Create SelectIslandPanel that allows to select island with consumer.

src/main/java/world/bentobox/visit/panels/admin/SelectIslandPanel.java

@@ -0,0 +1,215 @@
+package world.bentobox.visit.panels.admin;
+
+
+import org.bukkit.Material;
+import java.util.ArrayList;
+import java.util.Iterator;
+import java.util.List;
+import java.util.Objects;
+import java.util.function.Consumer;
+
+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.database.objects.Island;
+import world.bentobox.visit.VisitAddon;
+import world.bentobox.visit.database.object.IslandVisitSettings;
+
+
+/**
+ * This class contains all necessary things that allows to select single island.
+ */
+public class SelectIslandPanel
+{
+	/**
+	 * Defautl constructor object.
+	 * @param user User who opens Panel
+	 * @param inputList Input Island List
+	 * @param consumer Consumer that returns selected island object.
+	 */
+	private SelectIslandPanel(User user,
+		List<Island> inputList,
+		Consumer<Island> consumer)
+	{
+		this.consumer = consumer;
+		this.user = user;
+
+		this.elements = inputList;
+	}
+
+
+	/**
+	 * Simple warpper around panel.
+	 * @param user User who opens Panel
+	 * @param inputList Input Island List
+	 * @param consumer Consumer that returns selected island object.
+	 */
+	public static void open(User user, List<Island> inputList, Consumer<Island> consumer)
+	{
+		new SelectIslandPanel(user, inputList, consumer).build();
+	}
+
+
+// ---------------------------------------------------------------------
+// Section: Methods
+// ---------------------------------------------------------------------
+
+
+	/**
+	 * This method builds all necessary elements in GUI panel.
+	 */
+	private void build()
+	{
+		PanelBuilder panelBuilder = new PanelBuilder().user(this.user).
+			name(this.user.getTranslation("visit.gui.admin.title.select-island"));
+
+		final int MAX_ELEMENTS = 27;
+
+		int index;
+
+		if (this.pageIndex > 0)
+		{
+			panelBuilder.item(this.createPreviousPageButton());
+			// Multiple pages. Adjust index.
+
+			index = this.pageIndex * MAX_ELEMENTS;
+		}
+		else
+		{
+			index = 0;
+		}
+
+		// Create island iterator for sublist that contains elements from index till list size.
+		Iterator<Island> islandIterator = this.elements.subList(index, this.elements.size()).iterator();
+
+		// Fill every free spot till last block is not used.
+		while (islandIterator.hasNext() && panelBuilder.nextSlot() < 53)
+		{
+			panelBuilder.item(this.createIslandButton(islandIterator.next()));
+		}
+
+		// Check if there is spot for last island
+		if (islandIterator.hasNext())
+		{
+			Island lastIsland = islandIterator.next();
+
+			if (islandIterator.hasNext())
+			{
+				// There is more then one island left in the list.
+				panelBuilder.item(this.createNextPageButton());
+			}
+			else
+			{
+				// This is the last island.. no need to create next page button.
+				panelBuilder.item(this.createIslandButton(lastIsland));
+			}
+		}
+
+
+		panelBuilder.build();
+	}
+
+
+	/**
+	 * This method creates and returns button that switch to previous page in view mode.
+	 * @return PanelItem that allows to select previous island view page.
+	 */
+	private PanelItem createPreviousPageButton()
+	{
+		return new PanelItemBuilder().
+			icon(Material.TIPPED_ARROW).
+			name(this.user.getTranslation("visit.gui.player.button.previous.name")).
+			clickHandler((panel, user, clickType, index) -> {
+				this.pageIndex = Math.max(0, this.pageIndex - 1);
+				this.build();
+				return true;
+			}).
+			build();
+	}
+
+
+	/**
+	 * This method creates and returns button that switch to next page in view mode.
+	 * @return PanelItem that allows to select next island view page.
+	 */
+	private PanelItem createNextPageButton()
+	{
+		return new PanelItemBuilder().
+			icon(Material.TIPPED_ARROW).
+			name(this.user.getTranslation("visit.gui.player.button.next.name")).
+			clickHandler((panel, user, clickType, index) -> {
+				this.pageIndex++;
+				this.build();
+				return true;
+			}).
+			build();
+	}
+
+
+	/**
+	 * This method creates and returns button that switch to next page in view mode.
+	 * @return PanelItem that allows to select next island view page.
+	 */
+	private PanelItem createIslandButton(Island island)
+	{
+		PanelItemBuilder builder = new PanelItemBuilder();
+
+		if (VisitAddon.getInstance().getSettings().getIslandIcon() == Material.PLAYER_HEAD)
+		{
+			builder.icon(Objects.requireNonNull(User.getInstance(island.getOwner())).getName());
+		}
+		else
+		{
+			builder.icon(VisitAddon.getInstance().getSettings().getIslandIcon());
+		}
+
+		builder.name(this.user.getTranslation("visit.gui.player.button.island.name",
+			"[name]",
+			island.getName() != null ? island.getName() :
+				Objects.requireNonNull(User.getInstance(island.getOwner())).getName()));
+
+		List<String> description = new ArrayList<>();
+
+		IslandVisitSettings settings = VisitAddon.getInstance().getAddonManager().getIslandVisitSettings(island);
+
+		description.add(this.user.getTranslation("visit.gui.player.button.island.cost",
+			"[cost]", String.valueOf(settings.getPayment())));
+
+		builder.description(description);
+
+		// Glow icon if user can visit the island.
+		builder.glow(VisitAddon.getInstance().getAddonManager().hasDefaultValues(settings));
+
+		return builder.clickHandler((panel, user, clickType, index) ->
+		{
+			this.consumer.accept(island);
+			return true;
+		}).build();
+	}
+
+
+// ---------------------------------------------------------------------
+// Section: Variables
+// ---------------------------------------------------------------------
+
+	/**
+	 * List with elements that will be displayed in current GUI.
+	 */
+	private List<Island> elements;
+
+	/**
+	 * This variable stores consumer.
+	 */
+	private Consumer<Island> consumer;
+
+	/**
+	 * User who runs GUI.
+	 */
+	private User user;
+
+	/**
+	 * Stores current pageIndex.
+	 */
+	private int pageIndex;
+}