Always handle "input" and "output" signals in wxGTK wxSpinCtrl

No real changes yet, just refactor the code to always connect these
signals handlers and not just when using non-decimal base.

Add wxSpinCtrl::GTKInput() and GTKOutput() virtual methods to handle
these signals appropriately depending on the type of the control.

This will allow further customizing conversion to/from string in the
upcoming commit and will also make it possible to handle UI locale
different from the C locale in the future.

include/wx/gtk/spinctrl.h

@@ -58,6 +58,19 @@ public:
     // implementation
     void OnChar( wxKeyEvent &event );
 
+
+    // These values map to the possible return values of "input" GTK signal but
+    // are more readable and type-safe.
+    enum GTKInputResult
+    {
+        GTKInput_Error = -1,
+        GTKInput_Default,
+        GTKInput_Converted
+    };
+
+    virtual GTKInputResult GTKInput(double* value) const = 0;
+    virtual bool GTKOutput(wxString* text) const = 0;
+
 protected:
     double DoGetValue() const;
     double DoGetMin() const;
@@ -138,6 +151,9 @@ public:
     virtual int GetBase() const wxOVERRIDE { return m_base; }
     virtual bool SetBase(int base) wxOVERRIDE;
 
+    virtual GTKInputResult GTKInput(double* value) const wxOVERRIDE;
+    virtual bool GTKOutput(wxString* text) const wxOVERRIDE;
+
 protected:
     virtual void GtkSetEntryWidth() wxOVERRIDE;
 
@@ -206,6 +222,9 @@ public:
     virtual int GetBase() const wxOVERRIDE { return 10; }
     virtual bool SetBase(int WXUNUSED(base)) wxOVERRIDE { return false; }
 
+    virtual GTKInputResult GTKInput(double* value) const wxOVERRIDE;
+    virtual bool GTKOutput(wxString* text) const wxOVERRIDE;
+
 protected:
     virtual void GtkSetEntryWidth() wxOVERRIDE;
 

src/gtk/spinctrl.cpp

@@ -77,6 +77,47 @@ gtk_changed(GtkSpinButton*, wxSpinCtrl* win)
 }
 }
 
+//-----------------------------------------------------------------------------
+// "input" and "output"
+//-----------------------------------------------------------------------------
+
+extern "C"
+{
+
+static gint
+wx_gtk_spin_input(GtkSpinButton*, gdouble* val, wxSpinCtrlGTKBase* win)
+{
+    switch ( win->GTKInput(val) )
+    {
+        case wxSpinCtrl::GTKInput_Error:
+            return GTK_INPUT_ERROR;
+
+        case wxSpinCtrl::GTKInput_Default:
+            return FALSE;
+
+        case wxSpinCtrl::GTKInput_Converted:
+            return TRUE;
+    }
+
+    wxFAIL_MSG("unreachable");
+    return FALSE;
+}
+
+static gint
+wx_gtk_spin_output(GtkSpinButton* spin, wxSpinCtrlGTKBase* win)
+{
+    wxString text;
+    if ( !win->GTKOutput(&text) )
+        return FALSE;
+
+    if ( text != win->GetTextValue() )
+        gtk_entry_set_text(GTK_ENTRY(spin), text.utf8_str());
+
+    return TRUE;
+}
+
+} // extern "C"
+
 // ----------------------------------------------------------------------------
 // wxSpinCtrlEventDisabler: helper to temporarily disable GTK+ events
 // ----------------------------------------------------------------------------
@@ -146,6 +187,9 @@ bool wxSpinCtrlGTKBase::Create(wxWindow *parent, wxWindowID id,
     g_signal_connect_after(m_widget, "value_changed", G_CALLBACK(gtk_value_changed), this);
     g_signal_connect_after(m_widget, "changed", G_CALLBACK(gtk_changed), this);
 
+    g_signal_connect(m_widget, "input", G_CALLBACK(wx_gtk_spin_input), this);
+    g_signal_connect(m_widget, "output", G_CALLBACK(wx_gtk_spin_output), this);
+
     m_parent->DoAddChild( this );
 
     PostCreation(size);
@@ -399,42 +443,6 @@ wxSpinCtrlGTKBase::GetClassDefaultAttributes(wxWindowVariant WXUNUSED(variant))
 // wxSpinCtrl
 //-----------------------------------------------------------------------------
 
-extern "C"
-{
-
-static gboolean
-wx_gtk_spin_input(GtkSpinButton* spin, gdouble* val, wxSpinCtrl* win)
-{
-    // We might use g_ascii_strtoll() here but it's 2.12+ only, so use our own
-    // wxString function even if this requires an extra conversion.
-    const wxString
-        text(wxString::FromUTF8(gtk_entry_get_text(GTK_ENTRY(spin))));
-
-    long lval;
-    if ( !text.ToLong(&lval, win->GetBase()) )
-        return FALSE;
-
-    *val = lval;
-
-    return TRUE;
-}
-
-static gint
-wx_gtk_spin_output(GtkSpinButton* spin, wxSpinCtrl* win)
-{
-    const gint val = gtk_spin_button_get_value_as_int(spin);
-
-    gtk_entry_set_text
-    (
-        GTK_ENTRY(spin),
-        wxSpinCtrlImpl::FormatAsHex(val, win->GetMax()).utf8_str()
-    );
-
-    return TRUE;
-}
-
-} // extern "C"
-
 void wxSpinCtrl::GtkSetEntryWidth()
 {
     const int minVal = static_cast<int>(DoGetMin());
@@ -467,23 +475,6 @@ bool wxSpinCtrl::SetBase(int base)
     // We need to be able to enter letters for any base greater than 10.
     gtk_spin_button_set_numeric( GTK_SPIN_BUTTON(m_widget), m_base <= 10 );
 
-    if ( m_base != 10 )
-    {
-        g_signal_connect( m_widget, "input",
-                              G_CALLBACK(wx_gtk_spin_input), this);
-        g_signal_connect( m_widget, "output",
-                              G_CALLBACK(wx_gtk_spin_output), this);
-    }
-    else
-    {
-        g_signal_handlers_disconnect_by_func(m_widget,
-                                             (gpointer)wx_gtk_spin_input,
-                                             this);
-        g_signal_handlers_disconnect_by_func(m_widget,
-                                             (gpointer)wx_gtk_spin_output,
-                                             this);
-    }
-
     InvalidateBestSize();
 
     GtkSetEntryWidth();
@@ -494,6 +485,44 @@ bool wxSpinCtrl::SetBase(int base)
     return true;
 }
 
+wxSpinCtrl::GTKInputResult
+wxSpinCtrl::GTKInput(double* value) const
+{
+    // Don't override the default logic unless really needed.
+    if ( GetBase() == 10 )
+        return GTKInput_Default;
+
+    long lval;
+    if ( !GetTextValue().ToLong(&lval, GetBase()) )
+        return GTKInput_Error;
+
+    *value = lval;
+
+    return GTKInput_Converted;
+}
+
+bool wxSpinCtrl::GTKOutput(wxString* text) const
+{
+    switch ( GetBase() )
+    {
+        default:
+            wxFAIL_MSG("unsupported base");
+            wxFALLTHROUGH;
+
+        case 10:
+            // Don't override the default output format unless really needed.
+            return false;
+
+        case 16:
+            const gint val = gtk_spin_button_get_value_as_int(GTK_SPIN_BUTTON(m_widget));
+
+            *text = wxSpinCtrlImpl::FormatAsHex(val, GetMax());
+            break;
+    }
+
+    return true;
+}
+
 //-----------------------------------------------------------------------------
 // wxSpinCtrlDouble
 //-----------------------------------------------------------------------------
@@ -528,4 +557,15 @@ void wxSpinCtrlDouble::SetDigits(unsigned digits)
     GtkSetEntryWidth();
 }
 
+wxSpinCtrl::GTKInputResult
+wxSpinCtrlDouble::GTKInput(double* WXUNUSED(value)) const
+{
+    return GTKInput_Default;
+}
+
+bool wxSpinCtrlDouble::GTKOutput(wxString* WXUNUSED(text)) const
+{
+    return false;
+}
+
 #endif // wxUSE_SPINCTRL