01: /*
02: * IndentFoldHandler.java - Indent-based fold handler
03: * :tabSize=8:indentSize=8:noTabs=false:
04: * :folding=explicit:collapseFolds=1:
05: *
06: * Copyright (C) 2001, 2002 Slava Pestov
07: *
08: * This program is free software; you can redistribute it and/or
09: * modify it under the terms of the GNU General Public License
10: * as published by the Free Software Foundation; either version 2
11: * of the License, or any later version.
12: *
13: * This program is distributed in the hope that it will be useful,
14: * but WITHOUT ANY WARRANTY; without even the implied warranty of
15: * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16: * GNU General Public License for more details.
17: *
18: * You should have received a copy of the GNU General Public License
19: * along with this program; if not, write to the Free Software
20: * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
21: */
22:
23: package org.gjt.sp.jedit.buffer;
24:
25: import javax.swing.text.Segment;
26:
27: /**
28: * A fold handler that folds lines based on their indent level.
29: * @author Slava Pestov
30: * @version $Id: IndentFoldHandler.java 5339 2006-01-25 23:12:07Z spestov $
31: * @since jEdit 4.0pre1
32: */
33: public class IndentFoldHandler extends FoldHandler {
34: public IndentFoldHandler() {
35: super ("indent");
36: }
37:
38: //{{{ getFoldLevel() method
39: /**
40: * Returns the fold level of the specified line.
41: * @param buffer The buffer in question
42: * @param lineIndex The line index
43: * @param seg A segment the fold handler can use to obtain any
44: * text from the buffer, if necessary
45: * @return The fold level of the specified line
46: * @since jEdit 4.0pre1
47: */
48: public int getFoldLevel(JEditBuffer buffer, int lineIndex,
49: Segment seg) {
50: int tabSize = buffer.getTabSize();
51:
52: buffer.getLineText(lineIndex, seg);
53:
54: int offset = seg.offset;
55: int count = seg.count;
56:
57: int whitespace = 0;
58:
59: boolean seenNonWhiteSpace = false;
60:
61: loop: for (int i = 0; i < count; i++) {
62: switch (seg.array[offset + i]) {
63: case ' ':
64: whitespace++;
65: break;
66: case '\t':
67: whitespace += (tabSize - whitespace % tabSize);
68: break;
69: default:
70: seenNonWhiteSpace = true;
71: break loop;
72: }
73: }
74:
75: if (!seenNonWhiteSpace) {
76: // empty line. inherit previous line's fold level
77: if (lineIndex != 0)
78: return buffer.getFoldLevel(lineIndex - 1);
79: else
80: return 0;
81: }
82: return whitespace;
83: } //}}}
84: }
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