session-android/src/org/thoughtcrime/securesms/util/ThemeUtil.java

package org.thoughtcrime.securesms.util;

import android.content.Context;
import android.content.res.Resources;
import android.graphics.Color;
import android.support.annotation.AttrRes;
import android.support.annotation.NonNull;
import android.support.annotation.StyleRes;
import android.support.v7.view.ContextThemeWrapper;
import android.util.TypedValue;
import android.view.LayoutInflater;
import android.view.View;

import org.thoughtcrime.securesms.R;

public class ThemeUtil {

  public static boolean isDarkTheme(@NonNull Context context) {
    return getAttribute(context, R.attr.theme_type, "light").equals("dark");
  }

  public static int getThemedColor(@NonNull Context context, @AttrRes int attr) {
    TypedValue typedValue = new TypedValue();
    Resources.Theme theme = context.getTheme();

    if (theme.resolveAttribute(attr, typedValue, true)) {
      return typedValue.data;
    }
    return Color.RED;
  }

  public static LayoutInflater getThemedInflater(@NonNull Context context, @NonNull LayoutInflater inflater, @StyleRes int theme) {
    Context contextThemeWrapper = new ContextThemeWrapper(context, theme);
    return inflater.cloneInContext(contextThemeWrapper);
  }

  private static String getAttribute(Context context, int attribute, String defaultValue) {
    TypedValue outValue = new TypedValue();

    if (context.getTheme().resolveAttribute(attribute, outValue, true)) {
      return outValue.coerceToString().toString();
    } else {
      return defaultValue;
    }
  }
}