Lech Migdal's blog

Few things to keep in mind when you're trying to set a preview image for your android widget: Set the android:icon attribute on the corresponding receiver in your AndroidManifest.xml to the same drawable as the one mentioned in the android:previewImag e attribute of your widget.xml file. Don't use too big (when it comes to resolution) preview images, as android anyway will scale them up. As a rule of thumb I've noticed that I have to scale down preview images (from their original size after doing screenshot in ddms) to 75% for small widgets (taking 1 row) and approx 50% for full screen widgets. Otherwise you'll get error saying that the widget dragging couldn't be initialized. Most widgets anyway don't use preview, so don't worry about it too much :)

Recently I wanted to implement swipe functionality for activity in my android app but couldn't find a nice and simple example that would explain what do you really need to do. There are multiple sites that are bloated with code, but somehow I couldn't believe that to implement such a simple (and kinda basic if you think about it) functionality you need to write tens of lines of code. So if you're like me, looking for a simple and elegant solution for swipe gesture handling, here it is... First some theory - to implement swipe you will need to: 1. Create a GestureDetector 2. Create an OnGestureListener by extending GestureDetector.SimpleOnGestureListener 3. Implement onFling method in listener created in step 2 4. Handle the onTouchEvent in your activity Now let's jump to the code: import android.app.Activity; import android.os.Bundle; import android.view.GestureDetector; import android.view.MotionEvent; public class MySwipeSupportedActivity extends

Recently I saw a great TED talk about high quality free online courses offered by some of the most famous universities around the world (like MIT, Stanford) , "Daphne Koller: What we're learning from online education", available at   http://www.ted.com/talks/daphne_koller_what_we_re_learning_from_online_education.html The whole talk is really great, with some tips how to improve the effectiveness of online trainings. I did also some googling and found following websites that offer free learning courses (or index them) from various disciplines. Really worth checking and signing up: https://www.coursera.org/  - site mentioned by Daphne Koller. 124 courses offered. https://www.edx.org/  - MIT, Berkley, Harvard - some of the courses start in September and beginning of October http://www.schneider-electric.com.au/sites/australia/en/company/data-center-free-online-training-courses.page  - Data Center University offers a lot of computer-related courses http://ocw.mit.e

Recently while writing new Android code I decided that it's the highest time to have a Git repository not only on my hard drive, but also safe in the Internet. After quick search and finding out that I have accounts at almost every popular service that provides Git hosting, I figured out that one that covers everything I need (wiki, bug tracking, code hosting, forums) is the good old sourceforge. I used it also with no problems few months ago on another mobile project, so I was hoping that pushing code there will be a piece of cake. But then when I tried to do it (after configuring the project on the sourceforge site), I got very interesting error: ssh://USER@git.code.sf.net:22: org.eclipse.jgit.transport.CredentialItem$YesNoType:The authenticity of host 'git.code.sf.net' can't be established. RSA key fingerprint is 86:7b:1b:12:85:35:8a:b7:98:b6:d2:97:5e:96:58:1d. Are you sure you want to continue connecting? In theory it's nothing bad, you press the "Y

Force REST API usage with curl is really well documented, there are at least two official HowTO's, but both of the assume that you will get your OATH token with Java. Below I've described steps required to get the token and verify your token with curl. 1. Retrieve token curl -v -k https://DOMAIN.salesforce.com/services/oauth2/token -d "grant_type=password" -d "client_id=CONSUMER_KEY" -d "client_secret=CONSUMER_SECRET" -d "username=USERNAME" -d "password=USER_PASSWORDSECURITY_TOKEN" where: DOMAIN - is your salesforce domain (e.g. na9) CONSUMER_KEY, CONSUMER_SECRET - as taken from App Setup -> Develop -> Remote Access USERNAME, USER_PASSWORD, SECURITY_TOKEN - properties for the user that you want to connect with. Note that USER_PASSWORD and SECURITY_TOKEN are concatenated. Note that I used -k parameter in curl which results in the SSL certificate validation skipped (otherwise you need to add it or t

Having COUNT_DISTINCT() is a great advantage in apex over standard Salesforce reporting capabilities. Still what you need to remember is that it doesn't return Integer (as COUNT() is doing), but List<AggregateResult> with count stored in the expr0 attribute of the first element of the list. So while the following code is valid: public String getObjectsForSelectedApplication() { return String.valueOf([SELECT COUNT() FROM MyObjects__c WHERE Application__c = :selectedApplication]); } The following code will return a list: public String get UniqueUsersForSelectedApplication() { return String.valueOf([SELECT COUNT_DISTINCT(User__c) FROM MyObjects__c WHERE Application__c = :selectedApplication]); } What you need to do is take the count from the list, for example with the following code: public String getUniqueUsersForSelectedApplication() { List&ltAggregateResult&gt result = [SELECT COUNT_DISTINCT(User

While working on a Visualforce page that would automatically show/hide parts of its content I've stumbled upon problems with actionSupport. So the following code doesn't work (to be precise - the "details" pageBlock is not rerendered upon change in the select element): <apex:pageBlock> <apex:form> <apex:selectList value="{! selectedApplication}" size="1">  <apex:actionSupport event="onchange" reRender="details"/>  <apex:selectOptions value="{! availableApplications}"></apex:selectOptions>               </apex:selectList>  </apex:form>  </apex:pageBlock>  <apex:pageBlock id ="details" title="Details for {! selectedApplication}" rendered="{! NOT(ISNULL(selectedApplication))}">  </apex:pageBlock> After googling a bit I've stumbled upon posts suggesting that this happens if you try to rerender page

I was struggling a bit recently with importing few thousand rows into custom object in SF with Import Custom Objects feature. Everything was fine except of data for Date/Time column where I was always getting "Invalid format" error even though I tried multiple formats (including the one that was provided in files that I exported from SF). I tried also some of the format mentioned in the Data Loader Guide ( http://na1.salesforce.com/help/doc/en/salesforce_data_loader.pdf ). In the end, I downloaded the Data Loader and the same file was imported in a few seconds without any challenges. Kinda weird, I mean - you would expect the Import Custom Objects to support the same date formats as the Data Loader, but well, good news is that it works at least in one product :-)

For everyone who wants to do a remote demo of android app you may want to check the Droid@Screen application ( http://blog.ribomation.com/droid-at-screen/ ). This little app streams your android device screen onto PC (then you can share it via virtual room/webex/go2meetings). It works just out of the box (yes, that's the first Java app that I was able to run without using a command line - respect to the developer :)). Advantages - applications run smoothly and from what I was told look better than on the emulator. Challenges - frame rate is not too high. It's around 1 fps (yes, that's one frame per second, for applications that include video/transitioning effects/animations you should consider using emulator or a camera).

Three non-technical topics podcasts: 1. http://hbr.org/multimedia/audio  - Harvard Business Review - a lot of interesting interviews concentrated on soft skills, business, career, etc. 2.  http://philmckinney.com/killer-innovations  - very interesting (although not published as frequently as you may wish to) podcast about innovation and creativity in general, created by Phil McKinney whom I had chance to meet and talk to twice (and yea, in real life he is also an interesting person :)) 3.  http://www.twis.org/  - this week in science is apparently back!

I played with jQueryMobile during the weekend and was really surprised by the productivity you get with the framework. In like 4hrs I was able to create a great looking app that was running with any major glitches on my Android phone. Now when I compare that to the challenges I was experiencing when coding with Android :) Some lessons learned from the weekend: - Good IDE for javascript is a must. Aptana really rules in that area, you can add it to your Android Eclipse installation easily -  http://aptana.com/products/studio3/download - There are challenges on Android when you move between pages of the app. The whole screen blinks. Apparently you need to disable the transition effect on Android, like below: $.mobile.defaultDialogTransition = "none"; $.mobile.defaultPageTransition = "none"; - I18N is not built into the jQM, but there are some interesting workarounds, like  http://stackoverflow.com/questions/8134555/jquery-mobile-json-processing-before-mob