Here you can find the source of getBreakLocation(Segment s, FontMetrics metrics, int x0, int x, TabExpander e, int startOffset)
| Parameter | Description |
|---|---|
| s | the source of the text |
| metrics | the font metrics to use for the calculation |
| x0 | the starting view location representing the start of the given text. |
| x | the target view location to translate to an offset into the text. |
| e | how to expand the tabs. If this value is null, tabs will be expanded as a space character. |
| startOffset | starting offset in the document of the text |
public static final int getBreakLocation(Segment s, FontMetrics metrics, int x0, int x, TabExpander e, int startOffset)
//package com.java2s; /*// w w w . jav a 2s. c o m * @(#)Utilities.java 1.40 03/01/23 * * Copyright 2003 Sun Microsystems, Inc. All rights reserved. * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms. */ import java.awt.FontMetrics; import javax.swing.text.*; public class Main { /** * Determine where to break the given text to fit * within the the given span. This tries to find a * whitespace boundary. * @param s the source of the text * @param metrics the font metrics to use for the calculation * @param x0 the starting view location representing the start * of the given text. * @param x the target view location to translate to an * offset into the text. * @param e how to expand the tabs. If this value is null, * tabs will be expanded as a space character. * @param startOffset starting offset in the document of the text * @return the offset into the given text */ public static final int getBreakLocation(Segment s, FontMetrics metrics, int x0, int x, TabExpander e, int startOffset) { char[] txt = s.array; int txtOffset = s.offset; int txtCount = s.count; int index = Utilities.getTabbedTextOffset(s, metrics, x0, x, e, startOffset, false); for (int i = txtOffset + Math.min(index, txtCount - 1); i >= txtOffset; i--) { char ch = txt[i]; if (Character.isWhitespace(ch)) { // found whitespace, break here index = i - txtOffset + 1; break; } } return index; } /** * Determines the relative offset into the given text that * best represents the given span in the view coordinate * system. This is implemented in a 1.1 style coordinate * system where ints are used and 72dpi is assumed. * * @param s the source of the text * @param metrics the font metrics to use for the calculation * @param x0 the starting view location representing the start * of the given text >= 0. * @param x the target view location to translate to an * offset into the text >= 0. * @param e how to expand the tabs. If this value is null, * tabs will be expanded as a space character. * @param startOffset starting offset of the text in the document >= 0 * @return the offset into the text >= 0 */ public static final int getTabbedTextOffset(Segment s, FontMetrics metrics, int x0, int x, TabExpander e, int startOffset) { return getTabbedTextOffset(s, metrics, x0, x, e, startOffset, true); } public static final int getTabbedTextOffset(Segment s, FontMetrics metrics, int x0, int x, TabExpander e, int startOffset, boolean round) { if (x0 >= x) { // x before x0, return. return 0; } int currX = x0; int nextX = currX; // s may be a shared segment, so it is copied prior to calling // the tab expander char[] txt = s.array; int txtOffset = s.offset; int txtCount = s.count; int n = s.offset + s.count; for (int i = s.offset; i < n; i++) { if (txt[i] == '\t') { if (e != null) { nextX = (int) e.nextTabStop((float) nextX, startOffset + i - txtOffset); } else { nextX += metrics.charWidth(' '); } } else { nextX += metrics.charWidth(txt[i]); } if ((x >= currX) && (x < nextX)) { // found the hit position... return the appropriate side if ((round == false) || ((x - currX) < (nextX - x))) { return i - txtOffset; } else { return i + 1 - txtOffset; } } currX = nextX; } // didn't find, return end offset return txtCount; } }