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/***************************************************************************
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* Copyright (C) 2011 by Peter Penz <peter.penz19@gmail.com> *
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* This program is free software; you can redistribute it and/or modify *
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* it under the terms of the GNU General Public License as published by *
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* the Free Software Foundation; either version 2 of the License, or *
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* (at your option) any later version. *
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* This program is distributed in the hope that it will be useful, *
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* but WITHOUT ANY WARRANTY; without even the implied warranty of *
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
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* GNU General Public License for more details. *
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* You should have received a copy of the GNU General Public License *
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* along with this program; if not, write to the *
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* Free Software Foundation, Inc., *
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* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA *
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***************************************************************************/
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#ifndef KITEMLISTVIEWLAYOUTER_H
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#define KITEMLISTVIEWLAYOUTER_H
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#include <libdolphin_export.h>
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class KItemListSizeHintResolver;
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* @brief Internal helper class for KItemListView to layout the items.
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* The layouter is capable to align the items within a grid. If the
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* scroll-direction is horizontal the column-width of the grid can be
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* variable. If the scroll-direction is vertical the row-height of
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* the grid can be variable.
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* The layouter is implemented in a way that it postpones the expensive
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* layout operation until a property is read the first time after
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* marking the layouter as dirty (see markAsDirty()). This means that
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* changing properties of the layouter is not expensive, only the
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* first read of a property can get expensive.
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class LIBDOLPHINPRIVATE_EXPORT KItemListViewLayouter : public QObject
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KItemListViewLayouter(QObject* parent = 0);
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virtual ~KItemListViewLayouter();
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void setScrollOrientation(Qt::Orientation orientation);
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Qt::Orientation scrollOrientation() const;
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void setSize(const QSizeF& size);
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void setItemSize(const QSizeF& size);
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QSizeF itemSize() const;
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* Margin between the rows and columns of items.
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void setItemMargin(const QSizeF& margin);
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QSizeF itemMargin() const;
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* Sets the height of the header that is always aligned
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* at the top. A height of <= 0.0 means that no header is
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void setHeaderHeight(qreal height);
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qreal headerHeight() const;
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* Sets the height of the group header that is used
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* to indicate a new item group.
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void setGroupHeaderHeight(qreal height);
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qreal groupHeaderHeight() const;
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* Sets the margin between the last items of the group n and
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* the group header for the group n + 1.
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void setGroupHeaderMargin(qreal margin);
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qreal groupHeaderMargin() const;
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void setScrollOffset(qreal scrollOffset);
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qreal scrollOffset() const;
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qreal maximumScrollOffset() const;
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void setItemOffset(qreal scrollOffset);
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qreal itemOffset() const;
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qreal maximumItemOffset() const;
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void setModel(const KItemModelBase* model);
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const KItemModelBase* model() const;
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void setSizeHintResolver(const KItemListSizeHintResolver* sizeHintResolver);
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const KItemListSizeHintResolver* sizeHintResolver() const;
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* @return The first (at least partly) visible index. -1 is returned
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* if the item count is 0.
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int firstVisibleIndex() const;
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* @return The last (at least partly) visible index. -1 is returned
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* if the item count is 0.
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int lastVisibleIndex() const;
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* @return Rectangle of the item with the index \a index.
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* The top/left of the bounding rectangle is related to
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* the top/left of the KItemListView. An empty rectangle
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* is returned if an invalid index is given.
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QRectF itemRect(int index) const;
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* @return Rectangle of the group header for the item with the
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* index \a index. Note that the layouter does not check
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* whether the item really has a header: Usually only
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* the first item of a group gets a header (see
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* isFirstGroupItem()).
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QRectF groupHeaderRect(int index) const;
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* @return Column of the item with the index \a index.
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* -1 is returned if an invalid index is given.
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int itemColumn(int index) const;
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* @return Row of the item with the index \a index.
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* -1 is returned if an invalid index is given.
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int itemRow(int index) const;
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* @return Maximum number of (at least partly) visible items for
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int maximumVisibleItems() const;
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* @return True if the item with the index \p itemIndex
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* is the first item within a group.
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bool isFirstGroupItem(int itemIndex) const;
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* Marks the layouter as dirty. This means as soon as a property of
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* the layouter gets read, an expensive relayout will be done.
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* @return True if the layouter has been marked as dirty and hence has
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* not called yet doLayout(). Is enabled only in the debugging
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* mode, as it is not useful to check the dirty state otherwise.
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void updateVisibleIndexes();
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bool createGroupHeaders();
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* @return Minimum width of group headers when grouping is enabled in the horizontal
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* alignment mode. The header alignment is done like this:
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* Header-1 Header-2 Header-3
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* Item 1 Item 4 Item 7
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* Item 2 Item 5 Item 8
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* Item 3 Item 6 Item 9
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qreal minimumGroupHeaderWidth() const;
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bool m_visibleIndexesDirty;
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Qt::Orientation m_scrollOrientation;
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qreal m_headerHeight;
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const KItemModelBase* m_model;
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const KItemListSizeHintResolver* m_sizeHintResolver;
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qreal m_scrollOffset;
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qreal m_maximumScrollOffset;
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qreal m_maximumItemOffset;
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int m_firstVisibleIndex;
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int m_lastVisibleIndex;
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// Stores all item indexes that are the first item of a group.
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// Assures fast access for KItemListViewLayouter::isFirstGroupItem().
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QSet<int> m_groupItemIndexes;
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qreal m_groupHeaderHeight;
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qreal m_groupHeaderMargin;
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QList<ItemInfo> m_itemInfos;
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friend class KItemListControllerTest;