All posts by edwardm

Update on FB – website link and Volume 4 App Inventor Guide

Facebook – Web site link

Short update – my web site at http://appinventor.pevest.com was linked directly to FB so that comments entered here, appeared there, and comments entered on the web site, appeared here on Facebook. All automatically.

However, that link is now broken. I was using a WordPress plugin to cross link the web site and FB page but last week, the makers of the plugin discontinued its use and the cross linking is no longer working. Hopefully I can find a new plugin to perform that function!

It was a nice to have feature as I could just check for updates on the web site without having to also check on FB. Oops! Now that this feature is gone, I will try to check the FB page more frequently.

Volume 4 Update

Volume 4 of my App Inventor guides is nearing completion. I have to write one last demo program,  the  text for one chapter, proof read the entire text, and begin the publishing process. I will announce the book topic once I get the final chapter written (I prefer not to pre-announce until I know the availability). I can announce now that Volume 4 should be available in both print and e-book formats! Producing the print version adds a little delay to the final release but the final result should be very good.

UPDATE: Sales of the print version of Volume 4 are being discontinued as of October 18, 2016, due to rampant copyright theft. There are more used copies for sale than the total number of printed books actually sold. Based on sales, readers prefer the e-book version – therefore I am in process of discontinuing sales of the print version. The e-book continues to be available.

A “switch board” user interface panel for App Inventor apps

In the last post, we introduced some concepts for building “creative” App Inventor user interfaces that feature visually appealing user interface controls rather than the usual bland buttons.

In this post, we look at creating an array of toggle switches. Tapping a switch flips the switch from left to right, or right to left.

Concepts

In developing this user interface, we learn two concepts:

  1. We expand on the previous post and its use of images to create custom buttons.
  2. We see how a user interface control can be stored in a list and referenced like a variable within our apps.

Source code:

The User Interface

I called my app “Mission Control” because any good mission control panel needs lots of switches!

The user interface features 9 toggle switches in a 3 x 3 array. The purpose of this app is to demonstrate how to implement this type of interface – the app does not otherwise do anything interesting.

Tapping any toggle switch causes the switch lever to move to the other side of the switch. Here is a screen shot showing some toggle switches to the left and some to the right.

Screenshot_20160204-140323The Designer View

Continue reading A “switch board” user interface panel for App Inventor apps

Making “pretty” App Inventor user interface controls

In the real world, “user interfaces” look like electric light switches, push buttons or control knobs, temperature dials on ovens, volume controls on radios and so forth. We can mimic these types of controls for our touch screen Android apps. We do not have to rely on the boring desktop-like clickable button or checkboxes in the App Inventor user interface palette.

A previous tutorial showed a trick to make the color of a button vary continuously. This tutorial shows how to use our own images, instead of the boring button, together with a bit of code to bring these buttons to life.

User Interface View

Below is a sample “toggle switch”. Press the switch icon once and the toggle moves to the right; press it again and the toggle moves back to the left.

toggleswitch1

toggleswitch2

Here is a slide switch. Press the slide switch once and the switch position moves to the right and the switch illuminates in green. Press the slide switch again and the switch returns to the left.

switch1

switch3

Here is a concept for a raised momentary push button. Pressing the button changes the appearance of the button while your finger is on the button – to look like the button is pressed in.

UI1

UI2

The Designer View

Continue reading Making “pretty” App Inventor user interface controls

What if your App Inventor apps had cooler user interface controls?

How about this – a panel full of toggle switches! Tap a switch to flip the switch from On to Off!

Screenshot_20160118-164605I will soon post a tutorial on creating simpler interfaces than the above, but that will be followed by a tutorial to create the above “panel of toggle switches”.

I have ideas for many interesting interface components – I do not yet know if all of them can be built in App Inventor – but we will see!

appinventor.pevest.com server is back online, 18 Jan 2016

The server that hosts the appinventor.pevest.com virtual server suffered an outage late on January 17th, continuing into early January 18th. The Internet Service Provider that hosts the server has restored service. From their note to me, it seems there may have been a denial of service attack on their infrastructure.

I was in the midst of writing a new tutorial on creating “pretty user interface” components in App Inventor; that tutorial was lost in the outage. Not as bad as it sounds as the code and illustrations were all saved – I just need to rewrite the text.

Writing Android apps in Javascript

Another way to develop apps for Android is to write apps in the Javascript program scripting language (note – Javascript is not related to Java, in spite of the similar name). By using a special platform called Cordova, it is possible to package Javascript programs into a self contained Android .apk file that runs on the Android OS.

Even better – it is possible to package your Javascript app, using Cordova, into forms that run on iOS (iPhones and iPad) and Windows Phone too!

Continue reading Writing Android apps in Javascript