perf: add signal to invalidate buffers without doing layout

CHANGELOG.md

@@ -132,6 +132,7 @@
 - Dev: Fix `NotebookTab` emitting updates for every message. (#5068)
 - Dev: Added benchmark for parsing and building recent messages. (#5071)
 - Dev: Boost is depended on as a header-only library when using conan. (#5107)
+- Dev: Added signal to invalidate paint buffers of channel views without forcing a relayout. (#5123)
 
 ## 2.4.6
 

src/messages/layouts/MessageLayout.cpp

@@ -74,7 +74,8 @@ int MessageLayout::getWidth() const
 
 // Layout
 // return true if redraw is required
-bool MessageLayout::layout(int width, float scale, MessageElementFlags flags)
+bool MessageLayout::layout(int width, float scale, MessageElementFlags flags,
+                           bool shouldInvalidateBuffer)
 {
     //    BenchmarkGuard benchmark("MessageLayout::layout()");
 
@@ -108,6 +109,11 @@ bool MessageLayout::layout(int width, float scale, MessageElementFlags flags)
 
     if (!layoutRequired)
     {
+        if (shouldInvalidateBuffer)
+        {
+            this->invalidateBuffer();
+            return true;
+        }
         return false;
     }
 

src/messages/layouts/MessageLayout.hpp

@@ -56,7 +56,8 @@ class MessageLayout
 
     MessageLayoutFlags flags;
 
-    bool layout(int width, float scale_, MessageElementFlags flags);
+    bool layout(int width, float scale_, MessageElementFlags flags,
+                bool shouldInvalidateBuffer);
 
     // Painting
     MessagePaintResult paint(const MessagePaintContext &ctx);

src/singletons/WindowManager.cpp

@@ -211,6 +211,11 @@ void WindowManager::forceLayoutChannelViews()
     this->layoutChannelViews(nullptr);
 }
 
+void WindowManager::invalidateChannelViewBuffers(Channel *channel)
+{
+    this->invalidateBuffersRequested.invoke(channel);
+}
+
 void WindowManager::repaintVisibleChatWidgets(Channel *channel)
 {
     this->layoutRequested.invoke(channel);
@@ -407,10 +412,10 @@ void WindowManager::initialize(Settings &settings, const Paths &paths)
         this->forceLayoutChannelViews();
     });
     settings.alternateMessages.connect([this](auto, auto) {
-        this->forceLayoutChannelViews();
+        this->invalidateChannelViewBuffers();
     });
     settings.separateMessages.connect([this](auto, auto) {
-        this->forceLayoutChannelViews();
+        this->invalidateChannelViewBuffers();
     });
     settings.collpseMessagesMinLines.connect([this](auto, auto) {
         this->forceLayoutChannelViews();

src/singletons/WindowManager.hpp

@@ -66,6 +66,10 @@ class WindowManager final : public Singleton
     // This is called, for example, when the emote scale or timestamp format has
     // changed
     void forceLayoutChannelViews();
+
+    // Tell a channel (or all channels if channel is nullptr) to invalidate all paint buffers
+    void invalidateChannelViewBuffers(Channel *channel = nullptr);
+
     void repaintVisibleChatWidgets(Channel *channel = nullptr);
     void repaintGifEmotes();
 
@@ -124,6 +128,9 @@ class WindowManager final : public Singleton
     // This signal fires whenever views rendering a channel, or all views if the
     // channel is a nullptr, need to redo their layout
     pajlada::Signals::Signal<Channel *> layoutRequested;
+    // This signal fires whenever views rendering a channel, or all views if the
+    // channel is a nullptr, need to invalidate their paint buffers
+    pajlada::Signals::Signal<Channel *> invalidateBuffersRequested;
 
     pajlada::Signals::NoArgSignal wordFlagsChanged;
 

src/widgets/helper/ChannelView.cpp

@@ -425,6 +425,16 @@ void ChannelView::initializeSignals()
             }
         });
 
+    this->signalHolder_.managedConnect(
+        getIApp()->getWindows()->invalidateBuffersRequested,
+        [this](Channel *channel) {
+            if (this->isVisible() &&
+                (channel == nullptr || this->channel_.get() == channel))
+            {
+                this->invalidateBuffers();
+            }
+        });
+
     this->signalHolder_.managedConnect(getIApp()->getFonts()->fontChanged,
                                        [this] {
                                            this->queueLayout();
@@ -590,6 +600,12 @@ void ChannelView::queueUpdate(const QRect &area)
     this->update(area);
 }
 
+void ChannelView::invalidateBuffers()
+{
+    this->bufferInvalidationQueued_ = true;
+    this->queueLayout();
+}
+
 void ChannelView::queueLayout()
 {
     if (this->isVisible())
@@ -651,12 +667,13 @@ void ChannelView::layoutVisibleMessages(
         {
             const auto &message = messages[i];
 
-            redrawRequired |=
-                message->layout(layoutWidth, this->scale(), flags);
+            redrawRequired |= message->layout(layoutWidth, this->scale(), flags,
+                                              this->bufferInvalidationQueued_);
 
             y += message->getHeight();
         }
     }
+    this->bufferInvalidationQueued_ = false;
 
     if (redrawRequired)
     {
@@ -685,7 +702,7 @@ void ChannelView::updateScrollbar(
     {
         auto *message = messages[i].get();
 
-        message->layout(layoutWidth, this->scale(), flags);
+        message->layout(layoutWidth, this->scale(), flags, false);
 
         h -= message->getHeight();
 
@@ -1656,7 +1673,8 @@ void ChannelView::wheelEvent(QWheelEvent *event)
                 else
                 {
                     snapshot[i - 1]->layout(this->getLayoutWidth(),
-                                            this->scale(), this->getFlags());
+                                            this->scale(), this->getFlags(),
+                                            false);
                     scrollFactor = 1;
                     currentScrollLeft = snapshot[i - 1]->getHeight();
                 }
@@ -1690,7 +1708,8 @@ void ChannelView::wheelEvent(QWheelEvent *event)
                 else
                 {
                     snapshot[i + 1]->layout(this->getLayoutWidth(),
-                                            this->scale(), this->getFlags());
+                                            this->scale(), this->getFlags(),
+                                            false);
 
                     scrollFactor = 1;
                     currentScrollLeft = snapshot[i + 1]->getHeight();

src/widgets/helper/ChannelView.hpp

@@ -148,7 +148,9 @@ class ChannelView final : public BaseWidget
     bool hasSourceChannel() const;
 
     LimitedQueueSnapshot<MessageLayoutPtr> &getMessagesSnapshot();
+
     void queueLayout();
+    void invalidateBuffers();
 
     void clearMessages();
 
@@ -270,6 +272,7 @@ class ChannelView final : public BaseWidget
     bool canReplyToMessages() const;
 
     bool layoutQueued_ = false;
+    bool bufferInvalidationQueued_ = false;
 
     bool lastMessageHasAlternateBackground_ = false;
     bool lastMessageHasAlternateBackgroundReverse_ = true;