TintedProgressBar

attrs.xml

<?xml version="1.0" encoding="utf-8"?>

<declare-styleable name="TintedProgressBar">
    <attr name="tint" format="color|reference" />
</declare-styleable>

progress_bar.xml

<?xml version="1.0" encoding="utf-8"?>

<com.ifttt.lib.TintedProgressBar
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    style="@style/Widget.AppCompat.ProgressBar.Horizontal"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:indeterminate="true"
    app:tint="@color/ifttt_blue_light" />

TintedProgressBar.java

import android.annotation.TargetApi;
import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.PorterDuff;
import android.os.Build;
import android.util.AttributeSet;
import android.widget.ProgressBar;

public class TintedProgressBar extends ProgressBar {

    public TintedProgressBar(Context context) {
        super(context);
        init(context, null, 0);
    }

    public TintedProgressBar(Context context, AttributeSet attrs) {
        super(context, attrs);
        init(context, attrs, 0);
    }

    public TintedProgressBar(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        init(context, attrs, defStyleAttr);
    }

    @TargetApi(Build.VERSION_CODES.LOLLIPOP)
    public TintedProgressBar(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
        super(context, attrs, defStyleAttr, defStyleRes);
        init(context, attrs, defStyleAttr);
    }

    private void init(Context context, AttributeSet attrs, int defStyle) {
        final TypedArray a = context.obtainStyledAttributes(attrs,
                R.styleable.TintedProgressBar, defStyle, 0);
        if (a == null) {
            return;
        }
        if (a.hasValue(R.styleable.TintedProgressBar_tint)) {
            final int tintColor = a.getColor(R.styleable.TintedProgressBar_tint, 0);
            getIndeterminateDrawable().setColorFilter(tintColor, PorterDuff.Mode.SRC_IN);
            getProgressDrawable().setColorFilter(tintColor, PorterDuff.Mode.SRC_IN);
        }
        a.recycle();
    }
}

When we use the TintedProgressBar and AppCompat 23.4.0 with style="@style/Widget.AppCompat.ProgressBar" (instead of Widget.AppCompat.ProgressBar. Horizontal) it will crash.
Why? Because getProgressDrawable() or getIndeterminateDrawable() can be null.

Fix:

final Drawable progressDrawable = getProgressDrawable();
if (progressDrawable != null) {
    progressDrawable.setColorFilter(tintColor, PorterDuff.Mode.SRC_IN);
}
final Drawable indeterminateDrawable = getIndeterminateDrawable();
if (indeterminateDrawable != null) {
    indeterminateDrawable.setColorFilter(tintColor, PorterDuff.Mode.SRC_IN);
}