Speed ups for navigating Microsoft Excel spreadsheets, especially for…

… those containing comments / dropdowns (#9257)

* Initial stub for excel_getCellTextWidth in nvdaHelper

* Implement all of getCellTextWidth in-process and call it from the Excel cell NVDAObject.

* Excel: move all states calculation in-process.

* Excel: fetch text, address, states, input title, input message, row/column coordinates and outline level all via one in-process call.

* Excel: fix up handling of merged cells.

* Excel: no need to call cell.currentRegion in fetchAssociatedHeaderCells. It just slows things down and the variable was never used!

* Excel inProc: getCellInfo now uses a struct, rather than everything as separate arguments. Will be easier once eventually fetching multiple cells at once.

* Excel: If NvDA cannot inject in-process, such as when in Protected  View, fall back to fetching some very basic info for cells, such as address and text.

* Excel: move the fetching of comments and formulas for Elements list in-process.

* Excel: remove an unneeded method.

* Excel nvdaHelper: move constants into their own file.

* nvdaHelper: make use of InterfaceMarshaller in outlook.cpp.

* Excel: mark ExcelCellInfoQuicknavIterator as an abstract class requiring QuicknavItemClass and collectionFromWorksheet to be implemented.

* Excel: address review comments.

* Address review comments.

* Address review comments.

* Excel nvdaHelper support: check more errors and remove a redundant fetch of range.address.

* Excel nvdaHelper:: Excel's range.item is 1-based not 0-based. Listing formulas was 1 cell off.

* Excel NVDAHelper: fetching all cells from a filtered range must use IEnumVariant, not range.item otherwise cells in the gaps will also be fetched.

* Update what's new.

nvdaHelper/common/COMUtils.h

@@ -0,0 +1,54 @@
+#include <comdef.h>
+#include <common/log.h>
+
+namespace nvCOMUtils {
+
+class InterfaceMarshaller {
+	private:
+	DWORD cookie {(DWORD)(-1)};
+	IGlobalInterfaceTablePtr pGIT {nullptr};
+
+	public:
+	InterfaceMarshaller() {};
+
+	template<typename t> HRESULT marshal(t* p) {
+		if(cookie!=-1) {
+			LOG_ERROR(L"An interface is already marshalled");
+			return E_FAIL;
+		}
+		HRESULT res=pGIT.CreateInstance(CLSID_StdGlobalInterfaceTable);
+		if(res!=S_OK) {
+			LOG_ERROR(L"Could not create global interface table");
+			return res;
+		}
+		res=pGIT->RegisterInterfaceInGlobal(p,__uuidof(t),&cookie);
+		if(res!=S_OK) {
+			LOG_ERROR(L"Could not register object in global interface table");
+			return res;
+		}
+		return S_OK;
+	}
+
+	template<typename t> t* unmarshal() {
+		if(cookie==-1) {
+			LOG_ERROR(L"Nothing has been marshalled");
+			return nullptr;
+		}
+		t* p=nullptr;
+		HRESULT res=pGIT->GetInterfaceFromGlobal(cookie,__uuidof(t),reinterpret_cast<void**>(&p));
+		if(res!=S_OK) {
+			LOG_ERROR(L"Could not unmarshal object, code "<<res);
+			return nullptr;
+		}
+		return p;
+	}
+
+	~InterfaceMarshaller() {
+		if(cookie!=-1) {
+			pGIT->RevokeInterfaceFromGlobal(cookie);
+		}
+	}
+
+};
+
+};

nvdaHelper/interfaces/nvdaInProcUtils/nvdaInProcUtils.acf

@@ -24,4 +24,6 @@ interface NvdaInProcUtils {
 	[fault_status,comm_status] dumpOnCrash();
 	[fault_status,comm_status] IA2Text_findContentDescendant();
 	[fault_status,comm_status] outlook_getMAPIProp();
+
+	[fault_status,comm_status] excel_getCellInfos();
 }

nvdaHelper/interfaces/nvdaInProcUtils/nvdaInProcUtils.idl

@@ -29,6 +29,21 @@ cpp_quote("*/")
 import "wtypes.idl";
 import "oaidl.idl";
 
+typedef struct {
+	BSTR text;
+	BSTR address;
+	BSTR inputTitle;
+	BSTR inputMessage;
+	hyper states;
+	long rowNumber;
+	long rowSpan;
+	long columnNumber;
+	long columnSpan;
+	long outlineLevel;
+	BSTR comments;
+	BSTR formula;
+} EXCEL_CELLINFO;
+
 /**
  * Useful utlity methods that can be executed in-process from NVDA
  */
@@ -68,4 +83,6 @@ interface NvdaInProcUtils {
  */
  	error_status_t outlook_getMAPIProp(const long threadID, [in] IUnknown* mapiObject, const unsigned long mapiPropTag, [out] VARIANT* val);
 
+	error_status_t excel_getCellInfos([in] const unsigned long windowHandle,[in] IDispatch* rangeObj, [in] long cellInfoFlags, [in] long cellCount, [out,size_is(cellCount)] EXCEL_CELLINFO* cellInfos, [out] long* numCellsFetched);
+
 }

nvdaHelper/local/nvdaHelperLocal.def

@@ -16,6 +16,7 @@ EXPORTS
 	nvdaInProcUtils_winword_getTextInRange
 	nvdaInProcUtils_winword_moveByLine
 	nvdaInProcUtils_outlook_getMAPIProp
+	nvdaInProcUtils_excel_getCellInfos
 	VBuf_createBuffer
 	VBuf_destroyBuffer
 	VBuf_findNodeByAttributes