From 5b95abce92042f4c3157a8f6e27d9922abbc879e Mon Sep 17 00:00:00 2001
From: Qball <qball@blame.services>
Date: Mon, 20 Jan 2025 14:34:53 +0100
Subject: [PATCH] [Lexer] Allow for optional imports.

Adds the `?import` syntax.

fixes: #2078
---
 doc/rofi-theme.5.markdown |  8 ++++++++
 lexer/theme-lexer.l       | 24 +++++++++++++++++++-----
 2 files changed, 27 insertions(+), 5 deletions(-)

diff --git a/doc/rofi-theme.5.markdown b/doc/rofi-theme.5.markdown
index dd6c2b4f..2fc60df3 100644
--- a/doc/rofi-theme.5.markdown
+++ b/doc/rofi-theme.5.markdown
@@ -1658,6 +1658,14 @@ If a filename is provided, it will try to resolve it in the following order:
 A name is resolved (if it has no valid extension) as a filename by appending the `.rasi` and the `.rasinc` extension.
 It will first look for files with `.rasi`, then for files with `.rasinc`.
 
+If you want to do an optional import, e.g. no error when the file does not exists, you can do:
+
+```css
+?import "myfile"
+```
+
+This still throws an error on syntax error, but won't abort parsing if file does not exists.
+
 ## Examples
 
 Several examples are installed together with **rofi**. These can be found in
diff --git a/lexer/theme-lexer.l b/lexer/theme-lexer.l
index 5af651ca..bf5b5bd4 100644
--- a/lexer/theme-lexer.l
+++ b/lexer/theme-lexer.l
@@ -51,6 +51,8 @@
 int last_state = 0;
 extern int rofi_is_in_dmenu_mode;
 
+gboolean import_optional = FALSE;
+
 const char *rasi_theme_file_extensions[] = {".rasi", ".rasinc", NULL};
 /**
  * Type of Object to parse.
@@ -289,6 +291,7 @@ C_COMMENT_OPEN "/*"
 
 
 INCLUDE    "@import"
+OPT_INCLUDE    "?import"
 THEME "@theme"
 DEFAULT (?i:\"default\"?)
 
@@ -378,6 +381,12 @@ if ( queue == NULL ) {
      */
 <INITIAL>{INCLUDE} {
     g_queue_push_head ( queue, GINT_TO_POINTER (YY_START) );
+    import_optional = FALSE;
+    BEGIN(INCLUDE);
+}
+<INITIAL>{OPT_INCLUDE} {
+    g_queue_push_head ( queue, GINT_TO_POINTER (YY_START) );
+    import_optional = TRUE;
     BEGIN(INCLUDE);
 }
 <INITIAL>{THEME} {
@@ -437,10 +446,15 @@ if ( queue == NULL ) {
         yylloc->first_column = yylloc->last_column = 1;
         yylloc->filename = current->filename;
     } else {
-        char *str = g_markup_printf_escaped ( "Failed to open theme: <i>%s</i>\nError: <b>%s</b>",
-                filename, strerror ( errno ) );
-        rofi_add_warning_message ( g_string_new ( str ) );
-        g_free ( str );
+	if ( !import_optional ) {
+		char *str = g_markup_printf_escaped ( "Failed to open theme: <i>%s</i>\nError: <b>%s</b>",
+				filename, strerror ( errno ) );
+		rofi_add_warning_message ( g_string_new ( str ) );
+		g_free ( str );
+	} else {
+		g_warning("Trying to parse optional theme: '%s', Error: %s",
+			filename, strerror(errno));
+	}
         g_free(filename);
     }
     // Pop out of include. */
@@ -844,7 +858,7 @@ if ( queue == NULL ) {
  /**
   * Media defaults.
   */
-<MEDIA,MEDIA_CONTENT,MEDIA_ENV_VAR,MEDIA_ENV_VAR_DEFAULT,MEDIA_ENV_VAR_CONTENT>{WHITESPACE}+	; // ignore all whitespace 
+<MEDIA,MEDIA_CONTENT,MEDIA_ENV_VAR,MEDIA_ENV_VAR_DEFAULT,MEDIA_ENV_VAR_CONTENT>{WHITESPACE}+	; // ignore all whitespace
 
 <MEDIA,MEDIA_CONTENT,MEDIA_ENV_VAR,MEDIA_ENV_VAR_DEFAULT,MEDIA_ENV_VAR_CONTENT>. {
     yytext[yyleng-1] = '\0';