forked from AuroraMiddleware/gtk
gtk-demo: Cosmetic improvements to clocks demo
Reformat the code comments, and add a 10th clock.
This commit is contained in:
Matthias Clasen
parent
087f42d998
commit
11f971d870
@ -41,7 +41,8 @@ enum {
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/* This function returns the current time in the clock's timezone.
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* Note that this returns a new object every time, so we need to
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* remember to unref it after use. */
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* remember to unref it after use.
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*/
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static GDateTime *
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gtk_clock_get_time (GtkClock *clock)
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{
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@ -51,10 +52,11 @@ gtk_clock_get_time (GtkClock *clock)
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return g_date_time_new_now_local ();
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}
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/* Here, we implement the functionality required by the GdkPaintable interface.
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* This way we have a trivial way to display an analog clock.
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* It also allows demonstrating how to directly use objects in the listview
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* later by making this object do something interesting. */
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/* Here, we implement the functionality required by the GdkPaintable
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* interface. This way we have a trivial way to display an analog clock.
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* It also allows demonstrating how to directly use objects in the
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* listview later by making this object do something interesting.
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*/
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static void
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gtk_clock_snapshot (GdkPaintable *paintable,
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GdkSnapshot *snapshot,
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@ -68,26 +70,31 @@ gtk_clock_snapshot (GdkPaintable *paintable,
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#define BLACK ((GdkRGBA) { 0, 0, 0, 1 })
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/* save/restore() is necessary so we can undo the transforms we start
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* out with. */
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* out with.
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*/
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gtk_snapshot_save (snapshot);
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/* First, we move the (0, 0) point to the center of the area so
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* we can draw everything relative to it. */
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* we can draw everything relative to it.
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*/
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gtk_snapshot_translate (snapshot, &GRAPHENE_POINT_INIT (width / 2, height / 2));
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/* Next we scale it, so that we can pretend that the clock is
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* 100px in size. That way, we don't need to do any complicated
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* math later.
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* We use MIN() here so that we use the smaller dimension for sizing.
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* That way we don't overdraw but keep the aspect ratio. */
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* math later. We use MIN() here so that we use the smaller
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* dimension for sizing. That way we don't overdraw but keep
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* the aspect ratio.
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*/
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gtk_snapshot_scale (snapshot, MIN (width, height) / 100.0, MIN (width, height) / 100.0);
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/* Now we have a circle with diameter 100px (and radius 50px) that
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* has its (0, 0) point at the center.
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* Let's draw a simple clock into it. */
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/* Now we have a circle with diameter 100px (and radius 50px) that
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* has its (0, 0) point at the center. Let's draw a simple clock into it.
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*/
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time = gtk_clock_get_time (self);
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/* First, draw a circle. This is a neat little trick to draw a circle
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* without requiring Cairo. */
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* without requiring Cairo.
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*/
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gsk_rounded_rect_init_from_rect (&outline, &GRAPHENE_RECT_INIT(-50, -50, 100, 100), 50);
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gtk_snapshot_append_border (snapshot,
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&outline,
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@ -95,9 +102,11 @@ gtk_clock_snapshot (GdkPaintable *paintable,
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(GdkRGBA [4]) { BLACK, BLACK, BLACK, BLACK });
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/* Next, draw the hour hand.
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* We do this using tranforms again: Instead of computing where the angle points
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* to, we just rotate everything and then draw the hand as if if was :00.
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* We don't even need to care about am/pm here because rotations just work. */
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* We do this using tranforms again: Instead of computing where the angle
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* points to, we just rotate everything and then draw the hand as if it
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* was :00. We don't even need to care about am/pm here because rotations
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* just work.
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*/
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gtk_snapshot_save (snapshot);
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gtk_snapshot_rotate (snapshot, 30 * g_date_time_get_hour (time) + 0.5 * g_date_time_get_minute (time));
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gsk_rounded_rect_init_from_rect (&outline, &GRAPHENE_RECT_INIT(-2, -23, 4, 25), 2);
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@ -107,7 +116,8 @@ gtk_clock_snapshot (GdkPaintable *paintable,
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gtk_snapshot_restore (snapshot);
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/* And the same as above for the minute hand. Just make this one longer
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* so people can tell the hands apart. */
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* so people can tell the hands apart.
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*/
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gtk_snapshot_save (snapshot);
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gtk_snapshot_rotate (snapshot, 6 * g_date_time_get_minute (time));
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gsk_rounded_rect_init_from_rect (&outline, &GRAPHENE_RECT_INIT(-2, -43, 4, 45), 2);
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@ -125,8 +135,9 @@ gtk_clock_snapshot (GdkPaintable *paintable,
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gtk_snapshot_pop (snapshot);
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gtk_snapshot_restore (snapshot);
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/* And finally, don't forget to restore the initial save() that we did for
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* the initial transformations. */
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/* And finally, don't forget to restore the initial save() that
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* we did for the initial transformations.
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*/
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gtk_snapshot_restore (snapshot);
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g_date_time_unref (time);
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@ -145,10 +156,9 @@ gtk_clock_get_intrinsic_height (GdkPaintable *paintable)
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return 100;
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}
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/* Initialize the paintable interface. This way we turn our clock objects
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* into objects that can be drawn.
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* There are more functions to this interface to define desired size,
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* but this is enough.
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/* Initialize the paintable interface. This way we turn our clocks
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* into objects that can be drawn. There are more functions to this
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* interface to define desired size, but this is enough.
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*/
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static void
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gtk_clock_paintable_init (GdkPaintableInterface *iface)
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@ -158,8 +168,9 @@ gtk_clock_paintable_init (GdkPaintableInterface *iface)
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iface->get_intrinsic_height = gtk_clock_get_intrinsic_height;
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}
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/* Finally, we define the type. The important part is adding the paintable
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* interface, so GTK knows that this object can indeed be drawm.
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/* Finally, we define the type. The important part is adding the
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* paintable interface, so GTK knows that this object can indeed
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* be drawn.
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*/
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G_DEFINE_TYPE_WITH_CODE (GtkClock, gtk_clock, G_TYPE_OBJECT,
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G_IMPLEMENT_INTERFACE (GDK_TYPE_PAINTABLE,
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@ -221,11 +232,14 @@ gtk_clock_set_property (GObject *object,
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/* This is the list of all the ticking clocks */
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static GSList *ticking_clocks = NULL;
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/* This is the id of the timeout source that is updating all ticking clocks */
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/* This is the ID of the timeout source that is updating all
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* ticking clocks.
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*/
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static guint ticking_clock_id = 0;
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/* Every second, this function is called to tell everybody that the
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* clocks are ticking.
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/* Every second, this function is called to tell everybody that
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* the clocks are ticking.
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*/
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static gboolean
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gtk_clock_tick (gpointer unused)
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@ -240,6 +254,7 @@ gtk_clock_tick (gpointer unused)
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* so notify about that.
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*/
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g_object_notify_by_pspec (G_OBJECT (clock), properties[PROP_TIME]);
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/* We will also draw the hands of the clock differently.
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* So notify about that, too.
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*/
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@ -343,6 +358,9 @@ create_clocks_model (void)
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clock = gtk_clock_new ("San Francisco", g_time_zone_new ("America/Los_Angeles"));
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g_list_store_append (result, clock);
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g_object_unref (clock);
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clock = gtk_clock_new ("Xalapa", g_time_zone_new ("America/Mexico_City"));
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g_list_store_append (result, clock);
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g_object_unref (clock);
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clock = gtk_clock_new ("Boston", g_time_zone_new ("America/New_York"));
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g_list_store_append (result, clock);
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g_object_unref (clock);
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