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Resources
11:09As a project grows, managing external non-Java files becomes something you will want to do. Let's build a Resources Root and move our fxml and new CSS files to that new location.
As JavaFX apps grow, you end up needing
a little more structure then what is
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provided with the default
JavaFX IntelliJ template.
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We are going to be adding more and more
resources, files that are not in Java.
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We're gonna add those to our app.
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So resources include images,
sounds, FXML files,
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CSS files and really just about anything
else you might need in your app.
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First, let's switch our app to
have a place to add resources,
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then I'll show you how to add
that CSS file I told you about.
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You might've noticed that when
we called the FXML loader.load,
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that we used a method called getResource,
chained off of the getClass method.
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Now let's talk a little bit
about both of those calls.
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Well, first of all,
this getClass method here,
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this allows you to get a handle of
the class that created your instance.
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As you might've guessed,
this is inherited from java.lang.object,
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so every single object
can call that method,
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and it's a handy way to get what
class created this instance.
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The next bit, getResource,
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it attempts to find the non-Java
file with a specified name.
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It works a lot like a file system.
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It works from the relative directory, so
in our example here, it is stating look in
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the current directory, which is
source/sample, for the file sample.fxml.
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If it finds the file,
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it returns a URL that most functions
expecting resources accept.
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So, like I said, we're gonna need a little
better structure here, eventually.
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This is starting to
litter our file system.
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Now, one best practice in Java projects is
to separate out your non-Java files and
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set a resource route, so let's do that.
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So first what you do is you
create a new directory.
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You can call it whatever you want.
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I think it makes the most sense
usually to call it resources.
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It doesn't need to be named that.
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You can call it whatever you want.
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But now if we come in here and we choose
Mark Directory as > Resources Root,
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what'll happen is it'll see.
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See how it changed the way that
the folder looks a little bit here?
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It's got these three little gold
coins here sitting on the corner.
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Okay, so
now inside of our resources directory,
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let's start cleaning stuff up a little.
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Let's make a separate file for
our FXML file.
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So we'll make a new directory for FXML.
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Great, so
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now let's drag our sample.fxml file
into the fxml, the resources fxml file.
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Okay, so it's gonna say it's asking
if we wanna permanently move it, and
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it's asking if we wanna search for
references.
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So let's go ahead and
let it do the refactoring for us, and
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then we'll make sure it still works.
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So let's click OK.
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So if it moved it, and it popped it
open because I had the file open,
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so it moved it and gave me a new one, and
here you see that it did do a refactoring.
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Now, it's true that what happened here is
it's saying go to the parent directory
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from where I'm at and then go up another
one and then go over to resources.
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That works,
let's make it a little bit more clear.
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Because we have the resources route,
we can just go ahead and clear this off,
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and that says start at the absolute
path of /fxml/sample.fxml.
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We don't need the name
because it's the root, and
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then this is the folder
that it will look in.
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Okay, so let's save that, and let's run
it, make sure that we're still working.
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There's our beautiful app.
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So now we can add a new
resource file of type CSS.
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Let's make a folder called CSS.
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And again these folders are not required,
the folders or directories are not really
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required to have the same name,
but I think it makes sense.
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If somebody was coming to look for CSS,
they look in the resources CSS folder.
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So let's go ahead and
we'll make a CSS file called sample.css.
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Again, doesn't matter, but
we're just following the same,
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we got a sample.fxml, we'll do sample.css.
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Okay, so now over on our root node,
we'll do is we'll come in here and
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we will set styleSheets equals and we'll
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do /css/sample, and see how it's finding
it cuz it's looking in the resource there.
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So that's great.
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As a Java developer, you might be a bit
confused with some of the language in CSS.
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For example,
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CSS uses the term class to refer to a
style that you apply to multiple elements.
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Now don't confuse this with Java classes,
they're not really the same.
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A CSS class simply lets you
assign the same styling to
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any element that you'd like.
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In fact, you can apply more than
one CSS class to an element
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to combine styling attributes.
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You can add style classes to nodes as you
might imagine by using the style class
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attribute, so let's add one to the text
node that we've been using for
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the heading.
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Let's say styleClass, and
we'll just call it title so
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it'll be a descriptive
name of what the thing is.
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So now if we look in our sample.css class,
what we can do here is we can say
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anything that has been labeled with
the class title, and that looks like this.
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It uses a dot notation,
so you define a selector.
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So we say dot, title.
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Since we are going to try and
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style anything with the class title,
we'll use the class selector.
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CSS classes are denoted with
a period before their name.
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So basically we can just move
our inline style over like so.
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So we'll say .title, and
anything in between these curly braces,
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which also looks familiar, but
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don't be confused by that,
we'll flip over to our FXML.
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And we'll, let's grab all of these style
attributes that we had here before.
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So we'll grab those and
we'll get rid of this altogether.
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And the typical style is you put each one
of these on their own line like that.
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Awesome, so let's do that.
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Let's save that and see.
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Let's run, make sure everything's working.
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Great, it's still there, and
we've removed that style.
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So, there are also default classes
that could apply to all elements, for
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instance the root note here has
the class root automatically.
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So why don't we wipe out the style tag on
the grid pane here and use it in the CSS?
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So I'm gonna go ahead and
I'm gonna grab this and cut it, and
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I'm going to get rid of this style here,
and I'm gonna move that over to our file.
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So let's put that at the top here, .root.
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And we'll break this down here.
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There is also a class that is applied
that is the JavaFX class name.
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For instance if we wanted to,
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we can manipulate all text fields in
our app by using the class text-field.
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Note that's the dasherized
version of text field, so
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if we did .text.,
it's got a class of .text-field and
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we will set, we had over here.
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Let's go ahead and we'll set his
font differently, fx-font-family.
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Helvetica.
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Okay, so we come up here,
and we run that now.
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That's Helvetica there.
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So what we're saying is,
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we're saying everything under
here is of Papyrus, except for
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things that are text field, this is
being overridden with the Helvetica.
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We'd also previously defined an fx:id
on the TextField here, right?
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So, this TextField specifically
has a fx:id called firstName.
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So to state that you're referring to an id
as a selector, you can use a pound sign.
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So you say pound sign firstName fx.
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Let's set the background color to yellow.
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So this is a good place to show off
that the more specific a selector,
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the stronger it is.
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For instance,
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the first name text field has the font
family inherited from all fonts.
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That's inherited from all text fields is
over in, but finally I'm gonna come down
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here and I'm gonna show you that
if we put font-family: Impact,
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we'll show that it has,
this is just a font name here.
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Because we've been more specific here,
it overrides it.
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So the Impact overrides the Helvetica
because it's more specific with the ID.
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So here we see that even though we
overrode the default font set from
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the root, which is Papyrus.
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We then set all text fields
to be Helvetica, but
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then we specifically set this
specific text field to be Impact.
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This is how properties cascade.
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That's the C in the CSS.
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All right, so that's a brief overview of
what you can do with an external CSS file.
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Now, all of your future scenes
could share this one CSS file, so
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imagine having 30 scenes.
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If you point all of these scenes to this
file, you can make one single change in
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the CSS file and
update every single scene at once.
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So also note how successfully we separated
the structure from the presentation.
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So if you haven't noticed yet,
I'm not that great at visual design.
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I mean our sub app looks great.
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I mean, okay, it doesn't, and it's okay,
I led you down that path through example.
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Truth be told, I have always been
sorta bad at this stuff, and
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by this sorta stuff,
I mean art in any form really.
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Now, I'm not saying that I don't
appreciate art, I totally do.
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It's just in all my years of
development I can think of roughly, no,
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actually zero layouts that I've submitted
that actually made it into production,
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and I'm totally okay with that.
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It doesn't hurt my feelings.
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How does that not hurt
your feelings you ask.
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Well I guess if I think back to it,
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it goes way back to when I used
to create art in kindergarten.
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It's always been a mess.
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My mom tells some great stories about it.
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I should let her tell them sometime.
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Thick skin is an important
skill to grow in this field.
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People will review what you create,
especially the visual stuff.
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Everyone will have their two cents,
and I just want you to know,
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not everyone is good at it, and
you honestly don't have to be.
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You do need to understand
the beginning concepts, but
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after that it'll be up to
you to choose your path.
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Now there are people that aren't good
at this sort of design thing, and
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they find their way, and
they use the skills that they're good at.
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And if you're lucky,
you'll get to work alongside
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some of these amazing people
that call themselves designers.
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For the remainder of this course, we're
going to be using tools that we've learned
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thus far to build an app that a real
life Treehouse designer helped create.
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Her name is Susan, and
she's incredibly talented.
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Let's get started right after this break.
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