Read preset meta data in the same way as contexts

src/common/serialization/vst3/attribute-list.cpp

@@ -16,6 +16,8 @@
 
 #include "attribute-list.h"
 
+#include <pluginterfaces/vst/vstpresetkeys.h>
+
 #include "pluginterfaces/vst/ivstchannelcontextinfo.h"
 
 /**
@@ -47,6 +49,31 @@ const static char* channel_context_integer_keys[] = {
 const static char* channel_context_binary_keys[] = {
     Steinberg::Vst::ChannelContext::kChannelImageKey};
 
+/**
+ * These are the meta data keys used for `IStreamAttributes`. We need to keep
+ * track of this because `IAttributeList` has no way to just iterate over the
+ * stored keys. We'll read these from the host if the host supports this
+ * interface, and if the plugin writes an attribute with one of these keys we'll
+ * write the value back to the host.
+ *
+ * TODO: There's also `Steinberg::Vst::PresetAttributes::kFilePathStringType`
+ *       This would require translating between Windows and Unix style paths,
+ *       which we can't easily do outside of Wine. If this ends up being
+ *       important, then we'll have to shell out to `winepath` which is not
+ *       ideal. On the Wine side we can just use the `wine_get_dos_file_name`
+ *       and `wine_get_unix_file_name` functions instead. Requesting this should
+ *       also use a 1024 character buffer.
+ */
+const static char* stream_meta_data_string_keys[] = {
+    Steinberg::Vst::PresetAttributes::kPlugInName,
+    Steinberg::Vst::PresetAttributes::kPlugInCategory,
+    Steinberg::Vst::PresetAttributes::kInstrument,
+    Steinberg::Vst::PresetAttributes::kStyle,
+    Steinberg::Vst::PresetAttributes::kCharacter,
+    Steinberg::Vst::PresetAttributes::kStateType,
+    Steinberg::Vst::PresetAttributes::kName,
+    Steinberg::Vst::PresetAttributes::kFileName};
+
 YaAttributeList::YaAttributeList(){FUNKNOWN_CTOR}
 
 YaAttributeList::~YaAttributeList() {
@@ -115,6 +142,23 @@ YaAttributeList YaAttributeList::read_channel_context(
     return attributes;
 }
 
+YaAttributeList YaAttributeList::read_stream_attributes(
+    Steinberg::Vst::IAttributeList* stream_attributes) {
+    YaAttributeList attributes{};
+    // Copy over all predefined preset meta data. `IAttributeList` does not
+    // offer any interface to enumerate the stored keys.
+    Steinberg::Vst::String128 vst_string{0};
+    for (const auto& key : stream_meta_data_string_keys) {
+        vst_string[0] = 0;
+        if (stream_attributes->getString(key, vst_string, sizeof(vst_string)) ==
+            Steinberg::kResultOk) {
+            attributes.setString(key, vst_string);
+        }
+    }
+
+    return attributes;
+}
+
 tresult PLUGIN_API YaAttributeList::setInt(AttrID id, int64 value) {
     attrs_int[id] = value;
     return Steinberg::kResultOk;