From aa3527b39c79a9855e07275dbe9bb62f3fc1fb4e Mon Sep 17 00:00:00 2001
From: Jan-Willem Harmannij <jwharmannij@gmail.com>
Date: Sun, 29 Sep 2024 20:07:21 +0200
Subject: [PATCH] Set trailing flag parameters as varargs (fixes #140)

---
 .../javagi/generators/CallableGenerator.java  | 24 +++++++++++++++----
 .../github/jwharm/javagi/gir/Parameter.java   |  4 ++++
 2 files changed, 23 insertions(+), 5 deletions(-)

diff --git a/buildSrc/src/main/java/io/github/jwharm/javagi/generators/CallableGenerator.java b/buildSrc/src/main/java/io/github/jwharm/javagi/generators/CallableGenerator.java
index 0a5a6f88..c321b8b0 100644
--- a/buildSrc/src/main/java/io/github/jwharm/javagi/generators/CallableGenerator.java
+++ b/buildSrc/src/main/java/io/github/jwharm/javagi/generators/CallableGenerator.java
@@ -115,6 +115,15 @@ void generateMethodParameters(MethodSpec.Builder builder,
                 var generator = new TypedValueGenerator(p);
                 var type = generator.getType(setOfBitfield);
 
+                // Trailing flags parameter can be variadic
+                if ((!setOfBitfield)
+                        && p.isBitfield()
+                        && p.isLastParameter()
+                        && (!p.isOutParameter())) {
+                    type = ArrayTypeName.of(type);
+                    builder.varargs(true);
+                }
+
                 if (generic && type.equals(ClassNames.GOBJECT))
                     type = ClassNames.GENERIC_T;
 
@@ -292,14 +301,19 @@ else if ((!ctor) || namedCtor)
                 continue;
 
             TypedValueGenerator gen = new TypedValueGenerator(p);
+            String paramName = gen.getName();
 
             if (p.isBitfield()) {
-                if (p.isOutParameter())
-                    params.add(gen.getName() + " == null ? null : new $out:T($enumSet:T.of(" + gen.getName() + ".get()))");
-                else
-                    params.add("$enumSet:T.of(" + gen.getName() + ")");
+                if (p.isOutParameter()) {
+                    params.add(paramName + " == null ? null : new $out:T($enumSet:T.of(" + paramName + ".get()))");
+                } else if (p.isLastParameter()) {
+                    params.add("(" + paramName + " == null ? null : (" + paramName + ".length == 0) ? $enumSet:T.noneOf($typeName:T.class) : $enumSet:T.of(" + paramName + "[0], " + paramName + "))");
+                    stmt.add(null, "typeName", gen.getType(false));
+                } else {
+                    params.add("$enumSet:T.of(" + paramName + ")");
+                }
             } else {
-                params.add(gen.getName());
+                params.add(paramName);
             }
         }
         stmt.add(params.toString(),
diff --git a/buildSrc/src/main/java/io/github/jwharm/javagi/gir/Parameter.java b/buildSrc/src/main/java/io/github/jwharm/javagi/gir/Parameter.java
index 5230a410..4ef4e5b0 100644
--- a/buildSrc/src/main/java/io/github/jwharm/javagi/gir/Parameter.java
+++ b/buildSrc/src/main/java/io/github/jwharm/javagi/gir/Parameter.java
@@ -120,6 +120,10 @@ public boolean allocatesMemory() {
                 && target instanceof Alias a && a.type().isPrimitive();
     }
 
+    public boolean isLastParameter() {
+        return this == parent().parameters().getLast();
+    }
+
     public boolean nullable() {
         return "1".equals(attr("nullable"))
                 || "1".equals(attr("allow-none"))