/*
* Copyright (C) 2013 ZXing authors
*
* 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.zxing.client.android;
import java.util.EnumMap;
import java.util.HashMap;
import java.util.Map;
import java.util.regex.Pattern;
import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.util.Log;
import com.google.zxing.DecodeHintType;
/**
* @author Lachezar Dobrev
*/
final class DecodeHintManager {
private static final String TAG = DecodeHintManager.class.getSimpleName();
// This pattern is used in decoding integer arrays.
private static final Pattern COMMA = Pattern.compile(",");
private DecodeHintManager() {}
/**
* <p>Split a query string into a list of name-value pairs.</p>
*
* <p>This is an alternative to the {@link Uri#getQueryParameterNames()} and
* {@link Uri#getQueryParameters(String)}, which are quirky and not suitable
* for exist-only Uri parameters.</p>
*
* <p>This method ignores multiple parameters with the same name and returns the
* first one only. This is technically incorrect, but should be acceptable due
* to the method of processing Hints: no multiple values for a hint.</p>
*
* @param query query to split
* @return name-value pairs
*/
private static Map<String,String> splitQuery(String query) {
Map<String,String> map = new HashMap<String,String>();
int pos = 0;
while (pos < query.length()) {
if (query.charAt(pos) == '&') {
// Skip consecutive ampersand separators.
pos ++;
continue;
}
int amp = query.indexOf('&', pos);
int equ = query.indexOf('=', pos);
if (amp < 0) {
// This is the last element in the query, no more ampersand elements.
String name;
String text;
if (equ < 0) {
// No equal sign
name = query.substring(pos);
name = name.replace('+', ' '); // Preemptively decode +
name = Uri.decode(name);
text = "";
} else {
// Split name and text.
name = query.substring(pos, equ);
name = name.replace('+', ' '); // Preemptively decode +
name = Uri.decode(name);
text = query.substring(equ + 1);
text = text.replace('+', ' '); // Preemptively decode +
text = Uri.decode(text);
}
if (!map.containsKey(name)) {
map.put(name, text);
}
break;
}
if (equ < 0 || equ > amp) {
// No equal sign until the &: this is a simple parameter with no value.
String name = query.substring(pos, amp);
name = name.replace('+', ' '); // Preemptively decode +
name = Uri.decode(name);
if (!map.containsKey(name)) {
map.put(name, "");
}
pos = amp + 1;
continue;
}
String name = query.substring(pos, equ);
name = name.replace('+', ' '); // Preemptively decode +
name = Uri.decode(name);
String text = query.substring(equ+1, amp);
text = text.replace('+', ' '); // Preemptively decode +
text = Uri.decode(text);
if (!map.containsKey(name)) {
map.put(name, text);
}
pos = amp + 1;
}
return map;
}
static Map<DecodeHintType,?> parseDecodeHints(Uri inputUri) {
String query = inputUri.getEncodedQuery();
if (query == null || query.isEmpty()) {
return null;
}
// Extract parameters
Map<String, String> parameters = splitQuery(query);
Map<DecodeHintType, Object> hints = new EnumMap<DecodeHintType, Object>(DecodeHintType.class);
for (DecodeHintType hintType: DecodeHintType.values()) {
if (hintType == DecodeHintType.CHARACTER_SET ||
hintType == DecodeHintType.NEED_RESULT_POINT_CALLBACK ||
hintType == DecodeHintType.POSSIBLE_FORMATS) {
continue; // This hint is specified in another way
}
String parameterName = hintType.name();
String parameterText = parameters.get(parameterName);
if (parameterText == null) {
continue;
}
if (hintType.getValueType().equals(Object.class)) {
// This is an unspecified type of hint content. Use the value as is.
// TODO: Can we make a different assumption on this?
hints.put(hintType, parameterText);
continue;
}
if (hintType.getValueType().equals(Void.class)) {
// Void hints are just flags: use the constant specified by DecodeHintType
hints.put(hintType, Boolean.TRUE);
continue;
}
if (hintType.getValueType().equals(String.class)) {
// A string hint: use the decoded value.
hints.put(hintType, parameterText);
continue;
}
if (hintType.getValueType().equals(Boolean.class)) {
// A boolean hint: a few values for false, everything else is true.
// An empty parameter is simply a flag-style parameter, assuming true
if (parameterText.isEmpty()) {
hints.put(hintType, Boolean.TRUE);
} else if ("0".equals(parameterText) ||
"false".equalsIgnoreCase(parameterText) ||
"no".equalsIgnoreCase(parameterText)) {
hints.put(hintType, Boolean.FALSE);
} else {
hints.put(hintType, Boolean.TRUE);
}
continue;
}
if (hintType.getValueType().equals(int[].class)) {
// An integer array. Used to specify valid lengths.
// Strip a trailing comma as in Java style array initialisers.
if (!parameterText.isEmpty() && parameterText.charAt(parameterText.length() - 1) == ',') {
parameterText = parameterText.substring(0, parameterText.length() - 1);
}
String[] values = COMMA.split(parameterText);
int[] array = new int[values.length];
for (int i = 0; i < values.length; i++) {
try {
array[i] = Integer.parseInt(values[i]);
} catch (NumberFormatException ignored) {
Log.w(TAG, "Skipping array of integers hint " + hintType + " due to invalid numeric value: '" + values[i] + '\'');
array = null;
break;
}
}
if (array != null) {
hints.put(hintType, array);
}
continue;
}
Log.w(TAG, "Unsupported hint type '" + hintType + "' of type " + hintType.getValueType());
}
Log.i(TAG, "Hints from the URI: " + hints);
return hints;
}
static Map<DecodeHintType, Object> parseDecodeHints(Intent intent) {
Bundle extras = intent.getExtras();
if (extras == null || extras.isEmpty()) {
return null;
}
Map<DecodeHintType,Object> hints = new EnumMap<DecodeHintType,Object>(DecodeHintType.class);
for (DecodeHintType hintType: DecodeHintType.values()) {
if (hintType == DecodeHintType.CHARACTER_SET ||
hintType == DecodeHintType.NEED_RESULT_POINT_CALLBACK ||
hintType == DecodeHintType.POSSIBLE_FORMATS) {
continue; // This hint is specified in another way
}
String hintName = hintType.name();
if (extras.containsKey(hintName)) {
if (hintType.getValueType().equals(Void.class)) {
// Void hints are just flags: use the constant specified by the DecodeHintType
hints.put(hintType, Boolean.TRUE);
} else {
Object hintData = extras.get(hintName);
if (hintType.getValueType().isInstance(hintData)) {
hints.put(hintType, hintData);
} else {
Log.w(TAG, "Ignoring hint " + hintType + " because it is not assignable from " + hintData);
}
}
}
}
Log.i(TAG, "Hints from the Intent: " + hints);
return hints;
}
}