X-Git-Url: http://git.nikiroo.be/?a=blobdiff_plain;f=src%2Fjexer%2Fteditor%2FLine.java;fp=src%2Fjexer%2Fteditor%2FLine.java;h=7cd5febabee8462f6c51bc66e886903795aff698;hb=12b90437b5f22c2ae6e9b9b14c3b62b60f6143e5;hp=0000000000000000000000000000000000000000;hpb=b709b36e17eb8807819e51297bb398ef28ece52d;p=fanfix.git diff --git a/src/jexer/teditor/Line.java b/src/jexer/teditor/Line.java new file mode 100644 index 0000000..7cd5feb --- /dev/null +++ b/src/jexer/teditor/Line.java @@ -0,0 +1,365 @@ +/* + * Jexer - Java Text User Interface + * + * The MIT License (MIT) + * + * Copyright (C) 2019 Kevin Lamonte + * + * Permission is hereby granted, free of charge, to any person obtaining a + * copy of this software and associated documentation files (the "Software"), + * to deal in the Software without restriction, including without limitation + * the rights to use, copy, modify, merge, publish, distribute, sublicense, + * and/or sell copies of the Software, and to permit persons to whom the + * Software is furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER + * DEALINGS IN THE SOFTWARE. + * + * @author Kevin Lamonte [kevin.lamonte@gmail.com] + * @version 1 + */ +package jexer.teditor; + +import java.util.ArrayList; +import java.util.List; + +import jexer.bits.CellAttributes; +import jexer.bits.StringUtils; + +/** + * A Line represents a single line of text on the screen, as a collection of + * words. + */ +public class Line { + + // ------------------------------------------------------------------------ + // Variables -------------------------------------------------------------- + // ------------------------------------------------------------------------ + + /** + * The list of words. + */ + private ArrayList words = new ArrayList(); + + /** + * The default color for the TEditor class. + */ + private CellAttributes defaultColor = null; + + /** + * The text highlighter to use. + */ + private Highlighter highlighter = null; + + /** + * The current edition position on this line. + */ + private int position = 0; + + /** + * The current editing position screen column number. + */ + private int screenPosition = 0; + + /** + * The raw text of this line, what is passed to Word to determine + * highlighting behavior. + */ + private StringBuilder rawText; + + // ------------------------------------------------------------------------ + // Constructors ----------------------------------------------------------- + // ------------------------------------------------------------------------ + + /** + * Construct a new Line from an existing text string, and highlight + * certain strings. + * + * @param str the text string + * @param defaultColor the color for unhighlighted text + * @param highlighter the highlighter to use + */ + public Line(final String str, final CellAttributes defaultColor, + final Highlighter highlighter) { + + this.defaultColor = defaultColor; + this.highlighter = highlighter; + this.rawText = new StringBuilder(str); + + scanLine(); + } + + /** + * Construct a new Line from an existing text string. + * + * @param str the text string + * @param defaultColor the color for unhighlighted text + */ + public Line(final String str, final CellAttributes defaultColor) { + this(str, defaultColor, null); + } + + // ------------------------------------------------------------------------ + // Line ------------------------------------------------------------------- + // ------------------------------------------------------------------------ + + /** + * Get a (shallow) copy of the words in this line. + * + * @return a copy of the word list + */ + public List getWords() { + return new ArrayList(words); + } + + /** + * Get the current cursor position in the text. + * + * @return the cursor position + */ + public int getRawCursor() { + return position; + } + + /** + * Get the current cursor position on screen. + * + * @return the cursor position + */ + public int getCursor() { + return screenPosition; + } + + /** + * Set the current cursor position. + * + * @param cursor the new cursor position + */ + public void setCursor(final int cursor) { + if ((cursor < 0) + || ((cursor >= getDisplayLength()) + && (getDisplayLength() > 0)) + ) { + throw new IndexOutOfBoundsException("Max length is " + + getDisplayLength() + ", requested position " + cursor); + } + screenPosition = cursor; + position = screenToTextPosition(screenPosition); + } + + /** + * Get the character at the current cursor position in the text. + * + * @return the character, or -1 if the cursor is at the end of the line + */ + public int getChar() { + if (position == rawText.length()) { + return -1; + } + return rawText.codePointAt(position); + } + + /** + * Get the on-screen display length. + * + * @return the number of cells needed to display this line + */ + public int getDisplayLength() { + int n = StringUtils.width(rawText.toString()); + + if (n > 0) { + // If we have any visible characters, add one to the display so + // that the position is immediately after the data. + return n + 1; + } + return n; + } + + /** + * Get the raw string that matches this line. + * + * @return the string + */ + public String getRawString() { + return rawText.toString(); + } + + /** + * Scan rawText and make words out of it. + */ + private void scanLine() { + words.clear(); + Word word = new Word(this.defaultColor, this.highlighter); + words.add(word); + for (int i = 0; i < rawText.length();) { + int ch = rawText.codePointAt(i); + i += Character.charCount(ch); + Word newWord = word.addChar(ch); + if (newWord != word) { + words.add(newWord); + word = newWord; + } + } + for (Word w: words) { + w.applyHighlight(); + } + } + + /** + * Decrement the cursor by one. If at the first column, do nothing. + * + * @return true if the cursor position changed + */ + public boolean left() { + if (position == 0) { + return false; + } + screenPosition -= StringUtils.width(rawText.codePointBefore(position)); + position -= Character.charCount(rawText.codePointBefore(position)); + return true; + } + + /** + * Increment the cursor by one. If at the last column, do nothing. + * + * @return true if the cursor position changed + */ + public boolean right() { + if (getDisplayLength() == 0) { + return false; + } + if (position == getDisplayLength() - 1) { + return false; + } + if (position < rawText.length()) { + screenPosition += StringUtils.width(rawText.codePointAt(position)); + position += Character.charCount(rawText.codePointAt(position)); + } + assert (position <= rawText.length()); + return true; + } + + /** + * Go to the first column of this line. + * + * @return true if the cursor position changed + */ + public boolean home() { + if (position > 0) { + position = 0; + screenPosition = 0; + return true; + } + return false; + } + + /** + * Go to the last column of this line. + * + * @return true if the cursor position changed + */ + public boolean end() { + if (position != getDisplayLength() - 1) { + position = rawText.length(); + screenPosition = StringUtils.width(rawText.toString()); + return true; + } + return false; + } + + /** + * Delete the character under the cursor. + */ + public void del() { + assert (words.size() > 0); + + if (position < getDisplayLength()) { + int n = Character.charCount(rawText.codePointAt(position)); + for (int i = 0; i < n; i++) { + rawText.deleteCharAt(position); + } + } + + // Re-scan the line to determine the new word boundaries. + scanLine(); + } + + /** + * Delete the character immediately preceeding the cursor. + */ + public void backspace() { + if (left()) { + del(); + } + } + + /** + * Insert a character at the cursor. + * + * @param ch the character to insert + */ + public void addChar(final int ch) { + if (position < getDisplayLength() - 1) { + rawText.insert(position, Character.toChars(ch)); + } else { + rawText.append(Character.toChars(ch)); + } + position += Character.charCount(ch); + screenPosition += StringUtils.width(ch); + scanLine(); + } + + /** + * Replace a character at the cursor. + * + * @param ch the character to replace + */ + public void replaceChar(final int ch) { + if (position < getDisplayLength() - 1) { + // Replace character + String oldText = rawText.toString(); + rawText = new StringBuilder(oldText.substring(0, position)); + rawText.append(Character.toChars(ch)); + rawText.append(oldText.substring(position + 1)); + screenPosition += StringUtils.width(rawText.codePointAt(position)); + position += Character.charCount(ch); + } else { + rawText.append(Character.toChars(ch)); + position += Character.charCount(ch); + screenPosition += StringUtils.width(ch); + } + scanLine(); + } + + /** + * Determine string position from screen position. + * + * @param screenPosition the position on screen + * @return the equivalent position in text + */ + protected int screenToTextPosition(final int screenPosition) { + if (screenPosition == 0) { + return 0; + } + + int n = 0; + for (int i = 0; i < rawText.length(); i++) { + n += StringUtils.width(rawText.codePointAt(i)); + if (n >= screenPosition) { + return i + 1; + } + } + // screenPosition exceeds the available text length. + throw new IndexOutOfBoundsException("screenPosition " + screenPosition + + " exceeds available text length " + rawText.length()); + } + +}