From cbc7c912ddd056ce444efe045fd579b979e2fa72 Mon Sep 17 00:00:00 2001
From: Jean Pierre Cimalando <jp-dev@inbox.ru>
Date: Tue, 11 May 2021 19:43:44 +0200
Subject: [PATCH] Rate-limit volume meter updates

---
 plugins/editor/src/editor/GUIComponents.cpp | 18 +++++++++++++++++-
 plugins/editor/src/editor/GUIComponents.h   |  2 ++
 2 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/plugins/editor/src/editor/GUIComponents.cpp b/plugins/editor/src/editor/GUIComponents.cpp
index 88e48609..769503fc 100644
--- a/plugins/editor/src/editor/GUIComponents.cpp
+++ b/plugins/editor/src/editor/GUIComponents.cpp
@@ -991,7 +991,23 @@ void SLevelMeter::setValue(float value)
         return;
 
     value_ = value;
-    invalid();
+
+    // instantiate the timer lazily
+    if (!timer_) {
+        const uint32_t interval = 10;
+        timer_ = makeOwned<CVSTGUITimer>(
+            [this](CVSTGUITimer* timer) {
+                timer->stop();
+                timerArmed_ = false;
+                invalid();
+            }, interval, false);
+    }
+
+    // defer the update, but do not rearm the timer
+    if (!timerArmed_) {
+        timerArmed_ = true;
+        timer_->start();
+    }
 }
 
 void SLevelMeter::draw(CDrawContext* dc)
diff --git a/plugins/editor/src/editor/GUIComponents.h b/plugins/editor/src/editor/GUIComponents.h
index dfbd0be4..8161154f 100644
--- a/plugins/editor/src/editor/GUIComponents.h
+++ b/plugins/editor/src/editor/GUIComponents.h
@@ -402,6 +402,8 @@ private:
     CColor dangerFillColor_;
     CColor backColor_;
     CCoord radius_ = 5.0;
+    SharedPointer<CVSTGUITimer> timer_;
+    bool timerArmed_ = false;
 };
 
 ///