void QtTableView::paintEvent()

in win/Qt/qttableview.cpp [1273:1408]

• 114 lines of code
• 33 McCabe index (conditional complexity)

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
    QWMatrix 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.intersect( updateR );
	    if ( cellUR.isValid() ) {
		cellUpdateR = cellUR;
		cellUpdateR.moveBy( -xPos, -yPos ); // cell coordinates
		if ( eraseInPaint )
		    paint.eraseRect( cellUR );

#ifndef QT_NO_TRANSFORMATIONS
		matrix.translate( xPos, yPos );
		paint.setWorldMatrix( matrix );
		if ( testTableFlags(Tbl_clipCellPainting) ||
		     frameWidth() > 0 && !winR.contains( cellR ) ) { //##arnt
		    paint.setClipRect( cellUR );
		    paintCell( &paint, row, col );
		    paint.setClipping( FALSE );
		} else {
		    paintCell( &paint, row, col );
		}
		matrix.reset();
		paint.setWorldMatrix( matrix );
#else
		paint.translate( xPos, yPos );
		if ( testTableFlags(Tbl_clipCellPainting) ||
		     frameWidth() > 0 && !winR.contains( cellR ) ) { //##arnt
		    paint.setClipRect( cellUR );
		    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 reponsible for all pixels
    // outside the cells.

    QRect viewR = viewRect();
    const QColorGroup g = colorGroup();

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