From 652afb9875a8779e1e657f892971357c9e5fb2b6 Mon Sep 17 00:00:00 2001
From: Trevor Slocum <trevor@rocketnine.space>
Date: Sun, 6 Jun 2021 20:44:56 -0700
Subject: [PATCH] Update Application.QueueUpdateDraw to accept one or more
 primitives to draw instead of the whole screen

---
 CHANGELOG      |  3 ++-
 application.go | 22 ++++++++++++++++++----
 2 files changed, 20 insertions(+), 5 deletions(-)

diff --git a/CHANGELOG b/CHANGELOG
index d761022..60c1ff0 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -6,7 +6,8 @@ v1.5.6 (WIP)
 - Add DropDown.SetAlwaysDrawDropDownSymbol (DropDown symbols are now shown only when focused by default)
 - Add DropDown.SetDropDownOpenSymbolRune
 - Draw additional accents when rendering a list divider
-- Update Application.Draw to accept one or more primitives to draw instead of the whole screen
+- Update Application.Draw and Application.QueueUpdateDraw to accept one or more
+primitives to draw instead of the whole screen
 - Update List, Table and TreeView to not handle Tab or Backtab
 - Allow specifying TabbedPanels switcher height
 - Change default colors (fields and buttons are now green)
diff --git a/application.go b/application.go
index 2d23995..63fd5fc 100644
--- a/application.go
+++ b/application.go
@@ -862,12 +862,26 @@ func (a *Application) QueueUpdate(f func()) {
 	a.updates <- f
 }
 
-// QueueUpdateDraw works like QueueUpdate() except it refreshes the screen
-// immediately after executing f.
-func (a *Application) QueueUpdateDraw(f func()) {
+// QueueUpdateDraw works like QueueUpdate() except, when one or more primitives
+// are provided, the primitives are drawn after the provided function returns.
+// When no primitives are provided, the entire screen is drawn after the
+// provided function returns.
+func (a *Application) QueueUpdateDraw(f func(), p ...Primitive) {
 	a.QueueUpdate(func() {
 		f()
-		a.draw()
+
+		if len(p) == 0 {
+			a.draw()
+			return
+		}
+		a.Lock()
+		if a.screen != nil {
+			for _, primitive := range p {
+				primitive.Draw(a.screen)
+			}
+			a.screen.Show()
+		}
+		a.Unlock()
 	})
 }