DataBindingFunctions.java

import android.animation.ArgbEvaluator;
import android.databinding.BindingAdapter;
import android.support.annotation.ColorInt;
import android.support.constraint.ConstraintLayout;
import android.view.View;
import android.view.ViewGroup;

/**
 * Created by cattaka on 2016/10/24.
 */

public class DataBindingFunctions {
    private static ArgbEvaluator mArgbEvaluator;

    @BindingAdapter({"setWidth"})
    public static void setWidth(View view, int v) {
        ViewGroup.LayoutParams params = view.getLayoutParams();
        params.width = v;
        view.setLayoutParams(params);
    }

    @BindingAdapter({"setHeight"})
    public static void setHeight(View view, int v) {
        ViewGroup.LayoutParams params = view.getLayoutParams();
        params.height = v;
        view.setLayoutParams(params);
    }

    @BindingAdapter({"setLayoutConstraintHorizontalWeight"})
    public static void setLayoutConstraintHorizontalWeight(View view, float v) {
        if (v < 0.0001f) {
            v = 0.0001f;  // To avoid it goes match_parent.
        }

        ConstraintLayout.LayoutParams params = (ConstraintLayout.LayoutParams) view.getLayoutParams();
        params.horizontalWeight = v;
        view.setLayoutParams(params);
    }

    @BindingAdapter({"setLayoutConstraintVerticalWeight"})
    public static void setLayoutConstraintVerticalWeight(View view, float v) {
        if (v < 0.0001f) {
            v = 0.0001f;  // To avoid it goes match_parent.
        }

        ConstraintLayout.LayoutParams params = (ConstraintLayout.LayoutParams) view.getLayoutParams();
        params.verticalWeight = v;
        view.setLayoutParams(params);
    }

    @BindingAdapter({"setLayoutMarginLeft"})
    public static void setLayoutMarginLeft(View view, int v) {
        ViewGroup.MarginLayoutParams params = (ViewGroup.MarginLayoutParams) view.getLayoutParams();
        params.leftMargin = v;
        view.setLayoutParams(params);
    }

    @BindingAdapter({"setLayoutMarginTop"})
    public static void setLayoutMarginTop(View view, int v) {
        ViewGroup.MarginLayoutParams params = (ViewGroup.MarginLayoutParams) view.getLayoutParams();
        params.topMargin = v;
        view.setLayoutParams(params);
    }

    @BindingAdapter({"setLayoutMarginRight"})
    public static void setLayoutMarginRight(View view, int v) {
        ViewGroup.MarginLayoutParams params = (ViewGroup.MarginLayoutParams) view.getLayoutParams();
        params.rightMargin = v;
        view.setLayoutParams(params);
    }

    @BindingAdapter({"setLayoutMarginBottom"})
    public static void setLayoutMarginBottom(View view, int v) {
        ViewGroup.MarginLayoutParams params = (ViewGroup.MarginLayoutParams) view.getLayoutParams();
        params.bottomMargin = v;
        view.setLayoutParams(params);
    }

    public static int evaluateColor(float fraction, @ColorInt int startValue, @ColorInt int endValue) {
        if (mArgbEvaluator == null) {
            mArgbEvaluator = new ArgbEvaluator();
        }
        return (Integer) mArgbEvaluator.evaluate(fraction, startValue, endValue);
    }

    public static int evaluateColor(float fraction, @ColorInt int startValue, @ColorInt int centerValue, @ColorInt int endValue) {
        if (mArgbEvaluator == null) {
            mArgbEvaluator = new ArgbEvaluator();
        }
        if (fraction <= 0.5) {
            return (Integer) mArgbEvaluator.evaluate(fraction * 2, startValue, centerValue);
        } else {
            return (Integer) mArgbEvaluator.evaluate((fraction - 0.5f) * 2, centerValue, endValue);
        }
    }
}