[gnome-builder/wip/libide] libide: move xml indenter into libide

[Christian Hergert <chergert src gnome org>]

commit 464beb420bc0fc5885480ed4a1994d824aa21574
Author: Christian Hergert <christian hergert me>
Date:   Tue Feb 17 23:22:28 2015 -0800

    libide: move xml indenter into libide

 libide/Makefile.am            |    2 +
 libide/xml/ide-xml-indenter.c |  438 +++++++++++++++++++++++++++++++++++++++++
 libide/xml/ide-xml-indenter.h |   32 +++
 3 files changed, 472 insertions(+), 0 deletions(-)
---
diff --git a/libide/Makefile.am b/libide/Makefile.am
index 7a717cb..e65bfa3 100644
--- a/libide/Makefile.am
+++ b/libide/Makefile.am
@@ -138,6 +138,8 @@ libide_1_0_la_public_sources = \
        libide/ide.h \
        libide/local/ide-local-device.c \
        libide/local/ide-local-device.h \
+       libide/xml/ide-xml-indenter.c \
+       libide/xml/ide-xml-indenter.h \
        $(NULL)
 
 libide_1_0_la_SOURCES = \
diff --git a/libide/xml/ide-xml-indenter.c b/libide/xml/ide-xml-indenter.c
new file mode 100644
index 0000000..88ae18d
--- /dev/null
+++ b/libide/xml/ide-xml-indenter.c
@@ -0,0 +1,438 @@
+/* gb-source-auto-indenter-xml.c
+ *
+ * Copyright (C) 2014 Christian Hergert <christian hergert me>
+ *
+ * This file 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 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This file 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 General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#define G_LOG_DOMAIN "ide-xml-indenter"
+
+#include <gtksourceview/gtksource.h>
+#include <string.h>
+
+#include "ide-xml-indenter.h"
+
+#define ENTRY
+#define EXIT return
+#define GOTO(_l) goto _l
+#define RETURN(_v) return _v
+
+struct _IdeXmlIndenter
+{
+  IdeIndenter parent_class;
+};
+
+/*
+ * TODO:
+ *
+ * This is very naive. But let's see if it gets the job done enough to not
+ * be super annoying. Things like indent_width belong as fields in a private
+ * structure.
+ *
+ * Anywho, if you want to own this module, go for it.
+ */
+
+#define INDENT_WIDTH 2
+
+G_DEFINE_TYPE (IdeXmlIndenter, ide_xml_indenter, IDE_TYPE_INDENTER)
+
+static gunichar
+text_iter_peek_next_char (const GtkTextIter *location)
+{
+  GtkTextIter iter = *location;
+
+  if (gtk_text_iter_forward_char (&iter))
+    return gtk_text_iter_get_char (&iter);
+
+  return 0;
+}
+
+static gunichar
+text_iter_peek_prev_char (const GtkTextIter *location)
+{
+  GtkTextIter iter = *location;
+
+  if (gtk_text_iter_backward_char (&iter))
+    return gtk_text_iter_get_char (&iter);
+
+  return 0;
+}
+
+static void
+build_indent (IdeXmlIndenter *xml,
+              guint                    line_offset,
+              GtkTextIter             *matching_line,
+              GString                 *str)
+{
+  GtkTextIter iter;
+  gunichar ch;
+
+  if (!line_offset)
+    return;
+
+  gtk_text_buffer_get_iter_at_line (gtk_text_iter_get_buffer (matching_line),
+                                    &iter,
+                                    gtk_text_iter_get_line (matching_line));
+
+  do {
+    ch = gtk_text_iter_get_char (&iter);
+
+    switch (ch)
+      {
+      case '\t':
+      case ' ':
+        g_string_append_unichar (str, ch);
+        break;
+
+      default:
+        g_string_append_c (str, ' ');
+        break;
+      }
+  } while (gtk_text_iter_forward_char (&iter) &&
+           (gtk_text_iter_compare (&iter, matching_line) <= 0) &&
+           (str->len < line_offset));
+
+  while (str->len < line_offset)
+    g_string_append_c (str, ' ');
+}
+
+static gboolean
+text_iter_in_cdata (const GtkTextIter *location)
+{
+  GtkTextIter iter = *location;
+  gboolean ret = FALSE;
+
+  if (gtk_text_iter_backward_search (&iter, "<![CDATA[",
+                                     GTK_TEXT_SEARCH_TEXT_ONLY,
+                                     NULL, &iter, NULL))
+    {
+      if (!gtk_text_iter_forward_search (&iter, "]]>",
+                                         GTK_TEXT_SEARCH_TEXT_ONLY,
+                                         NULL, NULL, location))
+        {
+          ret = TRUE;
+          GOTO (cleanup);
+        }
+    }
+
+cleanup:
+  return ret;
+}
+
+static gboolean
+text_iter_backward_to_element_start (const GtkTextIter *iter,
+                                     GtkTextIter       *match_begin)
+{
+  GtkTextIter tmp = *iter;
+  gboolean ret = FALSE;
+  gint depth = 0;
+
+  g_return_val_if_fail (iter, FALSE);
+  g_return_val_if_fail (match_begin, FALSE);
+
+  while (gtk_text_iter_backward_char (&tmp))
+    {
+      gunichar ch;
+
+      ch = gtk_text_iter_get_char (&tmp);
+
+      if ((ch == '/') && (text_iter_peek_prev_char (&tmp) == '<'))
+        {
+          gtk_text_iter_backward_char (&tmp);
+          depth++;
+        }
+      else if ((ch == '/') && (text_iter_peek_next_char (&tmp) == '>'))
+        {
+          depth++;
+        }
+      else if ((ch == '<') && (text_iter_peek_next_char (&tmp) != '!'))
+        {
+          depth--;
+          if (depth < 0)
+            {
+              *match_begin = tmp;
+              ret = TRUE;
+              GOTO (cleanup);
+            }
+        }
+    }
+
+cleanup:
+  return ret;
+}
+
+static gchar *
+ide_xml_indenter_indent (IdeXmlIndenter *xml,
+                         GtkTextIter    *begin,
+                         GtkTextIter    *end,
+                         gint           *cursor_offset,
+                         guint           tab_width)
+{
+  GtkTextIter match_begin;
+  GString *str;
+  guint offset;
+
+  g_return_val_if_fail (IDE_IS_XML_INDENTER (xml), NULL);
+  g_return_val_if_fail (begin, NULL);
+  g_return_val_if_fail (end, NULL);
+
+  str = g_string_new (NULL);
+
+  if (text_iter_backward_to_element_start (begin, &match_begin))
+    {
+      offset = gtk_text_iter_get_line_offset (&match_begin);
+      build_indent (xml, offset + INDENT_WIDTH, &match_begin, str);
+
+      /*
+       * If immediately after our cursor is a closing tag, we will move it to
+       * a line after our indent line.
+       */
+      if ('<' == gtk_text_iter_get_char (end) &&
+          '/' == text_iter_peek_next_char (end))
+        {
+          GString *str2;
+
+          str2 = g_string_new (NULL);
+          build_indent (xml, offset, &match_begin, str2);
+
+          g_string_append (str, "\n");
+          g_string_append (str, str2->str);
+
+          *cursor_offset = -str2->len - 1;
+
+          g_string_free (str2, TRUE);
+        }
+
+      GOTO (cleanup);
+    }
+
+  /* do nothing */
+
+cleanup:
+  return g_string_free (str, (str->len == 0));
+}
+
+static gchar *
+ide_xml_indenter_maybe_unindent (IdeXmlIndenter *xml,
+                                            GtkTextIter             *begin,
+                                            GtkTextIter             *end)
+{
+  GtkTextIter tmp;
+  gunichar ch;
+
+  g_return_val_if_fail (IDE_IS_XML_INDENTER (xml), NULL);
+  g_return_val_if_fail (begin, NULL);
+  g_return_val_if_fail (end, NULL);
+
+  tmp = *begin;
+
+  if (!gtk_text_iter_backward_char (&tmp))
+    return NULL;
+
+  if (('/' == gtk_text_iter_get_char (&tmp)) &&
+      gtk_text_iter_backward_char (&tmp) &&
+      ('<' == gtk_text_iter_get_char (&tmp)) &&
+      (ch = text_iter_peek_prev_char (&tmp)) &&
+      ((ch == ' ') || (ch == '\t')))
+    {
+      if (ch == '\t')
+        {
+          gtk_text_iter_backward_char (&tmp);
+          *begin = tmp;
+          return g_strdup ("</");
+        }
+      else
+        {
+          gint count = INDENT_WIDTH;
+
+          while (count)
+            {
+              if (!gtk_text_iter_backward_char (&tmp) ||
+                  !(ch = gtk_text_iter_get_char (&tmp)) ||
+                  (ch != ' '))
+                return NULL;
+              count--;
+              if (count == 0)
+                GOTO (success);
+            }
+        }
+    }
+
+  return NULL;
+
+success:
+  *begin = tmp;
+  return g_strdup ("</");
+}
+
+static gboolean
+find_end (gunichar ch,
+          gpointer user_data)
+{
+  return (ch == '>' || g_unichar_isspace (ch));
+}
+
+static gchar *
+ide_xml_indenter_maybe_add_closing (IdeXmlIndenter *xml,
+                                               GtkTextIter             *begin,
+                                               GtkTextIter             *end,
+                                               gint                    *cursor_offset)
+{
+  GtkTextIter match_begin;
+  GtkTextIter match_end;
+  GtkTextIter copy;
+
+  g_return_val_if_fail (IDE_IS_XML_INDENTER (xml), NULL);
+  g_return_val_if_fail (begin, NULL);
+  g_return_val_if_fail (end, NULL);
+
+  copy = *begin;
+
+  gtk_text_iter_backward_char (&copy);
+  gtk_text_iter_backward_char (&copy);
+
+  if (gtk_text_iter_get_char (&copy) == '/')
+    return NULL;
+
+  copy = *begin;
+
+  if (gtk_text_iter_backward_search (&copy, "<", GTK_TEXT_SEARCH_TEXT_ONLY,
+                                     &match_begin, &match_end, NULL))
+    {
+      gchar *text;
+
+      /* avoid closing elements on spurious > */
+      gtk_text_iter_backward_char (&copy);
+      text = gtk_text_iter_get_slice (&match_begin, &copy);
+      if (strchr (text, '>'))
+        {
+          g_free (text);
+          return NULL;
+        }
+      g_free (text);
+
+      gtk_text_iter_forward_char (&match_begin);
+      if (gtk_text_iter_get_char (&match_begin) == '/')
+        return NULL;
+
+      match_end = match_begin;
+
+      if (gtk_text_iter_forward_find_char (&match_end, find_end, NULL, begin))
+        {
+          gchar *slice;
+          gchar *ret = NULL;
+
+          slice = gtk_text_iter_get_slice (&match_begin, &match_end);
+
+          if (slice && *slice && *slice != '!')
+            {
+              ret = g_strdup_printf ("</%s>", slice);
+              *cursor_offset = -strlen (ret);
+            }
+
+          g_free (slice);
+
+          return ret;
+        }
+    }
+
+  return NULL;
+}
+
+static gboolean
+ide_xml_indenter_is_trigger (IdeIndenter *indenter,
+                             GdkEventKey *event)
+{
+  switch (event->keyval)
+    {
+    case GDK_KEY_Return:
+    case GDK_KEY_KP_Enter:
+    case GDK_KEY_slash:
+    case GDK_KEY_greater:
+      return TRUE;
+
+    default:
+      break;
+    }
+
+  return FALSE;
+}
+
+static gchar *
+ide_xml_indenter_format (IdeIndenter *indenter,
+                         GtkTextView *view,
+                         GtkTextIter *begin,
+                         GtkTextIter *end,
+                         gint        *cursor_offset,
+                         GdkEventKey *trigger)
+{
+  IdeXmlIndenter *xml = (IdeXmlIndenter *)indenter;
+  GtkTextBuffer *buffer;
+  guint tab_width = 2;
+  gint indent_width = -1;
+
+  g_return_val_if_fail (IDE_IS_XML_INDENTER (xml), NULL);
+
+  buffer = gtk_text_view_get_buffer (view);
+
+  *cursor_offset = 0;
+
+  if (GTK_SOURCE_IS_VIEW (view))
+    {
+      tab_width = gtk_source_view_get_tab_width (GTK_SOURCE_VIEW (view));
+      indent_width = gtk_source_view_get_indent_width (GTK_SOURCE_VIEW (view));
+      if (indent_width != -1)
+        tab_width = indent_width;
+    }
+
+  /* do nothing if we are in a cdata section */
+  if (text_iter_in_cdata (begin))
+    return NULL;
+
+  switch (trigger->keyval)
+    {
+    case GDK_KEY_Return:
+    case GDK_KEY_KP_Enter:
+      if ((trigger->state & GDK_SHIFT_MASK) == 0)
+        return ide_xml_indenter_indent (xml, begin, end, cursor_offset,
+                                        tab_width);
+      return NULL;
+
+    case GDK_KEY_slash:
+      return ide_xml_indenter_maybe_unindent (xml, begin, end);
+
+    case GDK_KEY_greater:
+      return ide_xml_indenter_maybe_add_closing (xml, begin, end,
+                                                 cursor_offset);
+
+    default:
+      g_return_val_if_reached (NULL);
+    }
+
+  return NULL;
+}
+
+static void
+ide_xml_indenter_class_init (IdeXmlIndenterClass *klass)
+{
+  IdeIndenterClass *parent = IDE_INDENTER_CLASS (klass);
+
+  parent->format = ide_xml_indenter_format;
+  parent->is_trigger = ide_xml_indenter_is_trigger;
+}
+
+static void
+ide_xml_indenter_init (IdeXmlIndenter *self)
+{
+}
diff --git a/libide/xml/ide-xml-indenter.h b/libide/xml/ide-xml-indenter.h
new file mode 100644
index 0000000..7886f10
--- /dev/null
+++ b/libide/xml/ide-xml-indenter.h
@@ -0,0 +1,32 @@
+/* gb-source-auto-indenter-xml.h
+ *
+ * Copyright (C) 2014 Christian Hergert <christian hergert me>
+ *
+ * This file 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 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This file 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 General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef IDE_XML_INDENTER_H
+#define IDE_XML_INDENTER_H
+
+#include "ide-indenter.h"
+
+G_BEGIN_DECLS
+
+#define IDE_TYPE_XML_INDENTER (ide_xml_indenter_get_type())
+
+G_DECLARE_FINAL_TYPE (IdeXmlIndenter, ide_xml_indenter, IDE, XML_INDENTER, IdeIndenter)
+
+G_END_DECLS
+
+#endif /* IDE_XML_INDENTER_H */