qabstractitemview.cpp

奇趣公司比较新的qt/emd版本

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#include "qabstractitemview.h"

#ifndef QT_NO_ITEMVIEWS
#include <qpointer.h>
#include <qapplication.h>
#include <qclipboard.h>
#include <qpainter.h>
#include <qstyle.h>
#include <qdrag.h>
#include <qevent.h>
#include <qscrollbar.h>
#include <qwhatsthis.h>
#include <qtooltip.h>
#include <qdatetime.h>
#include <qlineedit.h>
#include <qspinbox.h>
#include <qitemdelegate.h>
#include <private/qabstractitemview_p.h>
#include <private/qabstractitemmodel_p.h>
#ifndef QT_NO_ACCESSIBILITY
#include <qaccessible.h>
#endif

QAbstractItemViewPrivate::QAbstractItemViewPrivate()
    :   model(QAbstractItemModelPrivate::staticEmptyModel()),
        itemDelegate(0),
        selectionModel(0),
        selectionMode(QAbstractItemView::ExtendedSelection),
        selectionBehavior(QAbstractItemView::SelectItems),
        currentlyCommittingEditor(0),
        pressedModifiers(Qt::NoModifier),
        pressedPosition(QPoint(-1, -1)),
        state(QAbstractItemView::NoState),
        editTriggers(QAbstractItemView::DoubleClicked|QAbstractItemView::EditKeyPressed),
        lastTrigger(QAbstractItemView::NoEditTriggers),
        tabKeyNavigation(false),
#ifndef QT_NO_DRAGANDDROP
        showDropIndicator(true),
        dragEnabled(false),
        dragDropMode(QAbstractItemView::NoDragDrop),
        overwrite(false),
        dropIndicatorPosition(QAbstractItemView::OnItem),
#endif
        autoScroll(true),
        autoScrollMargin(16),
        autoScrollCount(0),
        alternatingColors(false),
        textElideMode(Qt::ElideRight),
        verticalScrollMode(QAbstractItemView::ScrollPerItem),
        horizontalScrollMode(QAbstractItemView::ScrollPerItem),
        currentIndexSet(false),
        wrapItemText(false)
{
}

QAbstractItemViewPrivate::~QAbstractItemViewPrivate()
{
}

void QAbstractItemViewPrivate::init()
{
    Q_Q(QAbstractItemView);
    q->setItemDelegate(new QItemDelegate(q));

    q->verticalScrollBar()->setRange(0, 0);
    q->horizontalScrollBar()->setRange(0, 0);

    QObject::connect(q->verticalScrollBar(), SIGNAL(actionTriggered(int)),
                     q, SLOT(verticalScrollbarAction(int)));
    QObject::connect(q->horizontalScrollBar(), SIGNAL(actionTriggered(int)),
                     q, SLOT(horizontalScrollbarAction(int)));
    QObject::connect(q->verticalScrollBar(), SIGNAL(valueChanged(int)),
                     q, SLOT(verticalScrollbarValueChanged(int)));
    QObject::connect(q->horizontalScrollBar(), SIGNAL(valueChanged(int)),
                     q, SLOT(horizontalScrollbarValueChanged(int)));

    viewport->setBackgroundRole(QPalette::Base);

    doDelayedItemsLayout();

    q->setAttribute(Qt::WA_InputMethodEnabled);
}

/*!
    \class QAbstractItemView

    \brief The QAbstractItemView class provides the basic functionality for
    item view classes.

    \ingroup model-view
    \mainclass

    QAbstractItemView class is the base class for every standard view
    that uses a QAbstractItemModel. QAbstractItemView is an abstract
    class and cannot itself be instantiated. It provides a standard
    interface for interoperating with models through the signals and
    slots mechanism, enabling subclasses to be kept up-to-date with
    changes to their models.  This class provides standard support for
    keyboard and mouse navigation, viewport scrolling, item editing,
    and selections.

    The QAbstractItemView class is one of the \l{Model/View Classes}
    and is part of Qt's \l{Model/View Programming}{model/view framework}.

    The view classes that inherit QAbstractItemView only need
    to implement their own view-specific functionality, such as
    drawing items, returning the geometry of items, finding items,
    etc.

    QAbstractItemView provides common slots such as edit() and
    setCurrentIndex(). Many protected slots are also provided, including
    dataChanged(), rowsInserted(), rowsAboutToBeRemoved(), selectionChanged(),
    and currentChanged().

    The root item is returned by rootIndex(), and the current item by
    currentIndex(). To make sure that an item is visible use
    scrollTo().

    Some of QAbstractItemView's functions are concerned with
    scrolling, for example setHorizontalScrollMode() and
    setVerticalScrollMode(). To set the range of the scroll bars, you
    can, for example, reimplement the view's resizeEvent() function:

    \code
        void MyView::resizeEvent(QResizeEvent *event) {
            horizontalScrollBar()->setRange(0, realWidth - width());
            ...
        }
    \endcode

    Note that the range is not updated until the widget is shown.

    Several other functions are concerned with selection control; for
    example setSelectionMode(), and setSelectionBehavior(). This class
    provides a default selection model to work with
    (selectionModel()), but this can be replaced by using
    setSelectionModel() with an instance of QItemSelectionModel.

    For complete control over the display and editing of items you can
    specify a delegate with setItemDelegate().

    QAbstractItemView provides a lot of protected functions. Some are
    concerned with editing, for example, edit(), and commitData(),
    whilst others are keyboard and mouse event handlers.

    \sa {View Classes}, {Model/View Programming}, QAbstractItemModel, {Chart Example}
*/

/*!
    \enum QAbstractItemView::SelectionMode

    This enum indicates how the view responds to user selections:

    \value SingleSelection  When the user selects an item, any
    already-selected item becomes unselected, and the user cannot
    unselect the selected item.

    \value ContiguousSelection When the user selects an item in the
    usual way, the selection is cleared and the new item selected.
    However, if the user presses the Shift key while clicking on an item,
    all items between the current item and the clicked item are
    selected or unselected, depending on the state of the clicked
    item.

    \value ExtendedSelection When the user selects an item in the
    usual way, the selection is cleared and the new item selected.
    However, if the user presses the Ctrl key when clicking on an
    item, the clicked item gets toggled and all other items are left
    untouched.
    If the user presses the Shift key while clicking on an item,
    all items between the current item and the clicked item are
    selected or unselected, depending on the state of the clicked
    item. Multiple items can be selected by dragging the mouse
    over them.

    \value MultiSelection When the user selects an item in the usual
    way, the selection status of that item is toggled and the other
    items are left alone. Multiple items can be toggled by dragging
    the mouse over them.

    \value NoSelection  Items cannot be selected.

    The most commonly used modes are SingleSelection and
    ExtendedSelection.
*/

/*!
    \enum QAbstractItemView::SelectionBehavior

    \value SelectItems   Selecting single items.
    \value SelectRows    Selecting only rows.
    \value SelectColumns Selecting only columns.
*/

/*!
    \enum QAbstractItemView::ScrollHint

    \value EnsureVisible  Scroll to ensure that the item is visible.
    \value PositionAtTop  Scroll to position the item at the top of the viewport.
    \value PositionAtBottom  Scroll to position the item at the bottom of the viewport.
    \value PositionAtCenter  Scroll to position the item at the center of the viewport.
*/


/*!
  \enum QAbstractItemView::EditTrigger

  This enum describes actions which will initiate item editing.

  \value NoEditTriggers  No editing possible.
  \value CurrentChanged  Editing start whenever current item changes.
  \value DoubleClicked   Editing starts when an item is double clicked.
  \value SelectedClicked Editing starts when clicking on an already selected item.
  \value EditKeyPressed  Editing starts when the platform edit key has been pressed over an item.
  \value AnyKeyPressed   Editing starts when any key is pressed over an item.
  \value AllEditTriggers Editing starts for all above actions.
*/

/*!
  \enum QAbstractItemView::CursorAction

  This enum describes the different ways to navigate between items, \sa moveCursor()

  \value MoveUp       Move to the item above the current item.
  \value MoveDown     Move to the item below the current item.
  \value MoveLeft     Move to the item left of the current item.
  \value MoveRight    Move to the item right of the current item.
  \value MoveHome     Move to the top-left corner item.
  \value MoveEnd      Move to the bottom-right corner item.
  \value MovePageUp   Move one page up above the current item.
  \value MovePageDown Move one page down below the current item.
  \value MoveNext     Move to the item after the current item.
  \value MovePrevious Move to the item before the current item.
*/

/*!
    \enum QAbstractItemView::State

    Describes the different states the view can be in. This is usually
    only interesting when reimplementing your own view.

    \value NoState        The is the default state.
    \value DraggingState  The user is dragging items.
    \value DragSelectingState The user is selecting items.
    \value EditingState   The user is editing an item in a widget editor.
    \value ExpandingState   The user is opening a branch of items.
    \value CollapsingState   The user is closing a branch of items.
    \value AnimatingState The item view is performing an animation.
*/

/*!
  \since 4.2
  \enum QAbstractItemView::ScrollMode

  \value ScrollPerItem    The view will scroll the contents one item at a time.
  \value ScrollPerPixel   The view will scroll the contents one pixel at a time.
*/

/*!
    \fn QRect QAbstractItemView::visualRect(const QModelIndex &index) const = 0
    Returns the rectangle on the viewport occupied by the item at \a index.

    If your item is displayed in several areas then visualRect should return
    the primary area that contains index and not the complete area that index
    might encompasses, touch or cause drawing.

    In the base class this is a pure virtual function.

    \sa indexAt(), visualRegionForSelection()
*/

/*!
    \fn void QAbstractItemView::scrollTo(const QModelIndex &index, ScrollHint hint) = 0

    Scrolls the view if necessary to ensure that the item at \a index
    is visible. The view will try to position the item according to the given \a hint.

    In the base class this is a pure virtual function.
*/

/*!
    \fn QModelIndex QAbstractItemView::indexAt(const QPoint &point) const = 0

    Returns the model index of the item at the viewport coordinates \a point.

    In the base class this is a pure virtual function.

    \sa visualRect()
*/

/*!
    \fn void QAbstractItemView::activated(const QModelIndex &index)

    This signal is emitted when the item specified by \a index is
    activated by the user. How to activate items depends on the
    platform; e.g., by single- or double-clicking the item, or by
    pressing the Return or Enter key when the item is current.

    \sa clicked(), doubleClicked(), entered(), pressed()
*/

/*!
    \fn void QAbstractItemView::entered(const QModelIndex &index)

    This signal is emitted when the mouse cursor enters the item
    specified by \a index.
    Mouse tracking needs to be enabled for this feature to work.

    \sa viewportEntered(), activated(), clicked(), doubleClicked(), pressed()
*/

/*!
    \fn void QAbstractItemView::viewportEntered()

    This signal is emitted when the mouse cursor enters the viewport.
    Mouse tracking needs to be enabled for this feature to work.

    \sa entered()
*/

/*!
    \fn void QAbstractItemView::pressed(const QModelIndex &index)

    This signal is emitted when a mouse button is pressed. The item
    the mouse was pressed on is specified by \a index. The signal is
    only emitted when the index is valid.

    \sa activated(), clicked(), doubleClicked(), entered()
*/

/*!
    \fn void QAbstractItemView::clicked(const QModelIndex &index)

    This signal is emitted when a mouse button is clicked. The item
    the mouse was clicked on is specified by \a index. The signal is
    only emitted when the index is valid.

    \sa activated(), doubleClicked(), entered(), pressed()
*/

/*!
    \fn void QAbstractItemView::doubleClicked(const QModelIndex &index)

    This signal is emitted when a mouse button is double-clicked. The
    item the mouse was double-clicked on is specified by \a index.
    The signal is only emitted when the index is valid.

    \sa clicked(), activated()
*/

/*!
    \fn QModelIndex QAbstractItemView::moveCursor(CursorAction cursorAction, Qt::KeyboardModifiers modifiers) = 0

    Moves the cursor in the view according to the given \a cursorAction and