From http://www.jwz.org/xscreensaver/xscreensaver-5.36.tar.gz

[xscreensaver] / OSX / grabclient-ios.m

diff --git a/OSX/grabclient-ios.m b/OSX/grabclient-ios.m
new file mode 100644 (file)
index 0000000..e3e4a8e
--- /dev/null
+++ b/OSX/grabclient-ios.m
@@ -0,0 +1,128 @@
+/* xscreensaver, Copyright (c) 1992-2016 Jamie Zawinski <jwz@jwz.org>
+ *
+ * Permission to use, copy, modify, distribute, and sell this software and its
+ * documentation for any purpose is hereby granted without fee, provided that
+ * the above copyright notice appear in all copies and that both that
+ * copyright notice and this permission notice appear in supporting
+ * documentation.  No representations are made about the suitability of this
+ * software for any purpose.  It is provided "as is" without express or 
+ * implied warranty.
+ */
+
+/* This iOS code to choose and return a random image from the user's
+ * photo gallery.
+ *
+ * Much of the following written by:
+ *
+ *  Created by David Oster on 6/23/12.
+ *  Copyright (c) 2012 Google. All rights reserved.
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *       http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+
+#ifdef USE_IPHONE  // whole file
+
+#import <AssetsLibrary/AssetsLibrary.h>
+#import "grabscreen.h"
+#import "yarandom.h"
+
+/* ALAssetsLibrary is an async API, so we need to fire it off and then
+   call a callback when it's done.  Fortunately, this fits the same
+   interaction model already used in xscreensaver by load_image_async(),
+   so it works out nicely.
+ */
+
+typedef struct {
+  void (*callback) (void *uiimage, const char *fn, int width, int height,
+                    void *closure);
+  void *closure;
+
+  ALAssetsLibrary *library;
+  NSMutableArray *assets;
+
+} ios_loader_data;
+
+
+static void
+ios_random_image_done (ios_loader_data *d, BOOL ok)
+{
+  UIImage *img = 0;
+  const char *fn = 0;
+  NSUInteger n = ok ? [d->assets count] : 0;
+  if (n > 0) {
+    ALAsset *asset = [d->assets objectAtIndex: random() % n];
+    ALAssetRepresentation *rep = [asset defaultRepresentation];
+
+    // "fullScreenImage" returns a smaller image than "fullResolutionImage",
+    // but this function still takes a significant fraction of a second,
+    // causing a visible glitch in e.g. "glslideshow".
+    CGImageRef cgi = [rep fullScreenImage];
+    if (cgi) {
+      UIImageOrientation orient = (UIImageOrientation) 
+        [[asset valueForProperty:ALAssetPropertyOrientation] intValue];
+      img = [UIImage imageWithCGImage: cgi
+                     scale: 1
+                     orientation: orient];
+      if (img)
+        fn = [[[rep filename] stringByDeletingPathExtension]
+               cStringUsingEncoding:NSUTF8StringEncoding];
+    }
+  }
+
+  [d->assets release];
+  [d->library release];
+
+  d->callback (img, fn, [img size].width, [img size].height, d->closure);
+  free (d);
+}
+
+
+void
+ios_load_random_image (void (*callback) (void *uiimage, const char *fn,
+                                         int width, int height,
+                                         void *closure),
+                       void *closure)
+{
+  ios_loader_data *d = (ios_loader_data *) calloc (1, sizeof(*d));
+  d->callback = callback;
+  d->closure = closure;
+
+  d->library = [[[ALAssetsLibrary alloc] init] retain];
+  d->assets = [[NSMutableArray array] retain];
+
+  // The closures passed in here are called later, after we have returned.
+  //
+  [d->library enumerateGroupsWithTypes: ALAssetsGroupAll
+              usingBlock: ^(ALAssetsGroup *group, BOOL *stop) {
+    NSString *name = [group valueForProperty:ALAssetsGroupPropertyName];
+    if ([name length]) {
+      [group enumerateAssetsUsingBlock: ^(ALAsset *asset, NSUInteger index,
+                                          BOOL *stop) {
+        if ([[asset valueForProperty: ALAssetPropertyType]
+              isEqual: ALAssetTypePhoto]) {
+          [d->assets addObject:asset];
+        }
+      }];
+    }
+
+    if (! group) {   // done
+      ios_random_image_done (d, YES);
+    }
+  } failureBlock:^(NSError *error) {
+    // E.g., ALAssetsLibraryErrorDomain: "The user has denied the
+    // application access to their media."
+    NSLog(@"reading Photo Library: %@", error);
+    ios_random_image_done (d, NO);
+  }];
+}
+
+#endif  // USE_IPHONE - whole file