Make Notepad2 per monitor DPI aware.

metapath/res/metapath.exe.manifest

@@ -36,7 +36,7 @@
   </compatibility>
   <asmv3:application xmlns:asmv3="urn:schemas-microsoft-com:asm.v3">
     <asmv3:windowsSettings xmlns="http://schemas.microsoft.com/SMI/2005/WindowsSettings">
-      <dpiAware>true/pm</dpiAware>
+      <dpiAware>true/PM</dpiAware>
     </asmv3:windowsSettings>
     <asmv3:windowsSettings xmlns="http://schemas.microsoft.com/SMI/2016/WindowsSettings">
       <dpiAwareness>PerMonitorV2,PerMonitor</dpiAwareness>

res/Notepad2.exe.manifest

@@ -37,13 +37,13 @@
   </compatibility>
   <asmv3:application xmlns:asmv3="urn:schemas-microsoft-com:asm.v3">
     <asmv3:windowsSettings xmlns="http://schemas.microsoft.com/SMI/2005/WindowsSettings">
-      <dpiAware>true/pm</dpiAware>
+      <dpiAware>true/PM</dpiAware>
     </asmv3:windowsSettings>
     <asmv3:windowsSettings xmlns="http://schemas.microsoft.com/SMI/2016/WindowsSettings">
       <dpiAwareness>PerMonitorV2,PerMonitor</dpiAwareness>
     </asmv3:windowsSettings>
     <asmv3:windowsSettings xmlns="http://schemas.microsoft.com/SMI/2017/WindowsSettings">
-      <gdiScaling>true</gdiScaling>
+      <gdiScaling>false</gdiScaling>
     </asmv3:windowsSettings>
   </asmv3:application>
 </assembly>

scintilla/src/Editor.cxx

@@ -993,7 +993,7 @@ void Editor::VerticalCentreCaret() {
 
 // Avoid 64 bit compiler warnings.
 // Scintilla does not support text buffers larger than 2**31
-static int istrlen(const char *s) {
+static inline int istrlen(const char *s) {
 	return static_cast<int>(s ? strlen(s) : 0);
 }
 

src/Dialogs.h

@@ -34,6 +34,14 @@
  */
 #define APPM_CENTER_MESSAGE_BOX		(WM_APP + 1)
 
+// https://msdn.microsoft.com/en-us/library/windows/desktop/dn312083(v=vs.85).aspx
+#ifndef WM_DPICHANGED
+#define WM_DPICHANGED	0x02E0
+#endif
+#ifndef USER_DEFAULT_SCREEN_DPI
+#define USER_DEFAULT_SCREEN_DPI		96
+#endif
+
 int 	MsgBox(int iType, UINT uIdMsg, ...);
 void	DisplayCmdLineHelp(HWND hwnd);
 BOOL	GetDirectory(HWND hwndParent, int iTitle, LPWSTR pszFolder, LPCWSTR pszBase, BOOL bNewDialogStyle);

src/Notepad2.c

@@ -1348,6 +1348,19 @@ LRESULT CALLBACK MainWndProc(HWND hwnd, UINT umsg, WPARAM wParam, LPARAM lParam)
 		}
 		break;
 
+	case WM_DPICHANGED: {
+		int dpi = HIWORD(wParam);
+		RECT* const rc = (RECT *)lParam;
+#if 0
+		char buf[64];
+		sprintf(buf, "WM_DPICHANGED: dpi=%d\n", dpi);
+		SendMessage(hwndEdit, SCI_INSERTTEXT, 0, (LPARAM)buf);
+#endif
+		SetWindowPos(hwnd, NULL, rc->left, rc->top,  rc->right - rc->left, rc->bottom - rc->top, SWP_NOZORDER | SWP_NOACTIVATE);
+		Style_OnDPIChanged(hwndEdit, dpi);
+	}
+	break;
+
 	case APPM_CENTER_MESSAGE_BOX: {
 		HWND box = FindWindow(L"#32770", NULL);
 		HWND parent = GetParent(box);

src/Styles.c

@@ -190,6 +190,7 @@ BOOL	bUse2ndDefaultStyle;
 BOOL	fStylesModified = FALSE;
 BOOL	fWarnedNoIniFile = FALSE;
 int		iBaseFontSize = 11;
+int		iCurrentDPI = USER_DEFAULT_SCREEN_DPI;
 int		iDefaultLexer;
 BOOL	bAutoSelect;
 int		cxStyleSelectDlg;
@@ -452,6 +453,13 @@ BOOL Style_Export(HWND hwnd) {
 	return FALSE;
 }
 
+void Style_OnDPIChanged(HWND hwnd, int dpi) {
+	if (iCurrentDPI != dpi) {
+		iCurrentDPI = dpi;
+		Style_SetLexer(hwnd, pLexCurrent);
+	}
+}
+
 // set folding style; braces are for scoping only
 static const int iMarkerIDs[] = {
 	SC_MARKNUM_FOLDEROPEN,
@@ -2445,6 +2453,7 @@ void Style_SetStyles(HWND hwnd, int iStyle, LPCWSTR lpszStyle) {
 
 	// Size
 	if (Style_StrGetSize(lpszStyle, &iValue)) {
+		iValue = MulDiv(iValue, iCurrentDPI, USER_DEFAULT_SCREEN_DPI);
 		SendMessage(hwnd, SCI_STYLESETSIZE, iStyle, (LPARAM)iValue);
 	}
 

src/Styles.h

@@ -56,6 +56,7 @@ void	Style_Save(void);
 BOOL	Style_Import(HWND hwnd);
 BOOL	Style_Export(HWND hwnd);
 
+void	Style_OnDPIChanged(HWND hwnd, int dpi);
 void	Style_SetLexer(HWND hwnd, PEDITLEXER pLexNew);
 void	Style_SetLexerFromFile(HWND hwnd, LPCWSTR lpszFile);
 void	Style_SetLexerFromName(HWND hwnd, LPCWSTR lpszFile, LPCWSTR lpszName);