From 7cf5df31ea517c6dacb9456d7aee28c648c7e045 Mon Sep 17 00:00:00 2001
From: Richard Frith-MacDonald <rfm@gnu.org>
Date: Thu, 4 May 2000 18:28:00 +0000
Subject: [PATCH] NSScreen fixes

git-svn-id: svn+ssh://svn.gna.org/svn/gnustep/libs/gui/trunk@6560 72102866-910b-0410-8b05-ffd578937521
---
 Headers/gnustep/gui/NSGraphics.h |  3 +-
 Headers/gnustep/gui/NSScreen.h   |  4 +-
 Source/NSScreen.m                | 71 +++++++++++++++++++++++++-------
 3 files changed, 58 insertions(+), 20 deletions(-)

diff --git a/Headers/gnustep/gui/NSGraphics.h b/Headers/gnustep/gui/NSGraphics.h
index dcfeea344..80f0f89b1 100644
--- a/Headers/gnustep/gui/NSGraphics.h
+++ b/Headers/gnustep/gui/NSGraphics.h
@@ -30,6 +30,7 @@
 
 @class NSString;
 @class NSColor;
+@class NSGraphicsContext;
 
 /*
  * Colorspace Names 
@@ -119,8 +120,6 @@ int NSBitsPerSampleFromDepth(NSWindowDepth depth);
 NSString *NSColorSpaceFromDepth(NSWindowDepth depth);
 int NSNumberOfColorComponents(NSString *colorSpaceName);
 BOOL NSPlanarFromDepth(NSWindowDepth depth);
-NSWindowDepth GSWindowDepthForScreen(int screen);
-const NSWindowDepth *GSAvailableDepthsForScreen(int screen);
 
 /*
  * Read the Color at a Screen Position
diff --git a/Headers/gnustep/gui/NSScreen.h b/Headers/gnustep/gui/NSScreen.h
index 03617c9f3..0b236b3e8 100644
--- a/Headers/gnustep/gui/NSScreen.h
+++ b/Headers/gnustep/gui/NSScreen.h
@@ -38,7 +38,6 @@
 
 @class NSArray;
 @class NSDictionary;
-@class NSMutableDictionary;
 
 @interface NSScreen : NSObject
 {
@@ -46,8 +45,7 @@
   NSWindowDepth        _depth;
   NSRect               _frame;
   int                  _screenNumber;
-
-  void                *_reserved;
+  NSWindowDepth       *_supportedWindowDepths;
 }
 
 /*
diff --git a/Source/NSScreen.m b/Source/NSScreen.m
index 77e67e8bd..8046802eb 100644
--- a/Source/NSScreen.m
+++ b/Source/NSScreen.m
@@ -38,7 +38,18 @@
 #include <AppKit/NSGraphicsContext.h>
 #include <AppKit/DPSOperators.h>
 #include <AppKit/NSGraphics.h>
+#include <AppKit/AppKitExceptions.h>
 
+/* 
+ * Forward references
+ */ 
+NSWindowDepth GSWindowDepthForScreen(NSGraphicsContext *ctxt, int screen);
+const NSWindowDepth *GSAvailableDepthsForScreen(NSGraphicsContext *ctxt, 
+						int screen);
+
+/*
+ * Returns a list of the screens attached to the system.
+ */
 static int*
 _screenNumbers(int *count)
 {
@@ -106,12 +117,13 @@ _screenNumbers(int *count)
       RELEASE(self);
       return nil;
     }
-
+  
   // Fill in all of the i-vars with appropriate values.
   _screenNumber = screen;
-  DPScurrentwindowbounds(ctxt, screen, &x, &y, &w, &h);
+  DPScurrentwindowbounds(ctxt, _screenNumber, &x, &y, &w, &h);
   _frame = NSMakeRect(x, y, w, h);
-  _depth = GSWindowDepthForScreen(screen);
+  _depth = GSWindowDepthForScreen(ctxt, _screenNumber);
+  _supportedWindowDepths = NULL;
 
   return self;
 }
@@ -148,8 +160,8 @@ _screenNumbers(int *count)
   NSString		*colorSpaceName = nil;
 
   /*
-   * Testing of this method on OS4.2 indicates that the
-   * dictionary is re-created every time this method is called.
+   * This method generates a dictionary from the
+   * information we have gathered from the screen.
    */
 
   // Set the screen number in the current object.
@@ -186,14 +198,23 @@ _screenNumbers(int *count)
 // Mac OS X methods
 - (const NSWindowDepth*) supportedWindowDepths
 {
-  /*
-   * Skeletal implementation
-   * NSWindowDepth* retval = NSZoneMalloc([self zone], sizeof(NSWindowDepth)*2);
-   * retval[1] = _depth;
-   * retval[2] = 0;
-   * return retval;
-   */
-  return GSAvailableDepthsForScreen(_screenNumber);
+  // If the variable isn't initialized, get the info and
+  // store it for the future.
+  if (_supportedWindowDepths == NULL)
+    {
+      NSGraphicsContext	*ctxt = GSCurrentContext();
+      _supportedWindowDepths =
+	(NSWindowDepth *)GSAvailableDepthsForScreen(ctxt, _screenNumber);
+
+      // Check the results
+      if (_supportedWindowDepths == NULL)
+	{
+	  NSLog(@"Internal error: no depth list returned from window server.");
+	  return NULL;
+	}
+    }
+
+  return _supportedWindowDepths;
 }
 
 - (NSRect) visibleFrame
@@ -280,9 +301,14 @@ _screenNumbers(int *count)
   // Get the number of screens.
   windows = _screenNumbers(&count);
 
-  // If the list is empty quit...
+  // If the list is empty throw the appropriate exception and quit...
   if (windows == NULL)
-    return nil; // something is wrong. This shouldn't happen.
+    {
+      [NSException
+	raise:NSWindowServerCommunicationException
+	format:@"Unable to retrieve list of screens from window server."];
+      return nil; // something is wrong. This shouldn't happen.
+    }
 
   // Iterate over the list
   for (index = 0; index < count; index++)
@@ -297,6 +323,21 @@ _screenNumbers(int *count)
   
   return [NSArray arrayWithArray: screenArray];
 }
+
+// Release the memory for the depths array.
+- (void) dealloc
+{
+  // _supportedWindowDepths can be NULL since it may or may not
+  // be necessary to get this info.  The most common use of NSScreen
+  // is to get the depth and frame attributes.
+  if (_supportedWindowDepths != NULL)
+    {
+      NSZoneFree(NSDefaultMallocZone(), _supportedWindowDepths);
+    }
+
+  [super dealloc];
+}
+
 @end