| public GetFirstElementForStream ( IVwLayoutStream stream ) : SIL.FieldWorks.Common.PrintLayout.PageElement | ||
| stream | IVwLayoutStream | The stream |
| return | SIL.FieldWorks.Common.PrintLayout.PageElement | |
/// -------------------------------------------------------------------------------------
/// <summary>
/// Inserts additonal pages if needed at dydPosition to approximately match the new
/// estimated height when a lazy box has been expanded.
/// </summary>
/// <param name="changedSizePage">The last page whose top doesn't move (i.e., the one the
/// lazy box is actually on). We may need to insert pages just after this.</param>
/// <param name="strm">The IVwLayoutStream interface of the rootbox that is the main
/// stream on at least some of the pages of this publication (i.e., this publication
/// should be the IVwRootsite of the given rootbox).</param>
/// <param name="dydSize">The amount the rootbox grew, in printer pixels. This is
/// guaranteed to be positive.</param>
/// <param name="dydPosition">The top of the lazy box which was (partially) expanded,
/// split, etc (in printer pixels). Or the position of the top of the real box that got
/// relazified.
/// </param>
/// <returns>true if there are not enough pages for the AutoScrollPosition to increase as
/// much as required.</returns>
/// -------------------------------------------------------------------------------------
private bool InsertAdditionalPages(Page changedSizePage, IVwLayoutStream strm,
int dydSize, int dydPosition)
{
Debug.Assert(changedSizePage != null);
Debug.Assert(dydSize > 0);
Page nextPage = PageAfter(changedSizePage);
int heightOfChangedPage; // Current height, to next page or estimated end of doc.
int iDiv = DivisionIndexForMainStream(strm);
DivisionLayoutMgr divMgr = Divisions[iDiv];
if (nextPage == null)
{
heightOfChangedPage = dydSize;
// An empty page may have nothing from the main stream - can happen when project is
// empty or filter excludes all content
PageElement pe = changedSizePage.GetFirstElementForStream(strm);
if (pe != null)
heightOfChangedPage -= pe.OffsetToTopPageBoundary;
}
else
{
heightOfChangedPage = nextPage.OffsetFromTopOfDiv(divMgr) -
changedSizePage.OffsetFromTopOfDiv(divMgr);
}
int desiredPageHeight = divMgr.AvailablePageHeightInPrinterPixels;
// This computes the number of pages to add, if any, so that
// if the tops of the pages are more than a page and a half apart we
// insert enough pages so no page is more than an ideal page and a half long.
// Subtracting half the desired page height accounts both for rounding and
// the fact that one page (rather than zero) is the desired page height.
int numberOfPagesToAdd = (heightOfChangedPage - desiredPageHeight / 2) /
desiredPageHeight;
// Pathologically, it might be possible for that calculation to produce
// a negative number, if this page has shrunk to less than a half page from
// previous lazy box expansions.
if (numberOfPagesToAdd < 0)
numberOfPagesToAdd = 0;
Page pageToInsertAfter = changedSizePage;
for (int i = 0; i < numberOfPagesToAdd; i++)
{
// Insert a new page.
pageToInsertAfter = InsertPage(iDiv,
pageToInsertAfter.OffsetFromTopOfDiv(divMgr) + desiredPageHeight,
pageToInsertAfter);
}
// If we're increasing the autoscroll position, do it AFTER we possibly adjust
// the autoscroll range, otherwise, the increased value might be greater than
// the old range and get truncated.
// Remember: Microsoft's idea of how to set AutoScrollPosition is brain-dead. We read
// it as negative and have to set it as positive.
int dydPosScreen = (int)(dydPosition * DpiYScreen / DpiYPrinter);
if (-AutoScrollPosition.Y > dydPosScreen)
{
int dydDesiredAutoScrollY = (int)(AutoScrollPosition.Y - (dydSize * DpiYScreen /
DpiYPrinter)); // larger negative
AutoScrollPosition = new Point(
-AutoScrollPosition.X, -dydDesiredAutoScrollY);
// Something messy happened if we can't achieve that position (presumably
// it is out of range, we didn't add enough pages).
return (AutoScrollPosition.Y != dydDesiredAutoScrollY);
}
return false; // We get here only if we didn't have to adjust scroll position at all.
}
// /// ------------------------------------------------------------------------------------
// /// <summary>
// /// Determine the gap between the columns.
// /// </summary>
// /// <param name="numberColumns">The total number of columns.</param>
// /// <returns>
// /// If the element spans the whole width of the page, the column gap is 0.
// /// Otherwise, it is ColumnGapWidthInPrinterPixels;
// /// </returns>
// /// ------------------------------------------------------------------------------------
// private int ColumnGap(int numberColumns)
// {
// return (numberColumns > 1) ? ColumnGapWidthInPrinterPixels : 0;
// }
/// ------------------------------------------------------------------------------------
/// <summary>
/// Adds or adjusts the page element. Note that this is used ONLY for dependent objects,
/// it arranges them from the bottom up. These elements don't overlap, so no overlap is
/// passed.
/// </summary>
/// <param name="page">The page.</param>
/// <param name="ysTopOfPrevElement">The top of the previous element.</param>
/// <param name="ysStreamHeight">Height of the stream.</param>
/// <param name="stream">The stream.</param>
/// <param name="pagePosition">The page position.</param>
/// <returns></returns>
/// ------------------------------------------------------------------------------------
private int AddOrAdjustPageElement(Page page, int ysTopOfPrevElement, int ysStreamHeight,
IVwLayoutStream stream, int pagePosition)
{
Debug.Assert(!page.IsDisposed);
if (ysStreamHeight <= 0)
return ysTopOfPrevElement;
int ysTopOfThisElement = ysTopOfPrevElement - ysStreamHeight;
Rectangle rectLocationOnPage = new Rectangle(LeftMarginInPrinterPixels(page),
ysTopOfThisElement,
AvailablePageWidthInPrinterPixels,
ysStreamHeight);
PageElement element = page.GetFirstElementForStream(stream);
if (element == null)
{
// Create page element
page.AddPageElement(this, stream, false, rectLocationOnPage,
pagePosition, false, 1, 1, 0,
ysStreamHeight, 0, MainStreamIsRightToLeft, false);
}
else
{
// Increase size of page element
if (element.LocationOnPage.Height != ysStreamHeight)
{
// Increase size of/move location
page.AdjustPageElement(element, rectLocationOnPage, false);
}
}
return ysTopOfThisElement;
}
