From 425935a39a074b16a7e1fa90f0402469ef225b82 Mon Sep 17 00:00:00 2001
From: Blue Cat Audio <support@bluecataudio.com>
Date: Thu, 6 Jan 2022 14:59:45 +0100
Subject: [PATCH] Fix VST plug-ins disappearing when resized

Rather than resizing using the Windows API, perform resize on the Qt
wrapper window. This handles most situations of the plugin resizing.
---
 win/EditorWidget-win.cpp | 37 ++++++++-----------------------------
 1 file changed, 8 insertions(+), 29 deletions(-)

diff --git a/win/EditorWidget-win.cpp b/win/EditorWidget-win.cpp
index 7f87dfcac..0519ab907 100644
--- a/win/EditorWidget-win.cpp
+++ b/win/EditorWidget-win.cpp
@@ -36,7 +36,6 @@ void EditorWidget::buildEffectContainer(AEffect *effect)
 
 	QWidget *widget = QWidget::createWindowContainer(QWindow::fromWinId((WId)windowHandle), this);
 	widget->move(0, 0);
-	widget->resize(300, 300);
 
 	effect->dispatcher(effect, effEditOpen, 0, 0, windowHandle, 0);
 
@@ -44,6 +43,9 @@ void EditorWidget::buildEffectContainer(AEffect *effect)
 	effect->dispatcher(effect, effEditGetRect, 0, 0, &vstRect, 0);
 	if (vstRect) {
 		widget->resize(vstRect->right - vstRect->left, vstRect->bottom - vstRect->top);
+		resize(vstRect->right - vstRect->left, vstRect->bottom - vstRect->top);
+	} else {
+		widget->resize(300, 300);
 	}
 }
 
@@ -53,36 +55,13 @@ void EditorWidget::handleResizeRequest(int, int)
 	// so we must resize window manually
 
 	// get pointer to vst effect from window long
-	LONG_PTR    wndPtr   = (LONG_PTR)GetWindowLongPtrW(windowHandle, -21 /*GWLP_USERDATA*/);
-	AEffect *   effect   = (AEffect *)(wndPtr);
-	VstRect *   rec      = nullptr;
-	static RECT PluginRc = {0};
-	RECT        winRect  = {0};
+	LONG_PTR wndPtr = (LONG_PTR)GetWindowLongPtrW(windowHandle, -21 /*GWLP_USERDATA*/);
+	AEffect *effect = (AEffect *)(wndPtr);
+	VstRect *rec    = nullptr;
 
-	GetWindowRect(windowHandle, &winRect);
-	if (effect) {
-		effect->dispatcher(effect, effEditGetRect, 1, 0, &rec, 0);
-	}
+	effect->dispatcher(effect, effEditGetRect, 0, 0, &rec, 0);
 
-	// compare window rect with VST Rect
 	if (rec) {
-		if (PluginRc.bottom != rec->bottom || PluginRc.left != rec->left || PluginRc.right != rec->right ||
-		    PluginRc.top != rec->top) {
-			PluginRc.bottom = rec->bottom;
-			PluginRc.left   = rec->left;
-			PluginRc.right  = rec->right;
-			PluginRc.top    = rec->top;
-
-			// set rect to our window
-			AdjustWindowRectEx(&PluginRc, WS_CAPTION | WS_THICKFRAME | WS_OVERLAPPEDWINDOW, FALSE, 0);
-
-			// move window to apply pos
-			MoveWindow(windowHandle,
-			           winRect.left,
-			           winRect.top,
-			           PluginRc.right - PluginRc.left,
-			           PluginRc.bottom - PluginRc.top,
-			           TRUE);
-		}
+		resize(rec->right - rec->left, rec->bottom - rec->top);
 	}
 }