Visualizza wikitesto di Ottenere informazioni sulle icone presenti sulla Scrivania

In via generale, per ottenere informazioni sui file e anche sulle icone a essi correlate, si potranno usare alcune funzioni esterne della libreria: "''libgio-2.0.so.0.8000.2'' ".
<BR>Mostriamo un semplice codice, con il quale si conosceranno varie informazioni su un file e sulla sua icona correlata:
 Library "libgio-2.0:0.8000.2"
 
 <FONT Color=gray>' ''GFile * g_file_new_for_commandline_arg (const char *arg)''
 ' ''Creates a GFile with the given argument from the command line.''</font>
 Private Extern g_file_new_for_commandline_arg(arg As String) As Pointer
 
 <FONT Color=gray>' ''GFileInfo * g_file_query_info (GFile *file, const char *attributes, GFileQueryInfoFlags flags, GCancellable *cancellable, GError **error )''
 ' ''Gets the requested information about specified file.''</font>
 Private Extern g_file_query_info(gfile As Pointer, attributes As String, flags As Integer, cancellable As Pointer, gerror As Pointer) As Pointer
 
 <FONT Color=gray>' ''char ** g_file_info_list_attributes (GFileInfo *info, const char *name_space)''
 ' ''Lists the file info structure's attributes.''</font>
 Private Extern g_file_info_list_attributes(info As Pointer, name_space As String) As Pointer
 
 <FONT Color=gray>' ''char * g_file_info_get_attribute_as_string (GFileInfo *info, const char *attribute)''
 ' ''Gets the value of a attribute, formatted as a string.''</font>
 Private Extern g_file_info_get_attribute_as_string(info As Pointer, attribute As String) As Pointer
 
 <FONT Color=gray>' ''void g_object_unref (gpointer object)''
 ' ''Decreases the reference count of object.''</font>
 Private Extern g_object_unref(gobject As Pointer)
 
 
 Public Sub Main()
  
  Dim percorso As String
  Dim fl, info As Pointer
  
  percorso = "<FONT Color=darkgreen>''/percorso/del/file''</font>"
  
  fl = g_file_new_for_commandline_arg(percorso)
  If fl == 0 Then Error.Raise("Errore !")
  
  info = g_file_query_info(fl, "*", 0, Null, Null)
  If info == 0 Then Error.Raise("Errore !")
    
  MostraAttributi(info)
    
  g_object_unref(info)
  g_object_unref(fl)
   
 End
 
 
 Private Procedure MostraAttributi(inf As Pointer)
  
  Dim attr, p As Pointer
  Dim i As Integer
  Dim s As String
  
  attr = g_file_info_list_attributes(inf, Null)
  
  Print "ATTRIBUTI:\n"
  s = String@(Pointer@(attr + (i * 8)))
  Repeat 
    p = g_file_info_get_attribute_as_string(inf, s)
    Print String@(Pointer@(attr + (i * 8))); ":  \e[31m"; String@(p); "\e[0m"
    Inc i
    Wait 0.1
    s = String@(Pointer@(attr + (i * 8)))
  Until IsNull(s)
  
 End


===Individuare le icone poste sulla Scrivania passandoci sopra con il puntatore del mouse===
Mostriamo di seguito un codice che, utilizzando nuovamente le già viste funzioni esterne della libreria "libgio-2.0", permette di individuare le icone poste sulla Scrivania, mentre si sorvola su di esse con il puntatore del mouse, e di ottenere informazioni sulle icone stesse e sui file, ai quali esse sono collegate.
<BR>E' necessario attivare anche il Componente "gb.desktop".
 Public Struct IconaFileDesktop
   nome As String
   x As Short
   y As Short
   rt As Rect
 End Struct
 Private icone As New IconaFileDesktop[]
 Private PERCORSO As String = Desktop.GetDirectory("DESKTOP")
 Private TImer1 As Timer
 
 
 Public Sub Form_Open()
  
  Dim nomefile, s As String
  Dim ifd As IconaFileDesktop
  
 <FONT Color=gray>' ''Carica tutti i file corrispondenti alle icone presenti sulla Scrivania:''</font>
  For Each nomefile In Dir(PERCORSO, "*", gb.File)
 <FONT Color=gray>' ''Usa alcune funzioni esterne della libreria "libgio-2.0":''</font>
    s = LeggeInfo(PERCORSO &/ nomefile)
    If IsNull(s) Then Continue 
 <FONT Color=gray>' ''Carica nella "Struttura" i dati utili del file individuato dalla funzione "Dir()":''</font>
    With ifd = New IconaFileDesktop
      .nome = nomefile
      .x = Val(Scan(s, "*,*")[0])
      .y = Val(Scan(s, "*,*")[1])
 <FONT Color=gray>' ''Stabilisce un'area quadrata standard di 48x48 pixel per ciascuna icona di file individuato:''</font>
      .rt = New Rect(.x, .y, 48, 48)
    End With
    icone.Push(ifd)
  Next
  
  With timer1 = New Timer As "Timer1"
    .Delay = 50
    .Start
  End With
  
 End
 
 
 Public Sub Timer1_Timer()
  
  Dim c As Short
  
  TextArea1.Clear
  
  For c = 0 To icone.Max
 <FONT Color=gray>' ''Se le coordinate x,y in pixel correnti in cui si trova il puntatore del mouse rientrano in un'area quadrata caricata, va a vedere a quale icona e file appartiene:''</font>
    If icone[c].rt.Contains(Mouse.ScreenX, Mouse.ScreenY) Then 
 <FONT Color=gray>' ''Mostra alcune caratteristiche del file al quale corrisponde l'icona sorvolata dal puntatore del mouse:''</font>
      TextArea1.Text = "== Caratteristiche del file ==\n" &
                       "\nPercorso:        " & Stat(PERCORSO &/ icone[c].nome).Path &
                       "\nDimensione:      " & Stat(PERCORSO &/ icone[c].nome).Size & " Byte" &
                       "\nUltimo Accesso:  " & Stat(PERCORSO &/ icone[c].nome).LastAccess &
                       "\nUltima modifica: " & Stat(PERCORSO &/ icone[c].nome).LastModified &
                       "\nPermessi:        " & Stat(PERCORSO &/ icone[c].nome).Auth &
                       "\nUtente:          " & Stat(PERCORSO &/ icone[c].nome).User &
                       "\nGruppo:          " & Stat(PERCORSO &/ icone[c].nome).Group &
                       "\nMimetype icona:  " & DesktopMime.FromFile(Stat(PERCORSO &/ icone[c].nome).Path).Type
    Endif
  Next
  
 End
 
 
  Library "libgio-2.0:0.8000.2"
 
 <FONT Color=gray>' ''GFile * g_file_new_for_commandline_arg (const char *arg)''
 ' ''Creates a GFile with the given argument from the command line.''</font>
 Private Extern g_file_new_for_commandline_arg(arg As String) As Pointer
 
 <FONT Color=gray>' ''GFileInfo * g_file_query_info (GFile *file, const char *attributes, GFileQueryInfoFlags flags, GCancellable *cancellable, GError **error )''
 ' ''Gets the requested information about specified file.''</font>
 Private Extern g_file_query_info(gfile As Pointer, attributes As String, flags As Integer, cancellable As Pointer, gerror As Pointer) As Pointer
 
 <FONT Color=gray>' ''char ** g_file_info_list_attributes (GFileInfo *info, const char *name_space)''
 ' ''Lists the file info structure's attributes.''</font>
 Private Extern g_file_info_list_attributes(info As Pointer, name_space As String) As Pointer
 
 <FONT Color=gray>' ''char * g_file_info_get_attribute_as_string (GFileInfo *info, const char *attribute)''
 ' ''Gets the value of a attribute, formatted as a string.''</font>
 Private Extern g_file_info_get_attribute_as_string(info As Pointer, attribute As String) As Pointer
 
 <FONT Color=gray>' ''void g_object_unref (gpointer object)''
 ' ''Decreases the reference count of object.''</font>
 Private Extern g_object_unref(gobject As Pointer)
 
 
 Private Function LeggeInfo(percfile As String) As String
  
  Dim fl, info As Pointer
  
  fl = g_file_new_for_commandline_arg(percfile)
  If fl == 0 Then Error.Raise("Errore !")
    
  info = g_file_query_info(fl, "*", 0, Null, Null)
  If info == 0 Then Error.Raise("Errore !")
    
  percfile = EstraeAttributi(info)
    
  g_object_unref(info)
  g_object_unref(fl)
  
  Return percfile
  
 End
 
 
 Private Function EstraeAttributi(inf As Pointer) As String
  
  Dim attr, p As Pointer
  Dim i As Integer = -1
  Dim s As String
  
  attr = g_file_info_list_attributes(inf, Null)
  
  Repeat 
    Inc i
    s = String@(Pointer@(attr + (i * SizeOf(gb.Pointer))))
    p = g_file_info_get_attribute_as_string(inf, s)
  Until s == Trim("metadata::nemo-icon-position")
  
  Return String@(p)
  
 End