qlayout_widget_p.h

QT 开发环境里面一个很重要的文件

/****************************************************************************
**
** Copyright (C) 1992-2006 Trolltech ASA. All rights reserved.
**
** This file is part of the Qt Designer of the Qt Toolkit.
**
** This file may be used under the terms of the GNU General Public
** License version 2.0 as published by the Free Software Foundation
** and appearing in the file LICENSE.GPL included in the packaging of
** this file.  Please review the following information to ensure GNU
** General Public Licensing requirements will be met:
** http://www.trolltech.com/products/qt/opensource.html
**
** If you are unsure which license is appropriate for your use, please
** review the following information:
** http://www.trolltech.com/products/qt/licensing.html or contact the
** sales department at [e-mail].
**
** This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
** WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
**
****************************************************************************/

//
//  W A R N I N G
//  -------------
//
// This file is not part of the Qt API.  It exists for the convenience
// of Qt Designer.  This header
// file may change from version to version without notice, or even be removed.
//
// We mean it.
//

#ifndef QLAYOUT_WIDGET_H
#define QLAYOUT_WIDGET_H

#include "shared_global_p.h"
#include "layoutdecoration.h"

#include <QtDesigner/QDesignerMetaDataBaseInterface>

#include <QtCore/QPointer>
#include <QtGui/QWidget>
#include <QtGui/QGridLayout>

class QDesignerFormWindowInterface;

class QDESIGNER_SHARED_EXPORT QLayoutSupport: public QObject
{
    Q_OBJECT
public:
    QLayoutSupport(QDesignerFormWindowInterface *formWindow, QWidget *widget, QObject *parent = 0);
    virtual ~QLayoutSupport();

    inline QWidget *widget() const
    { return m_widget; }

    inline QLayout *layout() const
    { return widget()->layout(); }

    inline QGridLayout *gridLayout() const
    { return qobject_cast<QGridLayout*>(layout()); }

    inline QDesignerFormWindowInterface *formWindow() const
    { return m_formWindow; }

    QDesignerFormEditorInterface *core() const;

    inline int currentIndex() const
    { return m_currentIndex; }

    inline QDesignerLayoutDecorationExtension::InsertMode currentInsertMode() const
    { return m_currentInsertMode; }

    inline QPair<int, int> currentCell() const
    { return m_currentCell; }

    int findItemAt(const QPoint &pos) const;
    QRect itemInfo(int index) const;
    int indexOf(QWidget *widget) const;
    int indexOf(QLayoutItem *item) const;

    void adjustIndicator(const QPoint &pos, int index);

    void insertWidget(QWidget *widget, const QPair<int, int> &cell);
    void removeWidget(QWidget *widget);

    QList<QWidget*> widgets(QLayout *layout) const;

    void simplifyLayout();

    void insertRow(int row);
    void insertColumn(int column);

    void removeRow(int row);
    void removeColumn(int column);

    QRect extendedGeometry(int index) const;

//
// QGridLayout helpers
//
    int findItemAt(int row, int column) const;

    static int findItemAt(QGridLayout *, int row, int column);
    static void createEmptyCells(QGridLayout *&gridLayout);

    void computeGridLayout(QHash<QLayoutItem*, QRect> *layout);
    void rebuildGridLayout(QHash<QLayoutItem*, QRect> *layout);
    void insertWidget(int index, QWidget *widget);

    inline bool isEmptyItem(QLayoutItem *item) const
    { return item->spacerItem() != 0; }

protected:
    void tryRemoveRow(int row);
    void tryRemoveColumn(int column);

private:
    QDesignerFormWindowInterface *m_formWindow;
    QPointer<QWidget> m_widget;
    QPointer<QWidget> m_indicatorLeft;
    QPointer<QWidget> m_indicatorTop;
    QPointer<QWidget> m_indicatorRight;
    QPointer<QWidget> m_indicatorBottom;
    int m_currentIndex;
    QDesignerLayoutDecorationExtension::InsertMode m_currentInsertMode;
    QPair<int, int> m_currentCell;
};

class QDESIGNER_SHARED_EXPORT QLayoutWidget: public QWidget
{
    Q_OBJECT
    Q_PROPERTY(int margin READ layoutMargin WRITE setLayoutMargin STORED false DESIGNABLE true)
    Q_PROPERTY(int spacing READ layoutSpacing WRITE setLayoutSpacing STORED false DESIGNABLE true)
public:
    QLayoutWidget(QDesignerFormWindowInterface *formWindow, QWidget *parent = 0);

    int layoutMargin() const;
    void setLayoutMargin(int layoutMargin);

    int layoutSpacing() const;
    void setLayoutSpacing(int layoutSpacing);

    inline QDesignerFormWindowInterface *formWindow() const
    { return m_formWindow; }

    inline QLayoutSupport *support() const
    { return const_cast<QLayoutSupport*>(&m_support); }

    inline int findItemAt(const QPoint &pos) const
    { return m_support.findItemAt(pos); }

    inline QRect itemInfo(int index) const
    { return m_support.itemInfo(index); }

    inline void adjustIndicator(const QPoint &pos, int index)
    { m_support.adjustIndicator(pos, index); }

    inline void insertWidget(QWidget *widget, const QPair<int, int> &cell)
    { m_support.insertWidget(widget, cell); }

    inline void removeWidget(QWidget *widget)
    { m_support.removeWidget(widget); }

protected:
    virtual bool event(QEvent *e);
    virtual void paintEvent(QPaintEvent *e);

    void updateMargin();

    inline QList<QWidget*> widgets(QLayout *layout)
    { return m_support.widgets(layout); }

    inline void insertRow(int row)
    { m_support.insertRow(row); }

    inline void insertColumn(int column)
    { m_support.insertColumn(column); }

    inline void computeGridLayout(QHash<QLayoutItem*, QRect> *layout)
    { m_support.computeGridLayout(layout); }

    inline void rebuildGridLayout(QHash<QLayoutItem*, QRect> *layout)
    { m_support.rebuildGridLayout(layout); }

private:
    QDesignerFormWindowInterface *m_formWindow;
    QLayoutSupport m_support;
};

class QLayoutWidgetItem: public QWidgetItem
{
public:
    QLayoutWidgetItem(QWidget *widget);

    virtual void setGeometry(const QRect &r);
    virtual QSize sizeHint() const;
    virtual QSize minimumSize() const;
    virtual QSize maximumSize() const;
    virtual Qt::Orientations expandingDirections() const;
    virtual bool hasHeightForWidth() const;
    virtual int heightForWidth(int) const;
    virtual int minimumHeightForWidth(int) const;

    void addTo(QLayout *layout);
    void removeFrom(QLayout *layout);

protected:
    inline QLayoutWidgetItem *me() const
    { return const_cast<QLayoutWidgetItem*>(this); }

    inline QLayout *theLayout() const
    { Q_ASSERT(me()->widget()); return me()->widget()->layout(); }
};

#endif // QDESIGNER_WIDGET_H