X-Git-Url: https://git.cworth.org/git?a=blobdiff_plain;f=demo-item.c;fp=demo-item.c;h=2eaf830c2235faee43ec53633f3c7d2262e90ec7;hb=f8d083966703a2b0efb6db1782a14a1a0b5d56f4;hp=0000000000000000000000000000000000000000;hpb=80df493bc40d2f6d59719abccc0323653d05fca9;p=wordgame

diff --git a/demo-item.c b/demo-item.c
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+++ b/demo-item.c
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+/*
+ * GooCanvas Demo. Copyright (C) 2006 Damon Chaplin.
+ * Released under the GNU LGPL license. See COPYING for details.
+ *
+ * demo-item.c - a simple demo item.
+ */
+#include "goocanvas.h"
+#include "demo-item.h"
+
+/* Use the GLib convenience macro to define the type. GooDemoItem is the
+   class struct, goo_demo_item is the function prefix, and our class is a
+   subclass of GOO_TYPE_CANVAS_ITEM_SIMPLE. */
+G_DEFINE_TYPE (GooDemoItem, goo_demo_item, GOO_TYPE_CANVAS_ITEM_SIMPLE)
+
+/* The standard object initialization function. */
+    static void
+goo_demo_item_init (GooDemoItem *demo_item)
+{
+    demo_item->x = 0.0;
+    demo_item->y = 0.0;
+    demo_item->width = 0.0;
+    demo_item->height = 0.0;
+}
+
+/* The convenience function to create new items. This should start with a 
+   parent argument and end with a variable list of object properties to fit
+   in with the standard canvas items. */
+GooCanvasItem*
+goo_demo_item_new (GooCanvasItem      *parent,
+		   gdouble             x,
+		   gdouble             y,
+		   gdouble             width,
+		   gdouble             height,
+		   ...)
+{
+    GooCanvasItem *item;
+    GooDemoItem *demo_item;
+    const char *first_property;
+    va_list var_args;
+
+    item = g_object_new (GOO_TYPE_DEMO_ITEM, NULL);
+
+    demo_item = (GooDemoItem*) item;
+    demo_item->x = x;
+    demo_item->y = y;
+    demo_item->width = width;
+    demo_item->height = height;
+
+    va_start (var_args, height);
+    first_property = va_arg (var_args, char*);
+    if (first_property)
+	g_object_set_valist ((GObject*) item, first_property, var_args);
+    va_end (var_args);
+
+    if (parent)
+    {
+	goo_canvas_item_add_child (parent, item, -1);
+	g_object_unref (item);
+    }
+
+    return item;
+}
+
+/* The update method. This is called when the canvas is initially shown and
+   also whenever the object is updated and needs to change its size and/or
+   shape. It should calculate its new bounds, storing them in simple->bounds,
+   and it should convert these to device coordinates. */
+static void
+goo_demo_item_update  (GooCanvasItemSimple *simple,
+		       cairo_t             *cr)
+{
+    GooDemoItem *demo_item = (GooDemoItem*) simple;
+
+    /* Compute the new bounds. */
+    simple->bounds.x1 = demo_item->x;
+    simple->bounds.y1 = demo_item->y;
+    simple->bounds.x2 = demo_item->x + demo_item->width;
+    simple->bounds.y2 = demo_item->y + demo_item->height;
+
+    /* Convert to device coordinates. */
+    goo_canvas_item_simple_user_bounds_to_device (simple, cr, &simple->bounds);
+}
+
+/* The paint method. This should draw the item on the given cairo_t, using
+   the item's own coordinate space. */
+static void
+goo_demo_item_paint (GooCanvasItemSimple *simple,
+		     cairo_t             *cr,
+		     GooCanvasBounds     *bounds)
+{
+    GooDemoItem *demo_item = (GooDemoItem*) simple;
+
+    cairo_move_to (cr, demo_item->x, demo_item->y);
+    cairo_line_to (cr, demo_item->x, demo_item->y + demo_item->height);
+    cairo_line_to (cr, demo_item->x + demo_item->width,
+		   demo_item->y + demo_item->height);
+    cairo_line_to (cr, demo_item->x + demo_item->width, demo_item->y);
+    cairo_close_path (cr);
+    goo_canvas_style_set_fill_options (simple->simple_data->style, cr);
+    cairo_fill (cr);
+}
+
+/* Hit detection. This should check if the given coordinate (in the item's
+   coordinate space) is within the item. If it is it should return the item,
+   otherwise it should return NULL. */
+static GooCanvasItem*
+goo_demo_item_get_item_at (GooCanvasItemSimple *simple,
+			   gdouble              x,
+			   gdouble              y,
+			   cairo_t             *cr,
+			   gboolean             is_pointer_event)
+{
+    GooDemoItem *demo_item = (GooDemoItem*) simple;
+
+    if (x < demo_item->x || (x > demo_item->x + demo_item->width)
+	|| y < demo_item->y || (y > demo_item->y + demo_item->height))
+	return NULL;
+
+    return (GooCanvasItem*) simple;
+}
+
+/* The class initialization function. Here we set the class' update(), paint()
+   and get_item_at() methods. */
+static void
+goo_demo_item_class_init (GooDemoItemClass *klass)
+{
+    GooCanvasItemSimpleClass *simple_class = (GooCanvasItemSimpleClass*) klass;
+
+    simple_class->update        = goo_demo_item_update;
+    simple_class->paint         = goo_demo_item_paint;
+    simple_class->get_item_at   = goo_demo_item_get_item_at;
+}