Use the new wxDisplay(wxWindow*) ctor to simplify the code

Make the code simpler and, in a couple of places where the fall back to
the primary display in case wxDisplay::GetFromWindow() returned -1 was
missing, also more correct.

src/common/dlgcmn.cpp

@@ -871,7 +871,7 @@ int wxStandardDialogLayoutAdapter::DoMustScroll(wxDialog* dialog, wxSize& window
     wxSize minWindowSize = dialog->GetSizer()->GetMinSize();
     windowSize = dialog->GetSize();
     windowSize = wxSize(wxMax(windowSize.x, minWindowSize.x), wxMax(windowSize.y, minWindowSize.y));
-    displaySize = wxDisplay(wxDisplay::GetFromWindow(dialog)).GetClientArea().GetSize();
+    displaySize = wxDisplay(dialog).GetClientArea().GetSize();
 
     int flags = 0;
 

src/common/sizer.cpp

@@ -930,15 +930,9 @@ wxSize wxSizer::ComputeFittingClientSize(wxWindow *window)
             return tlw->GetClientSize();
         }
 
-        // limit the window to the size of the display it is on
-        int disp = wxDisplay::GetFromWindow(window);
-        if ( disp == wxNOT_FOUND )
-        {
-            // or, if we don't know which one it is, of the main one
-            disp = 0;
-        }
-
-        sizeMax = wxDisplay(disp).GetClientArea().GetSize();
+        // limit the window to the size of the display it is on (or the main
+        // one if the window display can't be determined)
+        sizeMax = wxDisplay(window).GetClientArea().GetSize();
 
         // If determining the display size failed, skip the max size checks as
         // we really don't want to create windows of (0, 0) size.

src/common/toplvcmn.cpp

@@ -249,8 +249,7 @@ void wxTopLevelWindowBase::DoCentre(int dir)
     // we need the display rect anyhow so store it first: notice that we should
     // be centered on the same display as our parent window, the display of
     // this window itself is not really defined yet
-    int nDisplay = wxDisplay::GetFromWindow(GetParent() ? GetParent() : this);
-    wxDisplay dpy(nDisplay == wxNOT_FOUND ? 0 : nDisplay);
+    wxDisplay dpy(GetParent() ? GetParent() : this);
     const wxRect rectDisplay(dpy.GetClientArea());
 
     // what should we centre this window on?

src/generic/richtooltipg.cpp

@@ -318,11 +318,7 @@ private:
 
         // Use GetFromWindow() and not GetFromPoint() here to try to get the
         // correct display even if the tip point itself is not visible.
-        int dpy = wxDisplay::GetFromWindow(GetParent());
-        if ( dpy == wxNOT_FOUND )
-            dpy = 0; // What else can we do?
-
-        const wxRect rectDpy = wxDisplay(dpy).GetClientArea();
+        const wxRect rectDpy = wxDisplay(GetParent()).GetClientArea();
 
 #ifdef __WXMAC__
         return pos.y > rectDpy.height/2 ? wxTipKind_Bottom : wxTipKind_Top;

src/msw/msgdlg.cpp

@@ -162,10 +162,7 @@ wxMessageDialog::HookFunction(int code, WXWPARAM wParam, WXLPARAM lParam)
 void wxMessageDialog::ReplaceStaticWithEdit()
 {
     // check if the message box fits the display
-    int nDisplay = wxDisplay::GetFromWindow(this);
-    if ( nDisplay == wxNOT_FOUND )
-        nDisplay = 0;
-    const wxRect rectDisplay = wxDisplay(nDisplay).GetClientArea();
+    const wxRect rectDisplay = wxDisplay(this).GetClientArea();
 
     if ( rectDisplay.Contains(GetRect()) )
     {

src/msw/toplevel.cpp

@@ -756,8 +756,7 @@ void wxTopLevelWindowMSW::DoGetPosition(int *x, int *y) const
             {
                 // we must use the correct display for the translation as the
                 // task bar might be shown on one display but not the other one
-                int n = wxDisplay::GetFromWindow(this);
-                wxDisplay dpy(n == wxNOT_FOUND ? 0 : n);
+                wxDisplay dpy(this);
                 const wxPoint ptOfs = dpy.GetClientArea().GetPosition() -
                                       dpy.GetGeometry().GetPosition();
 
@@ -916,11 +915,7 @@ bool wxTopLevelWindowMSW::ShowFullScreen(bool show, long style)
 
         // resize to the size of the display containing us, falling back to the
         // primary one
-        int dpy = wxDisplay::GetFromWindow(this);
-        if ( dpy == wxNOT_FOUND )
-            dpy = 0;
-
-        const wxRect rect = wxDisplay(dpy).GetGeometry();
+        const wxRect rect = wxDisplay(this).GetGeometry();
 
         SetSize(rect);
 

src/stc/PlatWX.cpp

@@ -1861,8 +1861,7 @@ void Window::SetPositionRelative(PRectangle rc, Window relativeTo) {
     position.x = wxRound(position.x + rc.left);
     position.y = wxRound(position.y + rc.top);
 
-    const int currentDisplay = wxDisplay::GetFromWindow(relativeWin);
-    const wxRect displayRect = wxDisplay(currentDisplay).GetClientArea();
+    const wxRect displayRect = wxDisplay(relativeWin).GetClientArea();
 
     if (position.x < displayRect.GetLeft())
         position.x = displayRect.GetLeft();