Simplify mouse wheel handler hook

(cherry picked from commit 2f54bdd; modified for Tenacity) Signed-off-by: Avery King <[email protected]>
tenacityteam · Apr 16, 2024 · 896a5d6 · 896a5d6
1 parent aff6ab1
commit 896a5d6
Show file tree

Hide file tree

Showing 3 changed files with 9 additions and 37 deletions.
diff --git a/src/ProjectWindow.cpp b/src/ProjectWindow.cpp
@@ -349,19 +349,11 @@ void ScrollBar::SetScrollbar(int position, int thumbSize,
 // Common mouse wheel handling in track panel cells, moved here to avoid
 // compilation dependencies on Track, TrackPanel, and Scrubbing at low levels
 // which made cycles
-static struct MouseWheelHandler {
-
-MouseWheelHandler()
-{
-   CommonTrackPanelCell::InstallMouseWheelHook( *this );
-}
-
+static CommonTrackPanelCell::MouseWheelHook::Scope scope{
 // Need a bit of memory from one call to the next
-mutable double mVertScrollRemainder = 0.0;
-
-unsigned operator()
-   ( const TrackPanelMouseEvent &evt, TenacityProject *pProject ) const
-{
+[mVertScrollRemainder = 0.0](
+   const TrackPanelMouseEvent &evt, TenacityProject *pProject )
+mutable -> unsigned {
    using namespace RefreshCode;
 
    if ( TrackList::Get( *pProject ).empty() )
@@ -488,9 +480,7 @@ unsigned operator()
    }
 
    return result;
-}
-
-} sMouseWheelHandler;
+} };
 
 AttachedWindows::RegisteredFactory sProjectWindowKey{
    []( TenacityProject &parent ) -> wxWeakRef< wxWindow > {

diff --git a/src/tracks/ui/CommonTrackPanelCell.cpp b/src/tracks/ui/CommonTrackPanelCell.cpp
@@ -21,23 +21,6 @@ Paul Licameli split from TrackPanel.cpp
 #include "../../TrackPanelMouseEvent.h"
 #include "ViewInfo.h"
 
-namespace {
-   CommonTrackPanelCell::Hook &GetHook()
-   {
-      static CommonTrackPanelCell::Hook theHook;
-      return theHook;
-   }
-}
-
-auto CommonTrackPanelCell::InstallMouseWheelHook( const Hook &hook )
-   -> Hook
-{
-   auto &theHook = GetHook();
-   auto result = theHook;
-   theHook = hook;
-   return result;
-}
-
 CommonTrackPanelCell::~CommonTrackPanelCell()
 {
 }
@@ -116,7 +99,7 @@ unsigned CommonTrackPanelCell::DoContextMenu( const wxRect &rect,
 unsigned CommonTrackPanelCell::HandleWheelRotation
 (const TrackPanelMouseEvent &evt, TenacityProject *pProject)
 {
-   auto hook = GetHook();
+   auto &hook = MouseWheelHook::Get();
    return hook ? hook( evt, pProject ) : RefreshCode::Cancelled;
 }
 

diff --git a/src/tracks/ui/CommonTrackPanelCell.h b/src/tracks/ui/CommonTrackPanelCell.h
@@ -18,6 +18,7 @@ Paul Licameli split from TrackPanel.cpp
 #include <memory>
 #include <functional>
 #include "ComponentInterfaceSymbol.h"
+#include "GlobalVariable.h"
 
 #include "XMLTagHandler.h"
 
@@ -29,12 +30,10 @@ class TENACITY_DLL_API CommonTrackPanelCell /* not final */
    : public TrackPanelCell
 {
 public:
-   // Type of function to dispatch mouse wheel events
-   using Hook = std::function<
+   // Function to dispatch mouse wheel events
+   using MouseWheelHook = GlobalHook< CommonTrackPanelCell,
       unsigned(const TrackPanelMouseEvent &evt, TenacityProject *pProject)
    >;
-   // Install a dispatcher function, returning the previous function
-   static Hook InstallMouseWheelHook( const Hook &hook );
 
    CommonTrackPanelCell()
    {}