From 62ee2daaba46ca5d1d28f0976ce0cbc353d175bd Mon Sep 17 00:00:00 2001
From: David Capello <davidcapello@gmail.com>
Date: Thu, 29 Mar 2018 11:13:47 -0300
Subject: [PATCH] Add a comment in the ColorSelector::Painter for future work

---
 src/app/ui/color_selector.cpp | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/src/app/ui/color_selector.cpp b/src/app/ui/color_selector.cpp
index 6a360e3ed..eb931771f 100644
--- a/src/app/ui/color_selector.cpp
+++ b/src/app/ui/color_selector.cpp
@@ -44,6 +44,19 @@ using namespace ui;
 // 2. When the painting is done, we flip the buffer onto the screen
 // 3. If we receive another onPaint() we can cancel the background
 //    painting and start another onPaintSurfaceInBgThread()
+//
+// An alternative (better) way:
+// 1. Create an alternative ui::Graphics implementation that generates
+//    a list commands for the render thread
+// 2. Widgets can still use the same onPaint()
+// 3. The background threads consume the list of commands and render
+//    the screen.
+//
+// The bad side is that is harder to invalidate the commands that will
+// render an old state of the widget. So the render thread should
+// start caring about invalidating old commands (outdated regions) or
+// cleaning the queue if it gets too big.
+//
 class ColorSelector::Painter {
 public:
   Painter() : m_canvas(nullptr) {