GAMBAS BOOK 3.19.3

The Desktop class of the component with the same name allows you to use desktop related routines based on the xdg-utils scripts of the Portland project. The number of properties and methods is manageable. Selected properties and methods are listed and described in a table:

Table 15.1.1: Overview of properties of the Desktop class (gb.desktop)

The virtual class _Desktop_ScreenSaver allows you to manipulate the screen saver and has the following property:

_Desktop_ScreenSaver.Enabled → Returns TRUE if the screen saver is turned on.

The following is a list of the methods of the virtual class _Desktop_ScreenSaver and a short explanation of the action triggered:

• _Desktop_ScreenSaver.Activate - Enables the screen saver immediately
• _Desktop_ScreenSaver.Reset - Disables the screen saver immediately
• _Desktop_ScreenSaver.Lock - Locks the screen saver immediately (→ unlock password)
• _Desktop_ScreenSaver.Resume - screen saver function is activated
• _Desktop_ScreenSaver.Suspend - screen saver function is deactivated

For a brief description of the methods of the Desktop class, see the following table, which contains a detailed description of selected methods in other (sub)chapters:

Table 15.1.2: Overview of methods of the class Desktop (gb. desktop)

(1)
The FindWindow(..) method returns an array of X11 window identifiers as a function value. The following applies to the optional parameters in the method:

Desktop.FindWindow ( [ Title As String, Application As String, Role As String ] ) As Integer[]

Title is the window title. This can be found in the X11 window property WM_NAME.Application is the window class. It is usually the name of the application that creates the window. It is stored in the X11 window property WM_CLASS, which is the role of the window. It is stored in the X11 window property WM_WINDOW_ROLE.

The arguments Title, Application and Role are regular expressions as defined in conjunction with the LIKE operator (→ chapter 19.6.3 Excursus LIKE and chapter 8.6 Special Operators).

[1] Public Sub GetDTWindowsList()
[2]   Dim iCount As Integer
[3]   Dim DTWindow As DesktopWindow
[4]   Dim aDTWindowsList As Integer[]
[5]   
[6]   txaWindowList.Clear
[7]   aDTWindowsList = Desktop.FindWindow(txbPatternBox.Text)
[8]   lblWindowCount.Text = aDTWindowsList.Count
[9]  For iCount = 0 To aDTWindowsList.Max
[10]      DTWindow = New DesktopWindow(aDTWindowsList[iCount])
[11]      If DTWindow.Id = aDTWindowsList[iCount] Then
[12]         txaWindowList.Text &= Str(iCount + 1) & "\t" & (DTWindow.Desktop + 1) & 
       "      " & DTWindow.Id & "\t" & DTWindow.Name & gb.NewLine
[13]      Endif ' DTWindow.Id = aDTWindowsList[iCount] ?
[14]  Next ' iCount
[15] 
[16]  End ' GetDTWindowsList()
[17] 
[18]  Public Sub btnGetDTWList_Click()
[19]    GetDTWindowsList()
[20]  End ' btnGetDTWList_Click()

The following results could be displayed in a TextArea. First, the regular expression [DGM]* (→ line 7) was used as the search pattern (window name begins with D, G or M):

Nummer	Desktop	Desktop.ID		Fenster-Name 
----------------------------------------------------------------------------------------------
1	3      	52428816		DesktopWatcher 0.0.6 - Gambas 3 
2	1      	62914563		GHex 
3	4      	65011850		Mozilla Firefox 
4	3      	37748751		DesktopWatcher 

The search pattern was then set to * and resulted in the following extended list of X11 top-level windows:

Nummer	Desktop	Desktop.ID		Fenster-Name 
----------------------------------------------------------------------------------------------
1	0      	23068676		Schreibtisch 
2	3      	52428816		DesktopWatcher 0.0.6 - Gambas 3 
3	1      	62914563		GHex 
4	1      	60817454		Unbenanntes Dokument 1 - gedit 
5	2      	48234565		15.1.odt - LibreOffice Writer 
6	4      	65011850		Mozilla Firefox 
7	3      	37748751		DesktopWatcher 
8	0      	14680084		Unteres Kanten-Panel, ausgedehnt 
9	0      	14680067		Oberes Kanten-Panel, ausgedehnt

(2)
The GetFileIcon(..)method returns the icon associated with the selected file:

• Path is the file path
• Size is the size of the icon (pixels)
• Preview - The default value of the optional argument is FALSE and the icon file of type Picture is returned.

' Gambas class file
Public picFileIcon As Picture
 
Public Sub Form_Open()
 
  picFileIcon = Desktop.GetFileIcon(User.Home &/ "DesktopWatcher.gambas", 32, False)
' Saving the icon in the global variables picFileIcon of type Picture
  PictureBox1.W = 72
  PictureBox1.H = PictureBox1.W
  PictureBox1.Stretch = True
  PictureBox1.Picture = Desktop.GetFileIcon(User.Home &/ "Arbeitsfläche/GetFileIcon/GetFileIcon.gambas", 32, False)
End ' Form_Open

(5)
With the RunAsRoot(…) method, many people hoped to be able to execute a command that required root privileges quite simply from within a Gambas program. Implementation in a project is simple:

Public Sub RunAsRoot(sCommand As String)
  Desktop.RunAsRoot(sCommand)
End ' RunAsRoot(sCommand As String)
 
Public Sub btnRunAsRoot_Click()
  RunAsRoot("apt-get install bluefish")
End ' btnRunAsRoot_Click()

A terminal window opens and you are prompted to enter the root password:

Figure 15.1.1: Terminal

But currently (→ 30.11.2014) nothing happens after entering the root password. The terminal window closes and you return to the program window.

What it already is - at least under Ubuntu 12.04.

Internally, the instruction Exec() is used and the following command - here in connection with the command to install the program 'bluefish' - is used:

hans@linux:~$ /tmp/gambas.1000/10857/xdg-utils/xdg-su -c "apt-get install bluefish"

For the virtual class _Desktop_ScreenSaver as well as for the class Desktop with its methods, descriptions and the presentation of relevant source code excerpts are given in separate chapters:

Virtual class _Desktop_ScreenSaver to manipulate the screen saver Desktop.

• Desktop.Open (URL As String[, Wait AsBoolean])
• Desktop.OpenTerminal ([ Dir As String])
• Desktop.SendKeys (Keys As String)
• Desktop.SendMail (To As String[][…, Subject As String, Body As String,…])