HTML and Image rendering fixes

Author: tomas-sexenian

dotnet/src/dotnetcore/GxPdfReportsCS/PDFReportItext7.cs

@@ -22,6 +22,7 @@
 using iText.Layout.Borders;
 using iText.Layout.Element;
 using iText.Layout.Font;
+using iText.Layout.Layout;
 using iText.Layout.Properties;
 using log4net;
 using NetTopologySuite.Utilities;
@@ -407,6 +408,7 @@ void GxDrawRect(int left, int top, int right, int bottom, int pen, Color foreCol
 		public override void GxDrawLine(int left, int top, int right, int bottom, int width, int foreRed, int foreGreen, int foreBlue, int style)
 		{
 			PdfCanvas cb = new PdfCanvas(pdfPage);
+
 			Color foreColor = new DeviceRgb(foreRed, foreGreen, foreBlue);
 
 			float widthAux = (float)convertScale(width);
@@ -447,6 +449,7 @@ public override void GxDrawLine(int left, int top, int right, int bottom, int wi
 		}
 		public override void GxDrawBitMap(String bitmap, int left, int top, int right, int bottom, int aspectRatio)
 		{
+
 			try
 			{
 				Image image;
@@ -497,7 +500,7 @@ public override void GxDrawBitMap(String bitmap, int left, int top, int right, i
 					float bottomAux = (float)convertScale(bottom);
 					float leftAux = (float)convertScale(left);
 					float topAux = (float)convertScale(top);
-					image.SetFixedPosition(leftAux + leftMargin, this.pageSize.GetTop() - bottomAux - topMargin - bottomMargin);
+					image.SetFixedPosition(this.getPage(),leftAux + leftMargin, this.pageSize.GetTop() - bottomAux - topMargin - bottomMargin);
 					if (aspectRatio == 0)
 						image.ScaleAbsolute(rightAux - leftAux, bottomAux - topAux);
 					else
@@ -769,26 +772,30 @@ public override void GxDrawText(String sTxt, int left, int top, int right, int b
 				bottomAux = (float)convertScale(bottom);
 				topAux = (float)convertScale(top);
 
-
-				Canvas cb = new Canvas(canvas, new Rectangle(leftAux + leftMargin, this.pageSize.GetTop() - bottomAux - topMargin - bottomMargin, rightAux - leftAux, bottomAux - topAux));
+				Rectangle htmlRectangle = new Rectangle(leftAux + leftMargin, this.pageSize.GetTop() - bottomAux - topMargin - bottomMargin, rightAux - leftAux, bottomAux - topAux);
+				Canvas cb = new Canvas(canvas, htmlRectangle);
 				TextAlignment colAlignment = (TextAlignment)GetTextAlignment(alignment);
 				cb.SetTextAlignment(colAlignment);
 
 				try
 				{
-					IList<IElement> objects = HtmlConverter.ConvertToElements(sTxt, properties);
+					bottomAux = (float)convertScale(bottom);
+					topAux = (float)convertScale(top);
+					float drawingPageHeight = this.pageSize.GetTop() - topMargin - bottomMargin;
 
-					foreach (IElement element in objects)
-					{
-						Paragraph p = element as Paragraph;
-						if (p != null)
-						{
-							if (alignment != 0)
-								p.SetTextAlignment(colAlignment);
-						}
-
-						cb.Add((IBlockElement)element);
-					}
+					float llx = leftAux + leftMargin;
+					float lly = drawingPageHeight - bottomAux;
+					float urx = rightAux + leftMargin;
+					float ury = drawingPageHeight - topAux;
+				
+					YPosition yPosition = new YPosition(htmlRectangle.GetTop());
+
+					ConverterProperties converterProperties = new ConverterProperties();
+					converterProperties.SetFontProvider(document.GetFontProvider());
+					//Iterate over the elements (a.k.a the parsed HTML string) and handle each case accordingly
+					IList<IElement> elements = HtmlConverter.ConvertToElements(sTxt, properties);
+					foreach (IElement element in elements)
+						processHTMLElement(cb, colAlignment, htmlRectangle, yPosition, (IBlockElement)element);
 				}
 				catch (Exception ex1)
 				{
@@ -974,6 +981,94 @@ public override void GxDrawText(String sTxt, int left, int top, int right, int b
 
 		}
 
+		private void processHTMLElement(Canvas cb, TextAlignment colAlignment, Rectangle htmlRectangle, YPosition currentYPosition, IBlockElement blockElement)
+		{
+			Div div = blockElement as Div;
+			if (div != null) {
+				// Iterate through the children of the Div and process each child element recursively
+				foreach (IElement child in div.GetChildren())
+					if (child is IBlockElement)
+						processHTMLElement(cb, colAlignment, htmlRectangle, currentYPosition, (IBlockElement)child);
+					
+			}
+
+			float blockElementHeight = getBlockElementHeight(blockElement, htmlRectangle);
+			float availableSpace = currentYPosition.CurrentYPosition - htmlRectangle.GetBottom();
+			if (blockElementHeight > availableSpace)
+			{
+				GXLogging.Error(log, "You are trying to render an element of height " + blockElementHeight + " in a space of height " + availableSpace);
+				return;
+			}
+
+			Link anchor = blockElement as Link;
+			if (anchor != null)
+			{
+				anchor.SetFixedPosition(this.getPage(), htmlRectangle.GetX(), currentYPosition.CurrentYPosition - blockElementHeight, htmlRectangle.GetWidth());
+				document.Add((IBlockElement) anchor);
+				currentYPosition.CurrentYPosition = currentYPosition.CurrentYPosition - blockElementHeight;
+				return;
+			}
+
+			Paragraph p = blockElement as Paragraph;
+			if (p != null)
+			{
+				p.SetFixedPosition(this.getPage(), htmlRectangle.GetX(), currentYPosition.CurrentYPosition - blockElementHeight, htmlRectangle.GetWidth());
+				document.Add(p);
+				currentYPosition.CurrentYPosition = currentYPosition.CurrentYPosition - blockElementHeight;
+				return;
+			}
+
+			Table table = blockElement as Table;
+			if (table != null)
+			{
+				table.SetFixedPosition(this.getPage(), htmlRectangle.GetX(), currentYPosition.CurrentYPosition - blockElementHeight, htmlRectangle.GetWidth());
+				table.SetTextAlignment(colAlignment);
+				cb.Add(table);
+				currentYPosition.CurrentYPosition = currentYPosition.CurrentYPosition - blockElementHeight;
+				return;
+			}
+
+			List list = blockElement as List;
+			if (list != null)
+			{
+				// This is a hack for the specific case of rendering a list as cb.Add(list) fails to add numeration to each element but document.Add(list) fails to
+				// consider the numeration of each element as part of it. Solution is to use document.Add(list) and move the list to the right.
+				float numWidth = new Paragraph("1. ").CreateRendererSubTree().SetParent(document.GetRenderer()).Layout(new LayoutContext(new LayoutArea(this.getPage(), htmlRectangle))).GetOccupiedArea().GetBBox().GetHeight();
+				list.SetFixedPosition(this.getPage(), htmlRectangle.GetX() + numWidth, currentYPosition.CurrentYPosition - blockElementHeight, htmlRectangle.GetWidth());
+
+				list.SetTextAlignment(colAlignment);
+				document.Add(list);
+				currentYPosition.CurrentYPosition = currentYPosition.CurrentYPosition - blockElementHeight;
+				return;
+			}
+
+			Image image = blockElement as Image;
+			if (image != null)
+			{
+				image.SetFixedPosition(this.getPage(), htmlRectangle.GetX(), currentYPosition.CurrentYPosition - blockElementHeight, htmlRectangle.GetWidth());
+				image.SetTextAlignment(colAlignment);
+				document.Add(image);
+				currentYPosition.CurrentYPosition = currentYPosition.CurrentYPosition - blockElementHeight;
+				return;
+			}
+
+		}
+
+		private float getBlockElementHeight(IBlockElement blockElement, Rectangle htmlRectangle)
+		{
+			return blockElement.CreateRendererSubTree().SetParent(document.GetRenderer()).Layout(new LayoutContext(new LayoutArea(this.getPage(), htmlRectangle))).GetOccupiedArea().GetBBox().GetHeight();
+		}
+
+		private class YPosition
+		{
+			public YPosition(float initialYPosition)
+			{
+				CurrentYPosition = initialYPosition;
+			}
+
+			public float CurrentYPosition { get; set; }
+		}
+
 		private BaseDirection? GetBaseDirection(int runDirection)
 		{
 			switch (runDirection)