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sdk-common library used by other Android tools libraries.
/*
* Copyright (C) 2015 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.android.ide.common.vectordrawable;
import java.util.ArrayList;
import java.util.List;
/**
* Utility functions for parsing path information.
* The implementation details should be the same as the PathParser in Android framework.
*/
public class PathParser {
private static class ExtractFloatResult {
// We need to return the position of the next separator and whether the
// next float starts with a '-' or a '.'.
int mEndPosition;
boolean mEndWithNegOrDot;
}
/**
* Copies elements from {@code original} into a new array, from indexes start (inclusive) to
* end (exclusive). The original order of elements is preserved.
* If {@code end} is greater than {@code original.length}, the result is padded
* with the value {@code 0.0f}.
*
* @param original the original array
* @param start the start index, inclusive
* @param end the end index, exclusive
* @return the new array
* @throws ArrayIndexOutOfBoundsException if {@code start < 0 || start > original.length}
* @throws IllegalArgumentException if {@code start > end}
* @throws NullPointerException if {@code original == null}
*/
private static float[] copyOfRange(float[] original, int start, int end) {
if (start > end) {
throw new IllegalArgumentException();
}
int originalLength = original.length;
if (start < 0 || start > originalLength) {
throw new ArrayIndexOutOfBoundsException();
}
int resultLength = end - start;
int copyLength = Math.min(resultLength, originalLength - start);
float[] result = new float[resultLength];
System.arraycopy(original, start, result, 0, copyLength);
return result;
}
/**
* Calculate the position of the next comma or space or negative sign
* @param s the string to search
* @param start the position to start searching
* @param result the result of the extraction, including the position of the
* the starting position of next number, whether it is ending with a '-'.
*/
private static void extract(String s, int start, ExtractFloatResult result) {
// Now looking for ' ', ',', '.' or '-' from the start.
int currentIndex = start;
boolean foundSeparator = false;
result.mEndWithNegOrDot = false;
boolean secondDot = false;
boolean isExponential = false;
for (; currentIndex < s.length(); currentIndex++) {
boolean isPrevExponential = isExponential;
isExponential = false;
char currentChar = s.charAt(currentIndex);
switch (currentChar) {
case ' ':
case ',':
foundSeparator = true;
break;
case '-':
// The negative sign following a 'e' or 'E' is not a separator.
if (currentIndex != start && !isPrevExponential) {
foundSeparator = true;
result.mEndWithNegOrDot = true;
}
break;
case '.':
if (!secondDot) {
secondDot = true;
} else {
// This is the second dot, and it is considered as a separator.
foundSeparator = true;
result.mEndWithNegOrDot = true;
}
break;
case 'e':
case 'E':
isExponential = true;
break;
}
if (foundSeparator) {
break;
}
}
// When there is nothing found, then we put the end position to the end
// of the string.
result.mEndPosition = currentIndex;
}
/**
* parse the floats in the string this is an optimized version of parseFloat(s.split(",|\\s"));
*
* @param s the string containing a command and list of floats
* @return array of floats
*/
private static float[] getFloats(String s) {
if (s.charAt(0) == 'z' || s.charAt(0) == 'Z') {
return new float[0];
}
try {
float[] results = new float[s.length()];
int count = 0;
int startPosition = 1;
int endPosition = 0;
ExtractFloatResult result = new ExtractFloatResult();
int totalLength = s.length();
// The startPosition should always be the first character of the
// current number, and endPosition is the character after the current
// number.
while (startPosition < totalLength) {
extract(s, startPosition, result);
endPosition = result.mEndPosition;
if (startPosition < endPosition) {
results[count++] = Float.parseFloat(
s.substring(startPosition, endPosition));
}
if (result.mEndWithNegOrDot) {
// Keep the '-' or '.' sign with next number.
startPosition = endPosition;
} else {
startPosition = endPosition + 1;
}
}
return copyOfRange(results, 0, count);
} catch (NumberFormatException e) {
throw new RuntimeException("error in parsing \"" + s + "\"", e);
}
}
private static void addNode(List list, char cmd, float[] val) {
list.add(new VdPath.Node(cmd, val));
}
private static int nextStart(String s, int end) {
char c;
while (end < s.length()) {
c = s.charAt(end);
// Note that 'e' or 'E' are not valid path commands, but could be
// used for floating point numbers' scientific notation.
// Therefore, when searching for next command, we should ignore 'e'
// and 'E'.
if ((((c - 'A') * (c - 'Z') <= 0) || ((c - 'a') * (c - 'z') <= 0))
&& c != 'e' && c != 'E') {
return end;
}
end++;
}
return end;
}
public static VdPath.Node[] parsePath(String value) {
int start = 0;
int end = 1;
value = value.trim();
List list = new ArrayList();
while (end < value.length()) {
end = nextStart(value, end);
String s = value.substring(start, end);
float[] val = getFloats(s);
char currentCommand = s.charAt(0);
if (start == 0) {
// For the starting command, special handling:
// add M 0 0 if there is none.
// This is good for transformation.
if (currentCommand != 'M' && currentCommand != 'm'){
addNode(list, 'M', new float[2]);
}
}
addNode(list, currentCommand, val);
start = end;
end++;
}
if ((end - start) == 1 && start < value.length()) {
addNode(list, value.charAt(start), new float[0]);
}
return list.toArray(new VdPath.Node[list.size()]);
}
}
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