pp Inventor 2
Programming mobile phones with Android 
by App Inventor 2 - Juan Antonio Villalpando

- Initiation Tutorial App Inventor 2 -

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Sensors

24.- Clock. Timer. Flashing colors on the screen.

ip24_clock

- We place one slider that this one ends between 1 and 2000.

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Design

- Moving the Slider to set a new interval in the Clock (timer) so that it will act each that time.

- When acting the clock three random numbers from 1 to 255, are created corresponding to each of the basic colors.
- The sum of these colors is presented as Background color of the screen.

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Blocks

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25.- Clock. Traffic light.

ip25_semaphore

- We place one Canvas. Width: Fill parent, and Height: 400 pixel.

- Three balls (50, 10) (50, 90) (50.170). Radio: 40

- A Slider with values ​​between MinValue 1 and MaxValue 200

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Design

- Variable: Add

- Each time a occurs Interval Timer:

one unit is counted: add = add + 1

If add is> 16 then add back to 0 (new series)

If add is <= 6 then Red
If add is> 6 And add is <= 9 then Yellow
If add is> 9 then Color Green

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Blocks

NOTE: This code is just one example of learning could be made more efficient.

Change orden color: First Red, then Green, then Yellow.

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26.- Animated GIFs.

ip26_gif_animated

- Android does not get along with animated Gif, you have to use complex codes or tricks.

- In this case the trick that we use is to put an image in a directory Android and see that image with web browser.

When we got to project an image, it is saved in ...

/mnt/sdcard/AppInventor/assets/ninja.gif

so using the Internet browser get that picture on the screen.

file:///mnt/sdcard/AppInventor/assets/ninja.gif

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Design

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Blocks

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26B.- Another way to animated GIFs.

- Another way to make animated GIF is carrying a series of "frames" that form the movement of the image and then presenting them to go through a timer (clock).

- In App Gallery we find this application inventor, who also participated in our contest in August 2015.

PHOTO_SURPRISE .aia

It is interesting to study the code and see how the effect of image motion occurs.

The objective of the application is to add a lively a photo immediately after being taken gif.

Imagination can place the gif in a room, in the hand of a child on a table ...

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