iPhone developers: you may have seen my DSActivityView open source project. Another developer was inspired by it, and created his own variation, WTFeedbackView, with support for progress bars, among other changes.

Here's his introduction:

WTFeedbackView is a class to display a HUD-like view with either an activity indicator view or a progress view. It's based on DSActivityView by David Sinclair (http://www.dejal.com/developer/dsactivityview), with some significant additions and modifications.

More specifically, WTFeedbackView offers:

• Client access through a single class, by means of class methods only, for all features;
• Changes to the text being shown trigger an animation that resizes the HUD view appropriately;
• Three built-in styles (like DSActivityView):
  • Simple style: displays a transparent view containing an activity indicator view next to the text explaining the ongoing activity;
  • Bezel style: displays a dark semi-transparent view containing either an activity indicator view or a progress view, above the text explaining the ongoing activity;
  • Keyboard style: same as the Bezel style, but covering only the keyboard;
• Three built-in kinds:
  • Activity kind: displays only an activity indicator view, plus the text explaining the ongoing activity;
  • Progress kind: displays only a progress view, plus the text explaining the ongoing activity;
  • Flexible kind: contains both an activity indicator view and a progress view (plus the text explaining the ongoing activity), but displays only one at a time, on demand. This is useful when the ongoing activity has parts whose lengths are sometimes known and sometimes unknown. Rather than create a new feedback view for each part, a single one can be used, minimizing screen distractions;
• Easy updating of the progress view, through a class method +updateProgress: (CGFloat) progress;
• Thread-safety where needed. For instance, +updateProgress: can be safely invoked from a background thread;
• Possibility to subclass WTFeedbackView to create custom feedback views having the general behavior of WTFeedbackView but looking differently.

Although iPhoneOS 3.x isn't a requirement, WTFeedbackView and the demo were compiled using iPhoneOS 3.1.2. They were *not* tested on any version prior to 3.x, so don't assume they will work with 2.x.

Enjoy!
Wagner

I'm hosting it for him: download now.

Sorry customers, another development blog post. :)

For a new iPhone app I'm working on (shh), I have a button that I wanted to behave like the Delete button in a table view. You know, when you tap the delete toggle to the left of a cell, a red Delete button appears. And tapping anywhere other than that button will hide it without doing anything else:

(Contacts app)

I couldn't see any obvious way to do it, so asked on the iPhone Developer forums, and got a helpful reply suggesting a UIWindow subclass, overriding -sendEvent:.

I tried implementing that, but what I really wanted was to override -hitTest:withEvent:, since I wanted to block taps on views other than a specific button, and the documentation says one should always invoke the superclass of -sendEvent:.

Then I noticed that -hitTest:withEvent: is actually defined in UIView, and further experimenting with the table Delete feature showed that it appears to be implemented UITableView, since the cancel tap behavior only occurs in the table, not the navigation bar or toolbar. Besides, implementing in a UIView subclass is more focal, so a better choice.

So here is my UIView subclass to do this. It uses a delegate approach, with a protocol to declare the method:

And the actual subclass interface; as conventional, the delegate is not retained:

With the implementation just overriding the hit test method. It simply invokes the superclass then gives the delegate a chance to change it (or perform some other action) if it implements the delegate protocol method:

To use this, simply change a container UIView to DSView in the view hierarchy, then set the delegate property to your view controller (via code or IB):

self.view.viewDelegate = self;

Then implement the -view:hitTest:withEvent:hitView: delegate method in your view controller, e.g. as follows — this will cause a tap on some special control to go through as normal, but tapping anywhere else in the view will hide the special control, without passing the tap on to whatever was actually tapped:

I hope this is useful to someone else too.

You can get the code from my Dejal Open Source Subversion repository via this Terminal command:

Or browse the source directly on the web.

If you haven't seen it already, check out DSActivityView, too.

I've committed a minor update to the DSActivityView open source project for iPhone. See the DSActivityView introductory post for more information, including a video demo.

This update adds a showNetworkActivityIndicator boolean property. It is NO by default, but if set to YES the network activity indicator in the status bar will be displayed, and automatically hidden when the DSActivityView is removed.

You can toggle this property as needed while the activity view is in use. For example, you might have the network activity indicator appear while fetching some data from the internet, then disable it while parsing it (while the activity view is still visible).

Of course, you can easily show and hide the network activity indicator yourself, but this tweak saves having to remember to disable both it and the DSActivityView.

You can set this property via:

or to toggle it on an already-visible activity view:

You can get the project from my Dejal Open Source Subversion repository via this Terminal command:

Or browse the source directly on the web.

I recently wrote a reusable class for a couple of iPhone apps I'm currently working on, called DSActivityView. I decided to release it as open source. Read on for details.

Firstly, I should say that this work was inspired in part by Matt Gallagher's excellent article, Showing a "Loading..." message over the iPhone keyboard. My code only uses the -keyboardView method from his article, but he deserves credit and thanks for that and many other helpful articles. If you're not reading his blog, Cocoa with Love, you're doing yourself a disservice.

Back to my class. Actually, there are three classes: DSActivityView, DSBezelActivityView, and DSKeyboardActivityView. They provide three styles of activity view, and could easily be extended to support more.

DSActivityView

This does a simple horizontal-style loading view, intended for situations where you have a blank view while loading data. It can be displayed very easily — for the default "Loading..." label text, simply use:

The activity view is automatically added as a subview of the specified view (e.g. the current content view). No need to save the result to an ivar. It automatically supports rotation to any orientation, too.

You can specify a custom label via:

Or specify a custom width, e.g. so you can change the label while it is being displayed without upsetting the geometry, via:

Then when you're done with it, simply invoke this to get rid of it:

DSBezelActivityView

This is a subclass of DSActivityView, which displays an animated round-rect-enclosed variation: it animates into view by zooming from full-screen, with a gray background fading in to cover the passed view, and animates out by zooming to half size and fading out the background (see below for a movie showing it in action). It is ideal for situations where you have content visible already, but want to do a network operation to validate or send data, or some other time-consuming activity.

Display it via:

The [DSBezelActivityView activityViewForView:withLabel:] and [DSBezelActivityView activityViewForView:withLabel:width:] variations are also available. To remove with animation, call:

DSKeyboardActivityView

This is a subclass of DSBezelActivityView, which displays over the keyboard, somewhat like the OS 2 Text app used to do. It is useful to simply prevent further typing while validating a field or sending data (though you might also want to disable the field, to prevent pasteboard operations on it). No need to specify a view to use for this, since it uses the keyboard:

Plus a [DSKeyboardActivityView activityViewWithLabel:] variation for custom text. Remove it the same as for the bezel style:

Demo

I've included a demo project that builds an app to show the various options: the three styles, default or custom label text, covering just the content view or whole window, etc. It requires iPhone OS 3. Here's a movie showing the demo app running:

You can get the project from my Dejal Open Source Subversion repository via this Terminal command:

Or browse the source directly on the web.

You can also download a snapshot, though it may not remain up-to-date; using Subversion is the recommended approach.

Follow @dejalopen on Twitter for automated Subversion commit message updates. You may also like to follow @dejaldevdiary for my behind-the-scenes development diary, and @dejal for general Dejal and personal tweets. Finally, there's also a RSS feed for the repository.

I hope these classes are useful. You are welcome to use them in any project, commercial or otherwise. I just ask that you give me credit; see the DSActivityView header for the easy and free licensing terms. If you do use this code in any form, please tell me (or comment here).

If you make improvements, e.g. to add other activity styles or fix bugs, please send them to me so I can share them with the community. Thanks.

Enjoy!