oshi.driver.unix.Xrandr Maven / Gradle / Ivy
/*
* Copyright 2020-2022 The OSHI Project Contributors
* SPDX-License-Identifier: MIT
*/
package oshi.driver.unix;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import oshi.annotation.concurrent.ThreadSafe;
import oshi.util.ExecutingCommand;
import oshi.util.ParseUtil;
/**
* Utility to query xrandr
*/
@ThreadSafe
public final class Xrandr {
private static final String[] XRANDR_VERBOSE = { "xrandr", "--verbose" };
private Xrandr() {
}
public static List getEdidArrays() {
// Special handling for X commands, don't use LC_ALL
List xrandr = ExecutingCommand.runNative(XRANDR_VERBOSE, null);
// xrandr reports edid in multiple lines. After seeing a line containing
// EDID, read subsequent lines of hex until 256 characters are reached
if (xrandr.isEmpty()) {
return Collections.emptyList();
}
List displays = new ArrayList<>();
StringBuilder sb = null;
for (String s : xrandr) {
if (s.contains("EDID")) {
sb = new StringBuilder();
} else if (sb != null) {
sb.append(s.trim());
if (sb.length() < 256) {
continue;
}
String edidStr = sb.toString();
byte[] edid = ParseUtil.hexStringToByteArray(edidStr);
if (edid.length >= 128) {
displays.add(edid);
}
sb = null;
}
}
return displays;
}
}