VST3: Improved stability of scaled plug-in windows

modules/juce_audio_plugin_client/VST3/juce_VST3_Wrapper.cpp

@@ -1227,8 +1227,8 @@ private:
             createContentWrapperComponentIfNeeded();
 
            #if JUCE_WINDOWS || JUCE_LINUX
-            component->addToDesktop (0, parent);
             component->setOpaque (true);
+            component->addToDesktop (0, (void*) systemWindow);
             component->setVisible (true);
 
             #if JUCE_WINDOWS && JUCE_WIN_PER_MONITOR_DPI_AWARE
@@ -1295,10 +1295,7 @@ private:
 
                 if (component != nullptr)
                 {
-                    auto w = rect.getWidth();
-                    auto h = rect.getHeight();
-
-                    component->setSize (w, h);
+                    component->setSize (rect.getWidth(), rect.getHeight());
 
                    #if JUCE_MAC
                     if (cubase10Workaround != nullptr)
@@ -1358,32 +1355,34 @@ private:
                     {
                         *rectToCheck = convertFromHostBounds (*rectToCheck);
 
-                        auto transformScale = std::sqrt (std::abs (editor->getTransform().getDeterminant()));
-
-                        auto minW = (double) constrainer->getMinimumWidth()  * transformScale;
-                        auto maxW = (double) constrainer->getMaximumWidth()  * transformScale;
-                        auto minH = (double) constrainer->getMinimumHeight() * transformScale;
-                        auto maxH = (double) constrainer->getMaximumHeight() * transformScale;
+                        auto editorBounds = editor->getLocalArea (component.get(),
+                                                                  Rectangle<int>::leftTopRightBottom (rectToCheck->left, rectToCheck->top,
+                                                                                                      rectToCheck->right, rectToCheck->bottom).toFloat());
 
-                        auto width  = (double) rectToCheck->right - (double) rectToCheck->left;
-                        auto height = (double) rectToCheck->bottom - (double) rectToCheck->top;
+                        auto minW = (float) constrainer->getMinimumWidth();
+                        auto maxW = (float) constrainer->getMaximumWidth();
+                        auto minH = (float) constrainer->getMinimumHeight();
+                        auto maxH = (float) constrainer->getMaximumHeight();
 
-                        width  = jlimit (minW, maxW, width);
-                        height = jlimit (minH, maxH, height);
+                        auto width  = jlimit (minW, maxW, editorBounds.getWidth());
+                        auto height = jlimit (minH, maxH, editorBounds.getHeight());
 
-                        auto aspectRatio = constrainer->getFixedAspectRatio();
+                        auto aspectRatio = (float) constrainer->getFixedAspectRatio();
 
                         if (aspectRatio != 0.0)
                         {
-                            bool adjustWidth = (width / height > aspectRatio);
-
-                            if (getHostType().type == PluginHostType::SteinbergCubase9)
+                            auto adjustWidth = [&]
                             {
-                                if (editor->getWidth() == width && editor->getHeight() != height)
-                                    adjustWidth = true;
-                                else if (editor->getHeight() == height && editor->getWidth() != width)
-                                    adjustWidth = false;
-                            }
+                                auto currentEditorBounds = editor->getBounds().toFloat();
+
+                                auto stretchingBottom = (currentEditorBounds.getBottom() != editorBounds.getBottom());
+                                auto stretchingRight  = (currentEditorBounds.getRight()  != editorBounds.getRight());
+
+                                if (getHostType().isReaper() || stretchingBottom == stretchingRight)
+                                    return currentEditorBounds.getAspectRatio() > (width / height);
+
+                                return stretchingBottom;
+                            }();
 
                             if (adjustWidth)
                             {
@@ -1407,8 +1406,11 @@ private:
                             }
                         }
 
-                        rectToCheck->right  = rectToCheck->left + roundToInt (width);
-                        rectToCheck->bottom = rectToCheck->top  + roundToInt (height);
+                        auto constrainedRect = component->getLocalArea (editor, Rectangle<float> (width, height))
+                                                  .getSmallestIntegerContainer();
+
+                        rectToCheck->right  = rectToCheck->left + roundToInt (constrainedRect.getWidth());
+                        rectToCheck->bottom = rectToCheck->top  + roundToInt (constrainedRect.getHeight());
 
                         *rectToCheck = convertToHostBounds (*rectToCheck);
                     }
@@ -1443,16 +1445,7 @@ private:
                     owner->lastScaleFactorReceived = editorScaleFactor;
 
                 if (component != nullptr)
-                {
-                    if (auto* editor = component->pluginEditor.get())
-                    {
-                        editor->setScaleFactor (editorScaleFactor);
-
-                        component->resizeHostWindow();
-                        component->setTopLeftPosition (0, 0);
-                        component->repaint();
-                    }
-                }
+                    component->setEditorScaleFactor (editorScaleFactor);
             }
 
             return kResultTrue;
@@ -1564,21 +1557,18 @@ private:
                 if (resizingChild)
                     return;
 
-                auto b = getSizeToContainChild();
+                auto newBounds = getSizeToContainChild();
 
-                if (lastBounds != b)
+                if (newBounds != lastBounds)
                 {
-                    lastBounds = b;
-
-                    {
-                        const ScopedValueSetter<bool> resizingParentSetter (resizingParent, true);
-                        resizeHostWindow();
-                    }
+                    resizeHostWindow();
 
                    #if JUCE_LINUX
                     if (getHostType().isBitwigStudio())
                         repaint();
                    #endif
+
+                    lastBounds = newBounds;
                 }
             }
 
@@ -1595,28 +1585,12 @@ private:
                             return;
                        #endif
 
-                        lastBounds = newBounds;
-
-                        const ScopedValueSetter<bool> resizingChildSetter (resizingChild, true);
-
-                        if (auto* constrainer = pluginEditor->getConstrainer())
                         {
-                            auto aspectRatio = constrainer->getFixedAspectRatio();
-
-                            if (aspectRatio != 0)
-                            {
-                                auto width = (double) lastBounds.getWidth();
-                                auto height = (double) lastBounds.getHeight();
-
-                                if (width / height > aspectRatio)
-                                    setBounds ({ 0, 0, roundToInt (height * aspectRatio), lastBounds.getHeight() });
-                                else
-                                    setBounds ({ 0, 0, lastBounds.getWidth(), roundToInt (width / aspectRatio) });
-                            }
+                            const ScopedValueSetter<bool> resizingChildSetter (resizingChild, true);
+                            pluginEditor->setBounds (pluginEditor->getLocalArea (this, newBounds).withPosition (0, 0));
                         }
 
-                        pluginEditor->setTopLeftPosition (0, 0);
-                        pluginEditor->setBounds (pluginEditor->getLocalArea (this, getLocalBounds()));
+                        lastBounds = newBounds;
                     }
                 }
             }
@@ -1634,31 +1608,45 @@ private:
             {
                 if (pluginEditor != nullptr)
                 {
-                    auto b = getSizeToContainChild();
-                    auto w = b.getWidth();
-                    auto h = b.getHeight();
-                    auto host = getHostType();
-
-                   #if JUCE_WINDOWS
-                    setSize (w, h);
-                   #endif
-
                     if (owner.plugFrame != nullptr)
                     {
-                        auto newSize = convertToHostBounds ({ 0, 0, b.getWidth(), b.getHeight() });
+                        auto editorBounds = getSizeToContainChild();
+                        auto newSize = convertToHostBounds ({ 0, 0, editorBounds.getWidth(), editorBounds.getHeight() });
 
                         {
                             const ScopedValueSetter<bool> resizingParentSetter (resizingParent, true);
                             owner.plugFrame->resizeView (&owner, &newSize);
                         }
 
+                        auto host = getHostType();
+
                        #if JUCE_MAC
                         if (host.isWavelab() || host.isReaper())
                        #else
                         if (host.isWavelab() || host.isAbletonLive() || host.isBitwigStudio())
                        #endif
-                            setBounds (0, 0, w, h);
+                            setBounds (editorBounds.withPosition (0, 0));
+                    }
+                }
+            }
+
+            void setEditorScaleFactor (float scale)
+            {
+                if (pluginEditor != nullptr)
+                {
+                    auto prevEditorBounds = pluginEditor->getLocalArea (this, lastBounds);
+
+                    {
+                        const ScopedValueSetter<bool> resizingChildSetter (resizingChild, true);
+
+                        pluginEditor->setScaleFactor (scale);
+                        pluginEditor->setBounds (prevEditorBounds.withPosition (0, 0));
                     }
+
+                    lastBounds = getSizeToContainChild();
+
+                    resizeHostWindow();
+                    repaint();
                 }
             }