I need to define IntentFilter
for single file named myfile.ext
. At the moment my manifest looks like:
<intent-filter>
<action android:name="android.intent.action.VIEW" />
<action android:name="android.intent.action.EDIT" />
<category android:name="android.intent.category.DEFAULT" />
<data
android:scheme="file"
android:mimeType="*/*"
android:host="*"
android:pathPattern=".*\\myfile\\.ext"
/>
</intent-filter>
I have also tried other variants like: android:pathPattern=".*\\myfile.ext"
and so on - but still it doesn't handle my file.
Any clues?
Android Pattern specifics :
.
matches any character.
*
matches 0 or more occurrences of the character preceding it.
.*
matches 0 or more occurrences of any character.
\
is used to escape special characters in pattern. \
is also used as an escape character when the string is read from the XML file. Hence to escape special character in a pattern, double-slash \\
has to be used.
Issue:
In this pattern ".*\\myfile\\.ext"
, you are trying to escape character m
which is a normal character. Hence it does not make any difference. It is equivalent to ".*myfile\\.ext"
. The data uri part of intent is file:///mnt/sdcard/tmp/myfile.ext
. The pattern is matched against /mnt/sdcard/tmp/myfile.ext
, but it fails.
.*
tries to match any character until the first occurrence of m
, which happens to be the 2nd char i.e. /mnt
. Pattern expects the next char to be y
, but it gets n
and hence the pattern match fails.
Solution:
For above path, the pattern /.*/.*/.*/myfile\\.ext
works.
For /mnt/sdcard/myfile.ext
path, pattern /.*/.*/myfile\\.ext
works. If you are not sure the sub-directory level, you will have to add multiple <data>
element with different pathPattern
values.
<data
android:scheme="file"
android:mimeType="*/*"
android:host="*" />
<data android:pathPattern="/.*/.*/.*/myfile\\.ext" /> <!-- matches file:///mnt/sdcard/tmp/myfile.ext -->
<data android:pathPattern="/.*/.*/myfile\\.ext" /> <!-- matches file:///mnt/sdcard/myfile.ext -->
Here is the PatternMatcher.matchPattern method used for pattern matching:
static boolean matchPattern(String pattern, String match, int type) {
if (match == null) return false;
if (type == PATTERN_LITERAL) {
return pattern.equals(match);
} if (type == PATTERN_PREFIX) {
return match.startsWith(pattern);
} else if (type != PATTERN_SIMPLE_GLOB) {
return false;
}
final int NP = pattern.length();
if (NP <= 0) {
return match.length() <= 0;
}
final int NM = match.length();
int ip = 0, im = 0;
char nextChar = pattern.charAt(0);
while ((ip<NP) && (im<NM)) {
char c = nextChar;
ip++;
nextChar = ip < NP ? pattern.charAt(ip) : 0;
final boolean escaped = (c == '\\');
if (escaped) {
c = nextChar;
ip++;
nextChar = ip < NP ? pattern.charAt(ip) : 0;
}
if (nextChar == '*') {
if (!escaped && c == '.') {
if (ip >= (NP-1)) {
// at the end with a pattern match, so
// all is good without checking!
return true;
}
ip++;
nextChar = pattern.charAt(ip);
// Consume everything until the next character in the
// pattern is found.
if (nextChar == '\\') {
ip++;
nextChar = ip < NP ? pattern.charAt(ip) : 0;
}
do {
if (match.charAt(im) == nextChar) {
break;
}
im++;
} while (im < NM);
if (im == NM) {
// Whoops, the next character in the pattern didn't
// exist in the match.
return false;
}
ip++;
nextChar = ip < NP ? pattern.charAt(ip) : 0;
im++;
} else {
// Consume only characters matching the one before '*'.
do {
if (match.charAt(im) != c) {
break;
}
im++;
} while (im < NM);
ip++;
nextChar = ip < NP ? pattern.charAt(ip) : 0;
}
} else {
if (c != '.' && match.charAt(im) != c) return false;
im++;
}
}
if (ip >= NP && im >= NM) {
// Reached the end of both strings, all is good!
return true;
}
// One last check: we may have finished the match string, but still
// have a '.*' at the end of the pattern, which should still count
// as a match.
if (ip == NP-2 && pattern.charAt(ip) == '.'
&& pattern.charAt(ip+1) == '*') {
return true;
}
return false;
}