From 6d5507313e6449ae1081ec7812c07a9c0fa708f5 Mon Sep 17 00:00:00 2001
From: Andreas Kling <awesomekling@gmail.com>
Date: Thu, 2 May 2019 03:46:37 +0200
Subject: [PATCH] GWidget: Add set_updates_enabled() for temporarily
 suppressing updates.

---
 LibGUI/GWidget.cpp | 26 ++++++++++++++++++++++----
 LibGUI/GWidget.h   |  4 ++++
 2 files changed, 26 insertions(+), 4 deletions(-)

diff --git a/LibGUI/GWidget.cpp b/LibGUI/GWidget.cpp
index 4b4cc35a52..fedecc8b74 100644
--- a/LibGUI/GWidget.cpp
+++ b/LibGUI/GWidget.cpp
@@ -283,6 +283,8 @@ void GWidget::leave_event(CEvent&)
 
 void GWidget::update()
 {
+    if (rect().is_empty())
+        return;
     update(rect());
 }
 
@@ -290,10 +292,17 @@ void GWidget::update(const Rect& rect)
 {
     if (!is_visible())
         return;
-    auto* w = window();
-    if (!w)
-        return;
-    w->update(rect.translated(window_relative_rect().location()));
+
+    GWindow* window = m_window;
+    GWidget* parent = parent_widget();
+    while (parent) {
+        if (!parent->updates_enabled())
+            return;
+        window = parent->m_window;
+        parent = parent->parent_widget();
+    }
+    if (window)
+        window->update(rect.translated(window_relative_rect().location()));
 }
 
 Rect GWidget::window_relative_rect() const
@@ -516,3 +525,12 @@ void GWidget::unregister_local_shortcut_action(Badge<GAction>, GAction& action)
 {
     m_local_shortcut_actions.remove(action.shortcut());
 }
+
+void GWidget::set_updates_enabled(bool enabled)
+{
+    if (m_updates_enabled == enabled)
+        return;
+    m_updates_enabled = enabled;
+    if (enabled)
+        update();
+}
diff --git a/LibGUI/GWidget.h b/LibGUI/GWidget.h
index 1cb7104fa1..9be5d9b02e 100644
--- a/LibGUI/GWidget.h
+++ b/LibGUI/GWidget.h
@@ -45,6 +45,9 @@ public:
     bool is_enabled() const { return m_enabled; }
     void set_enabled(bool);
 
+    bool updates_enabled() const { return m_updates_enabled; }
+    void set_updates_enabled(bool);
+
     virtual void event(CEvent&) override;
     virtual void paint_event(GPaintEvent&);
     virtual void resize_event(GResizeEvent&);
@@ -211,6 +214,7 @@ private:
     bool m_greedy_for_hits { false };
     bool m_enabled { true };
     bool m_layout_dirty { false };
+    bool m_updates_enabled { true };
 
     CElapsedTimer m_left_click_clock;
     CElapsedTimer m_right_click_clock;