ghosd.c

   1 /* Fast refactoring of ghosd-0.0.1/examples/text.c.
   2  */
   3
   4 #include <Python.h>
   5
   6 #include <cairo/cairo.h>
   7 #include <pango/pangocairo.h>
   8 #include <time.h>
   9 #include <unistd.h>
  10
  11 #include <X11/Xlib.h>
  12
  13 #include <ghosd/ghosd.h>
  14 #include <ghosd/ghosd-text.h>
  15
  16 struct _ghosd_render_info {
  17   PangoLayout * layout;
  18   float fgr, fgg, fgb, fga,
  19         bgr, bgg, bgb, bga;
  20 };
  21
  22 static void
  23 render(Ghosd *ghosd, cairo_t *cr, void* data) {
  24
  25   struct _ghosd_render_info * ri = data;
  26
  27   /* drop shadow! */
  28   cairo_set_source_rgba(cr, ri->bgr, ri->bgg, ri->bgb, ri->bga);
  29   cairo_move_to(cr, 2, 2);
  30   pango_cairo_show_layout(cr, ri->layout);
  31
  32   /* and the actual text. */
  33   cairo_set_source_rgba(cr, ri->fgr, ri->fgg, ri->fgb, ri->fga);
  34   cairo_move_to(cr, 0, 0);
  35   pango_cairo_show_layout(cr, ri->layout);
  36 }
  37
  38 static PyObject *
  39 ghosd_flash_text(PyObject * self, PyObject * args, PyObject * kw)
  40 {
  41   static char * kwlist[] = {"text", "x", "y",
  42                             "fade_time", "display_time",
  43                             "fg_color", "bg_color", NULL};
  44   Ghosd *ghosd;
  45   PangoContext * context;
  46   struct _ghosd_render_info ri;
  47   int x = -50, y = -50, fade = 300, dtime = 2000;
  48   char * text = NULL;
  49   PyObject * fg_color = NULL, * bg_color = NULL;
  50
  51   if (!PyArg_ParseTupleAndKeywords(args, kw, "s|iiiiOO",
  52                                    kwlist,
  53                                    &text,
  54                                    &x, &y, &fade, &dtime, &fg_color, &bg_color))
  55     return NULL;
  56
  57 #define cbcheck(nam, c) ((ri.nam ## c >= 0) && (ri.nam ## c <= 1))
  58 #define colcheck(nam)  \
  59   if (nam ## _color) { \
  60     if (!PyTuple_Check(nam ## _color)) { \
  61       PyErr_SetString(PyExc_TypeError, #nam "_color should be a tuple"); \
  62       return NULL; \
  63     } \
  64     if (!PyArg_ParseTuple(nam ## _color, "ffff",  \
  65                           & ri.nam ## r, & ri.nam## g, \
  66                           & ri.nam ## b, & ri.nam ## a)) {      \
  67       PyErr_SetString(PyExc_TypeError, \
  68                       #nam "_color should be a 4-tuple of floats"); \
  69       return NULL; \
  70     } \
  71     if (!cbcheck(nam, r) || !cbcheck(nam, g) || \
  72         !cbcheck(nam, b) || !cbcheck(nam, a)) { \
  73       PyErr_SetString(PyExc_ValueError, \
  74                       "all components in " #nam \
  75                       "_color should be between 0 and 1"); \
  76       return NULL; \
  77     } \
  78   }
  79
  80   ri.fgr = ri.fgg = ri.fgb = ri.fga = 1;
  81   ri.bgr = ri.bgg = ri.bgb          = 0; ri.bga = .5;
  82
  83   colcheck(fg)
  84   colcheck(bg)
  85
  86 #undef cbcheck
  87 #undef colcheck
  88
  89   /* Finally, we are there: let's use this ghosd lib!
  90    */
  91   if (!(context = pango_cairo_font_map_create_context(
  92                   PANGO_CAIRO_FONT_MAP(pango_cairo_font_map_get_default())))) {
  93     PyErr_SetString(PyExc_RuntimeError,
  94                     "could not create pango context");
  95     return NULL;
  96   }
  97
  98   if (!(ri.layout = pango_layout_new(context))) {
  99     PyErr_SetString(PyExc_RuntimeError,
 100                     "could not create pango layout");
 101     g_object_unref(context);
 102     return NULL;
 103   }
 104
 105   pango_layout_set_markup(ri.layout, text, -1);
 106
 107   if (!(ghosd = ghosd_new())) {
 108     PyErr_SetString(PyExc_RuntimeError,
 109                     "could not create ghosd object");
 110     g_object_unref(ri.layout);
 111     g_object_unref(context);
 112     return NULL;
 113   }
 114
 115   ghosd_text_set_position(ghosd, x, y, ri.layout);
 116   ghosd_set_render(ghosd, render, &ri);
 117
 118   ghosd_flash(ghosd, fade, dtime);
 119
 120   /* Free the various objects */
 121   free(ghosd);                /* See ghosd-0.0.1/ghosd/ghosd.c:
 122                                  no API for now, but that's just
 123                                  a calloc'ed struct: no API to close
 124                                  the display unfortunately. */
 125   g_object_unref(ri.layout);
 126   g_object_unref(context);
 127
 128   Py_INCREF(Py_None);
 129   return Py_None;
 130
 131 }
 132
 133 static PyMethodDef ghosdMethods[] = {
 134   { "flash_text", (PyCFunction)ghosd_flash_text, METH_VARARGS | METH_KEYWORDS ,
 135 "flash_text(text, x=-50, y=-50, fade_time=300, display_time=2000, \n\
 136 fg_color=(1, 1, 1, 1), bg_color=(0, 0, 0, .5)) => None\n\
 137 \n\
 138 Flash a given text message onto the screen.\n\
 139 \n\
 140 - text         text to be displayed, in Pango markup (see below)\n\
 141 - x, y         position onto the screen\n\
 142 - fade_time    time, in milliseconds, for fading the text in and out\n\
 143 - display_time time the text is to be displayed\n\
 144 - fg_color     RGBA default text color\n\
 145 - bg_color     RGBA text shadow color\n\
 146 \n\
 147 A concise description of the Pango Markup Language can be found\n\
 148 in PyGTK documentation:\n\
 149 \n\
 150 http://www.pygtk.org/docs/pygtk/pango-markup-language.html\n\
 151 "},
 152   {NULL}
 153 };
 154
 155
 156 PyMODINIT_FUNC
 157 init_ghosd(void)
 158 {
 159   g_type_init();
 160   Py_InitModule("_ghosd", ghosdMethods);
 161 }