NSIS: add a couple of uninstaller checkboxes

Add a new dialog/page which is shown right before
the final "uninstall" click.

The dialog may contains two checkboxes - for registry
entries and for the user path. These checkboxes will not be
created if the user has not run the application yet,
as no registry keys will be available.

Selecting the user directory checkbox shows a warning message box,
that the user should make sure no important files are present there.

Signed-off-by: Lubomir I. Ivanov <neolit123@gmail.com>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>

packaging/windows/subsurface.nsi.in

@@ -62,6 +62,58 @@
 
     Var StartMenuFolder
 
+#--------------------------------
+# Custom pages
+
+# Maintain some checkboxes in the uninstall dialog
+Var UninstallDialog
+Var Checkbox_Reg
+Var Checkbox_Reg_State
+Var Checkbox_UserDir
+Var Checkbox_UserDir_State
+Var UserDir
+
+Function un.UninstallOptions
+    nsDialogs::Create 1018
+    Pop $UninstallDialog
+    ${If} $UninstallDialog == error
+        Abort
+    ${EndIf}
+
+    StrCpy $Checkbox_Reg_State 0
+    StrCpy $Checkbox_UserDir 0
+
+    # if this key exists Subsurface was run at least once
+    ReadRegStr $UserDir HKCU "Software\Subsurface\Subsurface\GeneralSettings" "default_directory"
+    ${If} $UserDir != ""
+        # checkbox for removing registry entries
+        ${NSD_CreateCheckbox} 0 0u 100% 20u "Registry entries (HKEY_CURRENT_USER\Software\Subsurface)"
+        Pop $Checkbox_Reg
+        GetFunctionAddress $0 un.OnCheckbox_Reg
+        nsDialogs::OnClick $Checkbox_Reg $0
+
+        ${If} ${FileExists} "$UserDir\*.*"
+            # checkbox for removing the user directory
+            ${NSD_CreateCheckbox} 0 20u 100% 20u "User directory ($UserDir)"
+            Pop $Checkbox_UserDir
+            GetFunctionAddress $0 un.OnCheckbox_UserDir
+            nsDialogs::OnClick $Checkbox_UserDir $0
+       ${EndIf}
+    ${EndIf}
+
+    nsDialogs::Show
+FunctionEnd
+
+Function un.OnCheckbox_Reg
+    ${NSD_GetState} $Checkbox_Reg $Checkbox_Reg_State
+FunctionEnd
+Function un.OnCheckbox_UserDir
+    ${NSD_GetState} $Checkbox_UserDir $Checkbox_UserDir_State
+    ${If} $Checkbox_UserDir_State == 1
+       MessageBox MB_OK "WARNING!$\nMake sure you don't have important files in the user directory!"
+    ${EndIf}
+FunctionEnd
+
 #--------------------------------
 # Pages
 
@@ -73,6 +125,7 @@
 
     # Uninstaller pages
     !insertmacro MUI_UNPAGE_CONFIRM
+    UninstPage custom un.UninstallOptions
     !insertmacro MUI_UNPAGE_INSTFILES
 
 #--------------------------------
@@ -163,8 +216,19 @@ Section "Uninstall"
     RMDir "$SMPROGRAMS\$StartMenuFolder"
     Delete "$DESKTOP\Subsurface.lnk"
 
-    # Remove registry entries
-    DeleteRegKey /ifempty HKCU "Software\Subsurface"
+    # remove the registry entires
+    ${If} $Checkbox_Reg_State == 1
+        DeleteRegKey HKCU "Software\Subsurface"
+    ${EndIf}
+
+    # remove the user directory
+    ${If} $Checkbox_UserDir_State == 1
+    ${AndIf} $UserDir != ""
+    ${AndIf} ${FileExists} "$UserDir\*.*"
+        RMDir /r $UserDir
+    ${EndIf}
+
+    # remove the uninstaller entry
     DeleteRegKey HKCU "Software\Microsoft\Windows\CurrentVersion\Uninstall\Subsurface"
 
 SectionEnd