With AIR 2 Beta and the upcoming AIR 2 release, you can now use the command-line tool “screencapture” that comes with Mac OS. Nothing extra needs to be bundled with the application for this to work on a Mac, but on Windows, you need an additional piece of code to execute the screen capture process.

The process of doing a screen capture is pretty easy. You first create a File object that points to the location of the “screencapture” command line on the Mac:

Then create a NativeProcessStartupInfo object that will be used when we start the NativeProcess.The arguments property of the NativeProcessStartupInfo takes a list of arguments that will be passed to the command line tool when its started. For a complete list of arguments used by the screencapture command line tool, type “screencapture –help” in the terminal window. For this example I wanted to push out a file named “screencap.png” to the desktop from a selection of the screen. Optionally, you could capture the image to the clipboard and paste it directly.

Now we can start the native process:

The screencapture command tool will be launched and you will see the selection cursor on your screen. After you make a selection, the file will automatically be saved to the desktop as “screencapture.png”.

Here is the complete project code:

To get something like this to work on Windows, you need to know a little bit of C or C# so you can call your own service and launch the screen print functionality on Windows. For more about using the NativeProcess in AIR 2 for both Windows and Mac, you check out this Adobe article.

This solution has a couple of problems. First the application has focus the instance you click on any link within the application window. So fine, the way around that is to use some kind of timer so that your flag that says application is now active is not set until some time after the application receives focus. This leads to the second problem, at least for larger scale applications. You have to pipe the flag that says the application has no focus to every button and link through the entire application, this is a huge pain.

Today I just happened to be playing with the new FramerateThrottler class created by Grant Skinner to reduce CPU usage for AIR applications running on Mac (this is yet another gripe of mine). So on his bog there are some comments about using mouseChildren and mouseEnabled on all open AIR windows to reduce CPU. Anyways, when I was messing around with this suggestion, I happened to notice my application no longer scrolled when the application was in the background, but mouse events were still active.

So I then thought of combining my previous attempt at preventing links and buttons from being clicked on with mouseChildren and mouseEnabled. I ended up only setting mouseChildren and mouseEnabled to true if the application has focus, and after a small timer dalay of 500 miliseconds. That gives me just enough time to click on the application any where without also clicking on a link or button and activating it. So now I can click on the application to give it focus any place I like without firing off click events:

That’s it, a simple solution that was probably sitting under my nose the whole time but I never thought of it.

UPDATE

Jonnie Hallman from Adobe posted a great article that expands the idea of handling throttling and events (mouse wheel for example).

http://www.adobe.com/devnet/air/flex/articles/framerate_throttling.html

- Mister

I borrowed the click event action from an example by Peter deHaan posted on his blog Flex Examples. You will need the latest build of the Flex Builder 4 SDK and some helpful instructions on how to install the latest Flex Builder 4 SDK.

Example AIR Application Output

Main.mxml

CustomToolTip

The only think I couldn’t get working for this example (the commented out section) was changing the format of the hyperlinks within the TextFlow object.

Source File

Additional Resources

http://labs.adobe.com/technologies/flashbuilder4/
http://livedocs.adobe.com/flex/gumbo/langref/spark/primitives/RichEditableText.html
http://blog.flexexamples.com/2009/08/27/creating-a-linkelement-in-a-spark-richeditabletext-control-in-flex-4/
http://blog.flexexamples.com/2009/07/13/downloading-and-installing-flex-4-sdk-builds-from-opensource-adobe-com-flash-builder-4-beta-edition/

-Mister

As it turns out, I ran into just a small confusing snag that initially prevented the added application menu bar item from firing a select event. I eventually reached out to the Adobe AIR Tight discussion group and Jesse Warden had a quick fix. It turns out that if you do not use strong item references, they are swept away by Garbage Collection (GC) before you actually use the items. For example instead of creating the NativeMenuItem within the scope of the function, I had to create it within the scope of the class or in this case, the WindowedApplication.

In my application I only needed to add a single menu bar item. So instead of blowing away the entire application menu and then creating all my own menu items (as many of the examples show). I just wanted to add a single item to the exiting application menu bar. On Mac OS, you get 4 application menu items: YourAppName, File, Edit, and Window. YourAppName would be your applications name or if you are running in the Eclipse IDE, just simply “adl”. In my case I wanted to add a “Preferences” option under the YourAppName. You can do this by accessing the NativeMenuItem representing the YourAppName. Something like NativeApplication.nativeApplication.menu.items[0] will return a NativeMenuItem with that reference. Using that reference you can then add a new NativeMenuItem to the submenu of the referenced NativeMenuItem. In addition to adding items to the submenu, you can also detect when the new item is selected.

In any event, here is the complete application code example:

That’s it, so now you can have a new item under your application name in the application menu bar to fire whatever function you desire.

-Mister

Issue Context

The first image is a TextField with one HTML link. The link fires a TextEvent which is handled by a function which replaces the text. The original TextField out put is in the image below withe the “more” HTML link at the end:

The second image shows the result when the “more” link is clicked and the text is replaced. You can see that when the mouse is over the text the entire text becomes a “more” link even though the new content has no HTML links. The rollover style on the TextField underlines the text.

Below is the complete AIR application code that shows how I setup the application and changed the TextField content.

Code

Workaround

I can’t remember where in my web travels or blog reading I found this, but there seems to be a need to reset the TextField.htmlText value before setting the TextField.text value within AIR applications to clear the previous content. I couldn’t find any official bug that reported this issue. However, doing this will eliminate the bug and reset the TextField content properly. So in the event handler for TextEvent, just before setting the content of the TextField, do the textMessage.htmlText = “”:

The issue could be with setting the styles of the link tags of the TextField. However, I could not reproduce this issue with Flex in a browser, this only occurs within an AIR application. If anyone can explain why this works or point me to the bug report for this particular issue, please pass it on, thanks!

-Mister

- Mister

PhoneSeek is an application to track any device that uses InstaMapper. InstaMapper is free real-time GPS tracking service. To use InstaMapper you need a GPS enabled device with the free InstaMapper tracking software installed along with a API Key from InstaMapper’s web site for each device you own. You can track mobile phones (iPhone, G1, Blackberry) or even automobiles.

Use Case

With PhoneSeek I can add my InstaMapper API Key for my phone and track it from the desktop. I can also add and track multiple devices. On my G1 phone, I installed the Android version of the InstaMapper tracking software. This software allows me to send my phone’s GPS data to InstaMapper service where I can view it either on their website or consume the data through InstaMapper’s web service. In PhoneSeek I just add the API Key to begin tracking the advice as soon as your phone starts to transmit GPS data.

Get PhoneSeek

Download the latest version from this location.

Development Background

PhoneSeek might be used to track devices from your family members, or maybe track down a lost or stolen phone. However, Phoneseek was basically created as a test project to learn PureMVC and also experiment with the new Google Maps API SWC for Adobe AIR. Previous versions of the Google Maps API SWC only worked for web-based applications.

Coming from Cairngorm to PureMVC was quite an experience. At first it was really painful because I had a tendency to over think things, or try to structure things more the Cairngorm ways (like dude, where are my delegates and commands).

I really had a hard time understanding where to put certain code, like update code, or code to set the window location on startup, and even how to pass around value objects used by more than one view. It took some time to get used to the PureMVC way, but all in all, its not a bad framework to work with. However, I still prefer Cairngorm and have since started to investigate and really enjoy Mate.

Credit for some of the graphics goes to DragonArtz Designs.

- Mister

I did some searching around and found one example from the Adobe AIR cookbook that stores and retrieves an value object from the ELS, casting the object as a value object when retrieved. However, I really wanted to store a whole AC of value objects and retrieve them. So I did a little more searching and found one blog post that outlines the same issue I was having: “when I read the object from disk back into my application, the type of objects from Array Collection is lost.”

Ok, cool, so the blog post lists a generic function to solve the solution by transforming the objects stored in the AC back to a proper value object. I wanted to make a little demo that combines the AIR cookbook example with the solution for storing/retrieving AC from the ELS with a slight modification of the generic function.

The first step is to create our Contact value object similar to the cookbook example:

Contact.as

Now we create a function that creates an ArrayCollection of Contact value objects and stores those in the EncryptedLocalStore:

Ok, now we have stored out ArrayCollection of Contact VO’s in the EncryptedLocalStore, now we need to write a function that retrieves the AC and transforms all of the VO’s back to something that we can utilize within Flex:

The above serializeContacts function takes a Class file (VO) and an ArrayCollection pulled from the EncryptedLocalStore using the retrieveContacts function. The VO is our Contact VO that we want to use to transform our ArrayCollection of objects. This generic function is pretty much what Mihai Corlan used on his blog post, but I changed” xml..value.@name;” from the example he posted to “xml..accessor.@name;” in my example in this post because the dump using the describeType() utility method the node we want is “accessor”. (The describeType() method returns an xml dump of the details about the object that is passed into the method. This is a pretty cool function that I previously didn’t know about.) Here is the dump of our Contact value object when I trace out the “xml” value from the above serializeContacts function:

xml:

We are interested in the name property of accessor node, and we store those names in an XMLList called “properties”. This XMLList will be used later to assign the values of the Contact properties within the serializeContacts function. So this gives us a legitimate Contact value objects stored in the ArrayCollection, which we can then use in our application without any errors or null values.

Here is the complete sample application code that can be copied and used in an AIR application:

Main.mxml:

Now we can store and retrieve ArrayCollections from the EncryptedLocalStore without dealing with the hosed object in our application. Many thanks to Daniel Dura and Mihai Corlan who helped tackle this problem in their contributions to the community. Sweet!

Update

I recently read a way to persist typed objects when storing them to the ELS, method outlined on Sönke Rohde’s blog.

-Mister