make IsEnabled() return false even if the window parent, and not the window itself, is disabled and added IsThisEnabled() implementing the old IsEnabled() behaviour; also significantly simplify the window state management code in all ports by factoring out the common parts in wxWindowBase

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@45031 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/window.h

@@ -49,6 +49,19 @@
     #define wxUSE_MENUS_NATIVE wxUSE_MENUS
 #endif // __WXUNIVERSAL__/!__WXUNIVERSAL__
 
+
+// Define this macro if the corresponding operating system handles the state
+// of children windows automatically when the parent is enabled/disabled.
+// Otherwise wx itself must ensure that when the parent is disabled its
+// children are disabled too, and their initial state is restored when the
+// parent is enabled back.
+#if defined(__WXMSW__) || defined(__WXPM__)
+    // must do everything ourselves
+    #undef wxHAS_NATIVE_ENABLED_MANAGEMENT
+#else
+    #define wxHAS_NATIVE_ENABLED_MANAGEMENT
+#endif
+
 // ----------------------------------------------------------------------------
 // forward declarations
 // ----------------------------------------------------------------------------
@@ -366,7 +379,7 @@ public:
     void SetInitialSize(const wxSize& size=wxDefaultSize);
     wxDEPRECATED( void SetBestFittingSize(const wxSize& size=wxDefaultSize) );  // replaced by SetInitialSize
 
-    
+
         // the generic centre function - centers the window on parent by`
         // default or on screen if it doesn't have parent or
         // wxCENTER_ON_SCREEN flag is given
@@ -389,7 +402,7 @@ public:
         // and it is therefore overridden in wxTLW to do that.
         // In wxWindow(Base), it has (unfortunately) been abused
         // to mean the same as SetMinSize() and SetMaxSize().
-        
+
     virtual void SetSizeHints( int minW, int minH,
                                int maxW = wxDefaultCoord, int maxH = wxDefaultCoord,
                                int incW = wxDefaultCoord, int incH = wxDefaultCoord )
@@ -416,14 +429,14 @@ public:
     }
 
 
-        // Call these to override what GetBestSize() returns. This 
+        // Call these to override what GetBestSize() returns. This
         // method is only virtual because it is overriden in wxTLW
         // as a different API for SetSizeHints().
     virtual void SetMinSize(const wxSize& minSize) { m_minWidth = minSize.x; m_minHeight = minSize.y; }
     virtual void SetMaxSize(const wxSize& maxSize) { m_maxWidth = maxSize.x; m_maxHeight = maxSize.y; }
 
         // Override these methods to impose restrictions on min/max size.
-        // The easier way is to call SetMinSize() and SetMaxSize() which  
+        // The easier way is to call SetMinSize() and SetMaxSize() which
         // will have the same effect. Doing both is non-sense.
     virtual wxSize GetMinSize() const { return wxSize(m_minWidth, m_minHeight); }
     virtual wxSize GetMaxSize() const { return wxSize(m_maxWidth, m_maxHeight); }
@@ -491,7 +504,21 @@ public:
     bool Disable() { return Enable(false); }
 
     virtual bool IsShown() const { return m_isShown; }
-    virtual bool IsEnabled() const { return m_isEnabled; }
+        // returns true if the window is really enabled and false otherwise,
+        // whether because it had been explicitly disabled itself or because
+        // its parent is currently disabled -- then this method returns false
+        // whatever is the intrinsic state of this window, use IsThisEnabled(0
+        // to retrieve it. In other words, this relation always holds:
+        //
+        //   IsEnabled() == IsThisEnabled() && parent.IsEnabled()
+        //
+    bool IsEnabled() const;
+
+        // returns the internal window state independently of the parent(s)
+        // state, i.e. the state in which the window would be if all its
+        // parents were enabled (use IsEnabled() above to get the effective
+        // window state)
+    bool IsThisEnabled() const { return m_isEnabled; }
 
     // returns true if the window is visible, i.e. IsShown() returns true
     // if called on it and all its parents up to the first TLW
@@ -1174,6 +1201,18 @@ protected:
     virtual wxWindow *GetMainWindowOfCompositeControl()
         { return (wxWindow*)this; }
 
+    // this method should be implemented to use operating system specific code
+    // to really enable/disable the widget, it will only be called when we
+    // really need to enable/disable window and so no additional checks on the
+    // widgets state are necessary
+    virtual void DoEnable(bool WXUNUSED(enable)) { }
+
+    // called when the on-screen widget state changes and provides an
+    // an opportunity for the widget to update its visual state (colours,
+    // fonts, anything else) as necessary
+    virtual void OnEnabled(bool WXUNUSED(enabled)) { }
+
+
     // the window id - a number which uniquely identifies a window among
     // its siblings unless it is wxID_ANY
     wxWindowID           m_windowId;
@@ -1394,6 +1433,12 @@ protected:
     static void NotifyCaptureLost();
 
 private:
+    // recursively call our own and our children OnEnabled() when the
+    // enabled/disabled status changed because a parent window had been
+    // enabled/disabled
+    void NotifyWindowOnEnableChange(bool enabled);
+
+
     // contains the last id generated by NewControlId
     static int ms_lastControlId;