Warning fix.

[wxWidgets.git] / src / common / gdicmn.cpp

diff --git a/src/common/gdicmn.cpp b/src/common/gdicmn.cpp
index 6cbe1a5d9e6b0e2313f1f74aa233c805588ba7b8..ecf3f6b21ab404f3518b755421a164d7a0788637 100644 (file)
--- a/src/common/gdicmn.cpp
+++ b/src/common/gdicmn.cpp
@@ -42,7 +42,7 @@
 #include "wx/log.h"
 #include <string.h>
 
-#if defined(__WXMSW__) && !defined(__PALMOS__)
+#if defined(__WXMSW__)
 #include "wx/msw/wrapwin.h"
 #endif
 
@@ -138,8 +138,13 @@ wxRect wxRect::operator+(const wxRect& rect) const
 
 wxRect& wxRect::Union(const wxRect& rect)
 {
-    // ignore empty rectangles
-    if ( rect.width && rect.height )
+    // ignore empty rectangles: union with an empty rectangle shouldn't extend
+    // this one to (0, 0)
+    if ( !width || !height )
+    {
+        *this = rect;
+    }
+    else if ( rect.width && rect.height )
     {
         int x1 = wxMin(x, rect.x);
         int y1 = wxMin(y, rect.y);
@@ -151,29 +156,40 @@ wxRect& wxRect::Union(const wxRect& rect)
         width = x2 - x1;
         height = y2 - y1;
     }
+    //else: we're not empty and rect is empty
 
     return *this;
 }
 
 wxRect& wxRect::Inflate(wxCoord dx, wxCoord dy)
 {
-    x -= dx;
-    y -= dy;
-    width += 2*dx;
-    height += 2*dy;
-
-    // check that we didn't make the rectangle invalid by accident (you almost
-    // never want to have negative coords and never want negative size)
-    if ( x < 0 )
-        x = 0;
-    if ( y < 0 )
-        y = 0;
-
-    // what else can we do?
-    if ( width < 0 )
-        width = 0;
-    if ( height < 0 )
-        height = 0;
+     if (-2*dx>width)
+     {
+         // Don't allow deflate to eat more width than we have,
+         // a well-defined rectangle cannot have negative width.
+         x+=width/2;
+         width=0;
+     }
+     else
+     {
+         // The inflate is valid.
+         x-=dx;
+         width+=2*dx;
+     }
+
+     if (-2*dy>height)
+     {
+         // Don't allow deflate to eat more height than we have,
+         // a well-defined rectangle cannot have negative height.
+         y+=height/2;
+         height=0;
+     }
+     else
+     {
+         // The inflate is valid.
+         y-=dy;
+         height+=2*dy;
+     }
 
     return *this;
 }