[gnome-builder/wip/gtk4-port] plugins/markdown-preview: port to IdeHtmlGenerator

[Christian Hergert <chergert src gnome org>]

commit 4d18d26b781e2a01c17df3efdb648d87d8f2399e
Author: Christian Hergert <chergert redhat com>
Date:   Mon Jun 6 20:43:17 2022 -0700

    plugins/markdown-preview: port to IdeHtmlGenerator

 .../markdown-preview/gbp-markdown-html-generator.c | 197 +++++++++++++++++++++
 .../markdown-preview/gbp-markdown-html-generator.h |  31 ++++
 .../gbp-markdown-preview-workspace-addin.c         |  37 +---
 src/plugins/markdown-preview/meson.build           |   1 +
 4 files changed, 235 insertions(+), 31 deletions(-)
---
diff --git a/src/plugins/markdown-preview/gbp-markdown-html-generator.c 
b/src/plugins/markdown-preview/gbp-markdown-html-generator.c
new file mode 100644
index 000000000..51734f18f
--- /dev/null
+++ b/src/plugins/markdown-preview/gbp-markdown-html-generator.c
@@ -0,0 +1,197 @@
+/* gbp-markdown-html-generator.c
+ *
+ * Copyright 2022 Christian Hergert <chergert redhat com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+
+#define G_LOG_DOMAIN "gbp-markdown-html-generator"
+
+#include "config.h"
+
+#include <libide-code.h>
+#include <libide-threading.h>
+
+#include "gbp-markdown-html-generator.h"
+
+struct _GbpMarkdownHtmlGenerator
+{
+  IdeHtmlGenerator parent_instance;
+  GSignalGroup *buffer_signals;
+};
+
+enum {
+  PROP_0,
+  PROP_BUFFER,
+  N_PROPS
+};
+
+G_DEFINE_FINAL_TYPE (GbpMarkdownHtmlGenerator, gbp_markdown_html_generator, IDE_TYPE_HTML_GENERATOR)
+
+static char *markdown_html_prefix;
+static char *markdown_html_suffix;
+static GParamSpec *properties [N_PROPS];
+
+static void
+gbp_markdown_html_generator_generate_async (IdeHtmlGenerator    *generator,
+                                            GCancellable        *cancellable,
+                                            GAsyncReadyCallback  callback,
+                                            gpointer             user_data)
+{
+  GbpMarkdownHtmlGenerator *self = (GbpMarkdownHtmlGenerator *)generator;
+  g_autoptr(IdeBuffer) buffer = NULL;
+  g_autoptr(IdeTask) task = NULL;
+  g_autoptr(GBytes) bytes = NULL;
+  g_autofree char *escaped = NULL;
+  const char *input;
+  char *tmp;
+  gsize len;
+
+  g_assert (GBP_IS_MARKDOWN_HTML_GENERATOR (self));
+  g_assert (!cancellable || G_IS_CANCELLABLE (cancellable));
+
+  task = ide_task_new (self, cancellable, callback, user_data);
+  ide_task_set_source_tag (task, gbp_markdown_html_generator_generate_async);
+
+  if (!(buffer = g_signal_group_dup_target (self->buffer_signals)))
+    {
+      ide_task_return_new_error (task,
+                                 G_IO_ERROR,
+                                 G_IO_ERROR_CANCELLED,
+                                 "Operation was cancelled");
+      return;
+    }
+
+  bytes = ide_buffer_dup_content (buffer);
+  input = g_bytes_get_data (bytes, &len);
+  escaped = g_markup_escape_text (input, len);
+  tmp = g_strconcat (markdown_html_prefix,
+                     escaped,
+                     markdown_html_suffix,
+                     NULL);
+
+  ide_task_return_pointer (task,
+                           g_bytes_new_take (tmp, strlen (tmp)),
+                           g_bytes_unref);
+}
+
+static GBytes *
+gbp_markdown_html_generator_generate_finish (IdeHtmlGenerator  *generator,
+                                             GAsyncResult      *result,
+                                             GError           **error)
+{
+  g_assert (GBP_IS_MARKDOWN_HTML_GENERATOR (generator));
+  g_assert (IDE_IS_TASK (result));
+
+  return ide_task_propagate_pointer (IDE_TASK (result), error);
+}
+
+static void
+gbp_markdown_html_generator_dispose (GObject *object)
+{
+  GbpMarkdownHtmlGenerator *self = (GbpMarkdownHtmlGenerator *)object;
+
+  g_clear_object (&self->buffer_signals);
+
+  G_OBJECT_CLASS (gbp_markdown_html_generator_parent_class)->dispose (object);
+}
+
+static void
+gbp_markdown_html_generator_get_property (GObject    *object,
+                                          guint       prop_id,
+                                          GValue     *value,
+                                          GParamSpec *pspec)
+{
+  GbpMarkdownHtmlGenerator *self = GBP_MARKDOWN_HTML_GENERATOR (object);
+
+  switch (prop_id)
+    {
+    case PROP_BUFFER:
+      g_value_take_object (value, g_signal_group_dup_target (self->buffer_signals));
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+    }
+}
+
+static void
+gbp_markdown_html_generator_set_property (GObject      *object,
+                                          guint         prop_id,
+                                          const GValue *value,
+                                          GParamSpec   *pspec)
+{
+  GbpMarkdownHtmlGenerator *self = GBP_MARKDOWN_HTML_GENERATOR (object);
+
+  switch (prop_id)
+    {
+    case PROP_BUFFER:
+      g_signal_group_set_target (self->buffer_signals, g_value_get_object (value));
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+    }
+}
+
+static void
+gbp_markdown_html_generator_class_init (GbpMarkdownHtmlGeneratorClass *klass)
+{
+  g_autoptr(GBytes) markdown_view_js = g_resources_lookup_data 
("/plugins/markdown-preview/js/markdown-view.js", 0, NULL);
+  g_autoptr(GBytes) markdown_css = g_resources_lookup_data ("/plugins/markdown-preview/css/markdown.css", 0, 
NULL);
+  g_autoptr(GBytes) marked_js = g_resources_lookup_data ("/plugins/markdown-preview/js/marked.js", 0, NULL);
+
+  GObjectClass *object_class = G_OBJECT_CLASS (klass);
+  IdeHtmlGeneratorClass *generator_class = IDE_HTML_GENERATOR_CLASS (klass);
+
+  object_class->dispose = gbp_markdown_html_generator_dispose;
+  object_class->get_property = gbp_markdown_html_generator_get_property;
+  object_class->set_property = gbp_markdown_html_generator_set_property;
+
+  generator_class->generate_async = gbp_markdown_html_generator_generate_async;
+  generator_class->generate_finish = gbp_markdown_html_generator_generate_finish;
+
+  properties [PROP_BUFFER] =
+    g_param_spec_object ("buffer", NULL, NULL,
+                         IDE_TYPE_BUFFER,
+                         (G_PARAM_READWRITE | G_PARAM_CONSTRUCT_ONLY | G_PARAM_STATIC_STRINGS));
+
+  g_object_class_install_properties (object_class, N_PROPS, properties);
+
+  markdown_html_prefix = g_strconcat ("<html>\n",
+                                      " <head>\n",
+                                      "  <style>", g_bytes_get_data (markdown_css, NULL), "</style>\n",
+                                      "  <script>", g_bytes_get_data (marked_js, NULL), "</script>\n",
+                                      "  <script>", g_bytes_get_data (markdown_view_js, NULL), "</script>\n",
+                                      " </head>\n",
+                                      " <body onload=\"preview()\">\n",
+                                      "  <div class=\"markdown-body\" id=\"preview\"></div>\n",
+                                      "  <div id=\"markdown-source\">",
+                                      NULL);
+  markdown_html_suffix = (char *)"</div>\n </body>\n</html>\n";
+}
+
+static void
+gbp_markdown_html_generator_init (GbpMarkdownHtmlGenerator *self)
+{
+  self->buffer_signals = g_signal_group_new (IDE_TYPE_BUFFER);
+
+  g_signal_group_connect_object (self->buffer_signals,
+                                 "changed",
+                                 G_CALLBACK (ide_html_generator_invalidate),
+                                 self,
+                                 G_CONNECT_SWAPPED);
+}
diff --git a/src/plugins/markdown-preview/gbp-markdown-html-generator.h 
b/src/plugins/markdown-preview/gbp-markdown-html-generator.h
new file mode 100644
index 000000000..3eae01d29
--- /dev/null
+++ b/src/plugins/markdown-preview/gbp-markdown-html-generator.h
@@ -0,0 +1,31 @@
+/* gbp-markdown-html-generator.h
+ *
+ * Copyright 2022 Christian Hergert <chergert redhat com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+
+#pragma once
+
+#include <libide-webkit.h>
+
+G_BEGIN_DECLS
+
+#define GBP_TYPE_MARKDOWN_HTML_GENERATOR (gbp_markdown_html_generator_get_type())
+
+G_DECLARE_FINAL_TYPE (GbpMarkdownHtmlGenerator, gbp_markdown_html_generator, GBP, MARKDOWN_HTML_GENERATOR, 
IdeHtmlGenerator)
+
+G_END_DECLS
diff --git a/src/plugins/markdown-preview/gbp-markdown-preview-workspace-addin.c 
b/src/plugins/markdown-preview/gbp-markdown-preview-workspace-addin.c
index 7fe48d6f7..1401165c7 100644
--- a/src/plugins/markdown-preview/gbp-markdown-preview-workspace-addin.c
+++ b/src/plugins/markdown-preview/gbp-markdown-preview-workspace-addin.c
@@ -27,6 +27,7 @@
 #include <libide-gui.h>
 #include <libide-webkit.h>
 
+#include "gbp-markdown-html-generator.h"
 #include "gbp-markdown-preview-workspace-addin.h"
 
 struct _GbpMarkdownPreviewWorkspaceAddin
@@ -40,9 +41,6 @@ struct _GbpMarkdownPreviewWorkspaceAddin
 static void live_preview_action (GbpMarkdownPreviewWorkspaceAddin *self,
                                  GVariant                     *params);
 
-static char *markdown_html_prefix;
-static char *markdown_html_suffix;
-
 IDE_DEFINE_ACTION_GROUP (GbpMarkdownPreviewWorkspaceAddin, gbp_markdown_preview_workspace_addin, {
   { "markdown-preview", live_preview_action },
 })
@@ -191,21 +189,6 @@ G_DEFINE_FINAL_TYPE_WITH_CODE (GbpMarkdownPreviewWorkspaceAddin, gbp_markdown_pr
 static void
 gbp_markdown_preview_workspace_addin_class_init (GbpMarkdownPreviewWorkspaceAddinClass *klass)
 {
-  g_autoptr(GBytes) markdown_view_js = g_resources_lookup_data 
("/plugins/markdown-preview/js/markdown-view.js", 0, NULL);
-  g_autoptr(GBytes) markdown_css = g_resources_lookup_data ("/plugins/markdown-preview/css/markdown.css", 0, 
NULL);
-  g_autoptr(GBytes) marked_js = g_resources_lookup_data ("/plugins/markdown-preview/js/marked.js", 0, NULL);
-
-  markdown_html_prefix = g_strconcat ("<html>\n",
-                                      " <head>\n",
-                                      "  <style>", g_bytes_get_data (markdown_css, NULL), "</style>\n",
-                                      "  <script>", g_bytes_get_data (marked_js, NULL), "</script>\n",
-                                      "  <script>", g_bytes_get_data (markdown_view_js, NULL), "</script>\n",
-                                      " </head>\n",
-                                      " <body onload=\"preview()\">\n",
-                                      "  <div class=\"markdown-body\" id=\"preview\"></div>\n",
-                                      "  <div id=\"markdown-source\">",
-                                      NULL);
-  markdown_html_suffix = (char *)"</div>\n </body>\n</html>\n";
 }
 
 static void
@@ -214,20 +197,11 @@ gbp_markdown_preview_workspace_addin_init (GbpMarkdownPreviewWorkspaceAddin *sel
   gbp_markdown_preview_workspace_addin_set_action_enabled (self, "markdown-preview", FALSE);
 }
 
-static char *
-transform_content_to_html (const char *content,
-                           gpointer    user_data)
-{
-  return g_strconcat (markdown_html_prefix,
-                      content,
-                      markdown_html_suffix,
-                      NULL);
-}
-
 static void
 live_preview_action (GbpMarkdownPreviewWorkspaceAddin *self,
                      GVariant                     *params)
 {
+  g_autoptr(IdeHtmlGenerator) generator = NULL;
   g_autoptr(IdePanelPosition) position = NULL;
   g_autoptr(IdeBuffer) buffer = NULL;
   IdeWebkitPage *page;
@@ -241,9 +215,10 @@ live_preview_action (GbpMarkdownPreviewWorkspaceAddin *self,
   g_assert (IDE_IS_EDITOR_PAGE (self->editor_page));
 
   buffer = g_signal_group_dup_target (self->buffer_signals);
-  page = ide_webkit_page_new_for_buffer (GTK_TEXT_BUFFER (buffer),
-                                         transform_content_to_html,
-                                         NULL, NULL);
+  generator = g_object_new (GBP_TYPE_MARKDOWN_HTML_GENERATOR,
+                            "buffer", buffer,
+                            NULL);
+  page = ide_webkit_page_new_for_generator (generator);
   position = ide_page_get_position (IDE_PAGE (self->editor_page));
 
   if (!ide_panel_position_get_column (position, &column))
diff --git a/src/plugins/markdown-preview/meson.build b/src/plugins/markdown-preview/meson.build
index 002c22e53..c5bd3596d 100644
--- a/src/plugins/markdown-preview/meson.build
+++ b/src/plugins/markdown-preview/meson.build
@@ -6,6 +6,7 @@ endif
 
 plugins_sources += files([
   'markdown-preview-plugin.c',
+  'gbp-markdown-html-generator.c',
   'gbp-markdown-preview-workspace-addin.c',
 ])