NSIS SelectFolderDialog with specific drives

Question

In NSIS SelectFolderDialog can I somehow display tree only with HDDs? I need to restrict user from selecting any directory that is not located on the HDD.

Answer 1

To have full control over which items are present you would have to write a custom NSIS plug-in that calls SHBrowseForFolder and provides a implementation of IFolderFilterSite.

Another approach is to disable the OK button when the user has selected something that is unacceptable to you:

!include LogicLib.nsh

!ifndef DRIVE_FIXED
!define DRIVE_FIXED 3
!endif
; This function decides which items are acceptable
Function MyFolderValidator ; Input: $1=PIDL, $2=Path Output:$0=0 if invalid
System::Call 'KERNEL32::GetVolumePathName(tr2, t.r4, i ${NSIS_MAX_STRLEN})i.r5'
${If} $5 <> 0
    StrCpy $2 $4
${ElseIf} $5 == "error" ; GetVolumePathName is Win2000+
    StrCpy $2 $2 3 ; GetDriveType only accepts root paths (This will not work for UNC)
${EndIf}
System::Call 'KERNEL32::GetDriveType(tr2)i.r3'
${If} $3 = ${DRIVE_FIXED}
    StrCpy $0 1 ; Allow this path
${Else}
    StrCpy $0 0 ; Don't allow this path
${EndIf}
FunctionEnd

!include WinMessages.nsh
!define /math BFFM_ENABLEOK ${WM_USER} + 101
!define BFFM_SELCHANGED 2
!define BFFM_VALIDATEFAILEDA 3
!define BFFM_VALIDATEFAILEDW 4
!if "${NSIS_CHAR_SIZE}" > 1
!define BFFM_VALIDATEFAILED ${BFFM_VALIDATEFAILEDW}
!else
!define BFFM_VALIDATEFAILED ${BFFM_VALIDATEFAILEDA}
!endif
!if "${NSIS_PTR_SIZE}" <= 4
Function BrowseForValidatedFolder ; NSIS 2.51+
System::Store S
Pop $2 ; HeadingText
Pop $1 ; ValidatorFunc
System::Get "(p.R1, i.R2, p.R3, p)i R8R8" ; BFFCALLBACK
Pop $R9 ; The system plug-in callback function
StrCpy $4 "kR9" ; SHBrowseForFolder callback parameter
System::Call '*(&t261 "")p.r7' ; pszDisplayName buffer
System::Call '*(p $hwndparent, p0, pr7, t r2, i 0x51, $4, p0, i)p.r8' ; BROWSEINFO struct 
!if "${NSIS_CHAR_SIZE}" > 1
System::Call 'SHELL32::SHBrowseForFolderW(pr8)p.r9'
!else
System::Call 'SHELL32::SHBrowseForFolderA(pr8)p.r9'
!endif
BFFCALLBACK_loop:
    StrCpy $R8 $R8 8 ; HACKHACK: Working around 2.x bug where the callback IDs are never released
    StrCmp $R8 "callback" 0 BFFCALLBACK_done
    ${If} $R2 = ${BFFM_SELCHANGED}
    ${AndIf} $R3 P<> 0
        System::Store S
        StrCpy $0 $1
        StrCpy $1 $R3
        System::Call 'SHELL32::SHGetPathFromIDList(p $R3, t.r2)'
        Call $0
        SendMessage $R1 ${BFFM_ENABLEOK} 0 $0
        System::Store L
    ${EndIf}
    StrCpy $R8 0 ; Yep, the return value is in the same place as the callback id
    ${IfThen} $R2 = ${BFFM_VALIDATEFAILED} ${|} StrCpy $R8 1 ${|} ; Keep the dialog open
    System::Call $R9
    goto BFFCALLBACK_loop
BFFCALLBACK_done:
System::Free $R9 ; BFFCALLBACK
System::Free $7 ; pszDisplayName 
System::Free $8 ; BROWSEINFO
${If} $9 Z<> 0
    System::Call 'SHELL32::SHGetPathFromIDList(p r9, t.s)i'
    System::Call 'OLE32::CoTaskMemFree(p r9)'
${Else}
    Push "" ; Error/cancel, return empty string
${EndIf}
System::Store L
FunctionEnd
!endif
!macro BrowseForValidatedFolder HeadingText ValidatorFuncName VarResult
GetFunctionAddress ${VarResult} ${ValidatorFuncName}
Push ${VarResult}
Push "${HeadingText}"
Call BrowseForValidatedFolder
Pop ${VarResult}
!macroend

Section
!insertmacro BrowseForValidatedFolder "Choose a location for blah blah" MyFolderValidator $0
${If} $0 != ""
    MessageBox mb_ok "Result: $0"
${Else}
    MessageBox mb_iconstop "User cancelled"
${EndIf}
SectionEnd