Johannes is the co-founder of Jack just asked the following questions on the tutorial for animated GIFs I once wrote:
“I want to be able to place the GifMovieView in an existing layout (like any regular control).
Please give me a step-by-step of how to bind xml layout attributes to this custom view.”
A good question. Here’s the answer.
1 Use your own View in an XML
To place your own View in an layout XML file, just use it like a normal view, only that you have to append the whole package name up front. Something like:
< eu.andlabs.tutorial.animatedgifs.views.GifMovieView
android:layout_height="wrap_content"
android:layout_width="wrap_content"
android:id="@+id/my_id"
/>
In this XML, you can already use the standard Android attributes.
2 Define your custom attributes
If you want to define your own, custom attributes, go to the res/values-folder and create a file called attrs.xml.
You can define your custom attributes here. In the end, it should look like this:
< ?xml version="1.0" encoding="utf-8"?>
< resources>
< declare-styleable name = "eu.andlabs.tutorial.animatedgifs.view.GifMovieView">
< attr name="url" format="string" />
< attr name="fetchAutomatically" format="boolean" />
< /declare-styleable>
< /resources>
You can now address these attributes in your XML layout. To do so, add something like
xmlns:gif="http://schemas.android.com/apk/res-auto"
To your root layout element. Please notice that this only works with ADT 17 and older. Now you can access your attributes in your layout like this:
< eu.andlabs.tutorial.animatedgifs.views.GifMovieView
android:layout_height="wrap_content"
android:layout_width="wrap_content"
android:id="@+id/my_id"
gif:url="http://mygif.com/mygif.gif"
gif:fetchAutomatically="true"
/>
3 Handle the attributes in your View
Since the XML is done, it’s time to address the Java part, which means the custom View. You should at least overwrite the constructor that is receiving a Context and an Attributes-object. Like so:
public GifMovieView(final Context context, final AttributeSet attrs) {
super(context, attrs);
init(attrs);
}
You can now access your custom attributes in using the AttributeSet:
private void init(final AttributeSet attrs) {
if (attrs != null) {
String packageName = "http://schemas.android.com/apk/res-auto";
mUrl = attrs.getAttributeValue(packageName, "url");
mFetchAutomatically = attrs.getAttributeBooleanValue(packageName, "fetchAutomatically", false);
}
}
Do whatever is needed with it. That’s already it.
I hope you enjoyed this post. Please feel free to ask anything you want in the comments.
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