Allow Cut/Copy/Paste while still holding LMB

Fix the behavior of Notepad++ v8.6.1 and newer when if you hold the left mouse button, you cannot use the usual Ctrl+X/C/V.

Due to the N++ has registered the Ctrl+X/C/V accelerators in v8.6.1+ (before, the Scintilla handled that), we have to detect such a situation before calling the N++ TranslateAccelerator in the main message loop.

In such a situation we cannot use the usual WM_KEYDOWN message handler, as that TranslateAccelerator eats any Ctrl&X keydowns from the queue.

At the WM_KEYUP it works but behaves slightly different than the users expect.

Author: xomx

PowerEditor/src/Notepad_plus_Window.h

@@ -68,6 +68,10 @@ class Notepad_plus_Window : public Window
 		DPIManagerV2::loadIcon(hinst, MAKEINTRESOURCE(IDI_M30ICON), ::GetSystemMetrics(SM_CXSMICON), ::GetSystemMetrics(SM_CYSMICON), icon);
 	}
 
+	bool isCurrentScintillaEditViewWnd(HWND hWndToCheck) const {
+		return (hWndToCheck == _notepad_plus_plus_core._pEditView->getHSelf());
+	}
+
 private:
 	Notepad_plus _notepad_plus_plus_core;
 	static LRESULT CALLBACK Notepad_plus_Proc(HWND hwnd, UINT Message, WPARAM wParam, LPARAM lParam);

PowerEditor/src/winmain.cpp

@@ -846,6 +846,28 @@ int WINAPI wWinMain(_In_ HINSTANCE hInstance, _In_opt_ HINSTANCE /*hPrevInstance
 				// if the message doesn't belong to the notepad_plus_plus's dialog
 				if (!notepad_plus_plus.isDlgsMsg(&msg))
 				{
+					// enable the standard Ctrl+X/C/V while still holding the left mouse button (from the previous text selection etc...)
+					if ((msg.message == WM_KEYDOWN) && 
+						((msg.wParam == 'X') || (msg.wParam == 'C') || (msg.wParam == 'V')) && 
+						((::GetKeyState(VK_LBUTTON) & 0x8000) && (::GetKeyState(VK_CONTROL) & 0x8000)))
+					{
+						if (notepad_plus_plus.isCurrentScintillaEditViewWnd(msg.hwnd)) // allow in editor-wnd only (change it to if(msg.hwnd!=NULL) to be app-wide)
+						{
+							switch (msg.wParam)
+							{
+								case 'X':
+									::SendMessage(notepad_plus_plus.getHSelf(), WM_COMMAND, IDM_EDIT_CUT, 0);
+									break;
+								case 'C':
+									::SendMessage(notepad_plus_plus.getHSelf(), WM_COMMAND, IDM_EDIT_COPY, 0);
+									break;
+								case 'V':
+									::SendMessage(notepad_plus_plus.getHSelf(), WM_COMMAND, IDM_EDIT_PASTE, 0);
+									break;
+							}
+						}
+					}
+
 					if (::TranslateAccelerator(notepad_plus_plus.getHSelf(), notepad_plus_plus.getAccTable(), &msg) == 0)
 					{
 						::TranslateMessage(&msg);