/**********************************************************************
** $Id$
**
** Implementation of QtTableView class
**
** Created : 941115
**
** Copyright (C) 1992-2000 Trolltech AS.  All rights reserved.
**
** This file contains a class moved out of the Qt GUI Toolkit API. It
** may be used, distributed and modified without limitation.
**
**********************************************************************/

#include "qttableview.h"
#include <climits>
#include <qapplication.h>
#include <qdrawutil.h>
#include <qevent.h>
#include <qpainter.h>
#include <qscrollbar.h>

enum ScrollBarDirtyFlags {
    verGeometry = 0x01,
    verSteps = 0x02,
    verRange = 0x04,
    verValue = 0x08,
    horGeometry = 0x10,
    horSteps = 0x20,
    horRange = 0x40,
    horValue = 0x80,
    verMask = 0x0F,
    horMask = 0xF0
};

#define HSBEXT horizontalScrollBar()->sizeHint().height()
#define VSBEXT verticalScrollBar()->sizeHint().width()

class QCornerSquare : public QWidget // internal class
{
public:
    QCornerSquare(QWidget *);
};

QCornerSquare::QCornerSquare(QWidget *parent)
    : QWidget(parent)
{
    setAutoFillBackground(true);
}

// NOT REVISED
/*!
  \class QtTableView qttableview.h
  \brief The QtTableView class provides an abstract base for tables.

  \obsolete

  A table view consists of a number of abstract cells organized in rows
  and columns, and a visible part called a view. The cells are identified
  with a row index and a column index. The top-left cell is in row 0,
  column 0.

  The behavior of the widget can be finely tuned using
  setTableFlags(); a typical subclass will consist of little more than a
  call to setTableFlags(), some table content manipulation and an
  implementation of paintCell().  Subclasses that need cells with
  variable width or height must reimplement cellHeight() and/or
  cellWidth(). Use updateTableSize() to tell QtTableView when the
  width or height has changed.

  When you read this documentation, it is important to understand the
  distinctions among the four pixel coordinate systems involved.

  \list 1
  \i The \e cell coordinates.  (0,0) is the top-left corner of a cell.
  Cell coordinates are used by functions such as paintCell().

  \i The \e table coordinates.  (0,0) is the top-left corner of the cell at
  row 0 and column 0. These coordinates are absolute; that is, they are
  independent of what part of the table is visible at the moment. They are
  used by functions such as setXOffset() or maxYOffset().

  \i The \e widget coordinates. (0,0) is the top-left corner of the widget,
  \e including the frame.  They are used by functions such as repaint().

  \i The \e view coordinates.  (0,0) is the top-left corner of the view, \e
  excluding the frame.  This is the least-used coordinate system; it is used by
  functions such as viewWidth().  \endlist

  It is rather unfortunate that we have to use four different
  coordinate systems, but there was no alternative to provide a flexible and
  powerful base class.

  Note: The row,column indices are always given in that order,
  i.e., first the vertical (row), then the horizontal (column). This is
  the opposite order of all pixel operations, which take first the
  horizontal (x) and then the vertical (y).

  <img src=qtablevw-m.png> <img src=qtablevw-w.png>

  \warning the functions setNumRows(), setNumCols(), setCellHeight(),
  setCellWidth(), setTableFlags() and clearTableFlags() may cause
  virtual functions such as cellWidth() and cellHeight() to be called,
  even if autoUpdate() is 'false'.  This may cause errors if relevant
  state variables are not initialized.

  \warning Experience has shown that use of this widget tends to cause
  more bugs than expected and our analysis indicates that the widget's
  very flexibility is the problem.  If QScrollView or QListBox can
  easily be made to do the job you need, we recommend subclassing
  those widgets rather than QtTableView. In addition, QScrollView makes
  it easy to have child widgets inside tables, which QtTableView
  doesn't support at all.

  \sa QScrollView
  \link guibooks.html#fowler GUI Design Handbook: Table\endlink
*/

/*!
  Constructs a table view.  The \a parent, \a name and \f arguments
  are passed to the QFrame constructor.

  The \link setTableFlags() table flags\endlink are all cleared (set to 0).
  Set \c Tbl_autoVScrollBar or \c Tbl_autoHScrollBar to get automatic scroll
  bars and \c Tbl_clipCellPainting to get safe clipping.

  The \link setCellHeight() cell height\endlink and \link setCellWidth()
  cell width\endlink are set to 0.

  Frame line shapes (QFrame::HLink and QFrame::VLine) are disallowed;
  see QFrame::setFrameStyle().

  Note that the \a f argument is \e not \link setTableFlags() table
  flags \endlink but rather \link QWidget::QWidget() widget
  flags. \endlink

*/

QtTableView::QtTableView(QWidget *parent, const char *name)
    : QFrame(parent)
{
    nRows = nCols = 0; // zero rows/cols
    xCellOffs = yCellOffs = 0; // zero offset
    xCellDelta = yCellDelta = 0; // zero cell offset
    xOffs = yOffs = 0; // zero total pixel offset
    cellH = cellW = 0; // user defined cell size
    tFlags = 0;
    vScrollBar = hScrollBar = 0; // no scroll bars
    cornerSquare = 0;
    sbDirty = 0;
    eraseInPaint = false;
    verSliding = false;
    verSnappingOff = false;
    horSliding = false;
    horSnappingOff = false;
    coveringCornerSquare = false;
    inSbUpdate = false;

    setAttribute(Qt::WA_OpaquePaintEvent, true);
    setObjectName(name);
}

/*!
  Destroys the table view.
*/

QtTableView::~QtTableView()
{
    delete vScrollBar;
    delete hScrollBar;
    delete cornerSquare;
}

/*!
  \overload void QtTableView::repaint( bool erase )
  Repaints the entire view.
*/

/*!
  Repaints the table view directly by calling paintEvent() directly
  unless updates are disabled.

  Erases the view area \a (x,y,w,h) if \a erase is 'true'. Parameters \a
  (x,y) are in \e widget coordinates.

  If \a w is negative, it is replaced with <code>width() - x</code>.
  If \a h is negative, it is replaced with <code>height() - y</code>.

  Doing a repaint() usually is faster than doing an update(), but
  calling update() many times in a row will generate a single paint
  event.

  At present, QtTableView is the only widget that reimplements \link
  QWidget::repaint() repaint()\endlink.	 It does this because by
  clearing and then repainting one cell at at time, it can make the
  screen flicker less than it would otherwise.  */

void QtTableView::repaint(int x, int y, int w, int h, bool erase)
{
    if (!isVisible())
        return;
    if (w < 0)
        w = width() - x;
    if (h < 0)
        h = height() - y;
    QRect r(x, y, w, h);
    if (r.isEmpty())
        return; // nothing to do
    if (erase && testAttribute(Qt::WA_OpaquePaintEvent))
        eraseInPaint = true; // erase when painting
    QWidget::repaint(r);
    eraseInPaint = false;
}

/*!
  \overload void QtTableView::repaint( const QRect &r, bool erase )
  Repaints rectangle \a r. If \a erase is 'true' draws the background
  using the palette's background.
*/

/*!
  \fn int QtTableView::numRows() const
  Returns the number of rows in the table.
  \sa numCols(), setNumRows()
*/

/*!
  Sets the number of rows of the table to \a rows (must be non-negative).
  Does not change topCell().

  The table repaints itself automatically if autoUpdate() is set.

  \sa numCols(), setNumCols(), numRows()
*/

void QtTableView::setNumRows(int rows)
{
    if (rows < 0) {
#if defined(QT_CHECK_RANGE)
        qWarning("QtTableView::setNumRows: (%s) Negative argument %d.", name("unnamed"), rows);
#endif
        return;
    }
    if (nRows == rows)
        return;

    if (autoUpdate() && isVisible()) {
        int oldLastVisible = lastRowVisible();
        int oldTopCell = topCell();
        nRows = rows;
        if (autoUpdate() && isVisible() && (oldLastVisible != lastRowVisible() || oldTopCell != topCell()))
            repaint(oldTopCell != topCell());
    } else {
        // Be more careful - if destructing, bad things might happen.
        nRows = rows;
    }
    updateScrollBars(verRange);
    updateFrameSize();
}

/*!
  \fn int QtTableView::numCols() const
  Returns the number of columns in the table.
  \sa numRows(), setNumCols()
*/

/*!
  Sets the number of columns of the table to \a cols (must be non-negative).
  Does not change leftCell().

  The table repaints itself automatically if autoUpdate() is set.

  \sa numCols(), numRows(), setNumRows()
*/

void QtTableView::setNumCols(int cols)
{
    if (cols < 0) {
#if defined(QT_CHECK_RANGE)
        qWarning("QtTableView::setNumCols: (%s) Negative argument %d.", name("unnamed"), cols);
#endif
        return;
    }
    if (nCols == cols)
        return;
    int oldCols = nCols;
    nCols = cols;
    if (autoUpdate() && isVisible()) {
        int maxCol = lastColVisible();
        if (maxCol >= oldCols || maxCol >= nCols)
            repaint();
    }
    updateScrollBars(horRange);
    updateFrameSize();
}

/*!
  \fn int QtTableView::topCell() const
  Returns the index of the first row in the table that is visible in
  the view.  The index of the first row is 0.
  \sa leftCell(), setTopCell()
*/

/*!
  Scrolls the table so that \a row becomes the top row.
  The index of the very first row is 0.
  \sa setYOffset(), setTopLeftCell(), setLeftCell()
*/

void QtTableView::setTopCell(int row)
{
    setTopLeftCell(row, -1);
    return;
}

/*!
  \fn int QtTableView::leftCell() const
  Returns the index of the first column in the table that is visible in
  the view.  The index of the very leftmost column is 0.
  \sa topCell(), setLeftCell()
*/

/*!
  Scrolls the table so that \a col becomes the leftmost
  column.  The index of the leftmost column is 0.
  \sa setXOffset(), setTopLeftCell(), setTopCell()
*/

void QtTableView::setLeftCell(int col)
{
    setTopLeftCell(-1, col);
    return;
}

/*!
  Scrolls the table so that the cell at row \a row and column \a
  col becomes the top-left cell in the view.  The cell at the extreme
  top left of the table is at position (0,0).
  \sa setLeftCell(), setTopCell(), setOffset()
*/

void QtTableView::setTopLeftCell(int row, int col)
{
    int newX = xOffs;
    int newY = yOffs;

    if (col >= 0) {
        if (cellW) {
            newX = col * cellW;
            if (newX > maxXOffset())
                newX = maxXOffset();
        } else {
            newX = 0;
            while (col)
                newX += cellWidth(--col); // optimize using current! ###
        }
    }
    if (row >= 0) {
        if (cellH) {
            newY = row * cellH;
            if (newY > maxYOffset())
                newY = maxYOffset();
        } else {
            newY = 0;
            while (row)
                newY += cellHeight(--row); // optimize using current! ###
        }
    }
    setOffset(newX, newY);
}

/*!
  \fn int QtTableView::xOffset() const

  Returns the x coordinate in \e table coordinates of the pixel that is
  currently on the left edge of the view.

  \sa setXOffset(), yOffset(), leftCell() */

/*!
  Scrolls the table so that \a x becomes the leftmost pixel in the view.
  The \a x parameter is in \e table coordinates.

  The interaction with \link setTableFlags() Tbl_snapToHGrid
  \endlink is tricky.

  \sa xOffset(), setYOffset(), setOffset(), setLeftCell()
*/

void QtTableView::setXOffset(int x)
{
    setOffset(x, yOffset());
}

/*!
  \fn int QtTableView::yOffset() const

  Returns the y coordinate in \e table coordinates of the pixel that is
  currently on the top edge of the view.

  \sa setYOffset(), xOffset(), topCell()
*/

/*!
  Scrolls the table so that \a y becomes the top pixel in the view.
  The \a y parameter is in \e table coordinates.

  The interaction with \link setTableFlags() Tbl_snapToVGrid
  \endlink is tricky.

  \sa yOffset(), setXOffset(), setOffset(), setTopCell()
*/

void QtTableView::setYOffset(int y)
{
    setOffset(xOffset(), y);
}

/*!
  Scrolls the table so that \a (x,y) becomes the top-left pixel
  in the view. Parameters \a (x,y) are in \e table coordinates.

  The interaction with \link setTableFlags() Tbl_snapTo*Grid \endlink
  is tricky.  If \a updateScrBars is 'true', the scroll bars are
  updated.

  \sa xOffset(), yOffset(), setXOffset(), setYOffset(), setTopLeftCell()
*/

void QtTableView::setOffset(int x, int y, bool updateScrBars)
{
    if ((!testTableFlags(Tbl_snapToHGrid) || xCellDelta == 0) && (!testTableFlags(Tbl_snapToVGrid) || yCellDelta == 0) && (x == xOffs && y == yOffs))
        return;

    if (x < 0)
        x = 0;
    if (y < 0)
        y = 0;

    if (cellW) {
        if (x > maxXOffset())
            x = maxXOffset();
        xCellOffs = x / cellW;
        if (!testTableFlags(Tbl_snapToHGrid)) {
            xCellDelta = (short)(x % cellW);
        } else {
            x = xCellOffs * cellW;
            xCellDelta = 0;
        }
    } else {
        int xn = 0, xcd = 0, col = 0;
        while (col < nCols - 1 && x >= xn + (xcd = cellWidth(col))) {
            xn += xcd;
            col++;
        }
        xCellOffs = col;
        if (testTableFlags(Tbl_snapToHGrid)) {
            xCellDelta = 0;
            x = xn;
        } else {
            xCellDelta = (short)(x - xn);
        }
    }
    if (cellH) {
        if (y > maxYOffset())
            y = maxYOffset();
        yCellOffs = y / cellH;
        if (!testTableFlags(Tbl_snapToVGrid)) {
            yCellDelta = (short)(y % cellH);
        } else {
            y = yCellOffs * cellH;
            yCellDelta = 0;
        }
    } else {
        int yn = 0, yrd = 0, row = 0;
        while (row < nRows - 1 && y >= yn + (yrd = cellHeight(row))) {
            yn += yrd;
            row++;
        }
        yCellOffs = row;
        if (testTableFlags(Tbl_snapToVGrid)) {
            yCellDelta = 0;
            y = yn;
        } else {
            yCellDelta = (short)(y - yn);
        }
    }
    int dx = (x - xOffs);
    int dy = (y - yOffs);
    xOffs = x;
    yOffs = y;
    if (autoUpdate() && isVisible())
        scroll(dx, dy);
    if (updateScrBars)
        updateScrollBars(verValue | horValue);
}

/*!
  \overload int QtTableView::cellWidth() const

  Returns the column width in pixels.	Returns 0 if the columns have
  variable widths.

  \sa setCellWidth(), cellHeight()
*/

/*!
  Returns the width of column \a col in pixels.

  This function is virtual and must be reimplemented by subclasses that
  have variable cell widths. Note that if the total table width
  changes, updateTableSize() must be called.

  \sa setCellWidth(), cellHeight(), totalWidth(), updateTableSize()
*/

int QtTableView::cellWidth(int)
{
    return cellW;
}

/*!
  Sets the width in pixels of the table cells to \a cellWidth.

  Setting it to 0 means that the column width is variable.  When
  set to 0 (this is the default) QtTableView calls the virtual function
  cellWidth() to get the width.

  \sa cellWidth(), setCellHeight(), totalWidth(), numCols()
*/

void QtTableView::setCellWidth(int cellWidth)
{
    if (cellW == cellWidth)
        return;
#if defined(QT_CHECK_RANGE)
    if (cellWidth < 0 || cellWidth > SHRT_MAX) {
        qWarning("QtTableView::setCellWidth: (%s) Argument out of range (%d)", name("unnamed"), cellWidth);
        return;
    }
#endif
    cellW = (short)cellWidth;

    updateScrollBars(horSteps | horRange);
    if (autoUpdate() && isVisible())
        repaint();
}

/*!
  \overload int QtTableView::cellHeight() const

  Returns the row height, in pixels.  Returns 0 if the rows have
  variable heights.

  \sa setCellHeight(), cellWidth()
*/

/*!
  Returns the height of row \a row in pixels.

  This function is virtual and must be reimplemented by subclasses that
  have variable cell heights.  Note that if the total table height
  changes, updateTableSize() must be called.

  \sa setCellHeight(), cellWidth(), totalHeight()
*/

int QtTableView::cellHeight(int)
{
    return cellH;
}

/*!
  Sets the height in pixels of the table cells to \a cellHeight.

  Setting it to 0 means that the row height is variable.  When set
  to 0 (this is the default), QtTableView calls the virtual function
  cellHeight() to get the height.

  \sa cellHeight(), setCellWidth(), totalHeight(), numRows()
*/

void QtTableView::setCellHeight(int cellHeight)
{
    if (cellH == cellHeight)
        return;
#if defined(QT_CHECK_RANGE)
    if (cellHeight < 0 || cellHeight > SHRT_MAX) {
        qWarning("QtTableView::setCellHeight: (%s) Argument out of range (%d)", name("unnamed"), cellHeight);
        return;
    }
#endif
    cellH = (short)cellHeight;
    if (autoUpdate() && isVisible())
        repaint();
    updateScrollBars(verSteps | verRange);
}

/*!
  Returns the total width of the table in pixels.

  This function is virtual and should be reimplemented by subclasses that
  have variable cell widths and a non-trivial cellWidth() function, or a
  large number of columns in the table.

  The default implementation may be slow for very wide tables.

  \sa cellWidth(), totalHeight() */

int QtTableView::totalWidth()
{
    if (cellW) {
        return cellW * nCols;
    } else {
        int tw = 0;
        for (int i = 0; i < nCols; i++)
            tw += cellWidth(i);
        return tw;
    }
}

/*!
  Returns the total height of the table in pixels.

  This function is virtual and should be reimplemented by subclasses that
  have variable cell heights and a non-trivial cellHeight() function, or a
  large number of rows in the table.

  The default implementation may be slow for very tall tables.

  \sa cellHeight(), totalWidth()
*/

int QtTableView::totalHeight()
{
    if (cellH) {
        return cellH * nRows;
    } else {
        int th = 0;
        for (int i = 0; i < nRows; i++)
            th += cellHeight(i);
        return th;
    }
}

/*!
  \fn uint QtTableView::tableFlags() const

  Returns the union of the table flags that are currently set.

  \sa setTableFlags(), clearTableFlags(), testTableFlags()
*/

/*!
  \fn bool QtTableView::testTableFlags( uint f ) const

  Returns 'true' if any of the table flags in \a f are currently set,
  otherwise 'false'.

  \sa setTableFlags(), clearTableFlags(), tableFlags()
*/

/*!
  Sets the table flags to \a f.

  If a flag setting changes the appearance of the table, the table is
  repainted if - and only if - autoUpdate() is 'true'.

  The table flags are mostly single bits, though there are some multibit
  flags for convenience. Here is a complete list:

  <dl compact>
  <dt> Tbl_vScrollBar <dd> - The table has a vertical scroll bar.
  <dt> Tbl_hScrollBar <dd> - The table has a horizontal scroll bar.
  <dt> Tbl_autoVScrollBar <dd> - The table has a vertical scroll bar if
  - and only if - the table is taller than the view.
  <dt> Tbl_autoHScrollBar <dd> The table has a horizontal scroll bar if
  - and only if - the table is wider than the view.
  <dt> Tbl_autoScrollBars <dd> - The union of the previous two flags.
  <dt> Tbl_clipCellPainting <dd> - The table uses QPainter::setClipRect() to
  make sure that paintCell() will not draw outside the cell
  boundaries.
  <dt> Tbl_cutCellsV <dd> - The table will never show part of a
  cell at the bottom of the table; if there is not space for all of
  a cell, the space is left blank.
  <dt> Tbl_cutCellsH <dd> - The table will never show part of a
  cell at the right side of the table; if there is not space for all of
  a cell, the space is left blank.
  <dt> Tbl_cutCells <dd> - The union of the previous two flags.
  <dt> Tbl_scrollLastHCell <dd> - When the user scrolls horizontally,
  let him/her scroll the last cell left until it is at the left
  edge of the view.  If this flag is not set, the user can only scroll
  to the point where the last cell is completely visible.
  <dt> Tbl_scrollLastVCell <dd> - When the user scrolls vertically, let
  him/her scroll the last cell up until it is at the top edge of
  the view.  If this flag is not set, the user can only scroll to the
  point where the last cell is completely visible.
  <dt> Tbl_scrollLastCell <dd> - The union of the previous two flags.
  <dt> Tbl_smoothHScrolling <dd> - The table scrolls as smoothly as
  possible when the user scrolls horizontally. When this flag is not
  set, scrolling is done one cell at a time.
  <dt> Tbl_smoothVScrolling <dd> - The table scrolls as smoothly as
  possible when scrolling vertically. When this flag is not set,
  scrolling is done one cell at a time.
  <dt> Tbl_smoothScrolling <dd> - The union of the previous two flags.
  <dt> Tbl_snapToHGrid <dd> - Except when the user is actually scrolling,
  the leftmost column shown snaps to the leftmost edge of the view.
  <dt> Tbl_snapToVGrid <dd> - Except when the user is actually
  scrolling, the top row snaps to the top edge of the view.
  <dt> Tbl_snapToGrid <dd> - The union of the previous two flags.
  </dl>

  You can specify more than one flag at a time using bitwise OR.

  Example:
  \code
    setTableFlags( Tbl_smoothScrolling | Tbl_autoScrollBars );
  \endcode

  \warning The cutCells options (\c Tbl_cutCells, \c Tbl_cutCellsH and
  Tbl_cutCellsV) may cause painting problems when scrollbars are
  enabled. Do not combine cutCells and scrollbars.


  \sa clearTableFlags(), testTableFlags(), tableFlags()
*/

void QtTableView::setTableFlags(uint f)
{
    f = (f ^ tFlags) & f; // clear flags already set
    tFlags |= f;

    bool updateOn = autoUpdate();
    setAutoUpdate(false);

    uint repaintMask = Tbl_cutCellsV | Tbl_cutCellsH;

    if (f & Tbl_vScrollBar) {
        setVerScrollBar(true);
    }
    if (f & Tbl_hScrollBar) {
        setHorScrollBar(true);
    }
    if (f & Tbl_autoVScrollBar) {
        updateScrollBars(verRange);
    }
    if (f & Tbl_autoHScrollBar) {
        updateScrollBars(horRange);
    }
    if (f & Tbl_scrollLastHCell) {
        updateScrollBars(horRange);
    }
    if (f & Tbl_scrollLastVCell) {
        updateScrollBars(verRange);
    }
    if (f & Tbl_snapToHGrid) {
        updateScrollBars(horRange);
    }
    if (f & Tbl_snapToVGrid) {
        updateScrollBars(verRange);
    }
    if (f & Tbl_snapToGrid) { // Note: checks for 2 flags
        if ((f & Tbl_snapToHGrid) != 0 && xCellDelta != 0 || // have to scroll?
            (f & Tbl_snapToVGrid) != 0 && yCellDelta != 0) {
            snapToGrid((f & Tbl_snapToHGrid) != 0, // do snapping
                       (f & Tbl_snapToVGrid) != 0);
            repaintMask |= Tbl_snapToGrid; // repaint table
        }
    }

    if (updateOn) {
        setAutoUpdate(true);
        updateScrollBars();
        if (isVisible() && (f & repaintMask))
            repaint();
    }
}

/*!
  Clears the \link setTableFlags() table flags\endlink that are set
  in \a f.

  Example (clears a single flag):
  \code
    clearTableFlags( Tbl_snapToGrid );
  \endcode

  The default argument clears all flags.

  \sa setTableFlags(), testTableFlags(), tableFlags()
*/

void QtTableView::clearTableFlags(uint f)
{
    f = (f ^ ~tFlags) & f; // clear flags that are already 0
    tFlags &= ~f;

    bool updateOn = autoUpdate();
    setAutoUpdate(false);

    uint repaintMask = Tbl_cutCellsV | Tbl_cutCellsH;

    if (f & Tbl_vScrollBar) {
        setVerScrollBar(false);
    }
    if (f & Tbl_hScrollBar) {
        setHorScrollBar(false);
    }
    if (f & Tbl_scrollLastHCell) {
        int maxX = maxXOffset();
        if (xOffs > maxX) {
            setOffset(maxX, yOffs);
            repaintMask |= Tbl_scrollLastHCell;
        }
        updateScrollBars(horRange);
    }
    if (f & Tbl_scrollLastVCell) {
        int maxY = maxYOffset();
        if (yOffs > maxY) {
            setOffset(xOffs, maxY);
            repaintMask |= Tbl_scrollLastVCell;
        }
        updateScrollBars(verRange);
    }
    if (f & Tbl_smoothScrolling) { // Note: checks for 2 flags
        if ((f & Tbl_smoothHScrolling) != 0 && xCellDelta != 0 || // must scroll?
            (f & Tbl_smoothVScrolling) != 0 && yCellDelta != 0) {
            snapToGrid((f & Tbl_smoothHScrolling) != 0, // do snapping
                       (f & Tbl_smoothVScrolling) != 0);
            repaintMask |= Tbl_smoothScrolling; // repaint table
        }
    }
    if (f & Tbl_snapToHGrid) {
        updateScrollBars(horRange);
    }
    if (f & Tbl_snapToVGrid) {
        updateScrollBars(verRange);
    }
    if (updateOn) {
        setAutoUpdate(true);
        updateScrollBars(); // returns immediately if nothing to do
        if (isVisible() && (f & repaintMask))
            repaint();
    }
}

/*!
  \fn bool QtTableView::autoUpdate() const

  Returns 'true' if the view updates itself automatically whenever it
  is changed in some way.

  \sa setAutoUpdate()
*/

/*!
  Sets the auto-update option of the table view to \a enable.

  If \a enable is 'true' (this is the default), the view updates itself
  automatically whenever it has changed in some way (for example, when a
  \link setTableFlags() flag\endlink is changed).

  If \a enable is 'false', the view does NOT repaint itself or update
  its internal state variables when it is changed.  This can be
  useful to avoid flicker during large changes and is singularly
  useless otherwise. Disable auto-update, do the changes, re-enable
  auto-update and call repaint().

  \warning Do not leave the view in this state for a long time
  (i.e., between events). If, for example, the user interacts with the
  view when auto-update is off, strange things can happen.

  Setting auto-update to 'true' does not repaint the view; you must call
  repaint() to do this.

  \sa autoUpdate(), repaint()
*/

void QtTableView::setAutoUpdate(bool enable)
{
    if (updatesEnabled() == enable)
        return;
    setUpdatesEnabled(enable);
    if (enable) {
        showOrHideScrollBars();
        updateScrollBars();
    }
}

/*!
  Repaints the cell at row \a row, column \a col if it is inside the view.

  If \a erase is 'true', the relevant part of the view is cleared to the
  background color/pixmap before the contents are repainted.

  \sa isVisible()
*/

void QtTableView::updateCell(int row, int col, bool erase)
{
    int xPos, yPos;
    if (!colXPos(col, &xPos))
        return;
    if (!rowYPos(row, &yPos))
        return;
    QRect uR = QRect(xPos, yPos, cellW ? cellW : cellWidth(col), cellH ? cellH : cellHeight(row));
    repaint(uR.intersected(viewRect()), erase);
}

/*!
  \fn QRect QtTableView::cellUpdateRect() const

  This function should be called only from the paintCell() function in
  subclasses. It returns the portion of a cell that actually needs to be
  updated in \e cell coordinates. This is useful only for non-trivial
  paintCell().

*/

/*!
  Returns the rectangle that is the actual table, excluding any
  frame, in \e widget coordinates.
*/

QRect QtTableView::viewRect() const
{
    return {frameWidth(), frameWidth(), viewWidth(), viewHeight()};
}

/*!
  Returns the index of the last (bottom) row in the view.
  The index of the first row is 0.

  If no rows are visible it returns -1.	 This can happen if the
  view is too small for the first row and Tbl_cutCellsV is set.

  \sa lastColVisible()
*/

int QtTableView::lastRowVisible() const
{
    int cellMaxY;
    int row = findRawRow(maxViewY(), &cellMaxY);
    if (row == -1 || row >= nRows) { // maxViewY() past end?
        row = nRows - 1; // yes: return last row
    } else {
        if (testTableFlags(Tbl_cutCellsV) && cellMaxY > maxViewY()) {
            if (row == yCellOffs) // cut by right margin?
                return -1; // yes, nothing in the view
            else
                row = row - 1; // cut by margin, one back
        }
    }
    return row;
}

/*!
  Returns the index of the last (right) column in the view.
  The index of the first column is 0.

  If no columns are visible it returns -1.  This can happen if the
  view is too narrow for the first column and Tbl_cutCellsH is set.

  \sa lastRowVisible()
*/

int QtTableView::lastColVisible() const
{
    int cellMaxX;
    int col = findRawCol(maxViewX(), &cellMaxX);
    if (col == -1 || col >= nCols) { // maxViewX() past end?
        col = nCols - 1; // yes: return last col
    } else {
        if (testTableFlags(Tbl_cutCellsH) && cellMaxX > maxViewX()) {
            if (col == xCellOffs) // cut by bottom margin?
                return -1; // yes, nothing in the view
            else
                col = col - 1; // cell by margin, one back
        }
    }
    return col;
}

/*!
  Returns 'true' if \a row is at least partially visible.
  \sa colIsVisible()
*/

bool QtTableView::rowIsVisible(int row) const
{
    return rowYPos(row, 0);
}

/*!
  Returns 'true' if \a col is at least partially visible.
  \sa rowIsVisible()
*/

bool QtTableView::colIsVisible(int col) const
{
    return colXPos(col, 0);
}

/*!
  \internal
  Called when both scroll bars are active at the same time. Covers the
  bottom left corner between the two scroll bars with an empty widget.
*/

void QtTableView::coverCornerSquare(bool enable)
{
    coveringCornerSquare = enable;
    if (!cornerSquare && enable) {
        cornerSquare = new QCornerSquare(this);
        Q_CHECK_PTR(cornerSquare);
        cornerSquare->setGeometry(maxViewX() + frameWidth() + 1, maxViewY() + frameWidth() + 1, VSBEXT, HSBEXT);
    }
    if (autoUpdate() && cornerSquare) {
        if (enable)
            cornerSquare->show();
        else
            cornerSquare->hide();
    }
}

/*!
  \internal
  Scroll the view to a position such that:

  If \a horizontal is 'true', the leftmost column shown fits snugly
  with the left edge of the view.

  If \a vertical is 'true', the top row shown fits snugly with the top
  of the view.

  You can achieve the same effect automatically by setting any of the
  \link setTableFlags() Tbl_snapTo*Grid \endlink table flags.
*/

void QtTableView::snapToGrid(bool horizontal, bool vertical)
{
    int newXCell = -1;
    int newYCell = -1;
    if (horizontal && xCellDelta != 0) {
        int w = cellW ? cellW : cellWidth(xCellOffs);
        if (xCellDelta >= w / 2)
            newXCell = xCellOffs + 1;
        else
            newXCell = xCellOffs;
    }
    if (vertical && yCellDelta != 0) {
        int h = cellH ? cellH : cellHeight(yCellOffs);
        if (yCellDelta >= h / 2)
            newYCell = yCellOffs + 1;
        else
            newYCell = yCellOffs;
    }
    setTopLeftCell(newYCell, newXCell); // row,column
}

/*!
  \internal
  This internal slot is connected to the horizontal scroll bar's
  QScrollBar::valueChanged() signal.

  Moves the table horizontally to offset \a val without updating the
  scroll bar.
*/

void QtTableView::horSbValue(int val)
{
    if (horSliding) {
        horSliding = false;
        if (horSnappingOff) {
            horSnappingOff = false;
            tFlags |= Tbl_snapToHGrid;
        }
    }
    setOffset(val, yOffs, false);
}

/*!
  \internal
  This internal slot is connected to the horizontal scroll bar's
  QScrollBar::sliderMoved() signal.

  Scrolls the table smoothly horizontally even if \c Tbl_snapToHGrid is set.
*/

void QtTableView::horSbSliding(int val)
{
    if (testTableFlags(Tbl_snapToHGrid) && testTableFlags(Tbl_smoothHScrolling)) {
        tFlags &= ~Tbl_snapToHGrid; // turn off snapping while sliding
        setOffset(val, yOffs, false);
        tFlags |= Tbl_snapToHGrid; // turn on snapping again
    } else {
        setOffset(val, yOffs, false);
    }
}

/*!
  \internal
  This internal slot is connected to the horizontal scroll bar's
  QScrollBar::sliderReleased() signal.
*/

void QtTableView::horSbSlidingDone()
{
    if (testTableFlags(Tbl_snapToHGrid) && testTableFlags(Tbl_smoothHScrolling))
        snapToGrid(true, false);
}

/*!
  \internal
  This internal slot is connected to the vertical scroll bar's
  QScrollBar::valueChanged() signal.

  Moves the table vertically to offset \a val without updating the
  scroll bar.
*/

void QtTableView::verSbValue(int val)
{
    if (verSliding) {
        verSliding = false;
        if (verSnappingOff) {
            verSnappingOff = false;
            tFlags |= Tbl_snapToVGrid;
        }
    }
    setOffset(xOffs, val, false);
}

/*!
  \internal
  This internal slot is connected to the vertical scroll bar's
  QScrollBar::sliderMoved() signal.

  Scrolls the table smoothly vertically even if \c Tbl_snapToVGrid is set.
*/

void QtTableView::verSbSliding(int val)
{
    if (testTableFlags(Tbl_snapToVGrid) && testTableFlags(Tbl_smoothVScrolling)) {
        tFlags &= ~Tbl_snapToVGrid; // turn off snapping while sliding
        setOffset(xOffs, val, false);
        tFlags |= Tbl_snapToVGrid; // turn on snapping again
    } else {
        setOffset(xOffs, val, false);
    }
}

/*!
  \internal
  This internal slot is connected to the vertical scroll bar's
  QScrollBar::sliderReleased() signal.
*/

void QtTableView::verSbSlidingDone()
{
    if (testTableFlags(Tbl_snapToVGrid) && testTableFlags(Tbl_smoothVScrolling))
        snapToGrid(false, true);
}

/*!
  This virtual function is called before painting of table cells
  is started. It can be reimplemented by subclasses that want to
  to set up the painter in a special way and that do not want to
  do so for each cell.
*/

void QtTableView::setupPainter(QPainter *)
{
}

/*!
  \fn void QtTableView::paintCell( QPainter *p, int row, int col )

  This pure virtual function is called to paint the single cell at \a
  (row,col) using \a p, which is open when paintCell() is called and
  must remain open.

  The coordinate system is \link QPainter::translate() translated \endlink
  so that the origin is at the top-left corner of the cell to be
  painted, i.e. \e cell coordinates.  Do not scale or shear the coordinate
  system (or if you do, restore the transformation matrix before you
  return).

  The painter is not clipped by default and for maximum efficiency. For safety,
  call setTableFlags(Tbl_clipCellPainting) to enable clipping.

  \sa paintEvent(), setTableFlags() */

/*!
  Handles paint events, \a e, for the table view.

  Calls paintCell() for the cells that needs to be repainted.
*/

void QtTableView::paintEvent(QPaintEvent *e)
{
    QRect updateR = e->rect(); // update rectangle
    if (sbDirty) {
        bool e = eraseInPaint;
        updateScrollBars();
        eraseInPaint = e;
    }

    QPainter paint(this);

    if (!contentsRect().contains(updateR, true)) { // update frame ?
        drawFrame(&paint);
        if (updateR.left() < frameWidth()) //###
            updateR.setLeft(frameWidth());
        if (updateR.top() < frameWidth())
            updateR.setTop(frameWidth());
    }

    int maxWX = maxViewX();
    int maxWY = maxViewY();
    if (updateR.right() > maxWX)
        updateR.setRight(maxWX);
    if (updateR.bottom() > maxWY)
        updateR.setBottom(maxWY);

    setupPainter(&paint); // prepare for painting table

    int firstRow = findRow(updateR.y());
    int firstCol = findCol(updateR.x());
    int xStart, yStart;
    if (!colXPos(firstCol, &xStart) || !rowYPos(firstRow, &yStart)) {
        paint.eraseRect(updateR); // erase area outside cells but in view
        return;
    }
    int maxX = updateR.right();
    int maxY = updateR.bottom();
    int row = firstRow;
    int col;
    int yPos = yStart;
    int xPos = maxX + 1; // in case the while() is empty
    int nextX;
    int nextY;
    QRect winR = viewRect();
    QRect cellR;
    QRect cellUR;
#ifndef QT_NO_TRANSFORMATIONS
    QTransform matrix;
#endif

    while (yPos <= maxY && row < nRows) {
        nextY = yPos + (cellH ? cellH : cellHeight(row));
        if (testTableFlags(Tbl_cutCellsV) && nextY > (maxWY + 1))
            break;
        col = firstCol;
        xPos = xStart;
        while (xPos <= maxX && col < nCols) {
            nextX = xPos + (cellW ? cellW : cellWidth(col));
            if (testTableFlags(Tbl_cutCellsH) && nextX > (maxWX + 1))
                break;

            cellR.setRect(xPos, yPos, cellW ? cellW : cellWidth(col), cellH ? cellH : cellHeight(row));
            cellUR = cellR.intersected(updateR);
            if (cellUR.isValid()) {
                cellUpdateR = cellUR;
                cellUpdateR.translate(-xPos, -yPos); // cell coordinates
                if (eraseInPaint)
                    paint.eraseRect(cellUR);

#ifndef QT_NO_TRANSFORMATIONS
                matrix.translate(xPos, yPos);
                paint.setTransform(matrix);
                if (testTableFlags(Tbl_clipCellPainting) || frameWidth() > 0 && !winR.contains(cellR)) { //##arnt
#ifdef __GNUC__
#warning disable clipping for now as it interferes with drawText() in DiffView::paintCell()
#endif
                    // 		    paint.setClipRect( cellUpdateR );
                    paintCell(&paint, row, col);
                    // 		    paint.setClipping( false );
                } else {
                    paintCell(&paint, row, col);
                }
                matrix.reset();
                paint.setTransform(matrix);
#else
                paint.translate(xPos, yPos);
                if (testTableFlags(Tbl_clipCellPainting) || frameWidth() > 0 && !winR.contains(cellR)) { //##arnt
                    paint.setClipRect(cellUpdateR);
                    paintCell(&paint, row, col);
                    paint.setClipping(false);
                } else {
                    paintCell(&paint, row, col);
                }
                paint.translate(-xPos, -yPos);
#endif
            }
            col++;
            xPos = nextX;
        }
        row++;
        yPos = nextY;
    }

    // while painting we have to erase any areas in the view that
    // are not covered by cells but are covered by the paint event
    // rectangle these must be erased. We know that xPos is the last
    // x pixel updated + 1 and that yPos is the last y pixel updated + 1.

    // Note that this needs to be done regardless whether we do
    // eraseInPaint or not. Reason: a subclass may implement
    // flicker-freeness and encourage the use of repaint(false).
    // The subclass, however, cannot draw all pixels, just those
    // inside the cells. So QtTableView is responsible for all pixels
    // outside the cells.

    QRect viewR = viewRect();
    QPalette g = palette();

    if (xPos <= maxX) {
        QRect r = viewR;
        r.setLeft(xPos);
        r.setBottom(yPos < maxY ? yPos : maxY);
        if (inherits("QMultiLineEdit"))
            paint.fillRect(r.intersected(updateR), g.base());
        else
            paint.eraseRect(r.intersected(updateR));
    }
    if (yPos <= maxY) {
        QRect r = viewR;
        r.setTop(yPos);
        if (inherits("QMultiLineEdit"))
            paint.fillRect(r.intersected(updateR), g.base());
        else
            paint.eraseRect(r.intersected(updateR));
    }
}

/*!\reimp
 */
void QtTableView::resizeEvent(QResizeEvent *)
{
    updateScrollBars(horValue | verValue | horSteps | horGeometry | horRange | verSteps | verGeometry | verRange);
    showOrHideScrollBars();
    updateFrameSize();
    int maxX = qMin(xOffs, maxXOffset()); // ### can be slow
    int maxY = qMin(yOffs, maxYOffset());
    setOffset(maxX, maxY);
}

void QtTableView::showEvent(QShowEvent *e)
{
    showOrHideScrollBars();
    QFrame::showEvent(e);
}

void QtTableView::wheelEvent(QWheelEvent *e)
{
    if (e->orientation() == Qt::Vertical && vScrollBar && vScrollBar->isVisible())
        QApplication::sendEvent(vScrollBar, e);
}

/*!
  Redraws all visible cells in the table view.
*/

void QtTableView::updateView()
{
    repaint(viewRect());
}

/*!
  Returns a pointer to the vertical scroll bar mainly so you can
  connect() to its signals.  Note that the scroll bar works in pixel
  values; use findRow() to translate to cell numbers.
*/

QScrollBar *QtTableView::verticalScrollBar() const
{
    auto that = (QtTableView *)this; // semantic const
    if (!vScrollBar) {
        auto sb = new QScrollBar(Qt::Vertical, that);
        sb->setAttribute(Qt::WA_NoMousePropagation);
        sb->setAutoFillBackground(true);
#ifndef QT_NO_CURSOR
        sb->setCursor(Qt::ArrowCursor);
#endif
        sb->resize(sb->sizeHint()); // height is irrelevant
        Q_CHECK_PTR(sb);
        sb->setTracking(false);
        sb->setFocusPolicy(Qt::NoFocus);
        connect(sb, SIGNAL(valueChanged(int)), SLOT(verSbValue(int)));
        connect(sb, SIGNAL(sliderMoved(int)), SLOT(verSbSliding(int)));
        connect(sb, SIGNAL(sliderReleased()), SLOT(verSbSlidingDone()));
        sb->hide();
        that->vScrollBar = sb;
        return sb;
    }
    return vScrollBar;
}

/*!
  Returns a pointer to the horizontal scroll bar mainly so you can
  connect() to its signals. Note that the scroll bar works in pixel
  values; use findCol() to translate to cell numbers.
*/

QScrollBar *QtTableView::horizontalScrollBar() const
{
    auto that = (QtTableView *)this; // semantic const
    if (!hScrollBar) {
        auto sb = new QScrollBar(Qt::Horizontal, that);
        sb->setAutoFillBackground(true);
#ifndef QT_NO_CURSOR
        sb->setCursor(Qt::ArrowCursor);
#endif
        sb->resize(sb->sizeHint()); // width is irrelevant
        sb->setFocusPolicy(Qt::NoFocus);
        Q_CHECK_PTR(sb);
        sb->setTracking(false);
        connect(sb, SIGNAL(valueChanged(int)), SLOT(horSbValue(int)));
        connect(sb, SIGNAL(sliderMoved(int)), SLOT(horSbSliding(int)));
        connect(sb, SIGNAL(sliderReleased()), SLOT(horSbSlidingDone()));
        sb->hide();
        that->hScrollBar = sb;
        return sb;
    }
    return hScrollBar;
}

/*!
  Enables or disables the horizontal scroll bar, as required by
  setAutoUpdate() and the \link setTableFlags() table flags\endlink.
*/

void QtTableView::setHorScrollBar(bool on, bool update)
{
    if (on) {
        tFlags |= Tbl_hScrollBar;
        horizontalScrollBar(); // created
        if (update)
            updateScrollBars(horMask | verMask);
        else
            sbDirty = sbDirty | (horMask | verMask);
        if (testTableFlags(Tbl_vScrollBar))
            coverCornerSquare(true);
        if (autoUpdate())
            sbDirty = sbDirty | horMask;
    } else {
        tFlags &= ~Tbl_hScrollBar;
        if (!hScrollBar)
            return;
        coverCornerSquare(false);
        bool hideScrollBar = autoUpdate() && hScrollBar->isVisible();
        if (hideScrollBar)
            hScrollBar->hide();
        if (update)
            updateScrollBars(verMask);
        else
            sbDirty = sbDirty | verMask;
        if (hideScrollBar && isVisible())
            repaint(hScrollBar->x(), hScrollBar->y(), width() - hScrollBar->x(), hScrollBar->height());
    }
    if (update)
        updateFrameSize();
}

/*!
  Enables or disables the vertical scroll bar, as required by
  setAutoUpdate() and the \link setTableFlags() table flags\endlink.
*/

void QtTableView::setVerScrollBar(bool on, bool update)
{
    if (on) {
        tFlags |= Tbl_vScrollBar;
        verticalScrollBar(); // created
        if (update)
            updateScrollBars(verMask | horMask);
        else
            sbDirty = sbDirty | (horMask | verMask);
        if (testTableFlags(Tbl_hScrollBar))
            coverCornerSquare(true);
        if (autoUpdate())
            sbDirty = sbDirty | verMask;
    } else {
        tFlags &= ~Tbl_vScrollBar;
        if (!vScrollBar)
            return;
        coverCornerSquare(false);
        bool hideScrollBar = autoUpdate() && vScrollBar->isVisible();
        if (hideScrollBar)
            vScrollBar->hide();
        if (update)
            updateScrollBars(horMask);
        else
            sbDirty = sbDirty | horMask;
        if (hideScrollBar && isVisible())
            repaint(vScrollBar->x(), vScrollBar->y(), vScrollBar->width(), height() - vScrollBar->y());
    }
    if (update)
        updateFrameSize();
}

int QtTableView::findRawRow(int yPos, int *cellMaxY, int *cellMinY, bool goOutsideView) const
{
    int r = -1;
    if (nRows == 0)
        return r;
    if (goOutsideView || yPos >= minViewY() && yPos <= maxViewY()) {
        if (yPos < minViewY()) {
#if defined(QT_CHECK_RANGE)
            qWarning(
                "QtTableView::findRawRow: (%s) internal error: "
                "yPos < minViewY() && goOutsideView "
                "not supported. (%d,%d)",
                name("unnamed"),
                yPos,
                yOffs);
#endif
            return -1;
        }
        if (cellH) { // uniform cell height
            r = (yPos - minViewY() + yCellDelta) / cellH; // cell offs from top
            if (cellMaxY)
                *cellMaxY = (r + 1) * cellH + minViewY() - yCellDelta - 1;
            if (cellMinY)
                *cellMinY = r * cellH + minViewY() - yCellDelta;
            r += yCellOffs; // absolute cell index
        } else { // variable cell height
            auto tw = (QtTableView *)this;
            r = yCellOffs;
            int h = minViewY() - yCellDelta; //##arnt3
            int oldH = h;
            Q_ASSERT(r < nRows);
            while (r < nRows) {
                oldH = h;
                h += tw->cellHeight(r); // Start of next cell
                if (yPos < h)
                    break;
                r++;
            }
            if (cellMaxY)
                *cellMaxY = h - 1;
            if (cellMinY)
                *cellMinY = oldH;
        }
    }
    return r;
}

int QtTableView::findRawCol(int xPos, int *cellMaxX, int *cellMinX, bool goOutsideView) const
{
    int c = -1;
    if (nCols == 0)
        return c;
    if (goOutsideView || xPos >= minViewX() && xPos <= maxViewX()) {
        if (xPos < minViewX()) {
#if defined(QT_CHECK_RANGE)
            qWarning(
                "QtTableView::findRawCol: (%s) internal error: "
                "xPos < minViewX() && goOutsideView "
                "not supported. (%d,%d)",
                name("unnamed"),
                xPos,
                xOffs);
#endif
            return -1;
        }
        if (cellW) { // uniform cell width
            c = (xPos - minViewX() + xCellDelta) / cellW; // cell offs from left
            if (cellMaxX)
                *cellMaxX = (c + 1) * cellW + minViewX() - xCellDelta - 1;
            if (cellMinX)
                *cellMinX = c * cellW + minViewX() - xCellDelta;
            c += xCellOffs; // absolute cell index
        } else { // variable cell width
            auto tw = (QtTableView *)this;
            c = xCellOffs;
            int w = minViewX() - xCellDelta; //##arnt3
            int oldW = w;
            Q_ASSERT(c < nCols);
            while (c < nCols) {
                oldW = w;
                w += tw->cellWidth(c); // Start of next cell
                if (xPos < w)
                    break;
                c++;
            }
            if (cellMaxX)
                *cellMaxX = w - 1;
            if (cellMinX)
                *cellMinX = oldW;
        }
    }
    return c;
}

/*!
  Returns the index of the row at position \a yPos, where \a yPos is in
  \e widget coordinates.  Returns -1 if \a yPos is outside the valid
  range.

  \sa findCol(), rowYPos()
*/

int QtTableView::findRow(int yPos) const
{
    int cellMaxY;
    int row = findRawRow(yPos, &cellMaxY);
    if (testTableFlags(Tbl_cutCellsV) && cellMaxY > maxViewY())
        row = -1; //  cell cut by bottom margin
    if (row >= nRows)
        row = -1;
    return row;
}

/*!
  Returns the index of the column at position \a xPos, where \a xPos is
  in \e widget coordinates.  Returns -1 if \a xPos is outside the valid
  range.

  \sa findRow(), colXPos()
*/

int QtTableView::findCol(int xPos) const
{
    int cellMaxX;
    int col = findRawCol(xPos, &cellMaxX);
    if (testTableFlags(Tbl_cutCellsH) && cellMaxX > maxViewX())
        col = -1; //  cell cut by right margin
    if (col >= nCols)
        col = -1;
    return col;
}

/*!
  Computes the position in the widget of row \a row.

  Returns 'true' and stores the result in \a *yPos (in \e widget
  coordinates) if the row is visible.  Returns 'false' and does not modify
  \a *yPos if \a row is invisible or invalid.

  \sa colXPos(), findRow()
*/

bool QtTableView::rowYPos(int row, int *yPos) const
{
    int y;
    if (row >= yCellOffs) {
        if (cellH) {
            int lastVisible = lastRowVisible();
            if (row > lastVisible || lastVisible == -1)
                return false;
            y = (row - yCellOffs) * cellH + minViewY() - yCellDelta;
        } else {
            //##arnt3
            y = minViewY() - yCellDelta; // y of leftmost cell in view
            int r = yCellOffs;
            auto tw = (QtTableView *)this;
            int maxY = maxViewY();
            while (r < row && y <= maxY)
                y += tw->cellHeight(r++);
            if (y > maxY)
                return false;
        }
    } else {
        return false;
    }
    if (yPos)
        *yPos = y;
    return true;
}

/*!
  Computes the position in the widget of column \a col.

  Returns 'true' and stores the result in \a *xPos (in \e widget
  coordinates) if the column is visible.  Returns 'false' and does not
  modify \a *xPos if \a col is invisible or invalid.

  \sa rowYPos(), findCol()
*/

bool QtTableView::colXPos(int col, int *xPos) const
{
    int x;
    if (col >= xCellOffs) {
        if (cellW) {
            int lastVisible = lastColVisible();
            if (col > lastVisible || lastVisible == -1)
                return false;
            x = (col - xCellOffs) * cellW + minViewX() - xCellDelta;
        } else {
            //##arnt3
            x = minViewX() - xCellDelta; // x of uppermost cell in view
            int c = xCellOffs;
            auto tw = (QtTableView *)this;
            int maxX = maxViewX();
            while (c < col && x <= maxX)
                x += tw->cellWidth(c++);
            if (x > maxX)
                return false;
        }
    } else {
        return false;
    }
    if (xPos)
        *xPos = x;
    return true;
}

/*!
  Moves the visible area of the table right by \a xPixels and
  down by \a yPixels pixels.  Both may be negative.

  \warning You might find that QScrollView offers a higher-level of
    functionality than using QtTableView and this function.

  This function is \e not the same as QWidget::scroll(); in particular,
  the signs of \a xPixels and \a yPixels have the reverse semantics.

  \sa setXOffset(), setYOffset(), setOffset(), setTopCell(),
  setLeftCell()
*/

void QtTableView::scroll(int xPixels, int yPixels)
{
    QWidget::scroll(-xPixels, -yPixels, contentsRect());
}

/*!
  Returns the leftmost pixel of the table view in \e view
  coordinates.	This excludes the frame and any header.

  \sa maxViewY(), viewWidth(), contentsRect()
*/

int QtTableView::minViewX() const
{
    return frameWidth();
}

/*!
  Returns the top pixel of the table view in \e view
  coordinates.	This excludes the frame and any header.

  \sa maxViewX(), viewHeight(), contentsRect()
*/

int QtTableView::minViewY() const
{
    return frameWidth();
}

/*!
  Returns the rightmost pixel of the table view in \e view
  coordinates.	This excludes the frame and any scroll bar, but
  includes blank pixels to the right of the visible table data.

  \sa maxViewY(), viewWidth(), contentsRect()
*/

int QtTableView::maxViewX() const
{
    return width() - 1 - frameWidth() - (tFlags & Tbl_vScrollBar ? VSBEXT : 0);
}

/*!
  Returns the bottom pixel of the table view in \e view
  coordinates.	This excludes the frame and any scroll bar, but
  includes blank pixels below the visible table data.

  \sa maxViewX(), viewHeight(), contentsRect()
*/

int QtTableView::maxViewY() const
{
    return height() - 1 - frameWidth() - (tFlags & Tbl_hScrollBar ? HSBEXT : 0);
}

/*!
  Returns the width of the table view, as such, in \e view
  coordinates.  This does not include any header, scroll bar or frame,
  but it does include background pixels to the right of the table data.

  \sa minViewX() maxViewX(), viewHeight(), contentsRect() viewRect()
*/

int QtTableView::viewWidth() const
{
    return maxViewX() - minViewX() + 1;
}

/*!
  Returns the height of the table view, as such, in \e view
  coordinates.  This does not include any header, scroll bar or frame,
  but it does include background pixels below the table data.

  \sa minViewY() maxViewY() viewWidth() contentsRect() viewRect()
*/

int QtTableView::viewHeight() const
{
    return maxViewY() - minViewY() + 1;
}

void QtTableView::doAutoScrollBars()
{
    int viewW = width() - frameWidth() - minViewX();
    int viewH = height() - frameWidth() - minViewY();
    bool vScrollOn = testTableFlags(Tbl_vScrollBar);
    bool hScrollOn = testTableFlags(Tbl_hScrollBar);
    int w = 0;
    int h = 0;
    int i;

    if (testTableFlags(Tbl_autoHScrollBar)) {
        if (cellW) {
            w = cellW * nCols;
        } else {
            i = 0;
            while (i < nCols && w <= viewW)
                w += cellWidth(i++);
        }
        if (w > viewW)
            hScrollOn = true;
        else
            hScrollOn = false;
    }

    if (testTableFlags(Tbl_autoVScrollBar)) {
        if (cellH) {
            h = cellH * nRows;
        } else {
            i = 0;
            while (i < nRows && h <= viewH)
                h += cellHeight(i++);
        }

        if (h > viewH)
            vScrollOn = true;
        else
            vScrollOn = false;
    }

    if (testTableFlags(Tbl_autoHScrollBar) && vScrollOn && !hScrollOn)
        if (w > viewW - VSBEXT)
            hScrollOn = true;

    if (testTableFlags(Tbl_autoVScrollBar) && hScrollOn && !vScrollOn)
        if (h > viewH - HSBEXT)
            vScrollOn = true;

    setHorScrollBar(hScrollOn, false);
    setVerScrollBar(vScrollOn, false);
    updateFrameSize();
}

/*!
  \fn void QtTableView::updateScrollBars()

  Updates the scroll bars' contents and presence to match the table's
  state.  Generally, you should not need to call this.

  \sa setTableFlags()
*/

/*!
  Updates the scroll bars' contents and presence to match the table's
  state \c or \a f.

  \sa setTableFlags()
*/

void QtTableView::updateScrollBars(uint f)
{
    sbDirty = sbDirty | f;
    if (inSbUpdate)
        return;
    inSbUpdate = true;

    if (testTableFlags(Tbl_autoHScrollBar) && (sbDirty & horRange) || testTableFlags(Tbl_autoVScrollBar) && (sbDirty & verRange))
        // if range change and auto
        doAutoScrollBars(); // turn scroll bars on/off if needed

    if (!autoUpdate()) {
        inSbUpdate = false;
        return;
    }
    if (yOffset() > 0 && testTableFlags(Tbl_autoVScrollBar) && !testTableFlags(Tbl_vScrollBar)) {
        setYOffset(0);
    }
    if (xOffset() > 0 && testTableFlags(Tbl_autoHScrollBar) && !testTableFlags(Tbl_hScrollBar)) {
        setXOffset(0);
    }
    if (!isVisible()) {
        inSbUpdate = false;
        return;
    }

    if (testTableFlags(Tbl_hScrollBar) && (sbDirty & horMask) != 0) {
        if (sbDirty & horGeometry)
            hScrollBar->setGeometry(0, height() - HSBEXT, viewWidth() + frameWidth() * 2, HSBEXT);

        if (sbDirty & horSteps) {
            if (cellW)
                hScrollBar->setSingleStep(qMin((int)cellW, viewWidth() / 2));
            else
                hScrollBar->setSingleStep(16);

            hScrollBar->setPageStep(viewWidth());
        }

        if (sbDirty & horRange)
            hScrollBar->setRange(0, maxXOffset());

        if (sbDirty & horValue)
            hScrollBar->setValue(xOffs);

        // show scrollbar only when it has a sane geometry
        if (!hScrollBar->isVisible())
            hScrollBar->show();
    }

    if (testTableFlags(Tbl_vScrollBar) && (sbDirty & verMask) != 0) {
        if (sbDirty & verGeometry)
            vScrollBar->setGeometry(width() - VSBEXT, 0, VSBEXT, viewHeight() + frameWidth() * 2);

        if (sbDirty & verSteps) {
            if (cellH)
                vScrollBar->setSingleStep(qMin((int)cellH, viewHeight() / 2));
            else
                vScrollBar->setSingleStep(16); // fttb! ###

            vScrollBar->setPageStep(viewHeight());
        }

        if (sbDirty & verRange)
            vScrollBar->setRange(0, maxYOffset());

        if (sbDirty & verValue)
            vScrollBar->setValue(yOffs);

        // show scrollbar only when it has a sane geometry
        if (!vScrollBar->isVisible())
            vScrollBar->show();
    }
    if (coveringCornerSquare && ((sbDirty & verGeometry) || (sbDirty & horGeometry)))
        cornerSquare->move(maxViewX() + frameWidth() + 1, maxViewY() + frameWidth() + 1);

    sbDirty = 0;
    inSbUpdate = false;
}

void QtTableView::updateFrameSize()
{
    int rw = width() - (testTableFlags(Tbl_vScrollBar) ? VSBEXT : 0);
    int rh = height() - (testTableFlags(Tbl_hScrollBar) ? HSBEXT : 0);
    if (rw < 0)
        rw = 0;
    if (rh < 0)
        rh = 0;

    if (autoUpdate()) {
        int fh = frameRect().height();
        int fw = frameRect().width();
        setFrameRect(QRect(0, 0, rw, rh));

        if (rw != fw)
            update(qMin(fw, rw) - frameWidth() - 2, 0, frameWidth() + 4, rh);
        if (rh != fh)
            update(0, qMin(fh, rh) - frameWidth() - 2, rw, frameWidth() + 4);
    }
}

/*!
  Returns the maximum horizontal offset within the table of the
  view's left edge in \e table coordinates.

  This is used mainly to set the horizontal scroll bar's range.

  \sa maxColOffset(), maxYOffset(), totalWidth()
*/

int QtTableView::maxXOffset()
{
    int tw = totalWidth();
    int maxOffs;
    if (testTableFlags(Tbl_scrollLastHCell)) {
        if (nCols != 1)
            maxOffs = tw - (cellW ? cellW : cellWidth(nCols - 1));
        else
            maxOffs = tw - viewWidth();
    } else {
        if (testTableFlags(Tbl_snapToHGrid)) {
            if (cellW) {
                maxOffs = tw - (viewWidth() / cellW) * cellW;
            } else {
                int goal = tw - viewWidth();
                int pos = tw;
                int nextCol = nCols - 1;
                int nextCellWidth = cellWidth(nextCol);
                while (nextCol > 0 && pos > goal + nextCellWidth) {
                    pos -= nextCellWidth;
                    nextCellWidth = cellWidth(--nextCol);
                }
                if (goal + nextCellWidth == pos)
                    maxOffs = goal;
                else if (goal < pos)
                    maxOffs = pos;
                else
                    maxOffs = 0;
            }
        } else {
            maxOffs = tw - viewWidth();
        }
    }
    return maxOffs > 0 ? maxOffs : 0;
}

/*!
  Returns the maximum vertical offset within the table of the
  view's top edge in \e table coordinates.

  This is used mainly to set the vertical scroll bar's range.

  \sa maxRowOffset(), maxXOffset(), totalHeight()
*/

int QtTableView::maxYOffset()
{
    int th = totalHeight();
    int maxOffs;
    if (testTableFlags(Tbl_scrollLastVCell)) {
        if (nRows != 1)
            maxOffs = th - (cellH ? cellH : cellHeight(nRows - 1));
        else
            maxOffs = th - viewHeight();
    } else {
        if (testTableFlags(Tbl_snapToVGrid)) {
            if (cellH) {
                maxOffs = th - (viewHeight() / cellH) * cellH;
            } else {
                int goal = th - viewHeight();
                int pos = th;
                int nextRow = nRows - 1;
                int nextCellHeight = cellHeight(nextRow);
                while (nextRow > 0 && pos > goal + nextCellHeight) {
                    pos -= nextCellHeight;
                    nextCellHeight = cellHeight(--nextRow);
                }
                if (goal + nextCellHeight == pos)
                    maxOffs = goal;
                else if (goal < pos)
                    maxOffs = pos;
                else
                    maxOffs = 0;
            }
        } else {
            maxOffs = th - viewHeight();
        }
    }
    return maxOffs > 0 ? maxOffs : 0;
}

/*!
  Returns the index of the last column, which may be at the left edge
  of the view.

  Depending on the \link setTableFlags() Tbl_scrollLastHCell\endlink flag,
  this may or may not be the last column.

  \sa maxXOffset(), maxRowOffset()
*/

int QtTableView::maxColOffset()
{
    int mx = maxXOffset();
    if (cellW)
        return mx / cellW;
    else {
        int xcd = 0, col = 0;
        while (col < nCols && mx > (xcd = cellWidth(col))) {
            mx -= xcd;
            col++;
        }
        return col;
    }
}

/*!
  Returns the index of the last row, which may be at the top edge of
  the view.

  Depending on the \link setTableFlags() Tbl_scrollLastVCell\endlink flag,
  this may or may not be the last row.

  \sa maxYOffset(), maxColOffset()
*/

int QtTableView::maxRowOffset()
{
    int my = maxYOffset();
    if (cellH)
        return my / cellH;
    else {
        int ycd = 0, row = 0;
        while (row < nRows && my > (ycd = cellHeight(row))) {
            my -= ycd;
            row++;
        }
        return row;
    }
}

void QtTableView::showOrHideScrollBars()
{
    if (!autoUpdate())
        return;
    if (vScrollBar) {
        if (testTableFlags(Tbl_vScrollBar)) {
            if (!vScrollBar->isVisible())
                sbDirty = sbDirty | verMask;
        } else {
            if (vScrollBar->isVisible())
                vScrollBar->hide();
        }
    }
    if (hScrollBar) {
        if (testTableFlags(Tbl_hScrollBar)) {
            if (!hScrollBar->isVisible())
                sbDirty = sbDirty | horMask;
        } else {
            if (hScrollBar->isVisible())
                hScrollBar->hide();
        }
    }
    if (cornerSquare) {
        if (testTableFlags(Tbl_hScrollBar) && testTableFlags(Tbl_vScrollBar)) {
            if (!cornerSquare->isVisible())
                cornerSquare->show();
        } else {
            if (cornerSquare->isVisible())
                cornerSquare->hide();
        }
    }
}

/*!
  Updates the scroll bars and internal state.

  Call this function when the table view's total size is changed;
  typically because the result of cellHeight() or cellWidth() have changed.

  This function does not repaint the widget.
*/

void QtTableView::updateTableSize()
{
    bool updateOn = autoUpdate();
    setAutoUpdate(false);
    int xofs = xOffset();
    xOffs++; // so that setOffset will not return immediately
    setOffset(xofs, yOffset(), false); // to calculate internal state correctly
    setAutoUpdate(updateOn);

    updateScrollBars(horSteps | horRange | verSteps | verRange);
    showOrHideScrollBars();
}