--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/foosdk/sdk/libPPUI/CMiddleDragImpl.h	Mon Jan 05 02:15:46 2026 -0500
@@ -0,0 +1,275 @@
+#pragma once
+
+#include "CMiddleDragOverlay.h"
+#include <utility>
+
+class CMiddleDragCommon {
+public:
+	enum {
+		KTimerID = 0x389675f8,
+		KTimerPeriod = 15,
+	};
+	static double myPow(double p_val, double p_exp);
+	static double ProcessMiddleDragDeltaInternal(double p_delta);
+	static double radiusHelper(double p_x, double p_y);
+	static int mySGN(LONG v);
+	static int32_t Round(double val, double & acc);
+	static LONG LineToPixelsHelper(LONG & p_overflow, LONG p_pixels, LONG p_dpi, LONG p_lineWidth);
+};
+
+template<typename TBase>
+class CMiddleDragImpl : public TBase, protected CMiddleDragCommon {
+private:
+	typedef CMiddleDragImpl<TBase> TSelf;
+public:	
+	template<typename ... arg_t> CMiddleDragImpl( arg_t && ... arg ) : TBase(std::forward<arg_t>(arg) ... ) {}
+
+	BEGIN_MSG_MAP_EX(TSelf)
+		MESSAGE_HANDLER(WM_TIMER,OnTimer);
+		MESSAGE_HANDLER(WM_CAPTURECHANGED,OnCaptureChanged);
+		MESSAGE_HANDLER(WM_MBUTTONDOWN,OnMButtonDown);
+		MESSAGE_HANDLER(WM_MBUTTONDBLCLK,OnMButtonDown);
+		MESSAGE_HANDLER(WM_MBUTTONUP,OnMButtonUp);
+		MESSAGE_HANDLER(WM_LBUTTONDOWN,OnMouseAction);
+		MESSAGE_HANDLER(WM_RBUTTONDOWN,OnMouseAction);
+		MESSAGE_HANDLER(WM_LBUTTONDBLCLK,OnMouseAction);
+		MESSAGE_HANDLER(WM_RBUTTONDBLCLK,OnMouseAction);
+		MESSAGE_HANDLER(WM_LBUTTONUP,OnMouseAction);
+		MESSAGE_HANDLER(WM_RBUTTONUP,OnMouseAction);
+		MESSAGE_HANDLER(WM_XBUTTONDOWN,OnMouseAction);
+		MESSAGE_HANDLER(WM_XBUTTONDBLCLK,OnMouseAction);
+		MESSAGE_HANDLER(WM_XBUTTONUP,OnMouseAction);
+		MESSAGE_HANDLER(WM_MOUSEMOVE,OnMouseMove);
+		MESSAGE_HANDLER(WM_DESTROY,OnDestroyPassThru);
+		CHAIN_MSG_MAP(TBase);
+	END_MSG_MAP()
+protected:
+	bool CanSmoothScroll() const { 
+		return !m_active;
+	}
+private:
+	bool m_active = false, m_dragged = false;
+	CPoint m_base;
+	CMiddleDragOverlay m_overlay;
+	double m_accX = 0, m_accY = 0;
+
+	LRESULT OnDestroyPassThru(UINT,WPARAM,LPARAM,BOOL& bHandled) {
+		if (m_overlay != NULL) m_overlay.DestroyWindow();
+		bHandled = FALSE;
+		return 0;
+	}
+
+	LRESULT OnMButtonUp(UINT,WPARAM,LPARAM,BOOL&) {
+		if (m_active /*&& m_dragged*/) {
+			EndDrag();
+		}
+		return 0;
+	}
+
+	LRESULT OnMButtonDown(UINT,WPARAM,LPARAM p_lp,BOOL&) {
+		if (m_active) {
+			EndDrag();
+			return 0;
+		}
+		EndDrag();
+		this->SetFocus();
+		CPoint pt(p_lp);
+		WIN32_OP_D( this->ClientToScreen(&pt) );
+		StartDrag(pt);
+		return 0;
+	}
+
+	LRESULT OnMouseMove(UINT,WPARAM,LPARAM p_lp,BOOL& bHandled) {
+		if (m_active) {
+			if (!m_dragged) {
+				CPoint pt(p_lp);
+				WIN32_OP_D( this->ClientToScreen(&pt) );
+				if (pt != m_base) {
+					m_dragged = true;
+				}
+			}
+			bHandled = TRUE;
+		} else {
+			bHandled = FALSE;
+		}
+		return 0;
+	}
+
+	LRESULT OnMouseAction(UINT,WPARAM,LPARAM,BOOL& bHandled) {
+		EndDrag();
+		bHandled = FALSE;
+		return 0;
+	}
+
+	void StartDrag(CPoint const & p_point) {
+		::SetCapture(NULL);
+
+		if (m_overlay == NULL) {
+			PFC_ASSERT( this->m_hWnd != NULL );
+			WIN32_OP_D(m_overlay.Create(*this));
+		}
+
+		//todo sanity checks - don't drag when the entire content is visible, perhaps use a different icon when only vertical or horizontal drag is possible
+		SetCursor(::LoadCursor(NULL,IDC_SIZEALL));
+		m_active = true;
+		m_dragged = false;
+		m_base = p_point;
+		m_accX = m_accY = 0;
+		this->SetCapture();
+		this->SetTimer(KTimerID,KTimerPeriod);
+
+		m_overlay.ShowHere(p_point);
+	}
+
+	void EndDrag() {
+		if (m_active) ::SetCapture(NULL);
+	}
+
+	void HandleEndDrag() {
+		if (m_active) {
+			m_active = false;
+			this->KillTimer(KTimerID);
+			if (m_overlay != NULL) m_overlay.ShowWindow(SW_HIDE);
+		}
+	}
+
+	LRESULT OnCaptureChanged(UINT,WPARAM,LPARAM,BOOL& bHandled) {
+		HandleEndDrag();
+		bHandled = FALSE;
+		return 0;
+	}
+
+	LRESULT OnTimer(UINT,WPARAM p_wp,LPARAM,BOOL& bHandled) {
+		switch(p_wp) {
+		case KTimerID:
+		{
+			CPoint ptCursor;
+			if (GetCursorPos(&ptCursor)) {
+				this->MoveViewOriginDelta(ProcessMiddleDragDelta(ptCursor - m_base));
+			}
+		}
+			return 0;
+		default:
+			bHandled = FALSE;
+			return 0;
+		}
+	}
+
+	CPoint ProcessMiddleDragDelta(CPoint p_delta) {
+		const CSize dpi = QueryScreenDPIEx();
+		if (dpi.cx <= 0 || dpi.cy <= 0 || p_delta == CPoint(0, 0)) return CPoint(0, 0);
+		const double dpiMulX = 96.0 / (double)dpi.cx;
+		const double dpiMulY = 96.0 / (double)dpi.cy;
+
+		const double deltaTotal = ProcessMiddleDragDeltaInternal(radiusHelper((double)p_delta.x * dpiMulX, (double)p_delta.y * dpiMulY));
+
+		double xVal = 0, yVal = 0;
+
+		if (p_delta.x == 0) {
+			yVal = deltaTotal;
+		} else if (p_delta.y == 0) {
+			xVal = deltaTotal;
+		} else {
+			const double ratio = (double)p_delta.x / (double)p_delta.y;
+			yVal = sqrt((deltaTotal*deltaTotal) / (1.0 + (ratio*ratio)));
+			xVal = yVal * ratio;
+		}
+
+		xVal = mySGN(p_delta.x) * fabs(xVal);
+		yVal = mySGN(p_delta.y) * fabs(yVal);
+
+
+		return CPoint(Round(xVal / dpiMulX, m_accX), Round(yVal / dpiMulY, m_accY));
+	}
+
+};
+
+template<typename TBase>
+class CMiddleDragWrapper : public TBase {
+private:
+	typedef CMiddleDragWrapper<TBase> TSelf;
+public:
+	template<typename ... arg_t> CMiddleDragWrapper(arg_t && ... arg ) : TBase(std::forward<arg_t>(arg) ... ) { m_overflow = CPoint(0, 0); m_lineWidth = CSize(4, 16); }
+
+	BEGIN_MSG_MAP_EX(TSelf)
+		MESSAGE_HANDLER(WM_CAPTURECHANGED,OnCaptureChanged);
+		CHAIN_MSG_MAP(TBase)
+	END_MSG_MAP()
+
+	void MoveViewOriginDelta(CPoint p_delta) {
+		MoveViewOriginDeltaLines( MiddleDrag_PixelsToLines( m_overflow, p_delta ) );
+	}
+	void MoveViewOriginDeltaLines(CPoint p_delta) {
+		FireScrollMessage(WM_HSCROLL,p_delta.x);
+		FireScrollMessage(WM_VSCROLL,p_delta.y);
+	}
+	void SetLineWidth(CSize p_width) {m_lineWidth = p_width;}
+	
+private:
+	void FireScrollMessage(UINT p_msg,int p_delta) {
+		UINT count = (UINT)(p_delta<0?-p_delta:p_delta);
+		const UINT which = (p_msg == WM_HSCROLL ? SB_HORZ : SB_VERT);
+		SCROLLINFO si = {}; si.cbSize = sizeof(si); si.fMask = SIF_PAGE | SIF_RANGE;
+		if (!this->GetScrollInfo(which, &si) || si.nPage <= 0) return;
+		while(count >= si.nPage) {
+			const WPARAM code = p_delta < 0 ? SB_PAGEUP : SB_PAGEDOWN;
+			this->SendMessage(p_msg, code, 0);
+			count -= si.nPage;
+		}
+		const WPARAM code = p_delta < 0 ? SB_LINEUP : SB_LINEDOWN;
+		for(UINT walk = 0; walk < count; ++walk) this->SendMessage(p_msg, code, 0);
+	}
+	LRESULT OnCaptureChanged(UINT,WPARAM,LPARAM,BOOL& bHandled) {
+		m_overflow = CPoint(0,0);
+		bHandled = FALSE;
+		return 0;
+	}
+
+
+	CPoint MiddleDrag_PixelsToLines(CPoint & p_overflow,CPoint p_pixels) {
+		const CSize dpi = QueryScreenDPIEx();
+		if (dpi.cx <= 0 || dpi.cy <= 0) return CPoint(0,0);
+		CPoint pt;
+		pt.x = CMiddleDragCommon::LineToPixelsHelper(p_overflow.x,p_pixels.x,dpi.cx,m_lineWidth.cx);
+		pt.y = CMiddleDragCommon::LineToPixelsHelper(p_overflow.y,p_pixels.y,dpi.cy,m_lineWidth.cy);
+		return pt;
+	}
+
+	CSize m_lineWidth;
+
+	CPoint m_overflow;
+};
+
+template<typename TBase = CWindow>
+class CWindow_DummyMsgMap : public TBase , public CMessageMap {
+public:
+	BOOL ProcessWindowMessage(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam,
+		LRESULT& lResult, DWORD dwMsgMapID = 0) {return FALSE;}
+};
+
+typedef CMiddleDragImpl<CMiddleDragWrapper<CWindow_DummyMsgMap<> > > CMiddleDragImplSimple;
+
+template<typename TBase = CWindow>
+class CContainedWindow_MsgMap : public CContainedWindowT<CWindow_DummyMsgMap<TBase> > {
+protected:
+	CContainedWindow_MsgMap() : CContainedWindowT<CWindow_DummyMsgMap<TBase> >(msgMapCast(this)) {}
+private:
+	template<typename t> static CMessageMap * msgMapCast(t* arg) { return arg; }
+};
+
+template<typename TBase>
+class CMiddleDragImplCtrlHook : public CMiddleDragImpl<CMiddleDragWrapper<CContainedWindow_MsgMap<TBase> > > {
+};
+
+template<typename TBase> class CMiddleDragImplCtrlHookEx : public CMiddleDragImplCtrlHook<TBase> {
+public:
+	CMiddleDragImplCtrlHookEx(CMessageMap * hook, DWORD hookMapID = 0) : m_hook(*hook), m_hookMapID(hookMapID) {}
+	
+	BEGIN_MSG_MAP_EX(CMiddleDragImplCtrlHookEx)
+		CHAIN_MSG_MAP(CMiddleDragImplCtrlHook<TBase>)
+		CHAIN_MSG_MAP_ALT_MEMBER(m_hook,m_hookMapID);
+	END_MSG_MAP()
+private:
+	DWORD const m_hookMapID;
+	CMessageMap & m_hook;
+};