1 files changed, 68 insertions, 0 deletions
diff --git a/widget/cocoa/DesktopBackgroundImage.mm b/widget/cocoa/DesktopBackgroundImage.mm
new file mode 100644
index 0000000000..5ebb7ea938
--- /dev/null
+++ b/widget/cocoa/DesktopBackgroundImage.mm
@@ -0,0 +1,68 @@
+/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "mozilla/Logging.h"
+#include "nsCocoaUtils.h"
+#include "nsIFile.h"
+#include "DesktopBackgroundImage.h"
+
+#import <Foundation/Foundation.h>
+
+extern mozilla::LazyLogModule gCocoaUtilsLog;
+#undef LOG
+#define LOG(...) MOZ_LOG(gCocoaUtilsLog, LogLevel::Debug, (__VA_ARGS__))
+
+namespace mozilla {
+namespace widget {
+
+void SetDesktopImage(nsIFile* aImage) {
+  nsAutoCString imagePath;
+  nsresult rv = aImage->GetNativePath(imagePath);
+  if (NS_FAILED(rv)) {
+    LOG("%s ERROR: failed to get image path", __func__);
+    return;
+  }
+
+  bool exists = false;
+  rv = aImage->Exists(&exists);
+  if (NS_FAILED(rv) || !exists) {
+    LOG("%s ERROR: file \"%s\" does not exist", __func__, imagePath.get());
+    return;
+  }
+
+  NSString* urlString = [NSString stringWithUTF8String:imagePath.get()];
+  if (!urlString) {
+    LOG("%s ERROR: null image path \"%s\"", __func__, imagePath.get());
+    return;
+  }
+
+  NSURL* url = [NSURL fileURLWithPath:urlString];
+  if (!url) {
+    LOG("%s ERROR: null image path URL \"%s\"", __func__, imagePath.get());
+    return;
+  }
+
+  // Only apply the background to the screen with focus
+  NSScreen* currentScreen = [NSScreen mainScreen];
+  if (!currentScreen) {
+    LOG("%s ERROR: got null NSScreen", __func__);
+    return;
+  }
+
+  // Use existing options for this screen
+  NSDictionary* screenOptions =
+      [[NSWorkspace sharedWorkspace] desktopImageOptionsForScreen:currentScreen];
+
+  NSError* error = nil;
+  if (![[NSWorkspace sharedWorkspace] setDesktopImageURL:url
+                                               forScreen:currentScreen
+                                                 options:screenOptions
+                                                   error:&error]) {
+    LOG("%s ERROR: setDesktopImageURL failed (%ld)", __func__, (long)[error code]);
+  }
+}
+
+}  // namespace widget
+}  // namespace mozilla