From 72e5ec2c5eab426ce66f70e8a66fba24ff3ae86f Mon Sep 17 00:00:00 2001
From: Robin Gareus <robin@gareus.org>
Date: Wed, 6 Oct 2021 05:04:57 +0200
Subject: [PATCH] Prototype LV2 dialog-message feature extension

---
 gtk2_ardour/lv2_plugin_ui.cc        | 26 ++++++++++++++++++++++++--
 libs/ardour/ardour/lv2_extensions.h | 25 +++++++++++++++++++++++++
 2 files changed, 49 insertions(+), 2 deletions(-)

diff --git a/gtk2_ardour/lv2_plugin_ui.cc b/gtk2_ardour/lv2_plugin_ui.cc
index dbb3973b52..ae7f5b76ea 100644
--- a/gtk2_ardour/lv2_plugin_ui.cc
+++ b/gtk2_ardour/lv2_plugin_ui.cc
@@ -140,7 +140,9 @@ LV2PluginUI::request_response (int                        response,
 			}
 			break;
 		case Variant::BOOL:
-			set_path_property (desc.key, Variant (Variant::BOOL, response == Gtk::RESPONSE_YES));
+			if (response != Gtk::BUTTONS_OK) {
+				set_path_property (desc.key, Variant (Variant::BOOL, response == Gtk::RESPONSE_YES));
+			}
 			break;
 		default:
 			break;
@@ -197,7 +199,27 @@ LV2PluginUI::request_value(void*                     handle,
 
 		case Variant::BOOL:
 			{
-				ArdourMessageDialog* msg = new ArdourMessageDialog (desc.label, false, Gtk::MESSAGE_QUESTION, Gtk::BUTTONS_YES_NO, false);
+				std::string      message = desc.label;
+				Gtk::MessageType type    = Gtk::MESSAGE_QUESTION;
+				Gtk::ButtonsType buttons = Gtk::BUTTONS_YES_NO;
+
+#ifdef LV2_EXTENDED
+				for (int i = 0; features && features[i]; ++i) {
+					if (!strcmp (features[i]->URI, LV2_DIALOGMESSAGE_URI)) {
+						LV2_Dialog_Message* mt = NULL;
+						mt = (LV2_Dialog_Message*) features[i]->data;
+						if (mt->msg) {
+							message = mt->msg;
+							mt->free_msg (mt->msg);
+						}
+						if (!mt->requires_return) {
+							type    = Gtk::MESSAGE_INFO;
+							buttons = Gtk::BUTTONS_OK;
+						}
+					}
+				}
+#endif
+				ArdourMessageDialog* msg = new ArdourMessageDialog (message, false, type, buttons, false);
 				msg->signal_response().connect (sigc::bind (sigc::mem_fun (*me, &LV2PluginUI::request_response), desc, msg));
 				msg->present();
 			}
diff --git a/libs/ardour/ardour/lv2_extensions.h b/libs/ardour/ardour/lv2_extensions.h
index 26223c3d33..6c94e7369e 100644
--- a/libs/ardour/ardour/lv2_extensions.h
+++ b/libs/ardour/ardour/lv2_extensions.h
@@ -276,6 +276,31 @@ typedef struct {
 	void (*notify)(LV2_BankPatch_Handle handle, uint8_t channel, uint32_t bank, uint8_t pgm);
 } LV2_BankPatch;
 
+/**
+   @}
+*/
+
+/**
+   @defgroup LV2_Dialog_Message
+
+	 LV2 extension to allow a plugin to ask a host to display
+	 a dedicated dialog message when requesting a value
+
+   @{
+*/
+
+
+#define LV2_DIALOGMESSAGE_URI "http://ardour.org/lv2/dialog_message"
+
+/** a LV2 Feature provided by the Plugin, passed as optional feature to LV2_UI__requestValue */
+typedef struct {
+	void (*free_msg)(char const* msg);
+
+	char const* msg;
+	bool requires_return;
+
+} LV2_Dialog_Message;
+
 /**
    @}
 */