Add RAII wrapper for GTKDisableEvents/GTKEnableEvents() calls

Ensure GTKEnableEvents() is called automatically on scope exit whenever
GTKDisableEvents() is called.

This fixes a couple of potential bugs where GTKEnableEvents() could be not
called if wxCHECK() condition failed and makes the code shorter and safer.

include/wx/gtk/private/eventsdisabler.h

@@ -0,0 +1,41 @@
+///////////////////////////////////////////////////////////////////////////////
+// Name:        wx/gtk/private/eventsdisabler.h
+// Purpose:     Helper for temporarily disabling events.
+// Author:      Vadim Zeitlin
+// Created:     2016-02-06
+// Copyright:   (c) 2016 Vadim Zeitlin <vadim@wxwidgets.org>
+// Licence:     wxWindows licence
+///////////////////////////////////////////////////////////////////////////////
+
+#ifndef _GTK_PRIVATE_EVENTSDISABLER_H_
+#define _GTK_PRIVATE_EVENTSDISABLER_H_
+
+// ----------------------------------------------------------------------------
+// wxGtkEventsDisabler: calls GTKDisableEvents() and GTKEnableEvents() in dtor.
+// ----------------------------------------------------------------------------
+
+// Template parameter T must be a wxGTK class providing the required methods,
+// e.g. wxCheckBox, wxChoice, ...
+template <typename T>
+class wxGtkEventsDisabler
+{
+public:
+    // Disable the events for the specified (non-NULL, having lifetime greater
+    // than ours) window for the lifetime of this object.
+    explicit wxGtkEventsDisabler(T* win) : m_win(win)
+    {
+        m_win->GTKDisableEvents();
+    }
+
+    ~wxGtkEventsDisabler()
+    {
+        m_win->GTKEnableEvents();
+    }
+
+private:
+    T* const m_win;
+
+    wxDECLARE_NO_COPY_TEMPLATE_CLASS(wxGtkEventsDisabler, T);
+};
+
+#endif // _GTK_PRIVATE_EVENTSDISABLER_H_

include/wx/gtk/tglbtn.h

@@ -54,10 +54,10 @@ public:
     static wxVisualAttributes
     GetClassDefaultAttributes(wxWindowVariant variant = wxWINDOW_VARIANT_NORMAL);
 
-protected:
     void GTKDisableEvents();
     void GTKEnableEvents();
 
+protected:
     virtual wxSize DoGetBestSize() const wxOVERRIDE;
     virtual void DoApplyWidgetStyle(GtkRcStyle *style) wxOVERRIDE;
 

src/gtk/checkbox.cpp

@@ -15,6 +15,7 @@
 
 #include <gtk/gtk.h>
 #include "wx/gtk/private/gtk2-compat.h"
+#include "wx/gtk/private/eventsdisabler.h"
 
 //-----------------------------------------------------------------------------
 // data
@@ -45,7 +46,7 @@ static void gtk_checkbox_toggled_callback(GtkWidget *widget, wxCheckBox *cb)
             bool active = gtk_toggle_button_get_active(toggle) != 0;
             bool inconsistent = gtk_toggle_button_get_inconsistent(toggle) != 0;
 
-            cb->GTKDisableEvents();
+            wxGtkEventsDisabler<wxCheckBox> noEvents(cb);
 
             if (!active && !inconsistent)
             {
@@ -67,8 +68,6 @@ static void gtk_checkbox_toggled_callback(GtkWidget *widget, wxCheckBox *cb)
             {
                 wxFAIL_MSG(wxT("3state wxCheckBox in unexpected state!"));
             }
-
-            cb->GTKEnableEvents();
         }
         else
         {
@@ -171,11 +170,8 @@ void wxCheckBox::SetValue( bool state )
     if (state == GetValue())
         return;
 
-    GTKDisableEvents();
+    wxGtkEventsDisabler<wxCheckBox> noEvents(this);
-
     gtk_toggle_button_set_active( GTK_TOGGLE_BUTTON(m_widgetCheckbox), state );
-
-    GTKEnableEvents();
 }
 
 bool wxCheckBox::GetValue() const

src/gtk/choice.cpp

@@ -19,6 +19,7 @@
 #include <gtk/gtk.h>
 #include "wx/gtk/private.h"
 #include "wx/gtk/private/gtk2-compat.h"
+#include "wx/gtk/private/eventsdisabler.h"
 
 // ----------------------------------------------------------------------------
 // GTK callbacks
@@ -155,7 +156,7 @@ void wxChoice::DoClear()
 {
     wxCHECK_RET( m_widget != NULL, wxT("invalid control") );
 
-    GTKDisableEvents();
+    wxGtkEventsDisabler<wxChoice> noEvents(this);
 
     GtkComboBox* combobox = GTK_COMBO_BOX( m_widget );
     GtkTreeModel* model = gtk_combo_box_get_model( combobox );
@@ -166,8 +167,6 @@ void wxChoice::DoClear()
     if (m_strings)
         m_strings->Clear();
 
-    GTKEnableEvents();
-
     InvalidateBestSize();
 }
 
@@ -290,12 +289,10 @@ void wxChoice::SetSelection( int n )
 {
     wxCHECK_RET( m_widget != NULL, wxT("invalid control") );
 
-    GTKDisableEvents();
+    wxGtkEventsDisabler<wxChoice> noEvents(this);
 
     GtkComboBox* combobox = GTK_COMBO_BOX( m_widget );
     gtk_combo_box_set_active( combobox, n );
-
-    GTKEnableEvents();
 }
 
 void wxChoice::SetColumns(int n)

src/gtk/listbox.cpp

@@ -30,6 +30,7 @@
 
 #include <gtk/gtk.h>
 #include "wx/gtk/private.h"
+#include "wx/gtk/private/eventsdisabler.h"
 #include "wx/gtk/private/gtk2-compat.h"
 #include "wx/gtk/private/object.h"
 #include "wx/gtk/private/treeentry_gtk.h"
@@ -479,13 +480,13 @@ void wxListBox::DoClear()
 {
     wxCHECK_RET( m_treeview != NULL, wxT("invalid listbox") );
 
-    GTKDisableEvents(); // just in case
+    {
+        wxGtkEventsDisabler<wxListBox> noEvents(this);
 
-    InvalidateBestSize();
+        InvalidateBestSize();
 
-    gtk_list_store_clear( m_liststore ); /* well, THAT was easy :) */
+        gtk_list_store_clear( m_liststore ); /* well, THAT was easy :) */
-
+    }
-    GTKEnableEvents();
 
     UpdateOldSelections();
 }
@@ -496,7 +497,7 @@ void wxListBox::DoDeleteOneItem(unsigned int n)
 
     InvalidateBestSize();
 
-    GTKDisableEvents(); // just in case
+    wxGtkEventsDisabler<wxListBox> noEvents(this);
 
     GtkTreeIter iter;
     wxCHECK_RET( GTKGetIteratorFor(n, &iter), wxT("wrong listbox index") );
@@ -504,8 +505,6 @@ void wxListBox::DoDeleteOneItem(unsigned int n)
     // this returns false if iter is invalid (e.g. deleting item at end) but
     // since we don't use iter, we ignore the return value
     gtk_list_store_remove(m_liststore, &iter);
-
-    GTKEnableEvents();
 }
 
 // ----------------------------------------------------------------------------
@@ -701,7 +700,7 @@ void wxListBox::DoSetSelection( int n, bool select )
 {
     wxCHECK_RET( m_treeview != NULL, wxT("invalid listbox") );
 
-    GTKDisableEvents();
+    wxGtkEventsDisabler<wxListBox> noEvents(this);
 
     GtkTreeSelection* selection = gtk_tree_view_get_selection(m_treeview);
 
@@ -709,7 +708,6 @@ void wxListBox::DoSetSelection( int n, bool select )
     if ( n == wxNOT_FOUND )
     {
         gtk_tree_selection_unselect_all(selection);
-        GTKEnableEvents();
         return;
     }
 
@@ -728,8 +726,6 @@ void wxListBox::DoSetSelection( int n, bool select )
             gtk_tree_model_get_path(GTK_TREE_MODEL(m_liststore), &iter));
 
     gtk_tree_view_scroll_to_cell(m_treeview, path, NULL, FALSE, 0.0f, 0.0f);
-
-    GTKEnableEvents();
 }
 
 void wxListBox::DoScrollToCell(int n, float alignY, float alignX)

src/gtk/slider.cpp

@@ -20,6 +20,7 @@
 
 #include <gtk/gtk.h>
 #include "wx/gtk/private/gtk2-compat.h"
+#include "wx/gtk/private/eventsdisabler.h"
 
 //-----------------------------------------------------------------------------
 // data
@@ -231,9 +232,8 @@ gtk_event_after(GtkRange* range, GdkEvent* event, wxSlider* win)
             ProcessScrollEvent(win, wxEVT_SCROLL_THUMBRELEASE);
         }
         // Keep slider at an integral position
-        win->GTKDisableEvents();
+        wxGtkEventsDisabler<wxSlider> noEvents(win);
         gtk_range_set_value(GTK_RANGE (win->m_scale), win->GetValue());
-        win->GTKEnableEvents();
     }
 }
 }
@@ -422,21 +422,20 @@ void wxSlider::SetValue( int value )
 
 void wxSlider::GTKSetValue(int value)
 {
-    GTKDisableEvents();
+    wxGtkEventsDisabler<wxSlider> noEvents(this);
+
     gtk_range_set_value(GTK_RANGE (m_scale), value);
     // GTK only updates value label if handle moves at least 1 pixel
     gtk_widget_queue_draw(m_scale);
-    GTKEnableEvents();
 }
 
 void wxSlider::SetRange( int minValue, int maxValue )
 {
-    GTKDisableEvents();
+    wxGtkEventsDisabler<wxSlider> noEvents(this);
     if (minValue == maxValue)
        maxValue++;
     gtk_range_set_range(GTK_RANGE (m_scale), minValue, maxValue);
     gtk_range_set_increments(GTK_RANGE (m_scale), 1, (maxValue - minValue + 9) / 10);
-    GTKEnableEvents();
 
     if (HasFlag(wxSL_MIN_MAX_LABELS))
     {
@@ -471,9 +470,8 @@ int wxSlider::GetMax() const
 
 void wxSlider::SetPageSize( int pageSize )
 {
-    GTKDisableEvents();
+    wxGtkEventsDisabler<wxSlider> noEvents(this);
     gtk_range_set_increments(GTK_RANGE (m_scale), GetLineSize(), pageSize);
-    GTKEnableEvents();
 }
 
 int wxSlider::GetPageSize() const
@@ -494,9 +492,8 @@ int wxSlider::GetThumbLength() const
 
 void wxSlider::SetLineSize( int lineSize )
 {
-    GTKDisableEvents();
+    wxGtkEventsDisabler<wxSlider> noEvents(this);
     gtk_range_set_increments(GTK_RANGE (m_scale), lineSize, GetPageSize());
-    GTKEnableEvents();
 }
 
 int wxSlider::GetLineSize() const

src/gtk/tglbtn.cpp

@@ -22,6 +22,7 @@
 
 #include <gtk/gtk.h>
 #include "wx/gtk/private.h"
+#include "wx/gtk/private/eventsdisabler.h"
 #include "wx/gtk/private/list.h"
 
 extern bool      g_blockEventsOnDrag;
@@ -145,11 +146,9 @@ void wxToggleButton::SetValue(bool state)
     if (state == GetValue())
         return;
 
-    GTKDisableEvents();
+    wxGtkEventsDisabler<wxToggleButton> noEvents(this);
 
     gtk_toggle_button_set_active(GTK_TOGGLE_BUTTON(m_widget), state);
-
-    GTKEnableEvents();
 }
 
 // bool GetValue() const