![]() |
![]() |
![]() |
GooCanvas Reference Manual | ![]() |
---|
Simple Canvas ExampleSimple Canvas Example — how to create a simple canvas. |
Here's a complete example application that creates a GooCanvas with a rectangle and a text item in it:
#include <stdlib.h> #include <goocanvas.h> static gboolean on_rect_button_press (GooCanvasItem *view, GooCanvasItem *target, GdkEventButton *event, gpointer data); static gboolean on_delete_event (GtkWidget *window, GdkEvent *event, gpointer unused_data); int main (int argc, char *argv[]) { GtkWidget *window, *scrolled_win, *canvas; GooCanvasItem *root, *rect_item, *text_item; /* Initialize GTK+. */ gtk_set_locale (); gtk_init (&argc, &argv); /* Create the window and widgets. */ window = gtk_window_new (GTK_WINDOW_TOPLEVEL); gtk_window_set_default_size (GTK_WINDOW (window), 640, 600); gtk_widget_show (window); g_signal_connect (window, "delete_event", (GtkSignalFunc) on_delete_event, NULL); scrolled_win = gtk_scrolled_window_new (NULL, NULL); gtk_scrolled_window_set_shadow_type (GTK_SCROLLED_WINDOW (scrolled_win), GTK_SHADOW_IN); gtk_widget_show (scrolled_win); gtk_container_add (GTK_CONTAINER (window), scrolled_win); canvas = goo_canvas_new (); gtk_widget_set_size_request (canvas, 600, 450); goo_canvas_set_bounds (GOO_CANVAS (canvas), 0, 0, 1000, 1000); gtk_widget_show (canvas); gtk_container_add (GTK_CONTAINER (scrolled_win), canvas); root = goo_canvas_get_root_item (GOO_CANVAS (canvas)); /* Add a few simple items. */ rect_item = goo_canvas_rect_new (root, 100, 100, 400, 400, "line-width", 10.0, "radius-x", 20.0, "radius-y", 10.0, "stroke-color", "yellow", "fill-color", "red", NULL); text_item = goo_canvas_text_new (root, "Hello World", 300, 300, -1, GTK_ANCHOR_CENTER, "font", "Sans 24", NULL); goo_canvas_item_rotate (text_item, 45, 300, 300); /* Connect a signal handler for the rectangle item. */ g_signal_connect (rect_item, "button_press_event", (GtkSignalFunc) on_rect_button_press, NULL); /* Pass control to the GTK+ main event loop. */ gtk_main (); return 0; } /* This handles button presses in item views. We simply output a message to the console. */ static gboolean on_rect_button_press (GooCanvasItem *item, GooCanvasItem *target, GdkEventButton *event, gpointer data) { g_print ("rect item received button press event\n"); return TRUE; } /* This is our handler for the "delete-event" signal of the window, which is emitted when the 'x' close button is clicked. We just exit here. */ static gboolean on_delete_event (GtkWidget *window, GdkEvent *event, gpointer unused_data) { exit (0); }