From 9b98f4be0cd9d239a7b5d4c5df7028718b1e31ce Mon Sep 17 00:00:00 2001
From: Paul Licameli <paul.licameli@audacityteam.org>
Date: Sun, 7 Jul 2019 12:20:59 -0400
Subject: [PATCH] ScrubbingToolBar consumes less idle time

---
 src/toolbars/ScrubbingToolBar.cpp | 71 +++++++++++++++++++------------
 src/toolbars/ScrubbingToolBar.h   |  7 +++
 2 files changed, 51 insertions(+), 27 deletions(-)

diff --git a/src/toolbars/ScrubbingToolBar.cpp b/src/toolbars/ScrubbingToolBar.cpp
index bca717598..51b16fd39 100644
--- a/src/toolbars/ScrubbingToolBar.cpp
+++ b/src/toolbars/ScrubbingToolBar.cpp
@@ -142,6 +142,11 @@ void ScrubbingToolBar::UpdatePrefs()
 }
 
 void ScrubbingToolBar::RegenerateTooltips()
+{
+   DoRegenerateTooltips( true );
+}
+
+void ScrubbingToolBar::DoRegenerateTooltips( bool force )
 {
 #if wxUSE_TOOLTIPS
    auto fn = [&]
@@ -159,34 +164,46 @@ void ScrubbingToolBar::RegenerateTooltips()
       const auto seekButton = mButtons[STBSeekID];
 
       wxString label;
-      label = (
-               scrubber.Scrubs()
-               /* i18n-hint: These commands assist the user in finding a sound by ear. ...
-                "Scrubbing" is variable-speed playback, ...
-                "Seeking" is normal speed playback but with skips
-                */
-               ? _("Stop Scrubbing")
-               : _("Start Scrubbing")
-               );
-      fn(*scrubButton, label, wxT("Scrub"));
+      bool scrubs = scrubber.Scrubs();
+      if (force || mLastScrub != scrubs) {
+         label = (
+                  scrubs
+                  /* i18n-hint: These commands assist the user in finding a sound by ear. ...
+                   "Scrubbing" is variable-speed playback, ...
+                   "Seeking" is normal speed playback but with skips
+                   */
+                  ? _("Stop Scrubbing")
+                  : _("Start Scrubbing")
+                  );
+         fn(*scrubButton, label, wxT("Scrub"));
+      }
+      mLastScrub = scrubs;
 
-      label = (
-               scrubber.Seeks()
-               /* i18n-hint: These commands assist the user in finding a sound by ear. ...
-                "Scrubbing" is variable-speed playback, ...
-                "Seeking" is normal speed playback but with skips
-                */
-               ? _("Stop Seeking")
-               : _("Start Seeking")
-               );
-      fn(*seekButton, label, wxT("Seek"));
+      bool seeks = scrubber.Seeks();
+      if (force || mLastSeek != seeks) {
+         label = (
+                  seeks
+                  /* i18n-hint: These commands assist the user in finding a sound by ear. ...
+                   "Scrubbing" is variable-speed playback, ...
+                   "Seeking" is normal speed playback but with skips
+                   */
+                  ? _("Stop Seeking")
+                  : _("Start Seeking")
+                  );
+         fn(*seekButton, label, wxT("Seek"));
+      }
+      mLastSeek = seeks;
 
-      label = (
-               AdornedRulerPanel::Get( *project ).ShowingScrubRuler()
-               ? _("Hide Scrub Ruler")
-               : _("Show Scrub Ruler")
-               );
-      fn(*mButtons[STBRulerID], label, wxT("ToggleScrubRuler"));
+      bool showingRuler = AdornedRulerPanel::Get( *project ).ShowingScrubRuler();
+      if (force || mLastRuler != showingRuler) {
+         label = (
+                  showingRuler
+                  ? _("Hide Scrub Ruler")
+                  : _("Show Scrub Ruler")
+                  );
+         fn(*mButtons[STBRulerID], label, wxT("ToggleScrubRuler"));
+      }
+      mLastRuler = showingRuler;
    }
 #endif
 }
@@ -256,7 +273,7 @@ void ScrubbingToolBar::EnableDisableButtons()
       barButton->PushDown();
    else
       barButton->PopUp();
-   RegenerateTooltips();
+   DoRegenerateTooltips( false );
    scrubber.CheckMenuItems();
 }
 
diff --git a/src/toolbars/ScrubbingToolBar.h b/src/toolbars/ScrubbingToolBar.h
index fc692aea3..78a4343cd 100644
--- a/src/toolbars/ScrubbingToolBar.h
+++ b/src/toolbars/ScrubbingToolBar.h
@@ -78,6 +78,13 @@ public:
 
    DECLARE_CLASS(ScrubbingToolBar)
    DECLARE_EVENT_TABLE()
+
+private:
+   void DoRegenerateTooltips( bool force );
+
+   bool mLastScrub{ false };
+   bool mLastSeek{ false };
+   bool mLastRuler{ false };
 };
 
 #endif