Re: Win32::API Module

[Joe Yates]

At 05:04 AM 21-05-01 -0700, Helio S. Junior wrote:
>I would like to know how to use win32 functions which take structures as 
>their parameter.
>For example, the API 'SHBrowseForFolder' take the following structure:
>
>typedef struct _browseinfo {
>     HWND hwndOwner;
>     LPCITEMIDLIST pidlRoot;
>     LPTSTR pszDisplayName;
>     LPCTSTR lpszTitle;
>     UINT ulFlags;
>     BFFCALLBACK lpfn;
>     LPARAM lParam;
>     int iImage;
>};
>
>How do i 'translate' this structure and use this function with Win32::API 
>module?

First thing, I'm glad there's someone else out there using Win32::API.

1. decide what type of items you are dealing with and pack() them:

>typedef struct _browseinfo {
>     HWND hwndOwner;
>     LPCITEMIDLIST pidlRoot;
>     LPTSTR pszDisplayName;
>     LPCTSTR lpszTitle;
>     UINT ulFlags;
>     BFFCALLBACK lpfn;
>     LPARAM lParam;
>     int iImage;
>};

You've got the following (L = 32-bit integer (long or int), P = char pointer):
         LLPPLLLL

2. Get function pointers using WIN32::API->new
         my $SHBrowseForFolder = new Win32::API("shell32", 
"SHBrowseForFolder", ["P"], "L");
         etc

3. Call the functions.

Code is attached

Joe Yates

#!perl

use strict;
use WIN32::API;

my $SHBrowseForFolder = new Win32::API("shell32", "SHBrowseForFolder", ["P"], "L");
my $SHGetPathFromIDList = new Win32::API("shell32", "SHGetPathFromIDList", ["LP"], 
"L");
if($SHBrowseForFolder == 0)
  {
  print "Failed to initialise function SHBrowseForFolder().\r\n";
  }
if($SHGetPathFromIDList == 0)
  {
  print "Failed to initialise function SHGetPathFromIDList().\r\n";
  }
my $sFolder = ChooseFolder();
print "Folder: $sFolder\r\n";
exit 1;

=pod
typedef struct _browseinfo
  { 
  HWND hwndOwner; 
  LPCITEMIDLIST pidlRoot; 
  LPTSTR pszDisplayName; 
  LPCTSTR lpszTitle; 
  UINT ulFlags; 
  BFFCALLBACK lpfn; 
  LPARAM lParam; 
  int iImage; 
  } BROWSEINFO;
=cut

my $BIF_RETURNONLYFSDIRS = 1;
my $BIF_DONTGOBELOWDOMAIN = 2;

sub ChooseFolder()
  {
  my $pszDisplayName = "\0" x 0x200;
  my $lpszTitle = "Choose the folder\0";
  my $ulFlags = $BIF_RETURNONLYFSDIRS | $BIF_DONTGOBELOWDOMAIN;
  #                          hw pi DisplayName      Title       Flags     cb lp Im
  my $pbi = pack("LLPPLLLL", 0, 0, $pszDisplayName, $lpszTitle, $ulFlags, 0, 0, 0);
  my $lIDList = $SHBrowseForFolder->Call($pbi);
  if($lIDList == 0)
    {
    return "";
    }
  my $sBuffer = "\0" x 0x200;
  $SHGetPathFromIDList->Call($lIDList, $sBuffer);
  $sBuffer =~ /\0/o;
  my $sPath = $`;
  return "$sPath";
  }