branches/2d_boundary/Tests/svgfig/_viewer.c

   1 #include <Python.h>
   2 #include <gtk/gtk.h>
   3 #include <gdk/gdkdrawable.h>
   4 #include <gdk/gdkcairo.h>
   5 #include <librsvg-2/librsvg/rsvg.h>
   6 #include <librsvg-2/librsvg/rsvg-cairo.h>
   7 #include <time.h>
   8
   9 #ifndef PyMODINIT_FUNC
  10 #define PyMODINIT_FUNC void
  11 #endif
  12
  13 static GtkWidget *window;
  14 static GtkWidget *drawing_area;
  15 static char ready = 0;
  16 static char done = 1;
  17 static RsvgHandle *rsvg = NULL;
  18
  19 static void draw(GtkWidget *widget, cairo_t *cr) {
  20   if (rsvg == NULL) return;
  21
  22   double window_width, window_height;
  23   window_width = widget->allocation.width;
  24   window_height = widget->allocation.height;
  25
  26   RsvgDimensionData dimensions;
  27   rsvg_handle_get_dimensions(rsvg, &dimensions);
  28   unsigned int w, h;
  29   w = dimensions.width;
  30   h = dimensions.height;
  31   double aspect_ratio;
  32   aspect_ratio = 1.0 * w / h;
  33
  34   double page_width, page_height;
  35   page_height = window_height - 8;
  36   page_width = page_height * aspect_ratio;
  37   if (page_width > window_width - 8) {
  38     page_width = window_width - 8;
  39     page_height = page_width / aspect_ratio;
  40   }
  41   double x = (window_width - page_width + 4.) / 2.;
  42   double y = (window_height - page_height + 4.) / 2.;
  43
  44   cairo_rectangle(cr, x, y, page_width, page_height);
  45   cairo_set_source_rgb(cr, 1, 1, 1);
  46   cairo_fill(cr);
  47
  48   cairo_translate(cr, x, y);
  49   cairo_scale(cr, page_width/w, page_height/h);
  50   rsvg_handle_render_cairo(rsvg, cr);
  51 }
  52
  53 static gboolean expose_event(GtkWidget *widget, GdkEventExpose *event) {
  54   ready = 0;
  55
  56   cairo_t *cr;
  57   cr = gdk_cairo_create(widget->window);
  58   cairo_rectangle(cr, event->area.x, event->area.y, event->area.width, event->area.height);
  59   cairo_clip(cr);
  60   draw(widget, cr);
  61   cairo_destroy(cr);
  62
  63   ready = 1;
  64   return FALSE;
  65 }
  66
  67 static void *thread() {
  68   done = 0;
  69
  70   gtk_init(0, NULL);
  71   window = gtk_window_new(GTK_WINDOW_TOPLEVEL);
  72   gtk_window_set_title(GTK_WINDOW(window), "SVGFig");
  73   drawing_area = gtk_drawing_area_new();
  74   gtk_container_add(GTK_CONTAINER(window), drawing_area);
  75
  76   g_signal_connect(GTK_OBJECT(window), "delete_event", (GtkSignalFunc)(gtk_main_quit), NULL);
  77   g_signal_connect(GTK_OBJECT(drawing_area), "expose_event", (GtkSignalFunc)(expose_event), NULL);
  78   gtk_widget_set_events(drawing_area, GDK_EXPOSURE_MASK);
  79
  80   gtk_widget_show(drawing_area);
  81   gtk_widget_show(window);
  82
  83   ready = 1;
  84   gtk_main();
  85   done = 1;
  86   return NULL;
  87 }
  88
  89 static PyObject *_viewer_str(PyObject *self, PyObject *args) {
  90   char *str_source = NULL;
  91   int str_size;
  92   if (!PyArg_ParseTuple(args, "es#", "utf-16", &str_source, &str_size)) {
  93     PyErr_SetString(PyExc_TypeError, "source must be an SVG string or Unicode object.");
  94     return NULL;
  95   }
  96
  97   if (done) {
  98     GError *error = NULL;
  99     if (!g_thread_create(thread, NULL, FALSE, &error)) {
 100       PyErr_Format(PyExc_RuntimeError, "Could not create GDK thread: %s", error->message);
 101       PyMem_Free(str_source);
 102       return NULL;
 103     }
 104   }
 105
 106   if (rsvg != NULL) {
 107     g_object_unref(rsvg);
 108     rsvg = NULL;
 109   }
 110
 111   GError* error = NULL;
 112   rsvg = rsvg_handle_new_from_data((guint8*)(str_source), (gsize)(str_size), &error);
 113   if (rsvg == NULL) {
 114     PyErr_Format(PyExc_RuntimeError, "Couldn't parse SVG: %s", error->message);
 115     PyMem_Free(str_source);
 116     return NULL;
 117   }
 118
 119   /* wait for the window to appear, and don't wait forever */
 120   /* if 5 seconds are reached, don't explicitly throw an error, let */
 121   /* GDK do that if it needs to */
 122   g_thread_yield();
 123   time_t start = time(NULL);
 124   while (!ready) {
 125     time_t now = time(NULL);
 126     if (difftime(now, start) > 5) break;
 127   }
 128
 129   gdk_threads_enter();
 130   gtk_widget_queue_draw(drawing_area);
 131   gdk_threads_leave();
 132
 133   PyMem_Free(str_source);
 134   return Py_BuildValue("O", Py_None);
 135 }
 136
 137 static PyMethodDef _viewer_methods[] = {
 138   {"str", ((PyCFunction)(_viewer_str)), METH_VARARGS, ""},
 139   {NULL}
 140 };
 141
 142 PyMODINIT_FUNC init_viewer() {
 143   Py_InitModule3("_viewer", _viewer_methods, "");
 144   rsvg_init();
 145   g_thread_init(NULL);
 146   gdk_threads_init();
 147 }