| // Copyright (C) 2013 The Android Open Source Project |
| // |
| // Licensed under the Apache License, Version 2.0 (the "License"); |
| // you may not use this file except in compliance with the License. |
| // You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS IS" BASIS, |
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| // See the License for the specific language governing permissions and |
| // limitations under the License. |
| |
| package com.google.gerrit.client.diff; |
| |
| import com.google.gwt.core.client.JsArrayString; |
| import net.codemirror.lib.Pos; |
| |
| /** An iterator for intraline edits */ |
| class EditIterator { |
| private final JsArrayString lines; |
| private final int startLine; |
| private int line; |
| private int pos; |
| |
| EditIterator(JsArrayString lineArray, int start) { |
| lines = lineArray; |
| startLine = start; |
| } |
| |
| Pos advance(int numOfChar) { |
| numOfChar = adjustForNegativeDelta(numOfChar); |
| |
| while (line < lines.length()) { |
| int len = lines.get(line).length() - pos + 1; // + 1 for LF |
| if (numOfChar < len) { |
| Pos at = Pos.create(startLine + line, numOfChar + pos); |
| pos += numOfChar; |
| return at; |
| } |
| |
| numOfChar -= len; |
| line++; |
| pos = 0; |
| |
| if (numOfChar == 0) { |
| return Pos.create(startLine + line, 0); |
| } |
| } |
| |
| throw new IllegalStateException("EditIterator index out of bounds"); |
| } |
| |
| private int adjustForNegativeDelta(int n) { |
| while (n < 0) { |
| if (-n <= pos) { |
| pos += n; |
| return 0; |
| } |
| |
| n += pos; |
| line--; |
| if (line < 0) { |
| throw new IllegalStateException("EditIterator index out of bounds"); |
| } |
| pos = lines.get(line).length() + 1; |
| } |
| return n; |
| } |
| } |