App Inventor has introduced “copy and paste” of code blocks. Now you can copy blocks of code within a current screen, or from one screen to another screen, or even between projects. This is great news!
Look for the “backpack” icon at upper right of the blocks Viewer screen:
Select a block or blocks with the mouse pointer, and then click and drag the selected blocks into the backpack. A copy of the blocks are placed into the backpack and your original blocks also remain in the editing window.
Click on the backpack icon and it displays the code blocks currently stored in the backpack:
Click on the code block in the backpack (at right) and drag it into the Blocks Viewer. That is all you need to do to copy blocks.
Use this feature to copy blocks within your current screen, or to copy blocks from one screen to another screen, or to copy blocks from one app to another app.
You can put several blocks into the backpack, and then select only the ones you wish to copy over to another blocks Viewer.
How do you empty the backpack? It seems the only way to empty the backpack of saved items is to close the editing windows, go back to the MIT App Inventor home page (http://appinventor.mit.edu/) and select the Create apps! button to re-enter the designer and blocks editor.
Regardless, this is a GREAT NEW FEATURE! Thanks MIT App Inventor team!
For a complete description of Volume 1 (Introduction), Volume 2 (Advanced Concepts) and Volume 3 (Databases and Files), please see my App Inventor 2 e-books page where you can view the table of contents, download a sample chapter, and find links where you can obtain these ebooks online at Amazon, Google Play, Kobo Books and so on.
- Volume 3 covers TinyDB, TinyWebDB, Fusion Tables, Files and exchanging data with CSV format files.
Volume 3 is a big e-book – 322 pages long, says Amazon’s page counter.
Volume 3 is now available at
Links to all 3 books are available here.
My Guide to 3D Photography e-book is available from:
How did you discover MIT App Inventor?
I discovered App Inventor just as Google was handing AI classic off to MIT. At the time I was looking at different kinds of development tools for mobile devices, and App Inventor showed up in some online searches.
I took a look at it and found it intriguing – at the time, AI classic did not seem quite capable of doing the things I was likely to need, but I intended to keep an eye on it.
A few months later, I was asked if we could quickly train some high school students to write Android apps? I have been a volunteer engineering mentor with FIRST Robotics programs for eight years. The new high school team where I was volunteering had intriguing ideas for mobile apps. When I was asked about the feasibility of quickly building some Android apps, I immediately proposed MIT App Inventor!
Our first student was so enthralled he literally stayed up half the night teaching himself App Inventor and soon was writing bundles of code for our Android tablet applications. Eventually another student joined the effort (from an iPhone background!) and rapidly came up to speed, writing a neat app in App Inventor.
Continue reading How did you discover MIT App Inventor?
The Appril release of Quirky Linux includes the Android SDK (Software Development Kit), Android Studio, App Inventor, Oracle JDK (Java Development Kit), and LiveCode tools, as well as all of their dependencies, together with the JWM (Joe’s Window Manager) and ROX, providing one of the lightest environments for Android app developers.
“The intention is to have out-of-the-box, just-click-and-get-going Android app development, catering for total non-programmers with App Inventor, through intermediate with LiveCode, to hard-core coders with Android Studio,” says Barry Kauler, Puppy Linux creator.
Source: Puppy Linux’s Sister Quirky 7.1 Distro Arrives with Tools for Android App Developers
It actually runs the App Inventor system on the computer – does not require access to appinventor.mit.edu.
Download here (its free, of course). I have not tried this yet but would be interested to hear reports from users!
MIT App Inventor upgrade coming next Monday – the upgrade will support apps running on devices with different size screens, such as a smart phone versus a tablet.
There’s one important rule when using App Inventor to create apps with responsive design:
Specify widths and heights of components as percentages of the screen width and height, rather than as fixed numbers of pixels.
For example, to make a button whose width is half the screen width, set the button’s width to be 50 percent rather than setting it to a specific number of pixels.
See Responsive Design in App Inventor
Please see the link for details on this upcoming change.
Apps written in Java and the Android SDK have access to additional methods of creating flexible design layouts, or even multiple layouts, for different screen sizes.
MIT has begun testing a new App Inventor feature that will enable developers to create their own “extension components”. Extension components are written in Java. Once created and tested, these new components may be shared with other App Inventor developers for use in programs.
What this means: if App Inventor lacks a feature or capability, then a Java developer familiar with App Inventor and its components software development kit will be able to add new features to App Inventor. Over time, the capabilities and power of App Inventor are likely to grow enormously – and rapidly. The ability to extend App Inventor’s features/components is an exciting and tremendously important development for the future of App Inventor!
For now, this feature is in “test mode”.
Source: App Inventor Extension Components available for testing | Explore MIT App Inventor
Changes between nb143i and nb144 (June 30, 2015)
- When a component is renamed in the designer, any related collapsed blocks will be properly renamed now.
- Screen1 now has properties that permit you to hide both the top “Status” and “Title” Bars
- The selected item in a ListView is now highlighted
- Activity Starter component now has a “Activity Canceled” event
- Fix to the Player Component so it doesn’t spontaneously start playing after a phone call or other interruption
- Bugfix to Image Sprite rotation which had left screen artifacts on some devices
- Add Math blocks to convert between decimal, Hexidecimal and Binary representation
- Clock Component now permits you to format a date or time arbitrarily. You provide a “format string”
- You can now have both a Background Image and a Background Color and the “right thing” happens
- TextToSpeech: The designer now uses dropdown menus to select Country and Language. Added blocks to fetch the supports countries and languages on a given device
Source: Release Notes for MIT App Inventor 2 (Beta)
Source: MIT App Inventor usage for 2014-2015 Academic Year
As they point out, the cyclical ups and downs in usage suggest App Inventor is primarily used by students – with drop off in usage during school vacation periods.
That suggests an opportunity to expand usage of MIT App Inventor – by insuring that AI2 appeals to a wide audience of potential app developers and not just educational programs!
Most users are already using AI 2 and are unaffected by this change. But if you are still using AI Classic (version 1), then this message is very important – please click through the link to read the full story!
May 24, 2015 — MIT App Inventor Classic will shut down on July 15, 2015. After July 15, 2015, you will not be able to access or edit your existing AI Classic projects. It will be impossible to create new AI Classic projects.This shutdown applies only to AI Classic (AI1). App Inventor 2 (AI2) will not be affected.
MIT will not automatically convert your AI1 projects to AI2 projects. But MIT will provide a conversion tool that will help you convert the AI projects that are important to you into AI2 projects. We expect to release this converter in about 2 weeks (i.e., around June 8).
Source: App Inventor Classic to Shut Down on July 15 | Explore MIT App Inventor
How do you know which version you are using?
Login to App Inventor and create or open a project. If the URL address in your browser begins with
then you are using Version 2.
App Inventor has added a new source code “Gallery” for sharing source code with others.
From the My Projects list of your projects, at the far right, find a new feature to “Publish to Gallery”. To use, create a graphic image to illustrate your app – such as a screenshot. You will later upload this to the Gallery along with a description of what your source code does.
Add a link to a web page (if any) that contains a tutorial or video about your app or source code.
To find other code already added to the Gallery, click on the Gallery menu item near the top/upper right of the AI menu.
(And yes, I am back from recent travels – still recovering – fell a sleep after lunch today! I hope to start adding some of the source code from this blog to the Gallery soon!)
How to take a Screenshot
(This works on my Android devices) To take a snapshot of what is on your Android device screen, press the device power button and the volume control DOWN button simultaneously. This captures a screen snapshot and saves it to your Photo Gallery. Email that photo to yourself or do what ever you do to transfer files from your device to your computer, for subsequent processing/viewing, editing, re-sizing and what have you.