I've been working on the 'Tip Calculator' app for Android and I have a couple of questions.
I'm supposed to (in the process of creating the GUI) use some EditTexts to allow the user to enter the bill amount and read the calculated total bill. In the version I have, there is no EditText anywhere in the Visual Layout Editor, only CheckText. Are these the same?
Whenever I try to edit the Java code for the app, as per the book I have, I keep getting the message:
Thus and such is never used
For example, with
private static final String BILL_TOTAL = "BILL_TOTAL';
or anything from the import Android list, other than the one referring to a bundle. I'm Not sure how to resolve this. I have some experience with C and C++, but Java is new to me.
The warning that tells you that a variable or method or import is not used can be ignored, especially if you just haven't gotten to using it yet. It's a warning and not an error, so your app should compile regardless.
I don't know what you're using to build your layout (eclipse? I use Intellij Idea), but to add an EditText, you can edit the layout file by hand. Add a line similar to:
<EditText android:id="#+id/myEditText android:width="FILL_PARENT" android:height="WRAP_CONTENT"/>
As a general rule, I like to edit these things by hand. Then, when something breaks or doesn't work as I expect it to, I have some grasp of what's in there, and so I can usually fix it. The value gained by learning how to create a layout by hand easily offsets the value of the time that you'll save.
Good luck.
Related
I need to update several visual components in my app during a timeconsuming function, instead my app seems to hang during this function call, rather than update the visual components on the screen. When the function exit, I see only the last changes to the components.
Is there a simple way to do the updates, or do I need to create a parallel process and have a 'timer' to read the data simultaniously (using semaphores) and present them in the timer call ?
Any suggestions ?
I asked the same question yesterday here. Like mh taqia said you can use Application->ProcessMessages() but you have to be careful with it. For my application, it worked but look at some posts about the function first.
I tried following:
MainForm->Invalidate();
MyControlRoot->Repaint();
MyControlRoot is a control containing somewhat 50-60 different other controls
But MyControlRoot wouldn't repaint with this method. ..
Despite the warnings from you Remy, I tried Application->ProcessMessages();
...works for now...
By the way... I cannot see any warnings in Docwiki on using ProcessMessages... what could I expect?
RG
There are scenarios in feature files wherein I've use the text "Foo" and on click its open a new page. this text sometime changes to "Foo1" or "Foo2" or to something else. to avoid line by line change in feature file for "Foo" to "Foo1" or "Foo2" is there any way that I can globally declare variable in top/bottom of the feature file where I can set the required text in variable on fly and I shall start executing my test instantly?
This change exist in many feature files and around 1000 lines in feature file. To get solution for this, I try on setting environment variables but I couldn't reach all the way till end this issue to solve. So can anyone help me on this?
Thanks in advance
What if you do the replacement in your step implementation instead? Then you could have the desired value in a separate file or pass it as arguments. That way you don't need to hard code the values.
Could scenario outlines help you in any way or is the value only changing depending on external changes?
My first thought was scenario outlines like #homaxto said.
Then I thought you might want to affect it by which system you are connected to. You can do this through configuration. I have done this with Fig_Newton.
You can either set an environment varaible or use one in the commandline. Or you can use #hook type tags. With a hook tag, you can have a tag at the top of a feature file that you can use to set a variable that affects how the steps operate (but it needs to be handled inside the step).
I wasn't sure exactly what headline to give this question because I'm not sure what this is technically called. In Android Studio while typing out Espresso tests I noticed that it refuses to accept something like this:
onView(withId(R.id.someId)).perform(click());
and instead will only accept this:
Espresso.onView(ViewMatchers.withId(R.id.someId)).perform(ViewActions.click());
even though every example that I've seen online shows the first example as correct code. Why is Android Studio forcing me to preface every ViewMatcher/Espresso/ViewActions/etc. method with the classname even after the imports are included in my class?
To clarify - trying to use the first example shows "cannot resolve method" and using autocomplete on it (which I have to do several times before it will work) invariably autocompletes to the second example. In all the "regular" code for my project autocomplete works correctly and short method names are recognized. I've tried doing a "clean" and "invalidate cache and restart" but no change.
Example of Google doc that shows usage according to the shortened code:
https://developer.android.com/training/testing/ui-testing/espresso-testing.html
You can try to check out your Android Studio Preferences for imports. Just go to Preferences -> Search "imports"
Here are the settings that I use and I don't have that issue:
What fixed the issue for me: just removed red withId in one place. Then just re-entered "withId": after that all the other red withId were replaced with black text color withId and now it compiled successfull!
I use eclipse for android development, and I find it very annoying that every time I create an activity or add new views to my activity, I need to create the references to views in my layout. I am looking for some kind of eclipse plugin that can generate the calls to findViewById() from the layout. I couldn't really find anything because I didn't know what it would be named. It would be very useful and time saving if that kind of plugin existed.
EDIT: The answers you gave are great. Can these tools also add more references to an existing activity so I don't have to manually do that when I add a view to the layout?
You can use https://github.com/JakeWharton/butterknife library for View Injections.
You can also get eclipse plugin https://marketplace.eclipse.org/content/lazy-android for the same.
But the ButterKnife library is frequently being contributed by android devs than the mentioned eclipse plugin. With this library, you can also avoid instantiating listeners yourself by just using like,
#OnClick(R.id.submit) void submit() {
// TODO call server...
}
For View injections, simply,
#InjectView(R.id.user) EditText username;
#InjectView(R.id.pass) EditText password;
So, it will compile as,
username = (EditText) findViewById(R.id.user);
password = (EditText) findViewById(R.id.pass);
Try the morcinek code generator. Its really simple to use.
This are the steps to install the plugin:
http://tmorcinek.wordpress.com/2011/11/30/eclipse-plugin-for-automatic-generation-of-activity-code-from-xml-layout-file/
After install process you may want to configurate a package to get the classes built by the generator, on the IDE -> Window -> Preferences on Bookmark Android Code Generator you can change that parameter.
The plugin does need a better interface for custom activities, still you could get the code, its really simple to make the changes you need, at least the inline listeners.
This solution doesnt work to modify classes you already have, that would be a really good improvement... i'll give it a try in a couple days with more time.
I have been creating Spinner controls (Combo boxes/Drop downs) in one of my apps, and was surprised to find out how difficult it was to achieve all of the following features:
User facing Strings are externalized, taking advantage of strings.xml internationalisation (I18N) feature of Android.
Spinner selections operate using a System view, which facilitates not having to work with or map Strings to meaningful values (yuck).
User view to System view mapping should be easy, automated and minimal (i.e not hand rolled for every component).
Others have attempted solutions to this, but universally as far as I could see they suffer from one or many of the following problems:
UI code is creeping into their enum class which doesn’t belong there (messy), nearly all existing solutions suffered from this.
Hardcoded User facing Strings in their enum classes. Because these are not externalized you cannot do I18N using the stock Android features.
Authors typically make the Fragment or Activity an OnItemSelectedListener which perpetuates a common problem of inheritance for convenience, where composition is more appropriate.
I have developed my own solution which does this: http://www.androidanalyse.com/android-spinner-externalize-user-strings-mapped-to-system-enum/
My question is, have I missed something? This seems like something that should not have been this hard (which makes me feel like I'm possibly reinventing the wheel).
Below is some example code showing my solution in-use (which is available Apache 2 license from the link above).
String none = getString(R.string.none);
String light = getString(R.string.light);
String medium = getString(R.string.medium);
String strong = getString(R.string.strong);
SpinnerUtil.createNewSpinner(view, R.id.wind, Arrays.asList(none, light, medium, strong), WindLevel.values(),
new SpinnerItemSelectedListener<WindLevel>() {
public void onItemSelected(Spinner item, WindLevel value) {
// Take whatever action you wish to here.
}});
I would just use ArrayAdapter<WindLevel>. Yes, you created a custom typed listener, but the regular event listener gets the position and can call getItem() on the ArrayAdapter<WindLevel> to get a WindLevel properly typed.
IMHO, the vast majority of Spinner widgets will be populated with material read in from a database, the Internet, or some other dynamic data source, rather than populated by some sort of enum with display values coming from static strings that can be internationalized ahead of time.
This is not to say that your code is useless: if you find it useful, then it was worth writing. And I am sure that there are apps out there that contain your targeted pattern (i.e., a Spinner backed by an enum or equivalent where the display values are known in advance and can be internationalized) who might find your solution useful as well. Every developer who writes enough code cooks up these sorts of helper classes and the like that help map an OS or framework model into something that better fits the developer's own mental model. So long as you are not perceiving any performance issues, it's all good.
Also, note that OnItemSelectedListener is an interface; implementing that interface on an existing class is not inheritance.
I believe the reason nobody answered you is :
What problem are you trying to solve ? Spinners existed prior to your well designed attempt.
Why reinvent them in exactly the same way they exist in Android ?
http://developer.android.com/guide/topics/ui/controls/spinner.html
It is a beautiful wheel indeed you designed, but still, it is just a wheel :)
UPDATE :
I think I begin to understand what you did. This is interesting. I'm not sure why you did not go to the pattern implemented by the ListPreference with its entries and entryvalues.
In fact, I'm not sure I understand why the Android team did not go that route either.
In any case, it is worth proposing your idea to the Android framework. It is after all open source.