ShellState.h

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// SPDX-FileCopyrightText: 2026 fuddlesworth
// SPDX-License-Identifier: LGPL-2.1-or-later
 
#pragma once
 
// Per-screen state owned by ShellHost.
//
// Holds the shell-side bookkeeping for one screen: the layer-shell
// wl_surface, its QQuickWindow, the QScreen pointer the shell was
// constructed against, and the slot-Item map keyed by slot name.
//
// Consumer-specific per-screen state (e.g. content geometry,
// per-content sentinels) lives in the consumer's parallel per-screen
// map; ShellState only owns what the library mechanism owns.
//
// Mechanism pointers (shellSurface / shellWindow / physScreen) are
// readable via accessors but not writable from outside the library -
// only ShellHost (friended) writes them at create / destroy time.
// The slot map stays public because PostCreateCallback consumers
// populate it with their slot vocabulary at shell-attach time.
 
#include <PhosphorOverlay/SlotEntry.h>
#include <PhosphorOverlay/phosphoroverlay_export.h>
 
#include <QHash>
#include <QString>
 
class QQuickWindow;
class QScreen;
 
namespace PhosphorLayer {
class Surface;
}
 
namespace PhosphorOverlay {
 
class ShellHost;
 
class PHOSPHOROVERLAY_EXPORT ShellState
{
public:
    ShellState() = default;
    // Non-copyable, non-movable: ShellHost owns these objects as
    // heap-allocated raw pointers and consumers cache borrowed
    // references via `ShellHost::getOrCreateStateFor`. A copy (e.g.
    // `auto copy = host.getOrCreateStateFor(id)` instead of `auto&`)
    // would silently duplicate the mechanism pointers and slot map,
    // leaving the caller's mutations invisible to the host. Block at
    // compile time.
    ShellState(const ShellState&) = delete;
    ShellState(ShellState&&) = delete;
    ShellState& operator=(const ShellState&) = delete;
    ShellState& operator=(ShellState&&) = delete;
 
    PhosphorLayer::Surface* shellSurface() const
    {
        return m_shellSurface;
    }
 
    QQuickWindow* shellWindow() const
    {
        return m_shellWindow;
    }
 
    QScreen* physScreen() const
    {
        return m_physScreen;
    }
 
    QHash<QString, SlotEntry> slots;
 
private:
    friend class ShellHost;
    PhosphorLayer::Surface* m_shellSurface = nullptr;
    QQuickWindow* m_shellWindow = nullptr;
    QScreen* m_physScreen = nullptr;
};
 
} // namespace PhosphorOverlay