From b6c6f1e78cda6c7c4fbfd898441acba908b06c53 Mon Sep 17 00:00:00 2001
From: hippoz <10706925-hippoz@users.noreply.gitlab.com>
Date: Tue, 26 Jul 2022 04:47:17 +0300
Subject: [PATCH] fix batch system

---
 src/Window.cpp | 41 ++++++++++++++++++++++-------------------
 src/Window.hpp |  4 ++--
 2 files changed, 24 insertions(+), 21 deletions(-)

diff --git a/src/Window.cpp b/src/Window.cpp
index 888b6df..794509d 100644
--- a/src/Window.cpp
+++ b/src/Window.cpp
@@ -73,10 +73,8 @@ bool Window::dispatch_to_main_widget(Event &event) {
 
 void Window::repaint(Box geometry) {
     m_did_repaint_during_batch = true;
-
-    if (m_is_batching) {
+    if (m_batches)
         return;
-    }
 
     auto event = RepaintRectEvent(true, geometry);
     dispatch_to_main_widget(event);
@@ -92,10 +90,8 @@ void Window::repaint() {
 
 void Window::relayout(Widget *target) {
     m_did_relayout_during_batch = true;
-
-    if (m_is_batching) {
+    if (m_batches)
         return;
-    }
 
     auto event = RelayoutSubtreeEvent();
     target->dispatch_event(event);
@@ -103,10 +99,8 @@ void Window::relayout(Widget *target) {
 
 void Window::relayout() {
     m_did_relayout_during_batch = true;
-
-    if (m_is_batching) {
+    if (m_batches)
         return;
-    }
 
     auto event = RelayoutSubtreeEvent();
     dispatch_to_main_widget(event);
@@ -118,20 +112,29 @@ void Window::reflow() {
 }
 
 void Window::start_batch() {
-    m_is_batching = true;
-    m_did_relayout_during_batch = false;
-    m_did_repaint_during_batch = false;
+    m_batches++;
 }
 
 void Window::end_batch() {
-    if (m_is_batching) {
-        m_is_batching = false;
-        if (m_did_relayout_during_batch) {
-            reflow();
-        } else if (m_did_repaint_during_batch) {
-            repaint();
-        }
+    if (m_batches < 1)
+        return;
+
+    // we are only interested in performing batch operations for the last batch
+    if (m_batches > 1) {
+        m_batches--;
+        return;
     }
+
+    m_batches = 0;
+
+    if (m_did_relayout_during_batch) {
+        reflow();
+    } else if (m_did_repaint_during_batch) {
+        repaint();
+    }
+
+    m_did_relayout_during_batch = false;
+    m_did_repaint_during_batch = false;
 }
 
 void Window::run(bool block) {
diff --git a/src/Window.hpp b/src/Window.hpp
index e3e457a..74084b5 100644
--- a/src/Window.hpp
+++ b/src/Window.hpp
@@ -56,9 +56,9 @@ private:
     Box m_rect { 0, 0, 800, 600 };
     Painter m_painter {};
     Cairo::RefPtr<Cairo::XlibSurface> m_xlib_surface { nullptr };
-    bool m_is_batching { true };
-    bool m_did_relayout_during_batch { true };
+    int m_batches { 1 };
     bool m_did_repaint_during_batch { false };
+    bool m_did_relayout_during_batch { false };
 
     Display *m_x_display { nullptr };