xref: /frameworks/support/v4/java/android/support/v4/content/res/ResourcesCompat.java

/*
 * Copyright (C) 2014 The Android Open Source Project
 *
 * 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.
 */

package android.support.v4.content.res;

import android.content.res.Resources;
import android.content.res.Resources.NotFoundException;
import android.content.res.Resources.Theme;
import android.graphics.drawable.Drawable;
import android.os.Build;

/**
 * Helper for accessing features in {@link android.content.res.Resources}
 * introduced after API level 4 in a backwards compatible fashion.
 */
public class ResourcesCompat {
    /**
     * Return a drawable object associated with a particular resource ID and
     * styled for the specified theme. Various types of objects will be
     * returned depending on the underlying resource -- for example, a solid
     * color, PNG image, scalable image, etc.
     * <p>
     * Prior to API level 21, the theme will not be applied and this method
     * simply calls through to {@link Resources#getDrawable(int)}.
     *
     * @param id The desired resource identifier, as generated by the aapt
     *           tool. This integer encodes the package, type, and resource
     *           entry. The value 0 is an invalid identifier.
     * @param theme The theme used to style the drawable attributes, may be
     *              {@code null}.
     * @return Drawable An object that can be used to draw this resource.
     * @throws NotFoundException Throws NotFoundException if the given ID does
     *         not exist.
     */
    @SuppressWarnings("deprecation")
    public static Drawable getDrawable(Resources res, int id, Theme theme)
            throws NotFoundException {
        final int version = Build.VERSION.SDK_INT;
        if (version >= 21) {
            return ResourcesCompatApi21.getDrawable(res, id, theme);
        } else {
            return res.getDrawable(id);
        }
    }


    /**
     * Return a drawable object associated with a particular resource ID for
     * the given screen density in DPI and styled for the specified theme.
     * <p>
     * Prior to API level 15, the theme and density will not be applied and
     * this method simply calls through to {@link Resources#getDrawable(int)}.
     * <p>
     * Prior to API level 21, the theme will not be applied and this method
     * calls through to Resources.getDrawableForDensity(int, int).
     *
     * @param id The desired resource identifier, as generated by the aapt
     *           tool. This integer encodes the package, type, and resource
     *           entry. The value 0 is an invalid identifier.
     * @param density The desired screen density indicated by the resource as
     *                found in {@link android.util.DisplayMetrics}.
     * @param theme The theme used to style the drawable attributes, may be
     *              {@code null}.
     * @return Drawable An object that can be used to draw this resource.
     * @throws NotFoundException Throws NotFoundException if the given ID does
     *             not exist.
     */
    @SuppressWarnings("deprecation")
    public static Drawable getDrawableForDensity(Resources res, int id, int density, Theme theme)
            throws NotFoundException {
        final int version = Build.VERSION.SDK_INT;
        if (version >= 21) {
            return ResourcesCompatApi21.getDrawableForDensity(res, id, density, theme);
        } else if (version >= 15) {
            return ResourcesCompatIcsMr1.getDrawableForDensity(res, id, density);
        } else {
            return res.getDrawable(id);
        }
    }
}