Add One-Hand mice wheel scroll diff and merge (WinMerge#2435) (5). Al…

…t+Wheel Down and other commands now work not only in the editor but also in other windows.

Src/DirView.cpp

@@ -49,6 +49,7 @@
 #include "SyntaxColors.h"
 #include "Shell.h"
 #include "DirTravel.h"
+#include "LowLevelMouseHook.h"
 #include <numeric>
 #include <functional>
 
@@ -638,6 +639,8 @@ void CDirView::Redisplay()
  */
 void CDirView::OnContextMenu(CWnd*, CPoint point)
 {
+	if (CLowLevelMouseHook::IsRightWheelScrolling())
+		return;
 	if (GetListCtrl().GetItemCount() == 0)
 		return;
 	// Make sure window is active

Src/LowLevelMouseHook.cpp

@@ -0,0 +1,188 @@
+#include <StdAfx.h>
+#include "LowLevelMouseHook.h"
+
+void CALLBACK CLowLevelMouseHook::TimerProc(HWND unnamedParam1, UINT unnamedParam2, UINT_PTR id, DWORD unnamedParam4HWND)
+{
+	KillTimer(nullptr, id);
+	EndMenu();
+	m_bIgnoreRBUp = false;
+}
+
+LRESULT CALLBACK CLowLevelMouseHook::LowLevelMouseProc(int nCode, WPARAM wParam, LPARAM lParam)
+{
+	if (nCode < 0)
+		return CallNextHookEx(m_hMouseHook, nCode, wParam, lParam);
+
+	if (wParam == WM_RBUTTONDOWN)
+	{
+		m_bRButtonDown = true;
+	}
+	else if (wParam == WM_RBUTTONUP)
+	{
+		m_bRButtonDown = false;
+		if (m_bIgnoreRBUp)
+		{
+			LRESULT result = CallNextHookEx(m_hMouseHook, nCode, wParam, lParam);
+			SetTimer(nullptr, 0, USER_TIMER_MINIMUM, TimerProc);
+			return result;
+		}
+	}
+	else if (wParam == WM_MOUSEWHEEL)
+	{
+		MSLLHOOKSTRUCT* pMouseStruct = (MSLLHOOKSTRUCT*)lParam;
+		int zDelta = GET_WHEEL_DELTA_WPARAM(pMouseStruct->mouseData);
+		int nFlags = pMouseStruct->flags;
+
+		if (GetKeyState(VK_MENU) & 0x8000)
+		{
+			HWND hwndTarget = GetForegroundWindow();
+			// When hold Alt key, use nFlags to check MK_CONTROL MK_SHIFT holding got problem, Use GetKeyState() instead.
+			const auto bShiftDown = GetKeyState(VK_SHIFT) & 0x8000;
+			const auto bControlDown = GetKeyState(VK_CONTROL) & 0x8000;
+			// zDelta > 0 scrool up, < 0 scrool down
+			if (zDelta > 0)
+			{
+				// Check Shift key hold for mice without HWheel function
+				if (bShiftDown && bControlDown)
+				{
+					// Alt+Ctrl+Shift+ScrollUp as Alt+Ctrl+Left
+					PostMessage(hwndTarget, WM_COMMAND, ID_R2LNEXT, 0);
+					return 1;
+				}
+				else if (bShiftDown)
+				{
+					// Alt+Shift+ScrollUp as Alt+Left
+					PostMessage(hwndTarget, WM_COMMAND, ID_R2L, 0);
+					return 1;
+				}
+				else if (nFlags == 0)
+				{
+					// Alt+ScrollUp as Alt+Up
+					PostMessage(hwndTarget, WM_COMMAND, ID_PREVDIFF, 0);
+					return 1;
+				}
+			}
+			else if (zDelta < 0)
+			{
+				// Check Shift key hold for mice without HWheel function
+				if (bShiftDown && bControlDown)
+				{
+					// Alt+Ctrl+Shift+ScrollDown as Alt+Ctrl+Right
+					PostMessage(hwndTarget, WM_COMMAND, ID_L2RNEXT, 0);
+					return 1;
+				}
+				else if (bShiftDown)
+				{
+					// Alt+Shift+ScrollDown as Alt+Right
+					PostMessage(hwndTarget, WM_COMMAND, ID_L2R, 0);
+					return 1;
+				}
+				else if (nFlags == 0)
+				{
+					// Alt+ScrollDown as Alt+Down
+					PostMessage(hwndTarget, WM_COMMAND, ID_NEXTDIFF, 0);
+					return 1;
+				}
+			}
+		}
+
+		// Hold mice right button for One-handed operation
+		if (m_bRButtonDown)
+		{
+			HWND hwndTarget = GetForegroundWindow();
+			if (zDelta > 0)
+			{
+				// RButton+ScrollUp as Alt+Up
+				m_bIgnoreRBUp = true;
+				PostMessage(hwndTarget, WM_COMMAND, ID_PREVDIFF, 0);
+				return 1;
+			}
+			else if (zDelta < 0)
+			{
+				// RButton+ScrollDown as Alt+Down
+				m_bIgnoreRBUp = true;
+				PostMessage(hwndTarget, WM_COMMAND, ID_NEXTDIFF, 0);
+				return 1;
+			}
+		}
+	}
+	else if (wParam == WM_MOUSEHWHEEL)
+	{
+		MSLLHOOKSTRUCT* pMouseStruct = (MSLLHOOKSTRUCT*)lParam;
+		int zDelta = GET_WHEEL_DELTA_WPARAM(pMouseStruct->mouseData);
+		int nFlags = pMouseStruct->flags;
+
+		if (GetKeyState(VK_MENU) & 0x8000)
+		{
+			HWND hwndTarget = GetForegroundWindow();
+			const auto bControlDown = GetKeyState(VK_CONTROL) & 0x8000;
+			// zDelta > 0 scrool right, < 0 scrool left
+			if (zDelta > 0)
+			{
+				if (bControlDown)
+				{
+					// Alt+Ctrl+HScrollRight as Alt+Ctrl+Right
+					PostMessage(hwndTarget, WM_COMMAND, ID_L2RNEXT, 0);
+					return 1;
+				}
+				else if (nFlags == 0)
+				{
+					// Alt+HScrollRight as Alt+Right
+					PostMessage(hwndTarget, WM_COMMAND, ID_L2R, 0);
+					return 1;
+				}
+			}
+			else if (zDelta < 0)
+			{
+				if (bControlDown)
+				{
+					// Alt+Ctrl+HScrollLeft as Alt+Ctrl+Left
+					PostMessage(hwndTarget, WM_COMMAND, ID_R2LNEXT, 0);
+					return 1;
+				}
+				else if (nFlags == 0)
+				{
+					// Alt+HScrollLeft as Alt+Left
+					PostMessage(hwndTarget, WM_COMMAND, ID_R2L, 0);
+					return 1;
+				}
+			}
+		}
+
+		// Hold mice right button for One-handed operation
+		if (m_bRButtonDown)
+		{
+			HWND hwndTarget = GetForegroundWindow();
+			if (zDelta > 0)
+			{
+				// RButton+ScrollRight as Alt+Right
+				m_bIgnoreRBUp = true;
+				PostMessage(hwndTarget, WM_COMMAND, ID_L2R, 0);
+				return 1;
+			}
+			else if (zDelta < 0)
+			{
+				// RButton+ScrollLeft as Alt+Left
+				m_bIgnoreRBUp = true;
+				PostMessage(hwndTarget, WM_COMMAND, ID_R2L, 0);
+				return 1;
+			}
+		}
+	}
+	return CallNextHookEx(m_hMouseHook, nCode, wParam, lParam);
+}
+
+void CLowLevelMouseHook::SetMouseHook()
+{
+	m_hMouseHook = SetWindowsHookEx(WH_MOUSE_LL, LowLevelMouseProc, nullptr, 0);
+}
+
+void CLowLevelMouseHook::UnhookMouseHook()
+{
+	if (m_hMouseHook)
+	{
+		UnhookWindowsHookEx(m_hMouseHook);
+		m_hMouseHook = nullptr;
+	}
+}
+

Src/LowLevelMouseHook.h

@@ -0,0 +1,13 @@
+class CLowLevelMouseHook
+{
+public:
+	static void SetMouseHook();
+	static void UnhookMouseHook();
+	static bool IsRightWheelScrolling() { return m_bIgnoreRBUp; }
+private:
+	static LRESULT CALLBACK LowLevelMouseProc(int nCode, WPARAM wParam, LPARAM lParam);
+	static void CALLBACK TimerProc(HWND unnamedParam1, UINT unnamedParam2, UINT_PTR id, DWORD unnamedParam4HWND);
+	inline static HHOOK m_hMouseHook;
+	inline static bool m_bIgnoreRBUp;
+	inline static bool m_bRButtonDown;
+};

Src/Merge.cpp

@@ -64,6 +64,7 @@
 #include "RegKey.h"
 #include "Win_VersionHelper.h"
 #include "BCMenu.h"
+#include "LowLevelMouseHook.h"
 
 #ifdef _DEBUG
 #define new DEBUG_NEW
@@ -423,6 +424,8 @@ BOOL CMergeApp::InitInstance()
 			return FALSE;
 	}
 
+	CLowLevelMouseHook::SetMouseHook();
+
 	// create main MDI Frame window
 	CMainFrame* pMainFrame = new CMainFrame;
 	if (!pMainFrame->LoadFrame(IDR_MAINFRAME))
@@ -561,6 +564,8 @@ void CMergeApp::OnAppAbout()
  */
 int CMergeApp::ExitInstance()
 {
+	CLowLevelMouseHook::UnhookMouseHook();
+
 	charsets_cleanup();
 
 	//  Save registry keys if existing WinMerge.reg

Src/Merge.vcxproj

@@ -945,6 +945,7 @@
       <PrecompiledHeaderFile>pch.h</PrecompiledHeaderFile>
       <PrecompiledHeaderOutputFile>$(IntDir)$(TargetName)2.pch</PrecompiledHeaderOutputFile>
     </ClCompile>
+    <ClCompile Include="LowLevelMouseHook.cpp" />
     <ClCompile Include="MergeDocDiffCopy.cpp" />
     <ClCompile Include="MyReBar.cpp" />
     <ClCompile Include="PropCompareWebPage.cpp" />
@@ -1447,6 +1448,7 @@
     <ClInclude Include="AboutDlg.h" />
     <ClInclude Include="BasicFlatStatusBar.h" />
     <ClInclude Include="ClipboardHistory.h" />
+    <ClInclude Include="LowLevelMouseHook.h" />
     <ClInclude Include="MenuBar.h" />
     <ClInclude Include="Common\cio.h" />
     <ClInclude Include="Common\DebugNew.h" />