AndroidOS - Joel Lipman .Com

Android Background Image Resolutions

: Joel Lipman; AndroidOS; 01 December 2014; Hits: 10603

What?
A reference to what size an image background should be set to for various screen sizes.

Why?
A background image I was using was unedited at 1600x2133 (364kb) and was not displaying on smaller devices. Configuring drawables for each layout seemed to be the only solution.

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res/drawable-ldpi      240x320
res/drawable-mdpi      320x480
res/drawable-hdpi      480x800
res/drawable-xhdpi     640x960
res/drawable-xxhdpi    960x1440
res/drawable-xxxhdpi   // for launcher only 640dpi
res/drawable-tvdpi     1.33*mdpi // not needed as mdpi or hdpi is used

res/drawable-ldpi 240x320
res/drawable-mdpi 320x480
res/drawable-hdpi 480x800
res/drawable-xhdpi 640x960
res/drawable-xxhdpi 960x1440
res/drawable-xxxhdpi // for launcher only 640dpi
res/drawable-tvdpi 1.33*mdpi // not needed as mdpi or hdpi is used

Category: AndroidOS :: Article: 598

: Joel Lipman; AndroidOS; 25 November 2014; Hits: 20362

Applies to:

Android Studio (Beta) 0.8.9
Android Google Maps v2

What?
A sequel to my article "Basic Android App using Google Maps and Current Location", this article suggests how to add Map as a sub activity. Note that this article is based on a new blank project which does not include code from the previous example but you can still build this over the previous example (as I did).

Why?
The previous article meant that the Google map was your main activity and any other activity would be a sub-activity; returning to the map activity would restart the app as a menu item, it would need to launch a new intent... I wanted to change my previous example so that the homepage of the app (the starting page) will simply display a button to the map (in case of offline mode or incompatibility with the device).

How?
In this example, I'm going to add the map as a fragment. This is the most rudimentary example (display map, move camera and display marker) and can be run from any other activity:

: Joel Lipman; AndroidOS; 04 November 2014; Hits: 6178

What?
A quick article on a function to allow the user to take a photo using their built-in camera or to choose an existing photo from their gallery.

Why?
I wanted both options to be available to the user and for it to replace a displayed image in an ImageView.

How?

: Joel Lipman; AndroidOS; 03 November 2014; Hits: 7939

What?
A quick article on how to replace the return key on a soft keyboard (software based) on a touch-device.

Why?
I have an editText where a user can enter any text value but if they typed a return character, the app would crash because it didn't understand the data. I tried replacing the new lines but just stopping the return key or trying to catch it is an obsolete method.

How?

: Joel Lipman; AndroidOS; 31 October 2014; Hits: 7199

Applies To:

Microsoft Windows 7 Pro
Android Studio v0.8.6 beta
Java Development Kit v1.8.0_20

What?
The article below serves as a checklist to ensure I don't release an app that only displays maps to myself (again).

Why?
This took me a while to figure out so hopefully this will help others.

How?
The gist is that I was using the Test SHA1 when adding allowed Android Keys to the Google APIs console (there's so many) when I should be using the App SHA1 (I have now added both to the console).

: Joel Lipman; AndroidOS; 24 October 2014; Hits: 4746

What?
A quick article on how to remove the first two entries from a RSS feed produced by a bunch of java files collectively known as "SimpleRssReader.

Why?
The original file reads of a feed from PCWorld.com. I adapted this to read a google news rss feed and the first two entries are "<query> - Google News", everytime. This article documents what I did to fix it.

How?
Basic to some but I'm new to the game. I'm trying to remove the first two entries from a news feed from a Google News feed.

: Joel Lipman; AndroidOS; 20 October 2014; Hits: 2208

What?
If you're installing an app and it creates two icons:

Why?
I don't think I'll forget this one but I was stumped for a bit until I found it on the a forum: Stack Overflow: Android App Development.

How?
Basically don't have the following declared more than once in the AndroidManifest.xml

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<intent-filter>
     <action android:name="android.intent.action.MAIN" />
     <category android:name="android.intent.category.LAUNCHER" />
</intent-filter>

<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>

Category: AndroidOS :: Article: 587

MessageBox or AlertDialog in Android Java

: Joel Lipman; AndroidOS; 20 October 2014; Hits: 8473

What?
A quick article on how to display a OK/Cancel popup which I use as a message to the user for debug purposes.

Why?
It's similar to javascript's message box or confirm box, only Android let's you redesign the dialog. For my purposes I have used an XML as the layout.

How?
This displays a standard Ok/cancel message popup which you attach to some event

Basic Android App using Google Maps and Current Location

: Joel Lipman; AndroidOS; 10 October 2014; Hits: 74090

Applies to:

Android Studio (Beta) 0.8.6
Google Android Maps API

What?
I am writing an app for a tablet running Android and wanted to include a Google Map. The following exercise focuses solely on creating an app which opens Google Maps at your current location.

How?
I couldn't find any instructions using the tools I had (Android Studio) which is why I've written this article.