;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+import java.util.function.BiConsumer;
+
+import org.bukkit.Material;
+import org.bukkit.inventory.ItemStack;
+
+import world.bentobox.bentobox.api.panels.PanelItem;
+import world.bentobox.bentobox.api.panels.builders.PanelBuilder;
+import world.bentobox.bentobox.api.panels.builders.PanelItemBuilder;
+import world.bentobox.bentobox.api.user.User;
+import world.bentobox.bentobox.util.Util;
+import world.bentobox.challenges.database.object.Challenge;
+import world.bentobox.challenges.utils.Constants;
+import world.bentobox.challenges.utils.GuiUtils;
+
+
+/**
+ * This class creates new GUI that allows to select single challenge, which is returned via consumer.
+ */
+public class ChallengeSelector extends PagedSelector<Challenge>
+{
+	private ChallengeSelector(User user, Material border, Map<Challenge, List<String>> challengesDescriptionMap, BiConsumer<Boolean, Set<Challenge>> consumer)
+	{
+		super(user);
+		this.consumer = consumer;
+		this.challengesDescriptionMap = challengesDescriptionMap;
+		this.border = border;
+
+		this.elements = challengesDescriptionMap.keySet().stream().toList();
+		this.selectedElements = new HashSet<>(this.elements.size());
+	}
+
+
+	/**
+	 * This method opens GUI that allows to select challenge type.
+	 *
+	 * @param user User who opens GUI.
+	 * @param consumer Consumer that allows to get clicked type.
+	 */
+	public static void open(User user, Material border, Map<Challenge, List<String>> challengesDescriptionMap, BiConsumer<Boolean, Set<Challenge>> consumer)
+	{
+		new ChallengeSelector(user, border, challengesDescriptionMap, consumer).build();
+	}
+
+
+	/**
+	 * This method builds all necessary elements in GUI panel.
+	 */
+	@Override
+	protected void build()
+	{
+		PanelBuilder panelBuilder = new PanelBuilder().user(this.user);
+		panelBuilder.name(this.user.getTranslation(Constants.TITLE + "challenge-selector"));
+
+		GuiUtils.fillBorder(panelBuilder, this.border);
+
+		this.populateElements(panelBuilder, this.elements);
+
+		panelBuilder.item(3, this.createButton(Button.ACCEPT_SELECTED));
+		panelBuilder.item(5, this.createButton(Button.CANCEL));
+
+		panelBuilder.build();
+	}
+
+
+	/**
+	 * This method creates PanelItem button of requested type.
+	 * @param button Button which must be created.
+	 * @return new PanelItem with requested functionality.
+	 */
+	private PanelItem createButton(Button button)
+	{
+		final String reference = Constants.BUTTON + button.name().toLowerCase() + ".";
+
+		final String name = this.user.getTranslation(reference + "name");
+		final List<String> description = new ArrayList<>(3);
+		description.add(this.user.getTranslation(reference + "description"));
+
+		ItemStack icon;
+		PanelItem.ClickHandler clickHandler;
+
+		switch (button)
+		{
+			case ACCEPT_SELECTED -> {
+				if (!this.selectedElements.isEmpty())
+				{
+					description.add(this.user.getTranslation(reference + "title"));
+					this.selectedElements.forEach(challenge -> {
+						description.add(this.user.getTranslation(reference + "element",
+							"[element]", challenge.getFriendlyName()));
+					});
+				}
+
+				icon = new ItemStack(Material.COMMAND_BLOCK);
+				clickHandler = (panel, user1, clickType, slot) ->
+				{
+					this.consumer.accept(true, this.selectedElements);
+					return true;
+				};
+
+				description.add("");
+				description.add(this.user.getTranslation(Constants.TIPS + "click-to-save"));
+			}
+			case CANCEL -> {
+
+				icon = new ItemStack(Material.IRON_DOOR);
+
+				clickHandler = (panel, user1, clickType, slot) ->
+				{
+					this.consumer.accept(false, null);
+					return true;
+				};
+
+				description.add("");
+				description.add(this.user.getTranslation(Constants.TIPS + "click-to-cancel"));
+			}
+			default -> {
+				icon = new ItemStack(Material.PAPER);
+				clickHandler = null;
+			}
+		}
+
+		return new PanelItemBuilder().
+			icon(icon).
+			name(name).
+			description(description).
+			clickHandler(clickHandler).
+			build();
+	}
+
+
+	/**
+	 * This method creates button for given challenge.
+	 * @param challenge challenge which button must be created.
+	 * @return new Button for challenge.
+	 */
+	@Override
+	protected PanelItem createElementButton(Challenge challenge)
+	{
+		final String reference = Constants.BUTTON + "entity.";
+
+		List<String> description = new ArrayList<>(this.challengesDescriptionMap.get(challenge));
+		description.add("");
+
+		if (this.selectedElements.contains(challenge))
+		{
+			description.add(this.user.getTranslation(reference + "selected"));
+			description.add(this.user.getTranslation(Constants.TIPS + "click-to-deselect"));
+		}
+		else
+		{
+			description.add(this.user.getTranslation(Constants.TIPS + "click-to-select"));
+		}
+
+		return new PanelItemBuilder().
+			name(Util.translateColorCodes(challenge.getFriendlyName())).
+			icon(challenge.getIcon()).
+			description(description).
+			clickHandler((panel, user1, clickType, slot) -> {
+				// On right click change which entities are selected for deletion.
+				if (!this.selectedElements.add(challenge))
+				{
+					// Remove challenge if it is already selected
+					this.selectedElements.remove(challenge);
+				}
+
+				this.build();
+				return true;
+			}).
+			glow(this.selectedElements.contains(challenge)).
+			build();
+	}
+
+
+	/**
+	 * Functional buttons in current GUI.
+	 */
+	private enum Button
+	{
+		ACCEPT_SELECTED,
+		CANCEL
+	}
+
+
+// ---------------------------------------------------------------------
+// Section: Variables
+// ---------------------------------------------------------------------
+
+
+	/**
+	 * This variable stores consumer.
+	 */
+	private final BiConsumer<Boolean, Set<Challenge>> consumer;
+
+	/**
+	 * Current value.
+	 */
+	private final List<Challenge> elements;
+
+	/**
+	 * Selected challenges that will be returned to consumer.
+	 */
+	private final Set<Challenge> selectedElements;
+
+	/**
+	 * Map that contains all challenge descriptions
+	 */
+	private final Map<Challenge, List<String>> challengesDescriptionMap;
+
+	/**
+	 * Border Material.
+	 */
+	private final Material border;
+}