From d76777bef72aa8fe80d8381c9868e7f51c98909d Mon Sep 17 00:00:00 2001
From: Paul Licameli <paul.licameli@audacityteam.org>
Date: Sun, 29 Jul 2018 16:53:11 -0400
Subject: [PATCH] Each cell can define cursor, status, and tooltip in default
 of hit tests

---
 src/TrackPanel.cpp                     | 25 ++++++++++++++++++++++++-
 src/TrackPanelCell.h                   |  6 ++++++
 src/tracks/ui/CommonTrackPanelCell.cpp |  7 +++++++
 src/tracks/ui/CommonTrackPanelCell.h   |  4 ++++
 4 files changed, 41 insertions(+), 1 deletion(-)

diff --git a/src/TrackPanel.cpp b/src/TrackPanel.cpp
index d18e473f4..5a5359312 100644
--- a/src/TrackPanel.cpp
+++ b/src/TrackPanel.cpp
@@ -937,8 +937,21 @@ void TrackPanel::HandleMotion
       refreshCode |= code;
       mMouseOverUpdateFlags |= code;
    }
+   if (newCell &&
+       (!pCursor || status.empty() || tooltip.empty())) {
+      // Defaulting of cursor, tooltip, and status if there is no handle,
+      // or if the handle does not specify them
+      const auto preview = newCell->DefaultPreview( tpmState, GetProject() );
+      if (!pCursor)
+         pCursor = preview.cursor;
+      if (status.empty())
+         status = preview.message;
+      if (tooltip.empty())
+         tooltip = preview.tooltip;
+   }
    if (!pCursor) {
-      static wxCursor defaultCursor{ wxCURSOR_ARROW };
+      // Ultimate default cursor
+      static wxCursor defaultCursor{ wxCURSOR_DEFAULT };
       pCursor = &defaultCursor;
    }
 
@@ -946,11 +959,15 @@ void TrackPanel::HandleMotion
       /* i18n-hint Esc is a key on the keyboard */
       status += wxT(" "), status += _("(Esc to cancel)");
    mListener->TP_DisplayStatusMessage(status);
+   
+#if wxUSE_TOOLTIPS
    if (tooltip != GetToolTipText()) {
       // Unset first, by analogy with AButton
       UnsetToolTip();
       SetToolTip(tooltip);
    }
+#endif
+
    if (pCursor)
       SetCursor( *pCursor );
 
@@ -3531,6 +3548,12 @@ TrackPanelCell::~TrackPanelCell()
 {
 }
 
+HitTestPreview TrackPanelCell::DefaultPreview
+(const TrackPanelMouseState &, const AudacityProject *)
+{
+   return {};
+}
+
 unsigned TrackPanelCell::HandleWheelRotation
 (const TrackPanelMouseEvent &, AudacityProject *)
 {
diff --git a/src/TrackPanelCell.h b/src/TrackPanelCell.h
index 74b96e78d..c5bf1ddd1 100644
--- a/src/TrackPanelCell.h
+++ b/src/TrackPanelCell.h
@@ -14,6 +14,7 @@ Paul Licameli
 #include "MemoryX.h"
 
 class AudacityProject;
+struct HitTestPreview;
 struct TrackPanelMouseEvent;
 struct TrackPanelMouseState;
 class ViewInfo;
@@ -34,6 +35,11 @@ class AUDACITY_DLL_API TrackPanelCell /* not final */
 public:
    virtual ~TrackPanelCell () = 0;
 
+   // May supply default cursor, status message, and tooltip, when there is no
+   // handle to hit at the mouse position, or the handle does not supply them.
+   virtual HitTestPreview DefaultPreview
+      (const TrackPanelMouseState &state, const AudacityProject *pProject);
+
    // Return pointers to objects that can be queried for a status
    // bar message and cursor appropriate to the point, and that dispatch
    // mouse button events.
diff --git a/src/tracks/ui/CommonTrackPanelCell.cpp b/src/tracks/ui/CommonTrackPanelCell.cpp
index 0a06188b4..45cf92253 100644
--- a/src/tracks/ui/CommonTrackPanelCell.cpp
+++ b/src/tracks/ui/CommonTrackPanelCell.cpp
@@ -24,6 +24,13 @@ CommonTrackPanelCell::~CommonTrackPanelCell()
 {
 }
 
+HitTestPreview CommonTrackPanelCell::DefaultPreview
+(const TrackPanelMouseState &, const AudacityProject *)
+{
+   static wxCursor defaultCursor{ wxCURSOR_ARROW };
+   return { {}, &defaultCursor, {} };
+}
+
 unsigned CommonTrackPanelCell::HandleWheelRotation
 (const TrackPanelMouseEvent &evt, AudacityProject *pProject)
 {
diff --git a/src/tracks/ui/CommonTrackPanelCell.h b/src/tracks/ui/CommonTrackPanelCell.h
index 0f92f2bfc..b90819fbd 100644
--- a/src/tracks/ui/CommonTrackPanelCell.h
+++ b/src/tracks/ui/CommonTrackPanelCell.h
@@ -27,6 +27,10 @@ public:
 
    virtual ~CommonTrackPanelCell() = 0;
 
+   // Default to the arrow cursor
+   HitTestPreview DefaultPreview
+      (const TrackPanelMouseState &, const AudacityProject *) override;
+
    virtual std::shared_ptr<Track> FindTrack() = 0;
 
 protected: