{"id":6,"date":"2008-03-27T12:55:06","date_gmt":"2008-03-27T17:55:06","guid":{"rendered":"http:\/\/developer.casgrain.com\/?p=6"},"modified":"2009-05-18T11:56:22","modified_gmt":"2009-05-18T16:56:22","slug":"pimp-my-ikimagebrowserview-slide-show","status":"publish","type":"post","link":"http:\/\/developer.casgrain.com\/?p=6","title":{"rendered":"Pimp my IKImageBrowserView: Slide Show"},"content":{"rendered":"

After listening to Frasier Speirs<\/a> on Late Night Cocoa<\/a>, I decided to take a look at ImageKit<\/a>, a new Leopard-only technology that contains the most interesting parts of iPhoto.<\/p>\n\nI had a need for an Image Browser, so I tried the (very well-written) Browsing Images Programming Guide<\/a>. At the tutorial’s end, I had a “Browse Images” application:<\/p>\n

<\/a><\/div>\n<\/p>\n

If you haven’t done so, you can do this tutorial too<\/a>. I will wait until you’re done…<\/p>\n\n…<\/p>\n\nAll done? Great. I wanted some extras in “Browse Images”, for example a slideshow and a filter. There is a guide to build a slideshow application, but it makes you write a separate application. We already have “Browse Images”, surely we can re-use it?<\/p>\n

Adding a slideshow<\/h3>\n

The IKSlideShow<\/a> class is very simple. One call makes it all happen:<\/p>\n

\n[[IKSlideshow sharedSlideshow] runSlideshowWithDataSource: (id) self inMode: IKSlideshowModeImages options: nil]\n<\/pre>\n
The objects have to implement the IKSlideshowDataSource<\/a><\/tt> protocol, which requires at least two methods:<\/p>\n
\n\t- (NSUInteger) numberOfSlideshowItems\n\t- (id) slideshowItemAtIndex: (NSUInteger) index\n<\/pre>\n
That looks familiar. For the IKImageBrowserDataSource<\/tt> protocol, we already implemented similar methods:<\/p>\n
\n- (int) numberOfItemsInImageBrowser: (IKImageBrowserView*) view\n{\n\treturn [mImages count];\n}\n\n- (id) imageBrowser: (IKImageBrowserView*) view itemAtIndex: (int) index\n{\n\treturn [mImages objectAtIndex: index];\n}\n<\/pre>\n
The only difference is the objects returned by (id) imageBrowser: itemAtIndex:<\/tt> had to implement the IKImageBrowserItem<\/tt> protocol, but they still returned an NSString*<\/tt>, a path to the image file.<\/p>\n\n(Another difference is the objects could be of more image types, but we will leave that for another time.)<\/i><\/p>\n
 Implementing the IKSlideshowDataSource<\/tt> protocol<\/h3>\n
In your ImageBrowserController<\/tt> implementation, add the missing methods to make the slide show work:<\/p>\n
\n- (NSUInteger) numberOfSlideshowItems\n{\n\treturn [mImages count];\n}\n\n- (id) slideshowItemAtIndex: (NSUInteger) index\n{\n\tint i = index % [mImages count];\n\n\treturn [[mImages objectAtIndex: i] path]; \/\/ path? Where did that come from?\n}\n<\/pre>\n
The first method is the same as before, while the second one returns not a MyImageObject<\/tt> (what is stored in mImages<\/tt>), but the path of that object. To get this path, simply add an accessor to MyImageObject<\/tt>:<\/p>\n
\n- (NSString*) path \n{ \n\treturn mPath;\n}\n<\/pre>\n
(Also add the prototype to the interface, lest you get a warning…)<\/i><\/p>\n
Tying it together in Interface Builder<\/h3>\n
Now that our controller conforms to the IKSlideshowDataSource<\/tt> protocol, we need a way to start the slide show. To this end, create an IBAction<\/tt> in the controller’s interface, and implement it like this:<\/p>\n
\n- (IBAction) startSlideshow: (id) sender\n{\n\tif ([mImages count] > 0)\n\t{\n\t\t[[IKSlideshow sharedSlideshow] runSlideshowWithDataSource: (id) self inMode: IKSlideshowModeImages options: nil];\n\t}\n}\n<\/pre>\n
Create a button in Interface Builder, and Control-drag it to your controller to connect it to the startSlideShow:<\/tt> action (IB 3 should have automatically picked up the change in your header file and offer you the new action).<\/p>\n
\nBuild and run. You should be able to browse pictures like before, and pressing on the “Slideshow” button should start a full-screen slideshow, complete with index sheet.<\/p>\n","protected":false},"excerpt":{"rendered":"
After listening to Frasier Speirs on Late Night Cocoa, I decided to take a look at ImageKit, a new Leopard-only technology that contains the most interesting parts of iPhoto. I had a need for an Image Browser, so I tried the (very well-written) Browsing Images Programming Guide. At the tutorial’s end, I had a “Browse […]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[3,6,5],"tags":[],"class_list":["post-6","post","type-post","status-publish","format-standard","hentry","category-graphics","category-leopard","category-macosx"],"_links":{"self":[{"href":"http:\/\/developer.casgrain.com\/index.php?rest_route=\/wp\/v2\/posts\/6","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/developer.casgrain.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/developer.casgrain.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/developer.casgrain.com\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"http:\/\/developer.casgrain.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=6"}],"version-history":[{"count":2,"href":"http:\/\/developer.casgrain.com\/index.php?rest_route=\/wp\/v2\/posts\/6\/revisions"}],"predecessor-version":[{"id":28,"href":"http:\/\/developer.casgrain.com\/index.php?rest_route=\/wp\/v2\/posts\/6\/revisions\/28"}],"wp:attachment":[{"href":"http:\/\/developer.casgrain.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=6"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/developer.casgrain.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=6"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/developer.casgrain.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=6"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}