Create StringListGUI class that allows to edit list of strings.

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

@@ -0,0 +1,241 @@
+package world.bentobox.challenges.panel.util;
+
+
+import org.bukkit.Material;
+import org.bukkit.inventory.ItemStack;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.List;
+
+import world.bentobox.bentobox.api.commands.CompositeCommand;
+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.challenges.panel.CommonGUI;
+
+
+/**
+ * This GUI allows to edit List of strings. AnvilGUI has limited text space, so splitting
+ * text in multiple rows allows to edit each row separately.
+ */
+public class StringListGUI
+{
+	public StringListGUI(CommonGUI parentGUI,
+		User user,
+		List<String> value,
+		CompositeCommand command,
+		String... parameters)
+	{
+		this.parentGUI = parentGUI;
+		this.user = user;
+		this.value = value;
+		this.command = command;
+		this.parameters = parameters;
+
+		if (this.value.size() > 18)
+		{
+			// TODO: throw error that so large list cannot be edited.
+			this.parentGUI.build();
+		}
+		else
+		{
+			this.build();
+		}
+	}
+
+
+	/**
+	 * This method builds panel that allows to change given string value.
+	 */
+	private void build()
+	{
+		PanelBuilder panelBuilder = new PanelBuilder().name(this.user.getTranslation("challenges.gui.text-edit-title"));
+
+		panelBuilder.item(0, this.getButton(Button.SAVE));
+		panelBuilder.item(1, this.getButton(Button.VALUE));
+
+		panelBuilder.item(3, this.getButton(Button.ADD));
+		panelBuilder.item(4, this.getButton(Button.REMOVE));
+		panelBuilder.item(4, this.getButton(Button.CLEAR));
+
+		panelBuilder.item(8, this.getButton(Button.CANCEL));
+
+		for (String element : this.value)
+		{
+			panelBuilder.item(this.createStringElement(element));
+		}
+
+		panelBuilder.build();
+	}
+
+
+	/**
+	 * This method create button that does some functionality in current gui.
+	 * @param button Button functionality.
+	 * @return PanelItem.
+	 */
+	private PanelItem getButton(Button button)
+	{
+		ItemStack icon;
+		String name;
+		List<String> description;
+		PanelItem.ClickHandler clickHandler;
+
+		switch (button)
+		{
+			case SAVE:
+			{
+				name = this.user.getTranslation("challenges.gui.buttons.save");
+				description = Collections.emptyList();
+				icon = new ItemStack(Material.COMMAND_BLOCK);
+				clickHandler = (panel, user, clickType, slot) -> {
+					List<String> values = Arrays.asList(this.parameters);
+					values.addAll(this.value);
+
+					if (this.command.execute(this.user, "STRING_LIST_GUI", values))
+					{
+						this.user.closeInventory();
+						this.parentGUI.build();
+					}
+					else
+					{
+						this.build();
+					}
+
+					return true;
+				};
+				break;
+			}
+			case CANCEL:
+			{
+				name = this.user.getTranslation("challenges.gui.buttons.cancel");
+				description = Collections.emptyList();
+				icon = new ItemStack(Material.IRON_DOOR);
+				clickHandler = (panel, user, clickType, slot) -> {
+					this.parentGUI.build();
+					return true;
+				};
+				break;
+			}
+			case VALUE:
+			{
+				name = this.user.getTranslation("challenges.gui.buttons.value");
+				description = this.value;
+				icon = new ItemStack(Material.PAPER);
+				clickHandler = (panel, user, clickType, slot) -> true;
+				break;
+			}
+			case ADD:
+			{
+				name = this.user.getTranslation("challenges.gui.buttons.add");
+				description = Collections.emptyList();
+				icon = new ItemStack(Material.WHITE_STAINED_GLASS_PANE);
+				clickHandler = (panel, user, clickType, slot) -> {
+
+					// TODO: Open Anvil GUI.
+
+					this.build();
+					return true;
+				};
+				break;
+			}
+			case CLEAR:
+			{
+				name = this.user.getTranslation("challenges.gui.buttons.clear");
+				description = Collections.emptyList();
+				icon = new ItemStack(Material.RED_STAINED_GLASS_PANE);
+				clickHandler = (panel, user, clickType, slot) -> {
+					this.value.clear();
+					this.build();
+					return true;
+				};
+				break;
+			}
+			case REMOVE:
+			{
+				name = this.user.getTranslation("challenges.gui.buttons.remove");
+				description = Collections.emptyList();
+				icon = new ItemStack(Material.BLUE_STAINED_GLASS_PANE);
+				clickHandler = (panel, user, clickType, slot) -> {
+					this.value.removeIf(String::isEmpty);
+
+					this.build();
+					return true;
+				};
+				break;
+			}
+			default:
+				return null;
+		}
+
+		return new PanelItem(icon, name, description, false, clickHandler, false);
+	}
+
+
+	/**
+	 * This method creates paper icon that represents single line from list.
+	 * @param element Paper Icon name
+	 * @return PanelItem.
+	 */
+	private PanelItem createStringElement(String element)
+	{
+		return new PanelItemBuilder().
+			name(element).
+			icon(Material.PAPER).
+			clickHandler((panel, user1, clickType, i) -> {
+			// TODO: open anvil gui.
+			return true;
+		}).build();
+	}
+
+
+// ---------------------------------------------------------------------
+// Section: Enums
+// ---------------------------------------------------------------------
+
+
+	/**
+	 * This enum holds all button values in current gui.
+	 */
+	private enum Button
+	{
+		VALUE,
+		ADD,
+		REMOVE,
+		CANCEL,
+		CLEAR,
+		SAVE
+	}
+
+
+// ---------------------------------------------------------------------
+// Section: Variables
+// ---------------------------------------------------------------------
+
+
+	/**
+	 * This variable stores return GUI.
+	 */
+	private CommonGUI parentGUI;
+
+	/**
+	 * User who runs GUI.
+	 */
+	private User user;
+
+	/**
+	 * Current value.
+	 */
+	private List<String> value;
+
+	/**
+	 * Command that must be processed on save.
+	 */
+	private CompositeCommand command;
+
+	/**
+	 * Command input parameters before number.
+	 */
+	private String[] parameters;
+}