- Modified LayoutBase to emit events on focus terminate or wrap

- Updated LibraryLayout to use FocusTerminated event to simplify logic
  around focusing the transport, instead of using null checks in
  FocusNext() and FocusPrev().

src/musikbox/app/layout/LibraryLayout.cpp

@@ -105,10 +105,15 @@ void LibraryLayout::ChangeMainLayout(std::shared_ptr<cursespp::LayoutBase> newLa
 
         if (this->visibleLayout) {
            this->RemoveWindow(this->visibleLayout);
+           this->visibleLayout->FocusTerminated.disconnect(this);
            this->visibleLayout->Hide();
         }
 
         this->visibleLayout = newLayout;
+
+        this->visibleLayout->FocusTerminated.connect(
+            this, &LibraryLayout::OnMainLayoutFocusTerminated);
+
         this->AddWindow(this->visibleLayout);
         this->visibleLayout->Layout();
         this->visibleLayout->Show();
@@ -229,15 +234,7 @@ IWindowPtr LibraryLayout::FocusNext() {
         return this->FocusTransportNext();
     }
 
-    IWindowPtr focus = this->visibleLayout->FocusNext();
-
-    /* no next focus? kick over to the transport */
-    if (!focus) {
-        this->transportView->FocusFirst();
-        focus = this->transportView;
-    }
-
-    return focus;
+    return this->visibleLayout->FocusNext();
 }
 
 IWindowPtr LibraryLayout::FocusPrev() {
@@ -245,14 +242,18 @@ IWindowPtr LibraryLayout::FocusPrev() {
         return this->FocusTransportPrev();
     }
 
-    IWindowPtr focus = this->visibleLayout->FocusPrev();
+    return this->visibleLayout->FocusPrev();
+}
 
-    if (!focus) {
-        this->transportView->FocusLast();
-        focus = this->transportView;
+void LibraryLayout::OnMainLayoutFocusTerminated(
+    LayoutBase::FocusDirection direction)
+{
+    if (direction == LayoutBase::FocusForward) {
+        this->transportView->FocusFirst();
+    }
+    else {
+        this->transportView->FocusLast();
     }
-
-    return focus;
 }
 
 IWindowPtr LibraryLayout::GetFocus() {
@@ -260,16 +261,7 @@ IWindowPtr LibraryLayout::GetFocus() {
         return this->transportView;
     }
 
-    /* if nothing in the visible layout is focused, go
-    ahead and focus the transport so the user has something
-    to interact with. */
-    IWindowPtr focused = this->visibleLayout->GetFocus();
-    if (!focused) {
-        this->transportView->FocusFirst();
-        return this->transportView;
-    }
-
-    return focused;
+    return this->visibleLayout->GetFocus();
 }
 
 bool LibraryLayout::SetFocus(cursespp::IWindowPtr window) {

src/musikbox/app/layout/LibraryLayout.h

@@ -82,6 +82,9 @@ namespace musik {
                     std::string fieldType,
                     DBID fieldId);
 
+                void OnMainLayoutFocusTerminated(
+                    LayoutBase::FocusDirection direction);
+
                 void InitializeWindows();
 
                 void ShowNowPlaying();

src/musikbox/cursespp/LayoutBase.cpp

@@ -247,38 +247,61 @@ bool LayoutBase::SetFocus(IWindowPtr focus) {
 }
 
 IWindowPtr LayoutBase::FocusNext() {
+    sigslot::signal1<FocusDirection>* notify = nullptr;
+
     IWindowPtr oldFocus = GetFocus();
     if (this->focused == NO_FOCUS && this->focusMode == FocusModeTerminating) {
         /* nothing. we're already terminated. */
+        notify = &FocusTerminated;
     }
     else if (this->focused + 1 >= AUTO_FOCUS) {
         ++this->focused;
         if (this->focused >= (int) this->focusable.size()) {
             if (this->focusMode == FocusModeCircular) {
                 this->focused = 0;
+                notify = &FocusWrapped;
             }
             else {
                 this->focused = NO_FOCUS;
+                notify = &FocusTerminated;
             }
         }
     }
 
-    return adjustFocus(oldFocus, GetFocus());
+    IWindowPtr newFocus = GetFocus();
+    adjustFocus(oldFocus, newFocus);
+
+    if (notify) {
+        (*notify)(FocusForward);
+    }
+
+    return newFocus;
 }
 
 IWindowPtr LayoutBase::FocusPrev() {
+    sigslot::signal1<FocusDirection>* notify = nullptr;
+
     IWindowPtr oldFocus = GetFocus();
     --this->focused;
     if (this->focused < 0) {
         if (this->focusMode == FocusModeCircular) {
             this->focused = (int) this->focusable.size() - 1;
+            notify = &FocusWrapped;
         }
         else {
             this->focused = NO_FOCUS;
+            notify = &FocusTerminated;
         }
     }
 
-    return adjustFocus(oldFocus, GetFocus());
+    IWindowPtr newFocus = GetFocus();
+    adjustFocus(oldFocus, newFocus);
+
+    if (notify) {
+        (*notify)(FocusBackward);
+    }
+
+    return newFocus;
 }
 
 IWindowPtr LayoutBase::FocusFirst() {

src/musikbox/cursespp/LayoutBase.h

@@ -37,6 +37,7 @@
 #include "ILayout.h"
 #include "Window.h"
 
+#include <sigslot/sigslot.h>
 #include <vector>
 
 namespace cursespp {
@@ -48,6 +49,14 @@ namespace cursespp {
         public ILayout
     {
         public:
+            enum FocusDirection {
+                FocusForward,
+                FocusBackward
+            };
+
+            sigslot::signal1<FocusDirection> FocusTerminated;
+            sigslot::signal1<FocusDirection> FocusWrapped;
+
             LayoutBase(IWindow* parent = NULL);
             virtual ~LayoutBase();