WindowId.h

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// SPDX-FileCopyrightText: 2026 fuddlesworth
// SPDX-License-Identifier: LGPL-2.1-or-later
 
#pragma once
 
// PhosphorIdentity is an INTERFACE library — no generated export header.
// Every helper below is `inline` and lives entirely in this header.
 
#include <QString>
#include <QStringView>
 
namespace PhosphorIdentity {
 
namespace WindowId {
 
inline QString buildCompositeId(QStringView appId, QStringView instanceId)
{
    if (instanceId.isEmpty()) {
        return appId.toString();
    }
    QString out;
    out.reserve(appId.size() + 1 + instanceId.size());
    out.append(appId);
    out.append(QLatin1Char('|'));
    out.append(instanceId);
    return out;
}
 
inline QString extractAppId(const QString& windowId)
{
    if (windowId.isEmpty()) {
        return windowId;
    }
    int sep = windowId.indexOf(QLatin1Char('|'));
    return (sep >= 0) ? windowId.left(sep) : windowId;
}
 
inline QString extractInstanceId(const QString& windowId)
{
    if (windowId.isEmpty()) {
        return windowId;
    }
    int sep = windowId.indexOf(QLatin1Char('|'));
    return (sep >= 0) ? windowId.mid(sep + 1) : windowId;
}
 
inline QString normalizeAppId(const QString& desktopFileName, const QString& windowClass)
{
    QString appId = desktopFileName.trimmed();
    if (appId.isEmpty()) {
        // Trim the whole class BEFORE the split: a class with trailing
        // whitespace ("resourceName resourceClass ") would otherwise split at
        // the trailing space, yield an empty token, and drop an otherwise
        // valid identity.
        const QString trimmedClass = windowClass.trimmed();
        const int sep = trimmedClass.lastIndexOf(QLatin1Char(' '));
        appId = (sep >= 0 ? trimmedClass.mid(sep + 1) : trimmedClass);
    }
    return appId.toLower();
}
 
inline bool isValidAppId(const QString& appId)
{
    if (appId.isEmpty()) {
        return false;
    }
    for (const QChar c : appId) {
        if (c.isSpace()) {
            return false;
        }
    }
    return true;
}
 
inline QString deriveShortName(const QString& windowClass)
{
    if (windowClass.isEmpty()) {
        return QString();
    }
    // Strip a trailing dot first so "org.kde.foo." behaves the same as
    // "org.kde.foo" — the dot would otherwise short-circuit the segment
    // extraction below into returning the original string verbatim.
    QStringView trimmed(windowClass);
    while (!trimmed.isEmpty() && trimmed.back() == QLatin1Char('.')) {
        trimmed.chop(1);
    }
    if (trimmed.isEmpty()) {
        return QString();
    }
    const int dotIdx = trimmed.lastIndexOf(QLatin1Char('.'));
    if (dotIdx >= 0 && dotIdx < trimmed.length() - 1) {
        return trimmed.mid(dotIdx + 1).toString();
    }
    return trimmed.toString();
}
 
inline bool appIdMatches(const QString& appId, const QString& pattern)
{
    if (appId.isEmpty() || pattern.isEmpty()) {
        return false;
    }
    if (appId.compare(pattern, Qt::CaseInsensitive) == 0) {
        return true;
    }
    // Trailing dot-segment: "org.mozilla.firefox" ends with ".firefox"
    if (appId.length() > pattern.length() + 1 && appId[appId.length() - pattern.length() - 1] == QLatin1Char('.')
        && appId.endsWith(pattern, Qt::CaseInsensitive)) {
        return true;
    }
    // Reverse: appId is a trailing dot-segment of pattern
    if (pattern.length() > appId.length() + 1 && pattern[pattern.length() - appId.length() - 1] == QLatin1Char('.')
        && pattern.endsWith(appId, Qt::CaseInsensitive)) {
        return true;
    }
    // Last-segment prefix: pattern "systemsettings" matches start of appId's
    // last segment "systemsettings5". Here `pattern` is the prefix candidate,
    // so gate on its length.
    if (pattern.length() >= 5) {
        const int lastDot = appId.lastIndexOf(QLatin1Char('.'));
        if (lastDot >= 0) {
            QStringView lastSeg = QStringView(appId).mid(lastDot + 1);
            if (lastSeg.startsWith(pattern, Qt::CaseInsensitive) && lastSeg.length() != pattern.length()) {
                return true;
            }
        }
    }
    // Reverse: appId matches start of pattern's last segment. Here `appId`
    // is the prefix candidate, so gate on its length (not pattern's).
    if (appId.length() >= 5) {
        const int lastDot = pattern.lastIndexOf(QLatin1Char('.'));
        if (lastDot >= 0) {
            QStringView lastSeg = QStringView(pattern).mid(lastDot + 1);
            if (lastSeg.startsWith(appId, Qt::CaseInsensitive) && lastSeg.length() != appId.length()) {
                return true;
            }
        }
    }
    return false;
}
 
} // namespace WindowId
} // namespace PhosphorIdentity