gtk-builder-tool: Add a screenshot command

This is an obvious variation of the preview
command. It can save a .ui file as either
.png or .node.

6 files changed, 403 insertions, 5 deletions

diff --git a/docs/reference/gtk/gtk4-builder-tool.rst b/docs/reference/gtk/gtk4-builder-tool.rst
index 80998a9d96..9e011a330f 100644
--- a/docs/reference/gtk/gtk4-builder-tool.rst
+++ b/docs/reference/gtk/gtk4-builder-tool.rst
@@ -16,6 +16,7 @@ SYNOPSIS
 |   **gtk4-builder-tool** enumerate <FILE>
 |   **gtk4-builder-tool** simplify [OPTIONS...] <FILE>
 |   **gtk4-builder-tool** preview [OPTIONS...] <FILE>
+|   **gtk4-builder-tool** screenshot [OPTIONS...] <FILE>
 
 DESCRIPTION
 -----------
@@ -41,7 +42,7 @@ definition file.
 Preview
 ^^^^^^^
 
-The ``preview`` command displays the UI dfinition file.
+The ``preview`` command displays the UI definition file.
 
 This command accepts options to specify the ID of the toplevel object and a CSS
 file to use.
@@ -55,6 +56,33 @@ file to use.
 
   Load style information from the given CSS file.
 
+Screenshot
+^^^^^^^^^^
+
+The ``screenshot`` command saves a rendering of the UI definition file
+as a png image or node file. The name of the file to write can be specified as
+a second FILE argument.
+
+This command accepts options to specify the ID of the toplevel object and a CSS
+file to use.
+
+``--id=ID``
+
+  The ID of the object to preview. If not specified, gtk4-builder-tool will
+  choose a suitable object on its own.
+
+``--css=FILE``
+
+  Load style information from the given CSS file.
+
+``--node``
+
+  Write a serialized node file instead of a png image.
+
+``--force``
+
+  Overwrite an existing file.
+
 Simplification
 ^^^^^^^^^^^^^^
 
diff --git a/po/POTFILES.in b/po/POTFILES.in
index 99c2034b9a..0f408e8b7c 100644
--- a/po/POTFILES.in
+++ b/po/POTFILES.in
@@ -405,6 +405,7 @@ tools/encodesymbolic.c
 tools/gtk-builder-tool.c
 tools/gtk-builder-tool-enumerate.c
 tools/gtk-builder-tool-preview.c
+tools/gtk-builder-tool-screenshot.c
 tools/gtk-builder-tool-simplify.c
 tools/gtk-builder-tool-validate.c
 tools/gtk-launch.c
diff --git a/tools/gtk-builder-tool-screenshot.c b/tools/gtk-builder-tool-screenshot.c
new file mode 100644
index 0000000000..81bf22bd9a
--- /dev/null
+++ b/tools/gtk-builder-tool-screenshot.c
@@ -0,0 +1,362 @@
+/*  Copyright 2015 Red Hat, Inc.
+ *
+ * GTK+ is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * GLib is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with GTK+; see the file COPYING.  If not,
+ * see <http://www.gnu.org/licenses/>.
+ *
+ * Author: Matthias Clasen
+ */
+
+#include "config.h"
+
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+
+#include <glib/gi18n.h>
+#include <glib/gprintf.h>
+#include <glib/gstdio.h>
+#include <gtk/gtk.h>
+#include "gtkbuilderprivate.h"
+#include "gtk-builder-tool.h"
+
+static gboolean
+quit_when_idle (gpointer loop)
+{
+  g_main_loop_quit (loop);
+
+  return G_SOURCE_REMOVE;
+}
+
+static GMainLoop *loop;
+
+static void
+draw_paintable (GdkPaintable *paintable,
+                gpointer      out_texture)
+{
+  GtkSnapshot *snapshot;
+  GskRenderNode *node;
+  GdkTexture *texture;
+  GskRenderer *renderer;
+
+  snapshot = gtk_snapshot_new ();
+  gdk_paintable_snapshot (paintable,
+                          snapshot,
+                          gdk_paintable_get_intrinsic_width (paintable),
+                          gdk_paintable_get_intrinsic_height (paintable));
+  node = gtk_snapshot_free_to_node (snapshot);
+
+  /* If the window literally draws nothing, we assume it hasn't been mapped yet and as such
+   * the invalidations were only side effects of resizes.
+   */
+  if (node == NULL)
+    return;
+
+  renderer = gtk_native_get_renderer (
+                 gtk_widget_get_native (
+                     gtk_widget_paintable_get_widget (GTK_WIDGET_PAINTABLE (paintable))));
+  texture = gsk_renderer_render_texture (renderer,
+                                         node,
+                                         &GRAPHENE_RECT_INIT (
+                                           0, 0,
+                                           gdk_paintable_get_intrinsic_width (paintable),
+                                           gdk_paintable_get_intrinsic_height (paintable)
+                                         ));
+  g_object_set_data_full (G_OBJECT (texture),
+                          "source-render-node",
+                          node,
+                          (GDestroyNotify) gsk_render_node_unref);
+
+  g_signal_handlers_disconnect_by_func (paintable, draw_paintable, out_texture);
+
+  *(GdkTexture **) out_texture = texture;
+
+  g_idle_add (quit_when_idle, loop);
+}
+
+static GdkTexture *
+snapshot_widget (GtkWidget *widget)
+{
+  GdkPaintable *paintable;
+  GdkTexture *texture = NULL;
+
+  g_assert_true (gtk_widget_get_realized (widget));
+
+  loop = g_main_loop_new (NULL, FALSE);
+
+  /* We wait until the widget is drawn for the first time.
+   *
+   * We also use an inhibit mechanism, to give module functions a chance
+   * to delay the snapshot.
+   */
+  paintable = gtk_widget_paintable_new (widget);
+  g_signal_connect (paintable, "invalidate-contents", G_CALLBACK (draw_paintable), &texture);
+  g_main_loop_run (loop);
+
+  g_main_loop_unref (loop);
+  g_object_unref (paintable);
+  gtk_window_destroy (GTK_WINDOW (widget));
+
+  return texture;
+}
+
+static void
+set_window_title (GtkWindow  *window,
+                  const char *filename,
+                  const char *id)
+{
+  char *name;
+  char *title;
+
+  name = g_path_get_basename (filename);
+
+  if (id)
+    title = g_strdup_printf ("%s in %s", id, name);
+  else
+    title = g_strdup (name);
+
+  gtk_window_set_title (window, title);
+
+  g_free (title);
+  g_free (name);
+}
+
+static char *
+get_save_filename (const char *filename,
+                   gboolean    as_node)
+{
+  int length = strlen (filename);
+  const char *extension = as_node ? ".node" : ".png";
+  char *result;
+
+  if (strcmp (filename + (length - 3), ".ui") == 0)
+    {
+      char *basename = g_strndup (filename, length - 3);
+      result = g_strconcat (basename, extension, NULL);
+      g_free (basename);
+    }
+  else
+    result = g_strconcat (filename, extension, NULL);
+
+  return result;
+}
+
+static void
+screenshot_file (const char *filename,
+                 const char *id,
+                 const char *cssfile,
+                 const char *save_file,
+                 gboolean    as_node,
+                 gboolean    force)
+{
+  GtkBuilder *builder;
+  GError *error = NULL;
+  GObject *object;
+  GtkWidget *window;
+  GdkTexture *texture;
+  char *save_to;
+  GBytes *bytes;
+
+  if (cssfile)
+    {
+      GtkCssProvider *provider;
+
+      provider = gtk_css_provider_new ();
+      gtk_css_provider_load_from_path (provider, cssfile);
+
+      gtk_style_context_add_provider_for_display (gdk_display_get_default (),
+                                                  GTK_STYLE_PROVIDER (provider),
+                                                  GTK_STYLE_PROVIDER_PRIORITY_APPLICATION);
+    }
+
+  builder = gtk_builder_new ();
+  if (!gtk_builder_add_from_file (builder, filename, &error))
+    {
+      g_printerr ("%s\n", error->message);
+      exit (1);
+    }
+
+  object = NULL;
+
+  if (id)
+    {
+      object = gtk_builder_get_object (builder, id);
+    }
+  else
+    {
+      GSList *objects, *l;
+
+      objects = gtk_builder_get_objects (builder);
+      for (l = objects; l; l = l->next)
+        {
+          GObject *obj = l->data;
+
+          if (GTK_IS_WINDOW (obj))
+            {
+              object = obj;
+              break;
+            }
+          else if (GTK_IS_WIDGET (obj))
+            {
+              if (object == NULL)
+                object = obj;
+            }
+        }
+      g_slist_free (objects);
+    }
+
+  if (object == NULL)
+    {
+      if (id)
+        g_printerr ("No object with ID '%s' found\n", id);
+      else
+        g_printerr ("No object found\n");
+      exit (1);
+    }
+
+  if (!GTK_IS_WIDGET (object))
+    {
+      g_printerr ("Objects of type %s can't be screenshot\n", G_OBJECT_TYPE_NAME (object));
+      exit (1);
+    }
+
+  if (GTK_IS_WINDOW (object))
+    window = GTK_WIDGET (object);
+  else
+    {
+      GtkWidget *widget = GTK_WIDGET (object);
+
+      window = gtk_window_new ();
+
+      if (GTK_IS_BUILDABLE (object))
+        id = gtk_buildable_get_buildable_id (GTK_BUILDABLE (object));
+
+      set_window_title (GTK_WINDOW (window), filename, id);
+
+      g_object_ref (widget);
+      if (gtk_widget_get_parent (widget) != NULL)
+        gtk_box_remove (GTK_BOX (gtk_widget_get_parent (widget)), widget);
+      gtk_window_set_child (GTK_WINDOW (window), widget);
+      g_object_unref (widget);
+    }
+
+  gtk_widget_show (window);
+
+  texture = snapshot_widget (window);
+
+  g_object_unref (builder);
+
+  save_to = (char *)save_file;
+
+  if (save_to == NULL)
+    save_to = get_save_filename (filename, as_node);
+
+  if (g_file_test (save_to, G_FILE_TEST_EXISTS) && !force)
+    {
+      g_printerr ("File %s exists.\n"
+                  "Use --force to overwrite.\n", save_to);
+      exit (1);
+    }
+
+  if (as_node)
+    {
+      GskRenderNode *node;
+
+      node = (GskRenderNode *) g_object_get_data (G_OBJECT (texture), "source-render-node");
+      bytes = gsk_render_node_serialize (node);
+    }
+  else
+    {
+      bytes = gdk_texture_save_to_png_bytes (texture);
+    }
+
+  if (g_file_set_contents (save_to,
+                           g_bytes_get_data (bytes, NULL),
+                           g_bytes_get_size (bytes),
+                           &error))
+    {
+      g_print ("Output written to %s.\n", save_to);
+    }
+  else
+    {
+      g_printerr ("Failed to save %s: %s\n", save_to, error->message);
+      exit (1);
+    }
+
+  g_bytes_unref (bytes);
+
+  if (save_to != save_file)
+    g_free (save_to);
+
+  g_object_unref (texture);
+}
+
+void
+do_screenshot (int          *argc,
+               const char ***argv)
+{
+  GOptionContext *context;
+  char *id = NULL;
+  char *css = NULL;
+  char **filenames = NULL;
+  gboolean as_node = FALSE;
+  gboolean force = FALSE;
+  const GOptionEntry entries[] = {
+    { "id", 0, 0, G_OPTION_ARG_STRING, &id, N_("Screenshot only the named object"), N_("ID") },
+    { "css", 0, 0, G_OPTION_ARG_FILENAME, &css, N_("Use style from CSS file"), N_("FILE") },
+    { "node", 0, 0, G_OPTION_ARG_NONE, &as_node, N_("Save as node file instead of png"), NULL },
+    { "force", 0, 0, G_OPTION_ARG_NONE, &force, N_("Overwrite existing file"), NULL },
+    { G_OPTION_REMAINING, 0, 0, G_OPTION_ARG_FILENAME_ARRAY, &filenames, NULL, N_("FILE") },
+    { NULL, }
+  };
+  GError *error = NULL;
+
+  if (gdk_display_get_default () == NULL)
+    {
+      g_printerr ("Could not initialize windowing system\n");
+      exit (1);
+    }
+
+  g_set_prgname ("gtk4-builder-tool screenshot");
+  context = g_option_context_new (NULL);
+  g_option_context_set_translation_domain (context, GETTEXT_PACKAGE);
+  g_option_context_add_main_entries (context, entries, NULL);
+  g_option_context_set_summary (context, _("Take a screenshot of the file."));
+
+  if (!g_option_context_parse (context, argc, (char ***)argv, &error))
+    {
+      g_printerr ("%s\n", error->message);
+      g_error_free (error);
+      exit (1);
+    }
+
+  g_option_context_free (context);
+
+  if (filenames == NULL)
+    {
+      g_printerr ("No .ui file specified\n");
+      exit (1);
+    }
+
+  if (g_strv_length (filenames) > 2)
+    {
+      g_printerr ("Can only screenshot a single .ui file and a single output file\n");
+      exit (1);
+    }
+
+  screenshot_file (filenames[0], id, css, filenames[1], as_node, force);
+
+  g_strfreev (filenames);
+  g_free (id);
+  g_free (css);
+}
diff --git a/tools/gtk-builder-tool.c b/tools/gtk-builder-tool.c
index ff47e81bd3..278d3fb4db 100644
--- a/tools/gtk-builder-tool.c
+++ b/tools/gtk-builder-tool.c
@@ -17,6 +17,8 @@
  * Author: Matthias Clasen
  */
 
+#include "config.h"
+
 #include <stdlib.h>
 #include <string.h>
 #include <errno.h>
@@ -41,6 +43,7 @@ usage (void)
              "  simplify     Simplify the file\n"
              "  enumerate    List all named objects\n"
              "  preview      Preview the file\n"
+             "  screenshot   Take a screenshot of the file\n"
              "\n"));
   exit (1);
 }
@@ -127,6 +130,8 @@ main (int argc, const char *argv[])
     do_enumerate (&argc, &argv);
   else if (strcmp (argv[0], "preview") == 0)
     do_preview (&argc, &argv);
+  else if (strcmp (argv[0], "screenshot") == 0)
+    do_screenshot (&argc, &argv);
   else
     usage ();
 
diff --git a/tools/gtk-builder-tool.h b/tools/gtk-builder-tool.h
index 3d895d83bb..0f2575f5a5 100644
--- a/tools/gtk-builder-tool.h
+++ b/tools/gtk-builder-tool.h
@@ -2,9 +2,10 @@
 #ifndef __GTK_BUILDER_TOOL_H__
 #define __GTK_BUILDER_TOOL_H__
 
-void do_simplify  (int *argc, const char ***argv);
-void do_validate  (int *argc, const char ***argv);
-void do_enumerate (int *argc, const char ***argv);
-void do_preview   (int *argc, const char ***argv);
+void do_simplify   (int *argc, const char ***argv);
+void do_validate   (int *argc, const char ***argv);
+void do_enumerate  (int *argc, const char ***argv);
+void do_preview    (int *argc, const char ***argv);
+void do_screenshot (int *argc, const char ***argv);
 
 #endif
diff --git a/tools/meson.build b/tools/meson.build
index 1811b6969e..52afd5433d 100644
--- a/tools/meson.build
+++ b/tools/meson.build
@@ -28,6 +28,7 @@ gtk_tools = [
                          'gtk-builder-tool-simplify.c',
                          'gtk-builder-tool-validate.c',
                          'gtk-builder-tool-enumerate.c',
+                         'gtk-builder-tool-screenshot.c',
                          'gtk-builder-tool-preview.c'], [libgtk_dep] ],
   ['gtk4-update-icon-cache', ['updateiconcache.c'] + extra_update_icon_cache_objs, [ libgtk_static_dep ] ],
   ['gtk4-encode-symbolic-svg', ['encodesymbolic.c'], [ libgtk_static_dep ] ],