[New] Interface methods: GetCacheSize, GetData, GetDataMode, ModifyDa…

…ta. HEXMODIFY struct.

[Changes] GetData<>, SetData<> templated methods generalized and moved from CHexCtrl.h to Helper.h.
It's now GetIHexTData, SetIHexTData.
All remaining internal circular dependencies are finally resolved and removed.
[Fixes] As a consequence of above changes the old-standing bug is fixed with an inability to Undo after
DataInterpreter changes applying.

HexCtrl/HexCtrl.h

@@ -54,9 +54,12 @@ namespace HEXCTRL
 		virtual bool CreateDialogCtrl(UINT uCtrlID, HWND hParent) = 0; //Сreates custom dialog control.
 		virtual void Destroy() = 0;                             //Deleter.
 		virtual void ExecuteCmd(EHexCmd enCmd) = 0;                          //Execute a command within the control.
+		[[nodiscard]] virtual auto GetCacheSize()const->DWORD = 0;           //Returns Virtual/Message mode cache size.
 		[[nodiscard]] virtual DWORD GetCapacity()const = 0;                  //Current capacity.
 		[[nodiscard]] virtual ULONGLONG GetCaretPos()const = 0;              //Cursor position.
 		[[nodiscard]] virtual auto GetColors()const->HEXCOLORSSTRUCT = 0;    //Current colors.
+		[[nodiscard]] virtual auto GetData(HEXSPANSTRUCT hss)const->std::byte* = 0; //Get pointer to data offset, no matter what mode the control works in.
+		[[nodiscard]] virtual auto GetDataMode()const->EHexDataMode = 0;     //Get current Data mode.
 		[[nodiscard]] virtual auto GetDataSize()const->ULONGLONG = 0;        //Get currently set data size.
 		[[nodiscard]] virtual int GetEncoding()const = 0;                    //Get current code page ID.
 		[[nodiscard]] virtual long GetFontSize()const = 0;                   //Current font size.
@@ -75,6 +78,7 @@ namespace HEXCTRL
 		[[nodiscard]] virtual bool IsMutable()const = 0;       //Is edit mode enabled or not.
 		[[nodiscard]] virtual bool IsOffsetAsHex()const = 0;   //Is "Offset" currently represented (shown) as Hex or as Decimal.
 		[[nodiscard]] virtual HEXVISSTRUCT IsOffsetVisible(ULONGLONG ullOffset)const = 0; //Ensures that the given offset is visible.
+		virtual void ModifyData(const HEXMODIFY& hms) = 0;     //Main routine to modify data in IsMutable()==true mode.
 		virtual void Redraw() = 0;                             //Redraw the control's window.
 		virtual void SetCapacity(DWORD dwCapacity) = 0;        //Set the control's current capacity.
 		virtual void SetCaretPos(ULONGLONG ullOffset, bool fHighLow = true, bool fRedraw = true) = 0; //Set the caret position.

HexCtrl/HexCtrlDefs.h

@@ -229,4 +229,44 @@ namespace HEXCTRL
 		std::int8_t i8Horz { }; //Horizontal offset.
 		operator bool()const { return i8Vert == 0 && i8Horz == 0; }; //For test simplicity: if(IsOffsetVisible()).
 	};
+
+	/********************************************************************************************
+	* EHexModifyMode - Enum of the data modification mode, used in HEXMODIFY.                   *
+	********************************************************************************************/
+	enum class EHexModifyMode : WORD
+	{
+		MODIFY_DEFAULT, MODIFY_REPEAT, MODIFY_OPERATION
+	};
+
+	/********************************************************************************************
+	* EHexOperMode - Enum of the data operation mode, used in HEXMODIFY when                    *
+	* HEXMODIFY::enModifyMode is set to MODIFY_OPERATION.                                       *
+	********************************************************************************************/
+	enum class EHexOperMode : WORD
+	{
+		OPER_OR = 0x01, OPER_XOR, OPER_AND, OPER_NOT, OPER_SHL, OPER_SHR,
+		OPER_ADD, OPER_SUBTRACT, OPER_MULTIPLY, OPER_DIVIDE
+	};
+
+	/********************************************************************************************
+	* HEXMODIFY - used to represent data modification parameters.                               *
+	* When enModifyMode is set to EHexModifyMode::MODIFY_DEFAULT, bytes from pData just replace *
+	* corresponding data bytes as is. If enModifyMode is equal to EHexModifyMode::MODIFY_REPEAT *
+	* then block by block replacement takes place few times.                                    *
+	*   For example : if SUM(vecSpan.ullSize) = 9, ullDataSize = 3 and enModifyMode is set to   *
+	* EHexModifyMode::MODIFY_REPEAT, bytes in memory at vecSpan.ullOffset position are          *
+	* 123456789, and bytes pointed to by pData are 345, then, after modification, bytes at      *
+	* vecSpan.ullOffset will be 345345345. If enModifyMode is equal to                          *
+	* EHexModifyMode::MODIFY_OPERATION then enOperMode comes into play, showing what kind of    *
+	* operation must be performed on data.                                                      *
+	********************************************************************************************/
+	struct HEXMODIFY
+	{
+		EHexModifyMode enModifyMode { EHexModifyMode::MODIFY_DEFAULT }; //Modify mode.
+		EHexOperMode   enOperMode { };          //Operation mode, used only if enModifyMode == MODIFY_OPERATION.
+		std::byte*  pData { };                  //Pointer to a data to be set.
+		ULONGLONG   ullDataSize { };            //Size of the data pData is pointing to.
+		std::vector<HEXSPANSTRUCT> vecSpan { }; //Vector of data offsets and sizes.
+		bool        fRedraw { true };           //Redraw HexCtrl's window after data changes?
+	};
 };