Barber

Barber is your personal custom view stylist.

Simply annotate your fields using the @StyledAttr annotation
Call the appropriate Barber.style(this...) variant
Let Barber take care of all the obtainStyledAttributes() and TypedArray boilerplate for you.
Profit

This library is heavily influenced by Jake Wharton's Butterknife library, and was actually suggested to me by the man himself.

Usage

Barber has a single annotation that you use: @StyledAttr. This can be used on either fields (if you want to keep the value) or methods (specifically, setters).

public class BarberView extends FrameLayout {

    @StyledAttr(value = R.styleable.BarberView_stripeColor, kind = Kind.COLOR)
    public int stripeColor;

    @StyledAttr(R.styleable.BarberView_stripeCount)
    public int stripeCount;

    @StyledAttr(R.styleable.BarberView_animated)
    public boolean isAnimated;

    public BarberView(Context context) {
        super(context);
    }

    public BarberView(Context context, AttributeSet attrs) {
        this(context, attrs, 0);
    }

    public BarberView(Context context, AttributeSet attrs, int defStyleAttr) {
        this(context, attrs, defStyleAttr, 0);
    }

    public BarberView(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
        super(context, attrs, defStyleAttr, defStyleRes);
        Barber.style(this, attrs, R.styleable.BarberView, defStyleAttr, defStyleRes);
    }

    @StyledAttr(R.styleable.BarberView_toggleAnimation)
    public void setToggleAnimationDrawable(Drawable toggleAnimation) {
        // Do something with it
    }
}

The Barber class has 3 overloaded style() methods, so you can call the appropriate one from whichever constructor you prefer.

By default, Barber will resolve which TypedArray method to use based on the type of the target. That is, if you declare it on an int, then Barber will generate code that calls typedArray.getInt(...).

@StyledAttr(R.styleable.BarberView_stripeCount)
public int stripeCount;

"But wait, sometimes my int is a color!".

If you have a special case, such as colors, then you can specify the kind member of the annotation with the appropriate Kind enum to let Barber know.

@StyledAttr(value = R.styleable.BarberView_stripeColor, kind = Kind.COLOR)
public int stripeColor;

The color example above tells Barber it should use TypedArray's getColor(...) method. This works for other types as well!

@StyledAttr(value = R.styleable.TestView_testDimension, kind = Kind.DIMEN)
public float testDimension;

@StyledAttr(value = R.styleable.TestView_testDimensionPixelSize, kind = Kind.DIMEN_PIXEL_SIZE)
public int testDimensionPixelSize;

And, if you're one of the 10 people that use fraction attributes, you'll be happy to know that those are supported as well.

@StyledAttr(
        value = R.styleable.TestView_testFractionBase,
        kind = Kind.FRACTION,
        base = 2,
        pbase = 2
)
public float testFractionBase;

See the Kind enum for a full list of supported types.

Note that these fields or methods cannot be private, and must at least be package accessible. This is because Barber will generate a **$$Barbershop class in the same package as the target class.

A word about default values

Due to limitations of how annotations work, you cannot specify a default value in the annotation. However, Barber will not override any existing values on a field if there is no value at that index. So if you want a default value, initialize the field to it. Unfortunately, annotated setters are out of luck here.

Installation

buildscript {
    repositories {
        jcenter()
    }
    dependencies {
        classpath 'com.neenbedankt.gradle.plugins:android-apt:1.4'
    }
}

apply plugin: 'com.neenbedankt.android-apt'

dependencies {
    apt 'io.sweers.barber:barber-compiler:1.0.0'
    compile 'io.sweers.barber:barber-api:1.0.0'
}

The api module comes in the form of an AAR. If you want the api sources available in your IDE, consider using this handy gradle plugin.

Proguard

If you use Proguard, add the following lines to your rules

-keep class **$$Barbershop { *; }
-keep class io.sweers.barber.** { *; }

-keepclasseswithmembernames class * {
    @io.sweers.barber.* <fields>;
}

-keepclasseswithmembernames class * {
    @io.sweers.barber.* <methods>;
}

License

Copyright 2015 Henri Z. Sweers

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

   http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.

oliver32767 / barber