demos: Add a map demo

For now, this just shows a world map.

Once we have measures, we can make this
a little more interesting.

demos/gtk-demo/demo.gresource.xml

@@ -336,6 +336,7 @@
     <file>panes.c</file>
     <file>password_entry.c</file>
     <file>path_fill.c</file>
+    <file>path_walk.c</file>
     <file>peg_solitaire.c</file>
     <file>pickers.c</file>
     <file>printing.c</file>
@@ -421,6 +422,10 @@
   <gresource prefix="/fontrendering">
     <file>fontrendering.ui</file>
   </gresource>
+  <gresource prefix="/path_walk">
+    <file>path_walk.ui</file>
+    <file>path_world.c</file>
+  </gresource>
   <gresource prefix="/org/gtk/Demo4">
     <file>icons/16x16/actions/application-exit.png</file>
     <file>icons/16x16/actions/document-new.png</file>

demos/gtk-demo/meson.build

@@ -73,6 +73,7 @@ demos = files([
   'panes.c',
   'password_entry.c',
   'path_fill.c',
+  'path_walk.c',
   'peg_solitaire.c',
   'pickers.c',
   'printing.c',

demos/gtk-demo/path_walk.c

@@ -0,0 +1,190 @@
+/* Path/Map
+ *
+ * This demo shows how to draw a map using paths.
+ */
+
+#include <glib/gi18n.h>
+#include <gtk/gtk.h>
+
+#include "path_world.c"
+
+#define GTK_TYPE_PATH_WALK (gtk_path_walk_get_type ())
+G_DECLARE_FINAL_TYPE (GtkPathWalk, gtk_path_walk, GTK, PATH_WALK, GtkWidget)
+
+#define POINT_SIZE 8
+
+enum {
+  PROP_0,
+  PROP_PATH,
+  N_PROPS
+};
+
+struct _GtkPathWalk
+{
+  GtkWidget parent_instance;
+
+  GskPath *path;
+};
+
+struct _GtkPathWalkClass
+{
+  GtkWidgetClass parent_class;
+};
+
+static GParamSpec *properties[N_PROPS] = { NULL, };
+
+G_DEFINE_TYPE (GtkPathWalk, gtk_path_walk, GTK_TYPE_WIDGET)
+
+static void
+gtk_path_walk_snapshot (GtkWidget   *widget,
+                        GtkSnapshot *snapshot)
+{
+  GtkPathWalk *self = GTK_PATH_WALK (widget);
+  double width = gtk_widget_get_width (widget);
+  double height = gtk_widget_get_height (widget);
+  GskStroke *stroke;
+
+  if (self->path == NULL)
+    return;
+
+  gtk_snapshot_save (snapshot);
+
+  stroke = gsk_stroke_new (2.0);
+  gtk_snapshot_push_stroke (snapshot, self->path, stroke);
+  gtk_snapshot_append_color (snapshot, &(GdkRGBA) { 0, 0, 0, 1 }, &GRAPHENE_RECT_INIT (0, 0, width, height));
+  gtk_snapshot_pop (snapshot);
+  gsk_stroke_free (stroke);
+
+  gtk_snapshot_restore (snapshot);
+}
+
+static void
+gtk_path_walk_set_path (GtkPathWalk *self,
+                        GskPath     *path)
+{
+  if (self->path == path)
+    return;
+
+  g_clear_pointer (&self->path, gsk_path_unref);
+  if (path)
+    self->path = gsk_path_ref (path);
+
+  gtk_widget_queue_draw (GTK_WIDGET (self));
+
+  g_object_notify_by_pspec (G_OBJECT (self), properties[PROP_PATH]);
+}
+
+static void
+gtk_path_walk_set_property (GObject      *object,
+                            guint         prop_id,
+                            const GValue *value,
+                            GParamSpec   *pspec)
+
+{
+  GtkPathWalk *self = GTK_PATH_WALK (object);
+
+  switch (prop_id)
+    {
+    case PROP_PATH:
+      gtk_path_walk_set_path (self, g_value_get_boxed (value));
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+      break;
+    }
+}
+
+static void
+gtk_path_walk_get_property (GObject    *object,
+                            guint       prop_id,
+                            GValue     *value,
+                            GParamSpec *pspec)
+{
+  GtkPathWalk *self = GTK_PATH_WALK (object);
+
+  switch (prop_id)
+    {
+    case PROP_PATH:
+      g_value_set_boxed (value, self->path);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+      break;
+    }
+}
+
+static void
+gtk_path_walk_dispose (GObject *object)
+{
+  GtkPathWalk *self = GTK_PATH_WALK (object);
+
+  g_clear_pointer (&self->path, gsk_path_unref);
+
+  G_OBJECT_CLASS (gtk_path_walk_parent_class)->dispose (object);
+}
+
+static void
+gtk_path_walk_class_init (GtkPathWalkClass *klass)
+{
+  GtkWidgetClass *widget_class = GTK_WIDGET_CLASS (klass);
+  GObjectClass *object_class = G_OBJECT_CLASS (klass);
+
+  object_class->dispose = gtk_path_walk_dispose;
+  object_class->set_property = gtk_path_walk_set_property;
+  object_class->get_property = gtk_path_walk_get_property;
+
+  widget_class->snapshot = gtk_path_walk_snapshot;
+
+  properties[PROP_PATH] =
+    g_param_spec_boxed ("path",
+                        NULL, NULL,
+                        GSK_TYPE_PATH,
+                        G_PARAM_READWRITE | G_PARAM_EXPLICIT_NOTIFY | G_PARAM_STATIC_STRINGS);
+
+  g_object_class_install_properties (object_class, N_PROPS, properties);
+}
+
+static void
+gtk_path_walk_init (GtkPathWalk *self)
+{
+  self->path = gsk_path_parse (path_world);
+}
+
+GtkWidget *
+gtk_path_walk_new (void)
+{
+  GtkPathWalk *self;
+
+  self = g_object_new (GTK_TYPE_PATH_WALK, NULL);
+
+  return GTK_WIDGET (self);
+}
+
+GtkWidget *
+do_path_walk (GtkWidget *do_widget)
+{
+  static GtkWidget *window = NULL;
+
+  if (!window)
+    {
+      GtkBuilder *builder;
+
+      g_type_ensure (GTK_TYPE_PATH_WALK);
+
+      builder = gtk_builder_new_from_resource ("/path_walk/path_walk.ui");
+      window = GTK_WIDGET (gtk_builder_get_object (builder, "window"));
+      gtk_window_set_display (GTK_WINDOW (window),
+                              gtk_widget_get_display (do_widget));
+      g_object_add_weak_pointer (G_OBJECT (window), (gpointer *) &window);
+      g_object_unref (builder);
+    }
+
+  if (!gtk_widget_get_visible (window))
+    gtk_window_present (GTK_WINDOW (window));
+  else
+    gtk_window_destroy (GTK_WINDOW (window));
+
+  return window;
+}

demos/gtk-demo/path_walk.ui

@@ -0,0 +1,36 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<interface>
+  <object class="GtkWindow" id="window">
+    <property name="title" translatable="yes">Animation along a Path</property>
+    <child type="titlebar">
+      <object class="GtkHeaderBar">
+        <child type="end">
+          <object class="GtkToggleButton" id="edit-toggle">
+            <property name="icon-name">document-edit-symbolic</property>
+          </object>
+        </child>
+      </object>
+    </child>
+    <child>
+      <object class="GtkBox">
+        <property name="orientation">vertical</property>
+        <child>
+          <object class="GtkRevealer">
+            <property name="reveal-child" bind-source="edit-toggle" bind-property="active" bind-flags="sync-create"></property>
+            <child>
+              <object class="GtkEntry" id="text">
+                <property name="text">Through the looking glass</property>
+              </object>
+            </child>
+          </object>
+        </child>
+        <child>
+          <object class="GtkPathWalk" id="view">
+            <property name="hexpand">true</property>
+            <property name="vexpand">true</property>
+          </object>
+        </child>
+      </object>
+    </child>
+  </object>
+</interface>