[Xcb] drawing a font

[Jeremy Kolb]

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I think you need to handle the window's expose event.  When that event
is received you need to copy the buffer into the window.

Jeremy

Vincent Torri wrote:
| Hello,
|
| Easy question: how to draw a string with xcb ?? i've spent quite a lot of
| time trying to do that, without success.
|
| What i do is a bit like Xlib:
|
| * I query a font
| * I assign the font to a GC
| * I draw a string (in a pixmap) using this GC
| * I copy the pixmap onto my window
|
| but, nothing is drawn. The code that i use is attached.
|
| Does someone see what is wrong ?
|
| Vincent TORRI
|
|
| ------------------------------------------------------------------------
|
| /* gcc -O2 -Wall `pkg-config --cflags --libs xcb` -o xcb_test_font
xcb_test_font.c */
|
| #include <stdio.h>
| #include <stdlib.h>
| #include <string.h>
|
| #include <X11/XCB/xcb.h>
| #include <X11/XCB/xcbint.h>
|
| int
| get_depth(XCBConnection   *c,
| 	  XCBSCREEN       *root)
| {
|   XCBDRAWABLE drawable = { root->root };
|   XCBGetGeometryRep *geom;
|   geom = XCBGetGeometryReply(c, XCBGetGeometry(c, drawable), 0);
|   int depth;
|
|   if(!geom)
|     {
|       perror("GetGeometry(root) failed");
|       exit (0);
|     }
|
|   depth = geom->depth;
|   fprintf(stderr, "Root 0x%lx: %dx%dx%d\n",
| 	  root->root.xid, geom->width, geom->height, geom->depth);
|   free(geom);
|
|   return depth;
| }
|
| int
| main (int argc, char *argv[])
| {
|   XCBConnection   *c;
|   XCBSCREEN       *screen;
|   XCBDRAWABLE      win;
|   CARD32           mask = 0;
|   CARD32           values[2];
|
|   XCBGCONTEXT      bgcolor, fgcolor;
|   XCBRECTANGLE     rect = { 0, 0, 300, 300};
|   CARD32           valgc[2];
|   XCBDRAWABLE      p;
|
|   XCBGCONTEXT gcfont;
|   CARD32  valfont[1];
|   XCBFONTABLE fontable;
|   XCBQueryFontRep *fontrep;
|   char *fontname;
|   char *str = "toto";
|
|   /* Open the connexion to the X server */
|   c = XCBConnectBasic ();
|
|   /* Get the first screen */
|   screen = XCBConnSetupSuccessRepRootsIter (c->setup).data;
|
|   win.window = screen->root;
|
|   fgcolor = XCBGCONTEXTNew(c);
|   mask = GCForeground | GCGraphicsExposures;
|   valgc[0] = screen->black_pixel;
|   valgc[1] = 0; /* no graphics exposures */
|   XCBCreateGC(c, fgcolor, win, mask, valgc);
|
|   bgcolor = XCBGCONTEXTNew(c);
|   mask = GCForeground | GCGraphicsExposures;
|   valgc[0] = screen->white_pixel;
|   valgc[1] = 0; /* no graphics exposures */
|   XCBCreateGC(c, bgcolor, win, mask, valgc);
|
|   p.pixmap = XCBPIXMAPNew (c);
|   XCBCreatePixmap(c, get_depth (c, screen), p.pixmap, win, 300, 300);
|   XCBPolyFillRectangle(c, p, bgcolor, 1, &rect);
|
|   /* Ask for our window's Id */
|   win.window = XCBWINDOWNew(c);
|
|   /* Create the window */
|   mask = XCBCWBackPixel | XCBCWEventMask;
|   values[0] = screen->white_pixel;
|   values[1] = ExposureMask      | ButtonPressMask  | ButtonReleaseMask |
|               PointerMotionMask | ButtonMotionMask | EnterWindowMask   |
|               LeaveWindowMask   | KeyPressMask     | KeyReleaseMask;
|   XCBCreateWindow (c,                        /* Connection          */
| 		   get_depth (c, screen),    /* depth               */
| 		   win.window,               /* window Id           */
| 		   screen->root,             /* parent window       */
| 		   0, 0,                     /* x, y                */
| 		   300, 300,                 /* width, height       */
| 		   10,                       /* border_width        */
| 		   InputOutput,              /* class               */
| 		   screen->root_visual,      /* visual              */
| 		   mask, values);            /* masks */
|
|   /* Map the window on the screen */
|   XCBMapWindow (c, win.window);
|
|   /* The font stuff */
|
|   fontable.font = XCBFONTNew (c);
|   fontname = "*-helvetica-*-12-*";
|   XCBOpenFont(c, fontable.font, strlen(fontname), fontname);
|   fontrep = XCBQueryFontReply (c, XCBQueryFont (c, fontable), 0);
|
|   mask = GCForeground | GCFont;
|   valfont[0] = screen->black_pixel;
|   valfont[1] = fontable.font.xid;
|   gcfont = XCBGCONTEXTNew (c);
|   XCBCreateGC (c, gcfont, p, mask, valfont);
|
|   XCBPolyText8(c, p, gcfont, 10, 10, strlen(str), str);
|
|   XCBCopyArea(c, p, win, fgcolor,
| 	      0, 0, 0, 0, 300, 300);
|
|   XCBSync (c, 0);
|
|   free (fontrep);
|
|   while (1) {}
|
|   return 1;
| }
|
|
|
| ------------------------------------------------------------------------
|
| _______________________________________________
| xcb mailing list
| xcb at lists.freedesktop.org
| http://lists.freedesktop.org/mailman/listinfo/xcb

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