/// <summary>
/// Scrolls the image to make sure that the box is visible
/// </summary>
/// <param name="v">Annotate viewer</param>
/// <param name="imageBox">The box to make sure is visible</param>
private void EnsureAreaIsVisible(AnnotateViewer v, RectangleF imageBox)
{
Point sp = v.ScrollPosition;
int x = GetAdjustedScrollPos(sp.X, imageBox.Left, imageBox.Right, v.ClientSize.Width, v.Zoom);
int y = GetAdjustedScrollPos(sp.Y, imageBox.Top, imageBox.Bottom, v.ClientSize.Height, v.Zoom);
v.ScrollPosition = new Point(x, y);
}
/// <summary>
/// Puts a highlight rectangle over the box which is expressed in PDF coordinate space
/// </summary>
/// <param name="p">A PDF Text page</param>
/// <param name="v">The viewer to put the annotation on</param>
/// <param name="layer">The layer to put the annotation on</param>
/// <param name="pdfBox">The box to highlight in PDF coordinate space</param>
/// <param name="hiColor">The color to highlight with</param>
/// <param name="padding">Extra padding around the box in pixels</param>
private void HighlightPdfBox(PdfTextPage p, AnnotateViewer v, LayerAnnotation layer, RectangleF pdfBox, Color hiColor, int padding)
{
RectangleF imageBox = p.ConvertPdfUnitsToPixels(new QuadrilateralF(pdfBox), v.Image.Resolution).Bounds;
imageBox.X = imageBox.X - padding;
imageBox.Y = imageBox.Y - padding;
imageBox.Width = imageBox.Width + 2 * padding;
imageBox.Height = imageBox.Height + 2 * padding;
HighlightImageBox(v, layer, imageBox, hiColor);
}
/// <summary>
/// Puts an annotation over the characters in a PDF page
/// </summary>
/// <param name="v">Annotate viewer</param>
/// <param name="p">A PDF Text page</param>
/// <param name="hiColor">The highlight color</param>
/// <param name="index">The index of the first character within the page</param>
/// <param name="len">The number of characters to highlight</param>
private void HighlightChars(AnnotateViewer v, PdfTextPage p, Color hiColor, int index, int len)
{
// take off all existing hilights
LayerAnnotation layer = v.Annotations.CurrentLayer;
layer.Items.Clear();
// a single phrase can span a line and need more than one box to
// highlight it
QuadrilateralF[] pdfBoxes = p.GetBoxes(index, len);
foreach (QuadrilateralF b in pdfBoxes)
{
HighlightPdfBox(p, v, layer, b.Bounds, hiColor, 2);
}
}
/// <summary>
/// A class to highlight pdf documents that are in an annotation viewer and have a thumbnail viewer
/// </summary>
/// <param name="viewer">An annotation viewer with one layer for putting highlights on</param>
/// <param name="thumbnailViewer">An optional thumbnail viewer (can be null)</param>
public PdfFindHighlighter(AnnotateViewer viewer, ThumbnailView thumbnailViewer)
{
_viewer = viewer;
_thumbnailViewer = thumbnailViewer;
}
/// <summary>
/// Puts a highlight rectangle over the box which is expressed in the image's coordinate space
/// </summary>
/// <param name="layer">The layer to put the annotation on</param>
/// <param name="imageBox">The box to highlight in Image coordinate space</param>
/// <param name="hiColor">The color to highlight with</param>
private void HighlightImageBox(AnnotateViewer v, LayerAnnotation layer, RectangleF imageBox, Color hiColor)
{
CreateHighlightAnnotation(layer, imageBox, hiColor);
EnsureAreaIsVisible(v, imageBox);
}
