LayoutId.h

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// SPDX-FileCopyrightText: 2026 fuddlesworth
// SPDX-License-Identifier: LGPL-2.1-or-later
 
#pragma once
 
#include <QLatin1String>
#include <QString>
#include <QtGlobal>
 
namespace PhosphorLayout {
 
namespace LayoutId {
 
inline constexpr QLatin1String AutotilePrefix{"autotile:"};
inline constexpr QLatin1String ScrollingId{"scrolling:"};
 
inline bool isAutotile(const QString& id)
{
    return id.startsWith(AutotilePrefix);
}
 
inline bool isScrolling(const QString& id)
{
    // Exact compare, not startsWith: unlike AutotilePrefix, this sentinel
    // carries no payload — "scrolling:foo" is NOT a valid id, and prefix
    // matching would classify it as Scrolling while silently dropping the
    // "foo" in every consumer.
    return id == ScrollingId;
}
 
inline QString extractAlgorithmId(const QString& id)
{
    if (!isAutotile(id)) {
        qWarning("PhosphorLayout::LayoutId::extractAlgorithmId called with non-autotile id: %s", qUtf8Printable(id));
        return QString();
    }
    if (id.size() <= AutotilePrefix.size()) {
        return {};
    }
    return id.mid(AutotilePrefix.size());
}
 
inline QString makeAutotileId(const QString& algorithmId)
{
    // Empty algorithmId is a legitimate caller intent: "autotile mode, let
    // the engine pick the default algorithm". The KCM writes exactly this
    // shape via LayoutAdaptor::setAssignmentEntry (mode=Autotile,
    // tilingAlgorithm="") — see AssignmentEntry::activeLayoutId() and
    // LayoutRegistry::setAssignmentEntryDirect's comment. Returning the
    // bare prefix round-trips cleanly: isAutotile("autotile:") is true,
    // extractAlgorithmId("autotile:") returns empty (LayoutId.h above
    // handles id.size() <= prefix.size()), and the assignment cascade
    // treats the entry as non-empty so modeForScreen correctly reports
    // Autotile.
    return AutotilePrefix + algorithmId;
}
 
// ── The scrolling FAMILY: rules-visible template stamp ──────────────────────
//
// Two id namespaces share the "scrolling:" spelling and must not be mixed:
//
//  - ASSIGNMENT ids are always the bare sentinel. isScrolling stays an exact
//    compare, the cascade round-trips a payload-free id, and nothing on the
//    D-Bus assignment surface ever carries a prefixed form.
//  - The rules-visible WindowQuery::activeLayout value on a Scrolling context
//    is the PREFIXED "scrolling:<templateUuid>" when the context resolves a
//    template layout, and the bare sentinel when it does not — parity with
//    autotile's "autotile:<algorithmId>" stamp, so a rule can target one
//    specific template the way it targets one algorithm. Only the query
//    stamp in LayoutRegistry's context resolvers produces this form.
//
// A rule authored `ActiveLayout Equals "scrolling:"` therefore means
// "scrolling with no template"; "any scrolling screen" is `Mode Equals
// scrolling`.
 
inline bool isScrollingFamily(const QString& id)
{
    return id.startsWith(ScrollingId);
}
 
inline QString makeScrollingId(const QString& templateLayoutId)
{
    return ScrollingId + templateLayoutId;
}
 
inline QString extractTemplateId(const QString& id)
{
    if (!isScrollingFamily(id)) {
        qWarning("PhosphorLayout::LayoutId::extractTemplateId called with non-scrolling id: %s", qUtf8Printable(id));
        return QString();
    }
    if (id.size() <= ScrollingId.size()) {
        return {};
    }
    return id.mid(ScrollingId.size());
}
 
} // namespace LayoutId
} // namespace PhosphorLayout