Text editor: syntax highlighting + line numbers on by default

The most common use of the text editor seems to be for scripting. Having
line numbers and syntax highlighting enabled by default seems sensible.

Syntax highlighting is now enabled by default, but is automatically
disabled when the datablock has a non-highlighted extension.
Highlighting is enabled for filenames like:
    - Text
    - Text.001
    - somefile.py
and is automatically disabled when the datablock has an extension for
which Blender has no syntax highlighter registered.

Reviewers: billreynish, campbellbarton

Subscribers: brecht, billreynish

Differential Revision: https://developer.blender.org/D5472

4 files changed, 36 insertions, 0 deletions

diff --git a/source/blender/blenlib/BLI_path_util.h b/source/blender/blenlib/BLI_path_util.h
index 31b68204c51..99e86615e50 100644
--- a/source/blender/blenlib/BLI_path_util.h
+++ b/source/blender/blenlib/BLI_path_util.h
@@ -42,6 +42,8 @@ void BLI_split_dirfile(
     const char *string, char *dir, char *file, const size_t dirlen, const size_t filelen);
 void BLI_split_dir_part(const char *string, char *dir, const size_t dirlen);
 void BLI_split_file_part(const char *string, char *file, const size_t filelen);
+const char *BLI_path_extension(const char *filepath) ATTR_NONNULL();
+
 void BLI_path_append(char *__restrict dst, const size_t maxlen, const char *__restrict file)
     ATTR_NONNULL();
 void BLI_join_dirfile(char *__restrict string,
diff --git a/source/blender/blenlib/BLI_string_utils.h b/source/blender/blenlib/BLI_string_utils.h
index 9740629276d..13dbb2de659 100644
--- a/source/blender/blenlib/BLI_string_utils.h
+++ b/source/blender/blenlib/BLI_string_utils.h
@@ -38,6 +38,7 @@ struct ListBase;
 typedef bool (*UniquenameCheckCallback)(void *arg, const char *name);
 
 size_t BLI_split_name_num(char *left, int *nr, const char *name, const char delim);
+bool BLI_string_is_decimal(const char *string) ATTR_NONNULL();
 
 void BLI_string_split_suffix(const char *string, char *r_body, char *r_suf, const size_t str_len);
 void BLI_string_split_prefix(const char *string, char *r_pre, char *r_body, const size_t str_len);
diff --git a/source/blender/blenlib/intern/path_util.c b/source/blender/blenlib/intern/path_util.c
index 111b530a527..18acbca00a1 100644
--- a/source/blender/blenlib/intern/path_util.c
+++ b/source/blender/blenlib/intern/path_util.c
@@ -1685,6 +1685,24 @@ void BLI_split_file_part(const char *string, char *file, const size_t filelen)
 }
 
 /**
+ * Returns a pointer to the last extension (e.g. the position of the last period).
+ * Returns NULL if there is no extension.
+ */
+const char *BLI_path_extension(const char *filepath)
+{
+  const char *extension = strrchr(filepath, '.');
+  if (extension == NULL) {
+    return NULL;
+  }
+  if (BLI_first_slash(extension) != NULL) {
+    /* There is a path separator in the extension, so the '.' was found in a
+     * directory component and not in the filename. */
+    return NULL;
+  }
+  return extension;
+}
+
+/**
  * Append a filename to a dir, ensuring slash separates.
  */
 void BLI_path_append(char *__restrict dst, const size_t maxlen, const char *__restrict file)
diff --git a/source/blender/blenlib/intern/string_utils.c b/source/blender/blenlib/intern/string_utils.c
index f2b3ef2ad87..b956e1c0a7e 100644
--- a/source/blender/blenlib/intern/string_utils.c
+++ b/source/blender/blenlib/intern/string_utils.c
@@ -82,6 +82,21 @@ size_t BLI_split_name_num(char *left, int *nr, const char *name, const char deli
   return name_len;
 }
 
+bool BLI_string_is_decimal(const char *string)
+{
+  if (*string == '\0') {
+    return false;
+  }
+
+  /* Keep iterating over the string until a non-digit is found. */
+  while (isdigit(*string)) {
+    string++;
+  }
+
+  /* If the non-digit we found is the terminating \0, everything was digits. */
+  return *string == '\0';
+}
+
 static bool is_char_sep(const char c)
 {
   return ELEM(c, '.', ' ', '-', '_');