q3sqlpropertymap.cpp

奇趣公司比较新的qt/emd版本

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#include "q3sqlpropertymap.h"

#ifndef QT_NO_SQL_FORM

#include "qwidget.h"
#include "q3cleanuphandler.h"
#include "qmetaobject.h"
#include "qmap.h"

class Q3SqlPropertyMapPrivate
{
public:
    Q3SqlPropertyMapPrivate() {}
    QMap<QByteArray, QByteArray> propertyMap;
};

/*!
    \class Q3SqlPropertyMap qsqlpropertymap.h
    \brief The Q3SqlPropertyMap class is used to map widgets to SQL fields.

    \compat

    The SQL module uses Qt \link properties.html object
    properties\endlink to insert and extract values from editor
    widgets.

    This class is used to map editors to SQL fields. This works by
    associating SQL editor class names to the properties used to
    insert and extract values to/from the editor.

    For example, a QLineEdit can be used to edit text strings and
    other data types in Q3DataTables or Q3SqlForms. Several properties
    are defined in QLineEdit, but only the \e text property is used to
    insert and extract text from a QLineEdit. Both Q3DataTable and
    Q3SqlForm use the global Q3SqlPropertyMap for inserting and
    extracting values to and from an editor widget. The global
    property map defines several common widgets and properties that
    are suitable for many applications. You can add and remove widget
    properties to suit your specific needs.

    If you want to use custom editors with your Q3DataTable or
    Q3SqlForm, you must install your own Q3SqlPropertyMap for that table
    or form. Example:

    \code
    Q3SqlPropertyMap *myMap  = new Q3SqlPropertyMap();
    Q3SqlForm        *myForm = new Q3SqlForm(this);
    MyEditor myEditor(this);

    // Set the Q3SqlForm's record buffer to the update buffer of
    // a pre-existing Q3SqlCursor called 'cur'.
    myForm->setRecord(cur->primeUpdate());

    // Install the customized map
    myMap->insert("MyEditor", "content");
    myForm->installPropertyMap(myMap); // myForm now owns myMap
    ...
    // Insert a field into the form that uses a myEditor to edit the
    // field 'somefield'
    myForm->insert(&myEditor, "somefield");

    // Update myEditor with the value from the mapped database field
    myForm->readFields();
    ...
    // Let the user edit the form
    ...
    // Update the database fields with the values in the form
    myForm->writeFields();
    ...
    \endcode

    You can also replace the global Q3SqlPropertyMap that is used by
    default. (Bear in mind that Q3SqlPropertyMap takes ownership of the
    new default map.)

    \code
    Q3SqlPropertyMap *myMap = new Q3SqlPropertyMap;

    myMap->insert("MyEditor", "content");
    Q3SqlPropertyMap::installDefaultMap(myMap);
    ...
    \endcode

    \sa Q3DataTable, Q3SqlForm, Q3SqlEditorFactory
*/

/*!

Constructs a Q3SqlPropertyMap.

The default property mappings used by Qt widgets are:
\table
\header \i Widgets \i Property
\row \i \l QCheckBox,
        \l QRadioButton
     \i checked
\row \i \l QComboBox,
        \l Q3ListBox
     \i currentItem
\row \i \l Q3DateEdit
     \i date
\row \i \l Q3DateTimeEdit
        \l QDateTimeEdit
     \i dateTime
\row \i \l QTextBrowser
     \i source
\row \i \l QAbstractButton,
        \l QDial,
        \l QLabel,
        \l QLineEdit,
        \l Q3MultiLineEdit,
        \l QPushButton,
        \l QTextEdit,
     \i text
\row \i \l Q3TimeEdit
     \i time
\row \i \l QLCDNumber,
        \l QScrollBar
        \l QSlider,
        \l QSpinBox
     \i value
\endtable
*/

Q3SqlPropertyMap::Q3SqlPropertyMap()
{
    d = new Q3SqlPropertyMapPrivate();
    const struct MapData {
        const char *classname;
        const char *property;
    } mapData[] = {
        { "Q3DateEdit", "date" },
        { "Q3DateTimeEdit", "dateTime" },
        { "Q3ListBox", "currentItem" },
        { "Q3TimeEdit", "time" },
        { "QAbstractButton", "text" },
        { "QCheckBox", "checked" },
        { "QRadioButton", "checked" },
        { "QComboBox", "currentIndex" },
        { "QDateTimeEdit", "dateTime" },
        { "QDial", "value" },
        { "QLabel", "text" },
        { "QLCDNumber", "value" },
        { "QLineEdit", "text" },
        { "QPushButton", "text" },
        { "QScrollBar", "value" },
        { "QSlider", "value" },
        { "QSpinBox", "value" },
        { "QTabBar", "currentTab" },
        { "QTabWidget", "currentPage" },
        { "QTextBrowser", "source" },
        { "QTextEdit", "text" },
        { "QGroupBox", "checked" }
    };

    const MapData *m = mapData;
    for (uint i = 0; i < sizeof(mapData)/sizeof(MapData); i++, m++)
        d->propertyMap.insert(m->classname, m->property);
}

/*!
    Destroys the Q3SqlPropertyMap.

    Note that if the Q3SqlPropertyMap is installed with
    installPropertyMap() the object it was installed into, e.g. the
    Q3SqlForm, takes ownership and will delete the Q3SqlPropertyMap when
    necessary.
*/
Q3SqlPropertyMap::~Q3SqlPropertyMap()
{
    delete d;
}

/*!
    Returns the mapped property of \a widget as a QVariant.
*/
QVariant Q3SqlPropertyMap::property(QWidget * widget)
{
    if(!widget) return QVariant();
    const QMetaObject* mo = widget->metaObject();
    while (mo && !d->propertyMap.contains(mo->className()))
        mo = mo->superClass();

    if (!mo) {
        qWarning("Q3SqlPropertyMap::property: %s does not exist", widget->metaObject()->className());
        return QVariant();
    }
    return widget->property(d->propertyMap[mo->className()]);
}

/*!
    Sets the property of \a widget to \a value.
*/
void Q3SqlPropertyMap::setProperty(QWidget * widget, const QVariant & value)
{
    if(!widget) return;

    const QMetaObject* mo = widget->metaObject();
    while (mo && !d->propertyMap.contains(mo->className()))
        mo = mo->superClass();
    if (!mo) {
        qWarning("Q3SqlPropertyMap::setProperty: %s not handled by Q3SqlPropertyMap", widget->metaObject()->className());
        return;
    }

    widget->setProperty(d->propertyMap[mo->className()], value);
}

/*!
  Insert a new classname/property pair, which is used for custom SQL
  field editors. There \e must be a Q_PROPERTY() clause in the \a
  classname class declaration for the \a property.
*/
void Q3SqlPropertyMap::insert(const QString & classname,
                              const QString & property)
{
    d->propertyMap[classname.latin1()] = property.latin1();
}

/*!
    Removes \a classname from the map.
*/
void Q3SqlPropertyMap::remove(const QString & classname)
{
    d->propertyMap.remove(classname.latin1());
}

static Q3SqlPropertyMap * defaultmap = 0;
static Q3CleanupHandler< Q3SqlPropertyMap > qsql_cleanup_property_map;

/*!
    Returns the application global Q3SqlPropertyMap.
*/
Q3SqlPropertyMap * Q3SqlPropertyMap::defaultMap()
{
    if(defaultmap == 0){
        defaultmap = new Q3SqlPropertyMap();
        qsql_cleanup_property_map.add(&defaultmap);
    }
    return defaultmap;
}

/*!
    Replaces the global default property map with \a map. All
    Q3DataTable and Q3SqlForm instantiations will use this new map for
    inserting and extracting values to and from editors.
    \e{Q3SqlPropertyMap takes ownership of \a map, and destroys it
    when it is no longer needed.}
*/
void Q3SqlPropertyMap::installDefaultMap(Q3SqlPropertyMap * map)
{
    if(map == 0) return;

    if(defaultmap != 0){
        qsql_cleanup_property_map.remove(&defaultmap);
        delete defaultmap;
    }
    defaultmap = map;
    qsql_cleanup_property_map.add(&defaultmap);
}

#endif // QT_NO_SQL_FORM