Il seguente codice è un semplice esempio di uso delle risorse esterne del API di X11 mediante
, ed esempio di traduzione dal C in Gambas.
Funziona solo con sistemi a 64-bit.
'******************************************************************************************************************************************
' Il presente codice è la traduzione in Gambas, effettuata dal membro del foro gambas-it.org "vuott", con variazioni ed integrazioni,
' del codice originale, scritto in linguaggio C, del progetto di Kjetil Erga, chiamato "Xlib Calculator".
'
'
' Copyright (c) 2008 Kjetil Erga
'
' Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation
' files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use,
' copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom
' the Software is Furnished to do so, subject to the following conditions:
' The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
' THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
' OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
' BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
' OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
'******************************************************************************************************************************************
Private Const BLOCCHI_X As Integer = 4
Private Const BLOCCHI_Y As Integer = 6
Private Const SPAZIO As Integer = 5
Private valore_mostrato As Float
Private valore_buffer As Float
Private operazione As Byte
Private modo_decimale As Integer
Private disp_mod As Integer
Private simboli As String[][] = [["C", "/", "*", "-"], ["7", "8", "9", "+"], ["4", "5", "6", " "], ["1", "2", "3", " "], ["0", " ", ".", "="]]
Library "libX11:6.3.0"
Private Const ExposureMask As Long = 32768
Private Const KeyPressMask As Long = 1
Private Const ButtonPressMask As Long = 4
Private Const ClientMessage As Integer = 33
Private Enum KeyPress = 2, KeyRelease, ButtonPress, ButtonRelease, MotionNotify, EnterNotify, LeaveNotify,
FocusIn, FocusOut, KeymapNotify, Expose, GraphicsExpose, NoExpose
' Display *XOpenDisplay(char *display_name)
' Opens a connection to the X server that controls a display.
Private Extern XOpenDisplay(display As Pointer) As Pointer
' int XDefaultScreen(Display *display)
' Return the default screen number referenced by the XOpenDisplay() function.
Private Extern XDefaultScreen(display As Pointer) As Integer
' Window XRootWindow(Display *display, int screen_number)
' Return the root window for the default screen.
Private Extern XRootWindow(display As Pointer, screen_number As Integer) As Integer
' Window XCreateSimpleWindow(Display *display, Window parent, int x, int y, unsigned int width, unsigned int height, unsigned int border_width, unsigned long border, unsigned long background)
' creates an unmapped InputOutput subwindow for a specified parent window, returns the window ID of the created window.
Private Extern XCreateSimpleWindow(display As Pointer, parent As Long, x As Integer, y As Integer, width As Integer, height As Integer, border_width As Integer, border As Integer, background As Long) As Integer
' XSelectInput (Display *display, Window w, long event_mask)
' requests that the X server report the events associated with the specified Event mask.
Private Extern XSelectInput(display As Pointer, w As Long, event_mask As Long)
' XMapRaised (Display *display, Window w)
' raises the specified window to the top of the stack.
Private Extern XMapRaised(display As Pointer, w As Long)
' Atom XInternAtom(Display *display, char *atom_name, Bool only_if_exists)
' Returns the atom identifier associated with the specified atom_name string.
Private Extern XInternAtom(display As Pointer, atom_name As String, only_if_exists As Boolean) As Long
' Status XSetWMProtocols(Display *display, Window w, Atom *protocols, int count)
' Replaces the WM_PROTOCOLS property on the specified window with the list of atoms specified by the protocols argument.
Private Extern XSetWMProtocols(display As Pointer, w As Long, protocols As Pointer, count As Integer) As Integer
' XNextEvent (Display *display, XEvent *event_return)
' gets the next event and remove it from the queue
Private Extern XNextEvent(display As Pointer, event_return As Pointer)
' KeySym XkbKeycodeToKeysym (Display *dpy, KeyCode kc, unsigned int group, unsigned int level)
' Returns the keysym bound to a particular group and shift level for a particular key on the core keyboard.
Private Extern XkbKeycodeToKeysym(dpy As Pointer, kc As Integer, group As Integer, level As Integer) As Long
' Status XSendEvent(Display *display, Window w, Bool propagate, long event_mask, XEvent *event_send)
' Identifies the destination window, determines which clients should receive the specified events.
Private Extern XSendEvent(display As Pointer, w As Long, propagate As Boolean, event_mask As Long, event_send As Pointer) As Integer
' Status XGetWindowAttributes(Display *display, Window w, XWindowAttributes *window_attributes_return)
' Returns the current attributes for the specified window to an XWindowAttributes structure.
Private Extern XGetWindowAttributes(display As Pointer, w As Long, window_attributes As Pointer) As Integer
' GC XDefaultGC(Display *display, int screen_number)
' Returns the default graphics context for the root window of the specified screen.
Private Extern XDefaultGC(display As Pointer, screen_number As Integer) As Pointer
' int XClearArea(Display *display, Window w, int x, int y, unsigned int width, unsigned int height, Bool exposures)
' Paints a rectangular area in the specified window.
Private Extern XClearArea(display As Pointer, w As Long, x As Integer, y As Integer, width As Integer, height As Integer, exposures As Boolean) As Integer
' int XDrawRectangle(Display *display, Drawable d, GC gc, int x, int y, unsigned int width, unsigned int height)
' Draw the outlines of the specified rectangle.
Private Extern XDrawRectangle(display As Pointer, d As Long, gc As Pointer, x As Integer, y As Integer, width As Integer, height As Integer) As Integer
' int XDrawString(Display *display, Drawable d, GC gc, int x, int y, char *string, int length)
' Treats each character image as an additional mask for a fill operation on the drawable.
Private Extern XDrawString(display As Pointer, d As Long, gc As Pointer, x As Integer, y As Integer, stringc As String, length As Integer) As Integer
' XDestroyWindow(Display *display, Window w)
' destroys the specified window as well as all of its subwindows
Private Extern XDestroyWindow(display As Pointer, w As Long)
' XCloseDisplay(Display *display)
' Closes the connection to the X server for the display specified in the Display structure and destroys all windows.
Private Extern XCloseDisplay(display As Pointer)
Public Sub Main()
Dim disp, ev As Pointer
Dim scr As Integer
Dim id, atom, ks As Long
Dim st As Stream
' Apre la connessione con il server display del sistema grafico X:
disp = XOpenDisplay(0)
If disp = 0 Then Error.Raise("Impossibile aprire il server X !")
scr = XDefaultScreen(disp)
' Crea la finestra secondo i parametri previsti dalla funzione. L'ultimo parametro imposta il colore di fondo della finestra:
id = XCreateSimpleWindow(disp, XRootWindow(disp, scr), 0, 0, 200, 300, 0, 0, &FFEFDF)
Print "ID della finestra creata: "; Hex(id, 6)
' Dice al server display quali eventi deve vedere:
XSelectInput(disp, id, ExposureMask Or KeyPressMask Or ButtonPressMask)
' Apre la finestra sullo schermo. Si può utilizzare anche la funzione "XMapWindow(display, w)":
XMapRaised(disp, id)
atom = XInternAtom(disp, "WM_DELETE_WINDOW", False)
XSetWMProtocols(disp, id, VarPtr(atom), 1)
' Alloca un'area di memoria pari alla Struttura esterna 'XEvent' (192 byte):
ev = Alloc(192)
' Inizia il ciclo, restando in attesa di un evento stabilito con la precedente funzione XSelectInput():
While True
XNextEvent(disp, ev)
Select Case Int@(ev)
' Se viene premuta la X nell'angolo alto a destra, chiude la finestra:
Case ClientMessage
If Short@(ev + 56) = atom Then Break
Case Expose
DisegnaCalc(disp, id, scr)
Case KeyPress
ks = XkbKeycodeToKeysym(disp, Int@(ev + 84), 0, 0)
' Se viene premuto il tasto "q" della tastiera, la finestra viene chiusa:
If CByte(ks) = 113 Then
Break
Else
Calcolo(ks)
' Ridisegna la finestra:
st = Memory ev For Write
Write #st, Expose As Integer
st.Close
XSendEvent(disp, id, False, 0, ev)
Endif
Case ButtonPress
Pressione_Tasti(disp, id, Int@(ev + 64), Int@(ev + 68))
st = Memory ev For Write
Write #st, Expose As Integer
st.Close
XSendEvent(disp, id, False, 0, ev)
End Select
Wend
' Chiude la finestra e libera la memoria:
Free(ev)
XDestroyWindow(disp, id)
XCloseDisplay(disp)
End
Private Procedure DisegnaCalc(dis As Pointer, idW As Long, sc As Integer)
Dim i, j, buf_len As Integer
Dim buf As String
Dim attributes, gc As Pointer
' Alloca un'area di memoria pari alla Struttura esterna 'XWindowAttributes' (192 byte):
attributes = Alloc(136)
If XGetWindowAttributes(dis, idW, attributes) = 0 Then Return
gc = XDefaultGC(dis, sc)
XClearArea(dis, idW, SPAZIO, SPAZIO, Int@(attributes + 8) - (SPAZIO * 2), (Int@(attributes + 12) - ((BLOCCHI_Y - 1 + 2) * SPAZIO)) / BLOCCHI_Y, False)
XDrawRectangle(dis, idW, gc, SPAZIO, SPAZIO, Int@(attributes + 8) - (SPAZIO * 2), (Int@(attributes + 12) - ((BLOCCHI_Y - 1 + 2) * SPAZIO)) / BLOCCHI_Y)
buf = Format(valore_mostrato, "0.000000")
buf_len = Len(buf)
XDrawString(dis, idW, gc, 30, 30, buf, buf_len)
For i = 0 To BLOCCHI_X - 1
For j = 1 To BLOCCHI_Y - 1
XDrawRectangle(dis, idW, gc, (((Int@(attributes + 8) - (BLOCCHI_X - 1)) / BLOCCHI_X) * i) + SPAZIO,
(((Int@(attributes + 12) - (BLOCCHI_Y - 1)) / BLOCCHI_Y) * j) + SPAZIO,
(Int@(attributes + 8) - ((BLOCCHI_X - 1 + 2) * SPAZIO)) / BLOCCHI_X, (Int@(attributes + 12) - ((BLOCCHI_Y - 1 + 2) * SPAZIO)) / BLOCCHI_Y)
XDrawString(dis, idW, gc, (((Int@(attributes + 8) / BLOCCHI_X) * (i + 1))) - Int@(attributes + 8) / BLOCCHI_X / 2,
((Int@(attributes + 12) / BLOCCHI_Y) * (j + 1)) - Int@(attributes + 12) / BLOCCHI_Y / 2, simboli[j - 1][i], 1)
Next
Next
Free(attributes)
End
Private Procedure Calcolo(lo As Long)
Select Case CInt(lo)
Case 8, Asc("C"), Asc("c")
valore_mostrato = 0.0
valore_buffer = 0.0
modo_decimale = 0
operazione = 0
disp_mod = 0
Case 48 To 57
If disp_mod Then
valore_mostrato = 0.0
disp_mod = 0
Endif
If modo_decimale Then
If modo_decimale <= 6 Then
valore_mostrato += ((lo - &30) / CFloat(Decimali(10, modo_decimale)))
Inc modo_decimale
Endif
Else
valore_mostrato *= 10
valore_mostrato += (lo - &30)
Endif
Case 44, 46
If modo_decimale = 0 Then modo_decimale = 1
Case 42, 43, 45, 47
If operazione <> 0 Then
Select Case operazione
Case 42
valore_mostrato = valore_buffer * valore_mostrato
Case 43
valore_mostrato = valore_buffer + valore_mostrato
Case 45
valore_mostrato = valore_buffer - valore_mostrato
Case 47
valore_mostrato = valore_buffer / valore_mostrato
End Select
Endif
valore_buffer = valore_mostrato
operazione = lo
disp_mod = 1
modo_decimale = 0
Case &0D, 61
If operazione <> 0 Then
Select Case operazione
Case 42
valore_mostrato = valore_buffer * valore_mostrato
Case 43
valore_mostrato = valore_buffer + valore_mostrato
Case 45
valore_mostrato = valore_buffer - valore_mostrato
Case 47
valore_mostrato = valore_buffer / valore_mostrato
End Select
Endif
operazione = 0
disp_mod = 1
modo_decimale = 0
End Select
End
Private Function Decimali(i As Integer, n As Integer) As Integer
Return i ^ n
End
Private Procedure Pressione_Tasti(di As Pointer, wi As Long, x As Integer, y As Integer)
Dim i, j, x1, x2, y1, y2 As Integer
Dim attributes As Pointer
attributes = Alloc(136)
If XGetWindowAttributes(di, wi, attributes) = 0 Then Return
For i = 0 To BLOCCHI_X - 1
For j = 1 To BLOCCHI_Y - 1
x1 = (((Int@(attributes + 8) - (BLOCCHI_X - 1)) / BLOCCHI_X) * i) + SPAZIO
y1 = (((Int@(attributes + 12) - (BLOCCHI_Y - 1)) / BLOCCHI_Y) * j) + SPAZIO
x2 = x1 + (Int@(attributes + 8) - ((BLOCCHI_X - 1 + 2) * SPAZIO)) / BLOCCHI_X
y2 = y1 + (Int@(attributes + 12) - ((BLOCCHI_Y - 1 + 2) * SPAZIO)) / BLOCCHI_Y
If (x > x1) And (x < x2) And (y > y1) And (y < y2) Then Calcolo(CLong(Asc(simboli[j - 1][i])))
Next
Next
Free(attributes)
End
