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/*
SPDX-FileCopyrightText: 2019 Marco Martin <mart@kde.org>
SPDX-License-Identifier: LGPL-2.0-or-later
*/
#pragma once
#include "appletslayout.h"
#include <QObject>
class ItemContainer;
class AbstractLayoutManager : public QObject
{
Q_OBJECT
public:
AbstractLayoutManager(AppletsLayout *layout);
~AbstractLayoutManager();
AppletsLayout *layout() const;
void setCellSize(const QSizeF &size);
QSizeF cellSize() const;
/**
* A size aligned to the gid that fully contains the given size
*/
QSizeF cellAlignedContainingSize(const QSizeF &size) const;
/**
* Positions the item, does *not* assign the space as taken
*/
void positionItem(ItemContainer *item);
/**
* Positions the item and assigns the space as taken by this item
*/
void positionItemAndAssign(ItemContainer *item);
/**
* Set the space of item's rect as occupied by item.
* The operation may fail if some space of the item's geometry is already occupied.
* @returns true if the operation succeeded
*/
bool assignSpace(ItemContainer *item);
/**
* If item is occupying space, set it as available
*/
void releaseSpace(ItemContainer *item);
// VIRTUALS
virtual QString serializeLayout() const = 0;
virtual void parseLayout(const QString &savedLayout) = 0;
virtual void layoutGeometryChanged(const QRectF &newGeometry, const QRectF &oldGeometry);
/**
* true if the item is managed by the grid
*/
virtual bool itemIsManaged(ItemContainer *item) = 0;
/**
* Forget about layout information and relayout all items based solely on their current geometry
*/
virtual void resetLayout() = 0;
/**
* Forget about layout information and relayout all items based on their stored geometry first,
* and if that fails from their current geometry.
* If this function has been called from a resize, oldGeomety and newGeometry
* represent the geometries that this layout had before and after the resize, for placing strategies
* of items that weren't in the stored config.
* If one of those rects are empty, neither should be considered in the layouting strategy.
*/
virtual void resetLayoutFromConfig(const QRectF &newGeom, const QRectF &oldGeom) = 0;
/**
* Restores an item geometry from the serialized config
* parseLayout needs to be called before this
* @returns true if the item was stored in the config
* and the restore has been performed.
* Otherwise, the item is not touched and returns false
*/
virtual bool restoreItem(ItemContainer *item) = 0;
/**
* @returns true if the given rectangle is all free space
*/
virtual bool isRectAvailable(const QRectF &rect) = 0;
Q_SIGNALS:
/**
* Emitted when the layout has been changed and now needs saving
*/
void layoutNeedsSaving();
protected:
/**
* Subclasses implement their assignSpace logic here
*/
virtual bool assignSpaceImpl(ItemContainer *item) = 0;
/**
* Subclasses implement their releasespace logic here
*/
virtual void releaseSpaceImpl(ItemContainer *item) = 0;
/**
* @returns a rectangle big at least as minimumSize, trying to be as near as possible to the current item's geometry, displaced in the direction we asked,
* forwards or backwards
* @param item the item container we want to place an item in
* @param minimumSize the minimum size we need to make sure is available
* @param direction the preferred item layout direction, can be Closest, LeftToRight, RightToLeft, TopToBottom, and BottomToTop
*/
virtual QRectF nextAvailableSpace(ItemContainer *item, const QSizeF &minimumSize, AppletsLayout::PreferredLayoutDirection direction) const = 0;
private:
QRectF candidateGeometry(ItemContainer *item) const;
AppletsLayout *m_layout;
// size in pixels of a crid cell
QSizeF m_cellSize;
};
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