frameworks_base/packages/DocumentsUI/src/com/android/documentsui/MimePredicate.java

/*
 * Copyright (C) 2013 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 com.android.documentsui;

import android.annotation.Nullable;
import android.provider.DocumentsContract.Document;

import com.android.documentsui.model.DocumentInfo;
import com.android.internal.util.Predicate;

public class MimePredicate implements Predicate<DocumentInfo> {
    private final String[] mFilters;

    private static final String APK_TYPE = "application/vnd.android.package-archive";
    /**
     * MIME types that are visual in nature. For example, they should always be
     * shown as thumbnails in list mode.
     */
    public static final String[] VISUAL_MIMES = new String[] { "image/*", "video/*" };

    public MimePredicate(String[] filters) {
        mFilters = filters;
    }

    @Override
    public boolean apply(DocumentInfo doc) {
        if (doc.isDirectory()) {
            return true;
        }
        if (mimeMatches(mFilters, doc.mimeType)) {
            return true;
        }
        return false;
    }

    public static boolean mimeMatches(String[] filters, String[] tests) {
        if (tests == null) {
            return false;
        }
        for (String test : tests) {
            if (mimeMatches(filters, test)) {
                return true;
            }
        }
        return false;
    }

    public static boolean mimeMatches(String filter, String[] tests) {
        if (tests == null) {
            return true;
        }
        for (String test : tests) {
            if (mimeMatches(filter, test)) {
                return true;
            }
        }
        return false;
    }

    public static boolean mimeMatches(String[] filters, String test) {
        if (filters == null) {
            return true;
        }
        for (String filter : filters) {
            if (mimeMatches(filter, test)) {
                return true;
            }
        }
        return false;
    }

    public static boolean mimeMatches(String filter, String test) {
        if (test == null) {
            return false;
        } else if (filter == null || "*/*".equals(filter)) {
            return true;
        } else if (filter.equals(test)) {
            return true;
        } else if (filter.endsWith("/*")) {
            return filter.regionMatches(0, test, 0, filter.indexOf('/'));
        } else {
            return false;
        }
    }

    public static boolean isApkType(@Nullable String mimeType) {
        return APK_TYPE.equals(mimeType);
    }

    public static boolean isDirectoryType(@Nullable String mimeType) {
        return Document.MIME_TYPE_DIR.equals(mimeType);
    }
}