Help with PXCp_ET_GetElement in VB6

[HJBrown]

Below is a snippet of VB6 code to test PXCp_ET_GetElement. The code succeeds in returning GetElementCount but fails on the GetElement line. The error translates into "invalid argument". I have used a value of "1" for the index in the GetElement method assuming that this would get the character with that index. Clearly, I am doing something wrong. Your help would be much appreciated.

Public Function GetPageText(nDoc as long, nPage As Long) As String
Dim res As Long
Dim TextElement As PXP_TextElement
Dim TextElementsCount As Long

res = PXCp_ET_Prepare(nDoc)
res = PXCp_ET_AnalyzePageContent(nDoc, nPage)
res = PXCp_ET_GetElementCount(nDoc, TextElementsCount)
res = PXCp_ET_GetElement(nDoc, 1, TextElement, 0)

End Function

[Lzcat - Tracker Supp]

Hi.
You should read documentation before using SDK As I can see you did not fill cbSize element in PXP_TextElement structure.
Below is fully working sample how to deal with text elements (C++, not VB6, but I hope you will be able to do translation, or at least see corrects call sequence and function parameters).

Code: Select all

	// Example shows how to extract all text from the document
	// and save it to another document retaining formating
	
	void ExtractTextToOtherPDFDocument(PDFDocument hDoc, LPCWSTR OtherPDFFileName)
	{
		HRESULT hr = DS_OK;
		
		// Preparsing document
		
		hr = PXCp_ET_Prepare(hDoc);
		if (IS_DS_FAILED(hr))
		{
			// report error
			...
		}
				
		DWORD	fontCount = 0;
		DWORD*	fontIDs = NULL;
		PXCDocument hDstDoc = NULL;
		
		do 
		{
			// 1. Get all fonts from the doc
			hr = PXCp_ET_GetFontCount(hDoc, &fontCount);
			if (IS_DS_FAILED(hr))
				break;
			// 2. Create new doc
			hr = PXC_NewDocument(&hDstDoc, NULL, NULL);
			if(IS_DS_FAILED(hr))
				break;
			fontIDs = new DWORD[fontCount];
			::ZeroMemory(fontIDs, fontCount * sizeof(DWORD));
			
			// buffer for font name + font style
			LPWSTR	fontName = NULL;
			DWORD	curFontNameLen = 0;
			
			for (DWORD i = 0; i < fontCount; i++)
			{
				DWORD bufLen = 0;
				// get font name length
				// if it is equal to 1 then there is no font name
				// "1" is null-terminator in this case
				hr = PXCp_ET_GetFontName(hDoc, i, NULL, &bufLen);
				if (IS_DS_FAILED(hr))
					break;
				// Check if the font have any name set
				BOOL bNoFontNameSet = bufLen <= 1;
				// if there is no font name default 'Arial' will be used
				static LPCWSTR DefaultFontName = L"Arial";
				if (bNoFontNameSet)
					bufLen = 6; // ::lstrlenW(DefaultFontName)
				// Get the length of font style
				DWORD StyleLen = 0;
				hr = PXCp_ET_GetFontStyle(hDoc, i, NULL, &StyleLen);
				// Check if there is font style sºõ
				if (StyleLen <= 1)
					StyleLen = 0;
				if (IS_DS_SUCCESSFUL(hr) && StyleLen)
				{
					// if there is font style set - then adjust the buffer length
					bufLen += StyleLen;
				}
				// Check for necessary buffer
				if (bufLen > curFontNameLen)
				{
					if (fontName)
						delete[] fontName;
					fontName = new WCHAR[bufLen];
					curFontNameLen = bufLen;
				}
				if (bNoFontNameSet)
				{
					// if there is no file name - copy default name
					::lstrcpy(fontName, DefaultFontName);
				}
				else
				{
					// else aquire font name from the library
					DWORD tempBufLen = bufLen;
					hr = PXCp_ET_GetFontName(hDoc, i, fontName, &tempBufLen);
					if (IS_DS_FAILED(hr))
						break;
				}
				if (StyleLen)
				{
					// if there is font style set - aquire it
					hr = PXCp_ET_GetFontStyle(hDoc, i, fontName + (bufLen - StyleLen) - 1, &StyleLen);
				}
				// add the font into library
				hr = PXC_AddFontW(hDstDoc, FW_NORMAL, FALSE, fontName, fontIDs + i);
				if (IS_DS_FAILED(hr))
					break;
			}
			// clean unnecessary buffer
			if (fontName)
			{
				delete[] fontName;
				fontName = NULL;
			}
			if (IS_DS_FAILED(hr))
			{
				break;
			}
			DWORD PageCnt = 0;
			hr = PXCp_GetPagesCount(hDoc, &PageCnt);
			if (IS_DS_FAILED(hr) || !PageCnt)
				break;
			// 3. for each page
			for (DWORD CurPage = 0; CurPage < PageCnt; CurPage++)
			{
				// create new page in the new document
				PXC_RectF rcMediaBox;
				PXC_RectF rcCropBox;
				LONG nAngle;

				hr = PXCp_PageGetBox(hDoc, CurPage, PB_MediaBox, &rcMediaBox);
				if(IS_DS_FAILED(hr))
					break;
				// add to the new page
				PXCPage hDstPage = NULL;
				hr = PXC_AddPage(hDstDoc, rcMediaBox.right - rcMediaBox.left, rcMediaBox.top - rcMediaBox.bottom, &hDstPage);
				if(IS_DS_FAILED(hr))
					break;

				hr = PXCp_PageGetBox(hDoc, CurPage, PB_CropBox, &rcCropBox);
				if(IS_DS_SUCCESSFUL(hr))
				{
					hr = PXC_SetPageBox(hDstPage, PB_CropBox, &rcCropBox);
				}
				hr = PXCp_PageGetRotate(hDoc, CurPage, &nAngle);
				if(IS_DS_SUCCESSFUL(hr) && nAngle)
				{
					hr = PXC_SetPageRotation(hDstPage, nAngle);
				}
				PXC_TextOptions pto = { sizeof(PXC_TextOptions) };
				PXC_GetTextOptions(hDstPage, &pto);
				pto.nTextPosition = TextPosition_Baseline;
				PXC_SetTextOptions(hDstPage, &pto);
				//	for each element
				hr = PXCp_ET_AnalyzePageContent(hDoc, CurPage);
				if(IS_DS_FAILED(hr))
					break;

				DWORD TextElCount = 0;
				hr = PXCp_ET_GetElementCount(hDoc, &TextElCount);
				if(IS_DS_FAILED(hr) || TextElCount == 0)
					continue;

				PXP_TextElement TextElement = {0};
				TextElement.cbSize = sizeof(PXP_TextElement);
				DWORD CurCount = 0;

				PXC_PointF ptTextOrg = {0};
				WCHAR buf[2];
				buf[0] = buf[1] = 0;

				for (DWORD t = 0; t < TextElCount; t++)
				{
					TextElement.Count = 0;
					TextElement.mask = 0;
					hr = PXCp_ET_GetElement(hDoc, t, &TextElement, 0);
					if(IS_DS_FAILED(hr) || (LONG)TextElement.Count <= 0)
						continue;
					TextElement.mask = PTEM_Text | PTEM_Offsets | PTEM_Matrix |	PTEM_FontInfo | PTEM_TextParams;
					if (CurCount < TextElement.Count)
					{
						if (TextElement.Characters != NULL)
							delete TextElement.Characters;
						if (TextElement.Offsets != NULL)
							delete TextElement.Offsets;
						TextElement.Characters = new WCHAR[TextElement.Count];
						TextElement.Offsets = new double[TextElement.Count];
						CurCount = TextElement.Count;
					}
					hr = PXCp_ET_GetElement(hDoc, t, &TextElement, GTEF_IgnorePageRotation);
					if (IS_DS_FAILED(hr))
						continue;
					// Now add this text element into new PDF document
					hr = PXC_TCS_Transform(hDstPage, &TextElement.Matrix);

					if (fontCount <= TextElement.FontIndex)
						continue;

					hr = PXC_SetCurrentFont(hDstPage, fontIDs[TextElement.FontIndex], TextElement.FontSize);
									hr = PXC_SetFillColor(hDstPage, TextElement.FillColor);
					hr = PXC_SetStrokeColor(hDstPage, TextElement.StrokeColor);
					hr = PXC_SetTextRMode(hDstPage, TextElement.RenderingMode, NULL);
					hr = PXC_SetTextScaling(hDstPage, TextElement.Th, NULL);
					hr = PXC_SetTextLeading(hDstPage, TextElement.Leading, NULL);
					hr = PXC_SetCharSpacing(hDstPage, TextElement.CharSpace, NULL);
					hr = PXC_SetWordSpacing(hDstPage, TextElement.WordSpace, NULL);
					
					for(DWORD j = 0; j < TextElement.Count - 1; j++)
					{
						ptTextOrg.x = TextElement.Offsets[j];
						buf[0] = TextElement.Characters[j];
						hr = PXC_TextOutW(hDstPage, &ptTextOrg, buf, 1);
					}
				}
				if (TextElement.Characters != NULL)
					delete TextElement.Characters;
				if (TextElement.Offsets != NULL)
					delete TextElement.Offsets;
			}
			if (IS_DS_FAILED(hr))
				break;
		
			hr = PXC_WriteDocumentExW(hDstDoc, OtherPDFFileName, -1, WEF_ShowSaveDialog | WEF_RunApp, NULL);
			
		} while(FALSE);

		// clear up
		if (hDstDoc)
		{
			PXC_ReleaseDocument(hDstDoc);
			hDstDoc = NULL;
		}
		if (fontIDs)
		{
			delete[] fontIDs;
			fontIDs = NULL;
		}
		PXCp_ET_Finish(hDoc);
	}

[HJBrown]

Actually I read the entire SDK on this subject but I do not know how to translate the line:

TextElement.cbSize = sizeof(PXP_TextElement);

to VB6 and you do not provide any examples. Also, there is very little support on the internet.

[Lzcat - Tracker Supp]

The sizeof is C++ operator to calculate the size of a structure, class or any other type.

As I remember VB6 has no similar operator, but you can calculate the size manually (sizeof(PXP_TextElement) = 4 + 4 + 4 + 4 + 4 + 4 + 8 + 6*8 + 8 + 8 + 8 + 8 + 8 + 4 + 4 + 4 = 132 bytes).

HTH