q3combobox.cpp

奇趣公司比较新的qt/emd版本

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#include "q3combobox.h"
#ifndef QT_NO_COMBOBOX
#include "qpainter.h"
#include "qdrawutil.h"
#include "qpixmap.h"
#include "qtimer.h"
#include "qapplication.h"
#include "qlineedit.h"
#include "qbitmap.h"
#include "qstringlist.h"
#include "qstyle.h"
#include "qevent.h"
#include "qmenu.h"
#include "qmenudata.h"
#include "qstyleoption.h"
#include "qdesktopwidget.h"
#include "q3popupmenu.h"
#include "q3listbox.h"
#include "q3strlist.h"
#include "q3frame.h"
#include <limits.h>
#include <qdebug.h>
#ifndef QT_NO_EFFECTS
# include <private/qeffects_p.h>
#endif
#if defined(QT_ACCESSIBILITY_SUPPORT)
#include "qaccessible.h"
#endif

/*!
    \class Q3ComboBox q3combobox.h
    \brief The Q3ComboBox widget is a combined button and popup list.
    \since 4.1
    \compat

    A combobox is a selection widget which displays the current item
    and can pop up a list of items. A combobox may be editable in
    which case the user can enter arbitrary strings.

    Comboboxes provide a means of showing the user's current choice
    out of a list of options in a way that takes up the minimum amount
    of screen space.

    Q3ComboBox supports three different display styles: Aqua/Motif 1.x,
    Motif 2.0 and Windows. In Motif 1.x, a combobox was called
    XmOptionMenu. In Motif 2.0, OSF introduced an improved combobox
    and named that XmComboBox. Q3ComboBox provides both.

    Q3ComboBox provides two different constructors. The simplest
    constructor creates an "old-style" combobox in Motif (or Aqua)
    style:
    \code
        Q3ComboBox *c = new Q3ComboBox(this, tr("read-only combobox"));
    \endcode

    The other constructor creates a new-style combobox in Motif style,
    and can create both read-only and editable comboboxes:
    \code
        Q3ComboBox *c1 = new Q3ComboBox(false, this, tr("read-only combobox"));
        Q3ComboBox *c2 = new Q3ComboBox(true, this, tr("editable combobox"));
    \endcode

    New-style comboboxes use a list box in both Motif and Windows
    styles, and both the content size and the on-screen size of the
    list box can be limited with sizeLimit() and setMaxCount()
    respectively. Old-style comboboxes use a popup in Aqua and Motif
    style, and that popup will happily grow larger than the desktop if
    you put enough data into it.

    The two constructors create identical-looking comboboxes in
    Windows style.

    Comboboxes can contain pixmaps as well as strings; the
    insertItem() and changeItem() functions are suitably overloaded.
    For editable comboboxes, the function clearEdit() is provided,
    to clear the displayed string without changing the combobox's
    contents.

    A combobox emits two signals, activated() and highlighted(), when
    a new item has been activated (selected) or highlighted (made
    current). Both signals exist in two versions, one with a \c
    QString argument and one with an \c int argument. If the user
    highlights or activates a pixmap, only the \c int signals are
    emitted. Whenever the text of an editable combobox is changed the
    textChanged() signal is emitted.

    When the user enters a new string in an editable combobox, the
    widget may or may not insert it, and it can insert it in several
    locations. The default policy is is \c AtBottom but you can change
    this using setInsertionPolicy().

    It is possible to constrain the input to an editable combobox
    using QValidator; see setValidator(). By default, any input is
    accepted.

    If the combobox is not editable then it has a default
    focusPolicy() of \c TabFocus, i.e. it will not grab focus if
    clicked. This differs from both Windows and Motif. If the combobox
    is editable then it has a default focusPolicy() of \c StrongFocus,
    i.e. it will grab focus if clicked.

    A combobox can be populated using the insert functions,
    insertStringList() and insertItem() for example. Items can be
    changed with changeItem(). An item can be removed with
    removeItem() and all items can be removed with clear(). The text
    of the current item is returned by currentText(), and the text of
    a numbered item is returned with text(). The current item can be
    set with setCurrentItem() or setCurrentText(). The number of items
    in the combobox is returned by count(); the maximum number of
    items can be set with setMaxCount(). You can allow editing using
    setEditable(). For editable comboboxes you can set auto-completion
    using setAutoCompletion() and whether or not the user can add
    duplicates is set with setDuplicatesEnabled().

    Depending on the style, Q3ComboBox will use a list box or a
    popup menu to display the list of items. See setListBox() for
    more information.

    \sa QComboBox, QLineEdit, QSpinBox
        {GUI Design Handbook}{GUI Design Handbook: Combo Box, Drop-Down List Box}
*/


/*!
    \enum Q3ComboBox::Policy

    This enum specifies what the Q3ComboBox should do when a new string
    is entered by the user.

    \value NoInsertion the string will not be inserted into the
    combobox.

    \value AtTop insert the string as the first item in the combobox.

    \value AtCurrent replace the previously selected item with the
    string the user has entered.

    \value AtBottom insert the string as the last item in the
    combobox.

    \value AfterCurrent insert the string after the previously
    selected item.

    \value BeforeCurrent insert the string before the previously
    selected item.

    activated() is always emitted when the string is entered.

    If inserting the new string would cause the combobox to breach its
    content size limit, the item at the other end of the list is
    deleted. The definition of "other end" is
    implementation-dependent.

    \omitvalue NoInsert
    \omitvalue InsertAtTop
    \omitvalue InsertAtCurrent
    \omitvalue InsertAtBottom
    \omitvalue InsertAfterCurrent
    \omitvalue InsertBeforeCurrent
*/


/*!
    \fn void Q3ComboBox::activated( int index )

    This signal is emitted when a new item has been activated
    (selected). The \a index is the position of the item in the
    combobox.

    This signal is not emitted if the item is changed
    programmatically, e.g. using setCurrentItem().
*/

/*!
    \overload
    \fn void Q3ComboBox::activated( const QString &string )

    This signal is emitted when a new item has been activated
    (selected). \a string is the selected string.

    You can also use the activated(int) signal, but be aware that its
    argument is meaningful only for selected strings, not for user
    entered strings.
*/

/*!
    \fn void Q3ComboBox::highlighted( int index )

    This signal is emitted when a new item has been set to be the
    current item. The \a index is the position of the item in the
    combobox.

    This signal is not emitted if the item is changed
    programmatically, e.g. using setCurrentItem().
*/

/*!
    \overload
    \fn void Q3ComboBox::highlighted( const QString &string )

    This signal is emitted when a new item has been set to be the
    current item. \a string is the item's text.

    You can also use the highlighted(int) signal.
*/

/*!
    \fn void Q3ComboBox::textChanged( const QString &string )

    This signal is used for editable comboboxes. It is emitted
    whenever the contents of the text entry field changes. \a string
    contains the new text.
*/

/*!
    \property Q3ComboBox::autoCompletion
    \brief whether auto-completion is enabled

    This property can only be set for editable comboboxes, for
    non-editable comboboxes it has no effect. It is false by default.
*/

/*!
    \property Q3ComboBox::autoResize
    \brief whether auto-resize is enabled
    \obsolete

    If this property is set to true then the combobox will resize
    itself whenever its contents change. The default is false.
*/

/*!
    \property Q3ComboBox::count
    \brief the number of items in the combobox
*/

/*!
    \property Q3ComboBox::currentItem
    \brief the index of the current item in the combobox

    Note that the activated() and highlighted() signals are only
    emitted when the user changes the current item, not when it is
    changed programmatically.
*/

/*!
    \property Q3ComboBox::currentText
    \brief the text of the combobox's current item
*/

/*!
    \property Q3ComboBox::duplicatesEnabled
    \brief whether duplicates are allowed

    If the combobox is editable and the user enters some text in the
    combobox's lineedit and presses Enter (and the insertionPolicy()
    is not \c NoInsertion), then what happens is this:
    \list
    \i If the text is not already in the list, the text is inserted.
    \i If the text is in the list and this property is true (the
    default), the text is inserted.
    \i If the text is in the list and this property is false, the text
    is \e not inserted; instead the item which has matching text becomes
    the current item.
    \endlist

    This property only affects user-interaction. You can use
    insertItem() to insert duplicates if you wish regardless of this
    setting.
*/

/*!
    \property Q3ComboBox::editable
    \brief whether the combobox is editable

    This property's default is false. Note that the combobox will be
    cleared if this property is set to true for a 1.x Motif style
    combobox. To avoid this, use setEditable() before inserting any
    items. Also note that the 1.x version of Motif didn't have any
    editable comboboxes, so the combobox will change its appearance
    to a 2.0 style Motif combobox is it is set to be editable.
*/

/*!
    \property Q3ComboBox::insertionPolicy
    \brief the position of the items inserted by the user

    The default insertion policy is \c AtBottom. See \l Policy.
*/

/*!
    \property Q3ComboBox::maxCount
    \brief the maximum number of items allowed in the combobox
*/

/*!
    \property Q3ComboBox::sizeLimit
    \brief the maximum on-screen size of the combobox.

    This property is ignored for both Motif 1.x style and non-editable
    comboboxes in Mac style. The default limit is ten
    lines. If the number of items in the combobox is or grows larger
    than lines, a scroll bar is added.
*/

class Q3ComboBoxPopup : public Q3PopupMenu
{
public:
    Q3ComboBoxPopup( QWidget *parent=0, const char *name=0 )
	: Q3PopupMenu( parent, name )
    {
    }

    int itemHeight( int index )
    {
	return Q3PopupMenu::itemHeight( index );
    }
};

static inline QString escapedComboString(const QString &str)
{
    QString stringToReturn = str;
    return stringToReturn.replace(QLatin1Char('&'), QLatin1String("&&"));
}

class Q3ComboBoxPopupItem : public QMenuItem
{
    Q3ListBoxItem *li;
    QSize sc; // Size cache optimization
public:
    Q3ComboBoxPopupItem(Q3ListBoxItem *i) : QMenuItem(), li(i), sc(0, 0) {  }
    virtual bool fullSpan() const { return true; }
    virtual void paint( QPainter*, const QColorGroup&, bool, bool, int, int, int, int);
    virtual QSize sizeHint() { if (sc.isNull()) sc = QSize(li->width(li->listBox()), QMAX(25, li->height(li->listBox()))); return sc; }
};
void Q3ComboBoxPopupItem::paint( QPainter* p, const QColorGroup&, bool,
				bool, int x, int y, int, int)
{
    p->save();
    p->translate(x, y + ((sizeHint().height() / 2) - (li->height(li->listBox()) / 2)));
    li->paint(p);
    p->restore();
}


class Q3ComboBoxData
{
public:
    Q3ComboBoxData( Q3ComboBox *cb ): current( 0 ), arrowDown(false), ed( 0 ), usingLBox( false ), pop( 0 ), lBox( 0 ), combo( cb )
    {
	duplicatesEnabled = true;
	cb->setSizePolicy( QSizePolicy( QSizePolicy::Minimum, QSizePolicy::Fixed ) );
    }

    inline bool usingListBox()  { return usingLBox; }
    inline Q3ListBox * listBox() { return lBox; }
    inline Q3ComboBoxPopup * popup() { return pop; }
    void updateLinedGeometry();

    void setListBox( Q3ListBox *l ) { lBox = l ; usingLBox = true;
				l->setMouseTracking( true );}

    void setPopupMenu( Q3ComboBoxPopup * pm, bool isPopup=true )
	{ pop = pm; if(isPopup) usingLBox = false; }

    QStyleOptionComboBox getStyleOption() const
        {
            QStyleOptionComboBox opt;
            opt.init(combo);
            if (!combo->editable() && combo->hasFocus())
                opt.state |= QStyle::State_Selected;
            opt.subControls = QStyle::SC_All;
            if (arrowDown) {
                opt.activeSubControls = QStyle::SC_ComboBoxArrow;
                opt.state |= QStyle::State_Sunken;
            }
            opt.editable = combo->editable();
            opt.frame = 1; // ### get from style?
            if (current > -1 && current < combo->count()) {
                opt.currentText = combo->text(current);
                if (combo->pixmap(current))
                    opt.currentIcon = QIcon(*combo->pixmap(current));
            }
            opt.iconSize = QSize(22, 22); // ### need a sane value here
//             if (container && container->isVisible())
//                 opt.state |= QStyle::State_On;
            return opt;
        }

    int		current;
    int		maxCount;
    int		sizeLimit;
    Q3ComboBox::Policy p;
    bool	autoresize;
    bool	poppedUp;
    bool	mouseWasInsidePopup;
    bool	arrowPressed;
    bool	arrowDown;
    bool	discardNextMousePress;
    bool	shortClick;
    bool	useCompletion;
    bool	completeNow;
    int		completeAt;
    bool duplicatesEnabled;
    int fullHeight, currHeight;

    QLineEdit * ed;  // /bin/ed rules!
    QTimer *completionTimer;

    QSize sizeHint;
    QHash<int, QPixmap> popupPixmaps;

private:
    bool	usingLBox;
    Q3ComboBoxPopup *pop;
    Q3ListBox   *lBox;
    Q3ComboBox *combo;
};

void Q3ComboBoxData::updateLinedGeometry()
{
    if ( !ed || !combo )
	return;

    QStyleOptionComboBox opt = getStyleOption();
    QRect r = combo->style()->subControlRect(
        QStyle::CC_ComboBox, &opt, QStyle::SC_ComboBoxEditField, combo);

    const QPixmap *pix = current < combo->count() ? combo->pixmap( current ) : 0;
    if ( pix && pix->width() < r.width() )
	r.setLeft( r.left() + pix->width() + 4 );
    if ( r != ed->geometry() )
	ed->setGeometry( r );
}