1 /*

     2  * Copyright (c) 2009 Nokia Corporation.

     3  */

     4 

     5 #ifndef QASPECTRATIOLAYOUT_H_

     6 #define QASPECTRATIOLAYOUT_H_

     7 

     8 #include <QLayout>

     9 #include <QPointer>

    10 #include <QRect>

    11 #include <QWidgetItem>

    12 #include <QLayoutItem>

    13 

    14 

    15 class QAspectRatioLayout : public QLayout

    16 {

    17         Q_OBJECT

    18 

    19 public:

    20         QAspectRatioLayout(QWidget* parent, int spacing =-1);

    21         QAspectRatioLayout(int spacing = -1);

    22         ~QAspectRatioLayout();

    23 

    24         /* Convenience method */

    25         virtual void add(QLayoutItem* item);

    26 

    27 /* http://doc.trolltech.com/qlayout.html#addItem */

    28         virtual void addItem(QLayoutItem* item);

    29         /* http://doc.trolltech.com/qlayout.html#addWidget */

    30         virtual void addWidget(QWidget* widget);

    31         /* http://doc.trolltech.com/qlayout.html#takeAt */

    32         virtual QLayoutItem* takeAt(int index);

    33         /* http://doc.trolltech.com/qlayout.html#itemAt */

    34         virtual QLayoutItem* itemAt(int index) const;

    35         /* http://doc.trolltech.com/qlayout.html#count */

    36         virtual int count() const;

    37 

    38         /*

    39          * These are ours since we do have only one item.

    40          */

    41         virtual QLayoutItem* replaceItem(QLayoutItem* item);

    42         virtual QLayoutItem* take();

    43         virtual bool hasItem() const;

    44 

    45 /* http://doc.trolltech.com/qlayout.html#expandingDirections */

    46         virtual Qt::Orientations expandingDirections() const;

    47 

    48         /*

    49          * This method contains most of the juice of this article.

    50          * http://doc.trolltech.com/qlayoutitem.html#setGeometry

    51          */

    52         virtual void setGeometry(const QRect& rect);

    53         /* http://doc.trolltech.com/qlayoutitem.html#geometry */

    54         virtual QRect geometry();

    55 

    56         /* http://doc.trolltech.com/qlayoutitem.html#sizeHint */

    57         virtual QSize sizeHint() const;

    58         /* http://doc.trolltech.com/qlayout.html#minimumSize */

    59         virtual QSize minimumSize() const;

    60         /* http://doc.trolltech.com/qlayoutitem.html#hasHeightForWidth */

    61         virtual bool hasHeightForWidth() const;

    62 

    63 private:

    64         /* Saves the last received rect. */

    65         void setLastReceivedRect(const QRect& rect);

    66         /* Used to initialize the object. */

    67         void init(int spacing);

    68         /* Calculates the maximum size for the item from the assigned size. */

    69         QSize calculateProperSize(QSize from) const;

    70         /* Calculates the center location from the assigned size and

    71          * the items size. */

    72         QPoint calculateCenterLocation(QSize from, QSize itemSize) const;

    73         /* Check if two QRects are equal */

    74         bool areRectsEqual(const QRect& a, const QRect& b) const;

    75         /* Contains item reference */

    76         QLayoutItem* item;

    77         /*

    78          * Used for caching so we won't do calculations every time

    79          * setGeometry is called.

    80          */

    81         QRect* lastReceivedRect;

    82         /* Contains geometry */

    83         QRect* _geometry;

    84 

    85 };

    86 

    87 #endif /* QASPECTRATIOLAYOUT_H_ */