adding numberOfScreens to interface. minor cleanup.

gfx/idl/nsIScreenManager.idl

@@ -32,12 +32,15 @@ interface nsIScreenManager : nsISupports
     //
     // The coordinates are in pixels (not twips) and in screen coordinates.
     //
-  nsIScreen screenForRect ( in long top, in long left, in long width, in long height ) ;
+  nsIScreen screenForRect ( in long left, in long top, in long width, in long height ) ;
   
     // The screen with the menubar/taskbar. This shouldn't be needed very
     // often.
   readonly attribute nsIScreen primaryScreen;
   
+    // Holds the number of screens that are available
+  readonly attribute unsigned long numberOfScreens;
+  
 };
 
 

gfx/src/gtk/nsScreenManagerGtk.cpp

@@ -67,7 +67,7 @@ nsScreenManagerGtk :: CreateNewScreenObject (  )
 // The coordinates are in pixels (not twips) and in screen coordinates.
 //
 NS_IMETHODIMP
-nsScreenManagerGtk :: ScreenForRect ( PRInt32 /*inTop*/, PRInt32 /*inLeft*/, PRInt32 /*inWidth*/,
+nsScreenManagerGtk :: ScreenForRect ( PRInt32 /*inLeft*/, PRInt32 /*inTop*/, PRInt32 /*inWidth*/,
                                        PRInt32 /*inHeight*/, nsIScreen **outScreen )
 {
   GetPrimaryScreen ( outScreen );
@@ -90,3 +90,17 @@ nsScreenManagerGtk :: GetPrimaryScreen(nsIScreen * *aPrimaryScreen)
   
 } // GetPrimaryScreen
 
+
+//
+// GetNumberOfScreens
+//
+// Returns how many physical screens are available.
+//
+NS_IMETHODIMP
+nsScreenManagerGtk :: GetNumberOfScreens(PRUint32 *aNumberOfScreens)
+{
+  *aNumberOfScreens = 1;
+  return NS_OK;
+  
+} // GetNumberOfScreens
+

gfx/src/mac/nsScreenManagerMac.cpp

@@ -67,11 +67,11 @@ nsScreenManagerMac :: CreateNewScreenObject ( GDHandle inDevice )
 // The coordinates are in pixels (not twips) and in screen coordinates.
 //
 NS_IMETHODIMP
-nsScreenManagerMac :: ScreenForRect ( PRInt32 inTop, PRInt32 inLeft, PRInt32 inWidth, PRInt32 inHeight,
+nsScreenManagerMac :: ScreenForRect ( PRInt32 inLeft, PRInt32 inTop, PRInt32 inWidth, PRInt32 inHeight,
                                         nsIScreen **outScreen )
 {
-  if ( !(inTop || inLeft || inWidth || inHeight) ) {
-    NS_WARNING ( "trying to find screen for sizeless window" );
+  if ( !(inWidth || inHeight) ) {
+    NS_WARNING ( "trying to find screen for sizeless window, using primary monitor" );
     *outScreen = CreateNewScreenObject ( ::GetMainDevice() );    // addrefs
     return NS_OK;
   }
@@ -117,3 +117,23 @@ nsScreenManagerMac :: GetPrimaryScreen(nsIScreen * *aPrimaryScreen)
   
 } // GetPrimaryScreen
 
+
+//
+// GetNumberOfScreens
+//
+// Returns how many physical screens are available.
+//
+NS_IMETHODIMP
+nsScreenManagerMac :: GetNumberOfScreens(PRUint32 *aNumberOfScreens)
+{
+  *aNumberOfScreens = 0;
+  GDHandle currDevice = ::GetDeviceList();
+  while ( currDevice ) {
+    if ( ::TestDeviceAttribute(currDevice, screenDevice) && ::TestDeviceAttribute(currDevice, screenActive) )
+      ++(*aNumberOfScreens);
+    currDevice = ::GetNextDevice(currDevice);
+  }
+  return NS_OK;
+  
+} // GetNumberOfScreens
+

gfx/src/mac/nsScreenManagerMac.h

@@ -34,7 +34,7 @@ class nsScreenManagerMac : public nsIScreenManager
 {
 public:
   nsScreenManagerMac ( );
-  ~nsScreenManagerMac();
+  virtual ~nsScreenManagerMac();
 
   NS_DECL_ISUPPORTS
   NS_DECL_NSISCREENMANAGER

gfx/src/windows/nsScreenManagerWin.cpp

@@ -67,7 +67,7 @@ nsScreenManagerWin :: CreateNewScreenObject ( HDC inScreen )
 // The coordinates are in pixels (not twips) and in screen coordinates.
 //
 NS_IMETHODIMP
-nsScreenManagerWin :: ScreenForRect ( PRInt32 inTop, PRInt32 inLeft, PRInt32 inWidth, PRInt32 inHeight,
+nsScreenManagerWin :: ScreenForRect ( PRInt32 inLeft, PRInt32 inTop, PRInt32 inWidth, PRInt32 inHeight,
                                         nsIScreen **outScreen )
 {
   if ( !(inWidth || inHeight) ) {
@@ -108,3 +108,17 @@ nsScreenManagerWin :: GetPrimaryScreen(nsIScreen** aPrimaryScreen)
   
 } // GetPrimaryScreen
 
+
+//
+// GetNumberOfScreens
+//
+// Returns how many physical screens are available.
+//
+NS_IMETHODIMP
+nsScreenManagerWin :: GetNumberOfScreens(PRUint32 *aNumberOfScreens)
+{
+  *aNumberOfScreens = 1;
+  return NS_OK;
+  
+} // GetNumberOfScreens
+