kwin/src/placement.h

/*
    KWin - the KDE window manager
    This file is part of the KDE project.

    SPDX-FileCopyrightText: 1999, 2000 Matthias Ettrich <ettrich@kde.org>
    SPDX-FileCopyrightText: 1997-2002 Cristian Tibirna <tibirna@kde.org>
    SPDX-FileCopyrightText: 2003 Lubos Lunak <l.lunak@kde.org>

    SPDX-License-Identifier: GPL-2.0-or-later
*/

#ifndef KWIN_PLACEMENT_H
#define KWIN_PLACEMENT_H
// KWin
#include <kwinglobals.h>
// Qt
#include <QList>
#include <QPoint>
#include <QRect>

class QObject;

namespace KWin
{

class Window;

class KWIN_EXPORT Placement
{
public:
    virtual ~Placement();

    /**
     * Placement policies. How workspace decides the way windows get positioned
     * on the screen. The better the policy, the heavier the resource use.
     * Normally you don't have to worry. What the WM adds to the startup time
     * is nil compared to the creation of the window itself in the memory
     */
    enum Policy {
        NoPlacement, // not really a placement
        Default, // special, means to use the global default
        Unknown, // special, means the function should use its default
        Random,
        Smart,
        Cascade,
        Centered,
        ZeroCornered,
        UnderMouse, // special
        OnMainWindow, // special
        Maximizing
    };

    void place(Window *c, const QRect &area);
    void placeSmart(Window *c, const QRect &area, Policy next = Unknown);

    void placeCentered(Window *c, const QRect &area, Policy next = Unknown);

    void reinitCascading(int desktop);

    /**
     * Cascades all clients on the current desktop
     */
    void cascadeDesktop();
    /**
     *   Unclutters the current desktop by smart-placing all clients again.
     */
    void unclutterDesktop();

    static const char *policyToString(Policy policy);

private:
    void place(Window *c, const QRect &area, Policy policy, Policy nextPlacement = Unknown);
    void placeUnderMouse(Window *c, const QRect &area, Policy next = Unknown);
    void placeOnMainWindow(Window *c, const QRect &area, Policy next = Unknown);
    void placeTransient(Window *c);

    void placeAtRandom(Window *c, const QRect &area, Policy next = Unknown);
    void placeCascaded(Window *c, const QRect &area, Policy next = Unknown);
    void placeMaximizing(Window *c, const QRect &area, Policy next = Unknown);
    void placeZeroCornered(Window *c, const QRect &area, Policy next = Unknown);
    void placeDialog(Window *c, const QRect &area, Policy next = Unknown);
    void placeUtility(Window *c, const QRect &area, Policy next = Unknown);
    void placeOnScreenDisplay(Window *c, const QRect &area);

    // CT needed for cascading+
    struct DesktopCascadingInfo
    {
        QPoint pos;
        int col;
        int row;
    };

    QList<DesktopCascadingInfo> cci;

    KWIN_SINGLETON(Placement)
};

} // namespace

#endif