From ebf86b5f353f6849ac950d45b8a49461db5ea3c1 Mon Sep 17 00:00:00 2001
From: reuk <reuk@users.noreply.github.com>
Date: Mon, 27 Sep 2021 20:19:35 +0100
Subject: [PATCH] VST3 Host:  Correctly size unscalable editors when DPI
 changes

---
 .../format_types/juce_VST3PluginFormat.cpp    | 44 +++++++++----------
 1 file changed, 21 insertions(+), 23 deletions(-)

diff --git a/modules/juce_audio_processors/format_types/juce_VST3PluginFormat.cpp b/modules/juce_audio_processors/format_types/juce_VST3PluginFormat.cpp
index 839aac20f7..06d0ee3c84 100644
--- a/modules/juce_audio_processors/format_types/juce_VST3PluginFormat.cpp
+++ b/modules/juce_audio_processors/format_types/juce_VST3PluginFormat.cpp
@@ -1355,17 +1355,17 @@ private:
 
 //==============================================================================
 struct VST3PluginWindow : public AudioProcessorEditor,
-                          public ComponentMovementWatcher,
-                          public ComponentPeer::ScaleFactorListener,
-                          public IPlugFrame
+                          private ComponentMovementWatcher,
+                          private ComponentPeer::ScaleFactorListener,
+                          private IPlugFrame
 {
     VST3PluginWindow (AudioPluginInstance* owner, IPlugView* pluginView)
-      : AudioProcessorEditor (owner),
-        ComponentMovementWatcher (this),
-        view (pluginView, false)
-       #if JUCE_MAC
-      , embeddedComponent (*owner)
-       #endif
+        : AudioProcessorEditor (owner),
+          ComponentMovementWatcher (this),
+          view (pluginView, false)
+         #if JUCE_MAC
+        , embeddedComponent (*owner)
+         #endif
     {
         setSize (10, 10);
         setOpaque (true);
@@ -1437,6 +1437,7 @@ struct VST3PluginWindow : public AudioProcessorEditor,
     bool keyStateChanged (bool /*isKeyDown*/) override  { return true; }
     bool keyPressed (const KeyPress& /*key*/) override  { return true; }
 
+private:
     //==============================================================================
     void componentPeerChanged() override
     {
@@ -1508,15 +1509,9 @@ struct VST3PluginWindow : public AudioProcessorEditor,
 
     void nativeScaleFactorChanged (double newScaleFactor) override
     {
-        if (approximatelyEqual ((float) newScaleFactor, nativeScaleFactor))
-            return;
-
         nativeScaleFactor = (float) newScaleFactor;
-
-        if (pluginHandle != HandleFormat{} && scaleInterface != nullptr)
-            scaleInterface->setContentScaleFactor ((Steinberg::IPlugViewContentScaleSupport::ScaleFactor) nativeScaleFactor);
-        else
-            resizeToFit();
+        updatePluginScale();
+        componentMovedOrResized (false, true);
     }
 
     void resizeToFit()
@@ -1564,7 +1559,6 @@ struct VST3PluginWindow : public AudioProcessorEditor,
         return kInvalidArgument;
     }
 
-private:
     //==============================================================================
     static void resizeWithRect (Component& comp, const ViewRect& rect, float scaleFactor)
     {
@@ -1599,11 +1593,7 @@ private:
             }
 
             warnOnFailure (view->attached ((void*) pluginHandle, defaultVST3WindowType));
-
-            if (scaleInterface != nullptr)
-                scaleInterface->setContentScaleFactor ((Steinberg::IPlugViewContentScaleSupport::ScaleFactor) nativeScaleFactor);
-            else
-                resizeToFit();
+            updatePluginScale();
         }
     }
 
@@ -1617,6 +1607,14 @@ private:
                  currentPeer->removeScaleFactorListener (this);
     }
 
+    void updatePluginScale()
+    {
+        if (scaleInterface != nullptr)
+            warnOnFailure (scaleInterface->setContentScaleFactor ((Steinberg::IPlugViewContentScaleSupport::ScaleFactor) nativeScaleFactor));
+        else
+            resizeToFit();
+    }
+
     //==============================================================================
     Atomic<int> refCount { 1 };
     VSTComSmartPtr<IPlugView> view;