gst-indent: Refactor indent call to make it callable from other scripts

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/8409>

scripts/gst-indent.py

@@ -1,36 +1,8 @@
 #!/usr/bin/env python
 
-import subprocess
 from sys import argv
-import shutil
+from gst_indent_common import indent
+
 
 if __name__ == '__main__':
-    indent = shutil.which('gst-indent-1.0')
+    indent(argv[1:])
-
-    if not indent:
-        raise RuntimeError('''Did not find gst-indent-1.0, please install it before continuing.''')
-
-    version = subprocess.run([indent, '--version'], capture_output=True, text=True)
-
-    if 'GNU' not in version.stdout:
-        raise RuntimeError(f'''Did not find gst-indent-1.0, please install it before continuing.
-      (Found {indent}, but it doesn't seem to be gst-indent-1.0)''')
-
-    # Run twice. GNU indent isn't idempotent
-    # when run once
-    for i in range(2):
-        subprocess.check_call([indent,
-            '--braces-on-if-line',
-            '--case-brace-indentation0',
-            '--case-indentation2',
-            '--braces-after-struct-decl-line',
-            '--line-length80',
-            '--no-tabs',
-            '--cuddle-else',
-            '--dont-line-up-parentheses',
-            '--continuation-indentation4',
-            '--honour-newlines',
-            '--tab-size8',
-            '--indent-level2',
-            '--leave-preprocessor-space'] + argv[1:]
-        )

scripts/gst_indent_common.py

@@ -0,0 +1,34 @@
+import shutil
+import subprocess
+
+
+def indent(*args):
+    indent = shutil.which('gst-indent-1.0')
+
+    if not indent:
+        raise RuntimeError('''Did not find gst-indent-1.0, please install it before continuing.''')
+
+    version = subprocess.run([indent, '--version'], capture_output=True, text=True)
+
+    if 'GNU' not in version.stdout:
+        raise RuntimeError(f'''Did not find gst-indent-1.0, please install it before continuing.
+      (Found {indent}, but it doesn't seem to be gst-indent-1.0)''')
+
+    # Run twice. GNU indent isn't idempotent
+    # when run once
+    for i in range(2):
+        subprocess.check_call([indent,
+            '--braces-on-if-line',
+            '--case-brace-indentation0',
+            '--case-indentation2',
+            '--braces-after-struct-decl-line',
+            '--line-length80',
+            '--no-tabs',
+            '--cuddle-else',
+            '--dont-line-up-parentheses',
+            '--continuation-indentation4',
+            '--honour-newlines',
+            '--tab-size8',
+            '--indent-level2',
+            '--leave-preprocessor-space'] + list(args)
+        )