Exercise session 1

created and ran your first project?

If not yet, please, do

exercise 0 first to set up your environment
Install Android Studio and have “Hello world” running on your phone:
http://bit.ly/2LZVRZ4

with an EditText view and a “Preview” button

The user enters

a message into the EditText and hits “Preview”

a TextView that displays the message. You can check the text

and if it’s good enough, you can send it via email app by clicking “Email” button

which is installed on the device
(e.g. gmail)
with the

message as a new email’s content.

before the next lecture.

Now it’s time for you to make

progress!!

the lecture slides: https://goo.gl/sQpvP4

slide for more info

enter text.
When the user clicks on it, the keyboard opens.

Using

view attribute “inputType”, you can indicate which keyboard should pop up (only numbers, all caps, email etc…)

Documentation: https://developer.android.com/reference/android/widget/EditText.html

when no text was entered.

To get the entered text dynamically

at runtime use editText.getText().toString().

free to edit the design with what we learned in

class (don’t waste too much time on it, we have more stuff to do :) )

TextView which shows the message you typed in on the

previous activity.

[want more guidance? See steps 1-3 on next slides]

the activity’s layout as needed

the code:
Create an intent that starts the new activity and

passes the text from the EditText through the intent’s extras, like in the lecture slides.

from the intent’s extras
5. On the second activity: show the message

in the activity’s TextView

email “To” with your email address
Pre-fill the email “Subject” with

some predefined text
Pre-fill the email “Body” with your message



See next slide for more info

intent to open a specific activity which we created and

knew about.
What happens when we want to start just any activity that can perform our task? I.e. any activity that can send an email or take a photo or dial a number or navigate.
We can use an implicit intent. We just tell what we want to do and Android will suggest the apps those can provide that functionality.

email implicit intent and which keys to add to the

intent bundle. Hint: Look for SEND_TO action
WARNING: pay attention to this caution notice

show him some message about this. So that he won’t

be surprised if nothing happened after his click.

Toast is a simple feedback about an operation in a transient small popup.
The activity remains interactive - whereas the toast itself isn’t.

http://developer.android.com/guide/topics/ui/notifiers/toasts.html

Toast.makeText(this, "No Email app found", Toast.LENGTH_LONG).show();
BEWARE MOST COMMON BUG: don’t forget to call .show() to actually display it, not only create ;)

you wanna try.

If you have even a small question -

don’t forget to ask the mentors in class or on Slack.

not hardcoded in XML files, but rather are extracted to

the corresponding resource XML files (strings.xml, dimens.xml)
Create a different layout for landscape as we saw in the lecture.
Make your app Russian (or other language) compatible. See next slide for details.

: “open editor”
On the top left: click the globe icon

and select the language you want.

Project structure panel find the new strings.xml that was created

with the new locale. Click on it to explore the xml.

Change your device’s language settings (if not in Russian yet)
Run and check your Russianized app!
Check out real folder structure of your project to understand the concept