Bug 397381 - "Enable @try/@catch/@finally for Cocoa widgets" [p=cbarrett r=josh sr+a1.9=roc]

widget/src/cocoa/Makefile.in

@@ -181,5 +181,6 @@ LDFLAGS	+= \
 	$(NULL)
 
 CXXFLAGS += \
-  -DUSE_COCOA \
-  $(NULL)
+	-DUSE_COCOA \
+	-fobjc-exceptions \
+	$(NULL)

widget/src/cocoa/nsClipboard.mm

@@ -48,6 +48,7 @@
 #include "nsStringStream.h"
 #include "nsDragService.h"
 #include "nsEscape.h"
+#include "nsPrintfCString.h"
 
 // Screenshots use the (undocumented) png pasteboard type.
 #define IMAGE_PASTEBOARD_TYPES NSTIFFPboardType, @"Apple PNG pasteboard type", nil
@@ -73,6 +74,23 @@ nsClipboard::~nsClipboard()
 }
 
 
+// We separate this into its own function because after an @try, all local
+// variables within that function get marked as volatile, and our C++ type 
+// system doesn't like volatile things.
+static NSData* 
+GetDataFromPasteboard(NSPasteboard* aPasteboard, NSString* aType)
+{
+  NSData *data = nil;
+  @try {
+    data = [aPasteboard dataForType:aType];
+  } @catch (NSException* e) {
+    NS_WARNING(nsPrintfCString(256, "Exception raised while getting data from the pasteboard: \"%s - %s\"", 
+                               [[e name] UTF8String], [[e reason] UTF8String]).get());
+  }
+  return data;
+}
+
+
 NS_IMETHODIMP
 nsClipboard::SetNativeClipboardData(PRInt32 aWhichClipboard)
 {
@@ -213,14 +231,8 @@ nsClipboard::GetNativeClipboardData(nsITransferable* aTransferable, PRInt32 aWhi
       if (!type)
         continue;
 
-      // Read data off the clipboard, make sure to catch any exceptions (timeouts)
-      // XXX should convert to @try/@catch someday?
-      NSData *pasteboardData = nil;
-      NS_DURING
-        pasteboardData = [cocoaPasteboard dataForType:type];
-      NS_HANDLER
-        NS_ASSERTION(0, "Exception raised while getting data from the pasteboard.");
-      NS_ENDHANDLER
+      // Read data off the clipboard
+      NSData *pasteboardData = GetDataFromPasteboard(cocoaPasteboard, type);
       if (!pasteboardData)
         continue;
 

widget/src/cocoa/nsNativeThemeCocoa.mm

@@ -110,6 +110,23 @@ IsTransformOnlyTranslateOrFlip(CGAffineTransform aTransform)
 }
 
 
+// We separate this into its own function because after an @try, all local
+// variables within that function get marked as volatile, and our C++ type
+// system doesn't like volatile things.
+static PRBool
+LockFocusOnImage(NSImage* aImage)
+{
+  @try {
+    [aImage lockFocus];
+  } @catch (NSException* e) {
+    NS_WARNING(nsPrintfCString(256, "Exception raised while drawing to offscreen buffer: \"%s - %s\"", 
+                               [[e name] UTF8String], [[e reason] UTF8String]).get());
+    return PR_FALSE;
+  }
+  return PR_TRUE;
+}
+
+
 void
 nsNativeThemeCocoa::DrawCheckboxRadio(CGContextRef cgContext, ThemeButtonKind inKind,
                                       const HIRect& inBoxRect, PRBool inChecked,
@@ -189,13 +206,10 @@ nsNativeThemeCocoa::DrawButton(CGContextRef cgContext, ThemeButtonKind inKind,
     drawFrame.size.height = offscreenHeight - NATIVE_PUSH_BUTTON_HEIGHT_DIFF;
 
     // draw into offscreen image
-    NS_DURING
-      [image lockFocus];
-    NS_HANDLER
-      NS_ASSERTION(0, "Could not lock focus on offscreen buffer");
+    if (!LockFocusOnImage(image)) {
       [image release];
       return;
-    NS_ENDHANDLER
+    }
     [[NSGraphicsContext currentContext] setImageInterpolation:NSImageInterpolationLow];
     HIThemeDrawButton(&drawFrame, &bdi, (CGContext*)[[NSGraphicsContext currentContext] graphicsPort], kHIThemeOrientationInverted, NULL);
     [image unlockFocus];
@@ -520,13 +534,10 @@ nsNativeThemeCocoa::DrawScrollbar(CGContextRef aCGContext, const HIRect& aBoxRec
     ::HIThemeDrawTrack(&tdi, NULL, aCGContext, HITHEME_ORIENTATION);
   else {
     NSImage *buffer = [[NSImage alloc] initWithSize:NSMakeSize(aBoxRect.size.width, aBoxRect.size.height)];
-    NS_DURING
-      [buffer lockFocus];
-    NS_HANDLER
-      NS_ASSERTION(0, "Could not lock focus on offscreen buffer");
+    if (!LockFocusOnImage(buffer)) {
       [buffer release];
       return;
-    NS_ENDHANDLER
+    }
     ::HIThemeDrawTrack(&tdi, NULL, (CGContextRef)[[NSGraphicsContext currentContext] graphicsPort],
                        kHIThemeOrientationInverted);
     [buffer unlockFocus];