minecraft-src/net/minecraft/client/gui/font/TextFieldHelper.java

package net.minecraft.client.gui.font;

import java.util.function.Consumer;
import java.util.function.Predicate;
import java.util.function.Supplier;
import net.fabricmc.api.EnvType;
import net.fabricmc.api.Environment;
import net.minecraft.ChatFormatting;
import net.minecraft.Util;
import net.minecraft.client.Minecraft;
import net.minecraft.client.StringSplitter;
import net.minecraft.client.gui.screens.Screen;
import net.minecraft.util.Mth;
import net.minecraft.util.StringUtil;

@Environment(EnvType.CLIENT)
public class TextFieldHelper {
	private final Supplier<String> getMessageFn;
	private final Consumer<String> setMessageFn;
	private final Supplier<String> getClipboardFn;
	private final Consumer<String> setClipboardFn;
	private final Predicate<String> stringValidator;
	private int cursorPos;
	private int selectionPos;

	public TextFieldHelper(
		Supplier<String> getMessage, Consumer<String> setMessage, Supplier<String> getClipboard, Consumer<String> setClipboard, Predicate<String> stringValidator
	) {
		this.getMessageFn = getMessage;
		this.setMessageFn = setMessage;
		this.getClipboardFn = getClipboard;
		this.setClipboardFn = setClipboard;
		this.stringValidator = stringValidator;
		this.setCursorToEnd();
	}

	public static Supplier<String> createClipboardGetter(Minecraft minecraft) {
		return () -> getClipboardContents(minecraft);
	}

	public static String getClipboardContents(Minecraft minecraft) {
		return ChatFormatting.stripFormatting(minecraft.keyboardHandler.getClipboard().replaceAll("\\r", ""));
	}

	public static Consumer<String> createClipboardSetter(Minecraft minecraft) {
		return string -> setClipboardContents(minecraft, string);
	}

	public static void setClipboardContents(Minecraft minecraft, String text) {
		minecraft.keyboardHandler.setClipboard(text);
	}

	public boolean charTyped(char character) {
		if (StringUtil.isAllowedChatCharacter(character)) {
			this.insertText((String)this.getMessageFn.get(), Character.toString(character));
		}

		return true;
	}

	public boolean keyPressed(int key) {
		if (Screen.isSelectAll(key)) {
			this.selectAll();
			return true;
		} else if (Screen.isCopy(key)) {
			this.copy();
			return true;
		} else if (Screen.isPaste(key)) {
			this.paste();
			return true;
		} else if (Screen.isCut(key)) {
			this.cut();
			return true;
		} else {
			TextFieldHelper.CursorStep cursorStep = Screen.hasControlDown() ? TextFieldHelper.CursorStep.WORD : TextFieldHelper.CursorStep.CHARACTER;
			if (key == 259) {
				this.removeFromCursor(-1, cursorStep);
				return true;
			} else {
				if (key == 261) {
					this.removeFromCursor(1, cursorStep);
				} else {
					if (key == 263) {
						this.moveBy(-1, Screen.hasShiftDown(), cursorStep);
						return true;
					}

					if (key == 262) {
						this.moveBy(1, Screen.hasShiftDown(), cursorStep);
						return true;
					}

					if (key == 268) {
						this.setCursorToStart(Screen.hasShiftDown());
						return true;
					}

					if (key == 269) {
						this.setCursorToEnd(Screen.hasShiftDown());
						return true;
					}
				}

				return false;
			}
		}
	}

	private int clampToMsgLength(int textIndex) {
		return Mth.clamp(textIndex, 0, ((String)this.getMessageFn.get()).length());
	}

	private void insertText(String text, String clipboardText) {
		if (this.selectionPos != this.cursorPos) {
			text = this.deleteSelection(text);
		}

		this.cursorPos = Mth.clamp(this.cursorPos, 0, text.length());
		String string = new StringBuilder(text).insert(this.cursorPos, clipboardText).toString();
		if (this.stringValidator.test(string)) {
			this.setMessageFn.accept(string);
			this.selectionPos = this.cursorPos = Math.min(string.length(), this.cursorPos + clipboardText.length());
		}
	}

	public void insertText(String text) {
		this.insertText((String)this.getMessageFn.get(), text);
	}

	private void resetSelectionIfNeeded(boolean keepSelection) {
		if (!keepSelection) {
			this.selectionPos = this.cursorPos;
		}
	}

	public void moveBy(int direction, boolean keepSelection, TextFieldHelper.CursorStep cursorStep) {
		switch (cursorStep) {
			case CHARACTER:
				this.moveByChars(direction, keepSelection);
				break;
			case WORD:
				this.moveByWords(direction, keepSelection);
		}
	}

	public void moveByChars(int direction) {
		this.moveByChars(direction, false);
	}

	public void moveByChars(int direction, boolean keepSelection) {
		this.cursorPos = Util.offsetByCodepoints((String)this.getMessageFn.get(), this.cursorPos, direction);
		this.resetSelectionIfNeeded(keepSelection);
	}

	public void moveByWords(int direction) {
		this.moveByWords(direction, false);
	}

	public void moveByWords(int direction, boolean keepSelection) {
		this.cursorPos = StringSplitter.getWordPosition((String)this.getMessageFn.get(), direction, this.cursorPos, true);
		this.resetSelectionIfNeeded(keepSelection);
	}

	public void removeFromCursor(int direction, TextFieldHelper.CursorStep step) {
		switch (step) {
			case CHARACTER:
				this.removeCharsFromCursor(direction);
				break;
			case WORD:
				this.removeWordsFromCursor(direction);
		}
	}

	public void removeWordsFromCursor(int direction) {
		int i = StringSplitter.getWordPosition((String)this.getMessageFn.get(), direction, this.cursorPos, true);
		this.removeCharsFromCursor(i - this.cursorPos);
	}

	public void removeCharsFromCursor(int direction) {
		String string = (String)this.getMessageFn.get();
		if (!string.isEmpty()) {
			String string2;
			if (this.selectionPos != this.cursorPos) {
				string2 = this.deleteSelection(string);
			} else {
				int i = Util.offsetByCodepoints(string, this.cursorPos, direction);
				int j = Math.min(i, this.cursorPos);
				int k = Math.max(i, this.cursorPos);
				string2 = new StringBuilder(string).delete(j, k).toString();
				if (direction < 0) {
					this.selectionPos = this.cursorPos = j;
				}
			}

			this.setMessageFn.accept(string2);
		}
	}

	public void cut() {
		String string = (String)this.getMessageFn.get();
		this.setClipboardFn.accept(this.getSelected(string));
		this.setMessageFn.accept(this.deleteSelection(string));
	}

	public void paste() {
		this.insertText((String)this.getMessageFn.get(), (String)this.getClipboardFn.get());
		this.selectionPos = this.cursorPos;
	}

	public void copy() {
		this.setClipboardFn.accept(this.getSelected((String)this.getMessageFn.get()));
	}

	public void selectAll() {
		this.selectionPos = 0;
		this.cursorPos = ((String)this.getMessageFn.get()).length();
	}

	private String getSelected(String text) {
		int i = Math.min(this.cursorPos, this.selectionPos);
		int j = Math.max(this.cursorPos, this.selectionPos);
		return text.substring(i, j);
	}

	private String deleteSelection(String text) {
		if (this.selectionPos == this.cursorPos) {
			return text;
		} else {
			int i = Math.min(this.cursorPos, this.selectionPos);
			int j = Math.max(this.cursorPos, this.selectionPos);
			String string = text.substring(0, i) + text.substring(j);
			this.selectionPos = this.cursorPos = i;
			return string;
		}
	}

	public void setCursorToStart() {
		this.setCursorToStart(false);
	}

	public void setCursorToStart(boolean keepSelection) {
		this.cursorPos = 0;
		this.resetSelectionIfNeeded(keepSelection);
	}

	public void setCursorToEnd() {
		this.setCursorToEnd(false);
	}

	public void setCursorToEnd(boolean keepSelection) {
		this.cursorPos = ((String)this.getMessageFn.get()).length();
		this.resetSelectionIfNeeded(keepSelection);
	}

	public int getCursorPos() {
		return this.cursorPos;
	}

	public void setCursorPos(int textIndex) {
		this.setCursorPos(textIndex, true);
	}

	public void setCursorPos(int textIndex, boolean keepSelection) {
		this.cursorPos = this.clampToMsgLength(textIndex);
		this.resetSelectionIfNeeded(keepSelection);
	}

	public int getSelectionPos() {
		return this.selectionPos;
	}

	public void setSelectionPos(int textIndex) {
		this.selectionPos = this.clampToMsgLength(textIndex);
	}

	public void setSelectionRange(int selectionStart, int selectionEnd) {
		int i = ((String)this.getMessageFn.get()).length();
		this.cursorPos = Mth.clamp(selectionStart, 0, i);
		this.selectionPos = Mth.clamp(selectionEnd, 0, i);
	}

	public boolean isSelecting() {
		return this.cursorPos != this.selectionPos;
	}

	@Environment(EnvType.CLIENT)
	public static enum CursorStep {
		CHARACTER,
		WORD;
	}
}