transdroid/app/src/main/java/org/transdroid/core/gui/navigation/NavigationHelper.java

/* 
 * Copyright 2010-2013 Eric Kok et al.
 * 
 * Transdroid is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 * 
 * Transdroid is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with Transdroid.  If not, see <http://www.gnu.org/licenses/>.
 */
package org.transdroid.core.gui.navigation;

import android.annotation.SuppressLint;
import android.content.Context;
import android.content.pm.ApplicationInfo;
import android.content.pm.PackageInfo;
import android.content.pm.PackageManager.NameNotFoundException;
import android.net.Uri;
import android.text.Spannable;
import android.text.SpannableString;
import android.text.style.TypefaceSpan;

import com.nostra13.universalimageloader.cache.disc.impl.ext.LruDiscCache;
import com.nostra13.universalimageloader.cache.disc.naming.Md5FileNameGenerator;
import com.nostra13.universalimageloader.cache.memory.impl.UsingFreqLimitedMemoryCache;
import com.nostra13.universalimageloader.core.DisplayImageOptions;
import com.nostra13.universalimageloader.core.ImageLoader;
import com.nostra13.universalimageloader.core.ImageLoaderConfiguration.Builder;
import com.nostra13.universalimageloader.core.assist.ImageScaleType;

import org.androidannotations.annotations.EBean;
import org.androidannotations.annotations.RootContext;
import org.transdroid.R;

import java.io.IOException;

import de.keyboardsurfer.android.widget.crouton.Crouton;
import de.keyboardsurfer.android.widget.crouton.Style;

/**
 * Helper for activities to make navigation-related decisions, such as when a device can display a larger, tablet style
 * layout or how to display errors.
 * @author Eric Kok
 */
@SuppressLint("ResourceAsColor")
@EBean
public class NavigationHelper {

	@RootContext
	protected Context context;
	private Boolean inDebugMode;
	private static ImageLoader imageCache;

	/**
	 * Use with {@link Crouton#showText(android.app.Activity, int, Style)} (and variants) to display error messages.
	 */
	public static Style CROUTON_ERROR_STYLE =
			new Style.Builder().setBackgroundColor(R.color.crouton_error).setTextSize(13).build();

	/**
	 * Use with {@link Crouton#showText(android.app.Activity, int, Style)} (and variants) to display info messages.
	 */
	public static Style CROUTON_INFO_STYLE =
			new Style.Builder().setBackgroundColor(R.color.crouton_info).setTextSize(13).build();

	/**
	 * Returns (and initialises, if needed) an image cache that uses memory and (1MB) local storage.
	 * @return An image cache that loads web images synchronously and transparently
	 */
	public ImageLoader getImageCache() {
		if (imageCache == null) {
			imageCache = ImageLoader.getInstance();
			try {
				LruDiscCache diskCache =
						new LruDiscCache(context.getCacheDir(), null, new Md5FileNameGenerator(), 640000, 25);
				// @formatter:off
				Builder imageCacheBuilder = new Builder(context)
						.defaultDisplayImageOptions(
								new DisplayImageOptions.Builder()
										.cacheInMemory()
										.cacheOnDisc()
										.imageScaleType(ImageScaleType.IN_SAMPLE_INT)
										.showImageForEmptyUri(R.drawable.ic_launcher).build())
						.memoryCache(new UsingFreqLimitedMemoryCache(1024 * 1024))
						.discCache(diskCache);
				imageCache.init(imageCacheBuilder.build());
			// @formatter:on
			} catch (IOException e) {
				// The cache directory is always available on Android; ignore this exception
			}
		}
		return imageCache;
	}

	/**
	 * Whether any search-related UI components should be shown in the interface. At the moment returns false only if we
	 * run as Transdroid Lite version.
	 * @return True if search is enabled, false otherwise
	 */
	public String getAppNameAndVersion() {
		String appName = context.getString(R.string.app_name);
		try {
			PackageInfo m = context.getPackageManager().getPackageInfo(context.getPackageName(), 0);
			return appName + " " + m.versionName + " (" + m.versionCode + ")";
		} catch (NameNotFoundException e) {
			return appName;
		}
	}

	/**
	 * Returns whether the application is running in debug mode, as opposed to release mode. Use to show/hide features
	 * in the ui based on the build mode.
	 * @return True if the app is compiled in/running as debug mode, false otherwise
	 */
	public boolean inDebugMode() {
		try {
			if (inDebugMode == null) {
				PackageInfo pi = context.getPackageManager().getPackageInfo(context.getPackageName(), 0);
				inDebugMode = (pi.applicationInfo.flags & ApplicationInfo.FLAG_DEBUGGABLE) != 0;
			}
			return inDebugMode;
		} catch (NameNotFoundException e) {
			return false;
		}
	}

	/**
	 * Returns whether the device is considered small (i.e. a phone) rather than large (i.e. a tablet). Can, for
	 * example, be used to determine if a dialog should be shown full screen. Currently is true if the device's smallest
	 * dimension is 500 dip.
	 * @return True if the app runs on a small device, false otherwise
	 */
	public boolean isSmallScreen() {
		return context.getResources().getBoolean(R.bool.show_dialog_fullscreen);
	}

	/**
	 * Whether any search-related UI components should be shown in the interface. At the moment returns false only if we
	 * run as Transdroid Lite version.
	 * @return True if search is enabled, false otherwise
	 */
	public boolean enableSearchUi() {
		return context.getResources().getBoolean(R.bool.search_available);
	}

	/**
	 * Whether any RSS-related UI components should be shown in the interface. At the moment returns false only if we
	 * run as Transdroid Lite version.
	 * @return True if search is enabled, false otherwise
	 */
	public boolean enableRssUi() {
		return context.getResources().getBoolean(R.bool.rss_available);
	}

	/**
	 * Returns whether any seedbox-related components should be shown in the interface; specifically the option to add
	 * server settings via easy seedbox-specific screens.
	 * @return True if seedbox settings should be shown, false otherwise
	 */
	public boolean enableSeedboxes() {
		return context.getResources().getBoolean(R.bool.seedboxes_available);
	}

	/**
	 * Whether the custom app update checker should be used to check for new app and search module versions.
	 * @return True if it should be checked against transdroid.org if there are app updates (as opposed to using the
	 * Play Store for updates, for example), false otherwise
	 */
	public boolean enableUpdateChecker() {
		return context.getResources().getBoolean(R.bool.updatecheck_available);
	}

	/**
	 * Converts a string into a {@link Spannable} that displays the string in the Roboto Condensed font
	 * @param string A plain text {@link String}
	 * @return A {@link Spannable} that can be applied to supporting views (such as the action bar title) so that the
	 * input string will be displayed using the Roboto Condensed font (if the OS has this)
	 */
	public static SpannableString buildCondensedFontString(String string) {
		if (string == null) {
			return null;
		}
		SpannableString s = new SpannableString(string);
		s.setSpan(new TypefaceSpan("sans-serif-condensed"), 0, s.length(), Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
		return s;
	}

	/**
	 * Analyses a torrent http or magnet URI and tries to come up with a reasonable human-readable name.
	 * @param rawTorrentUri The raw http:// or magnet: link to the torrent
	 * @return A best-guess, reasonably long name for the linked torrent
	 */
	public static String extractNameFromUri(Uri rawTorrentUri) {

		if (rawTorrentUri.getScheme() == null) {
			// Probably an incorrect URI; just return the whole thing
			return rawTorrentUri.toString();
		}

		if (rawTorrentUri.getScheme().equals("magnet")) {
			// Magnet links might have a dn (display name) parameter
			String dn = getQueryParameter(rawTorrentUri, "dn");
			if (dn != null && !dn.equals("")) {
				return dn;
			}
			// If not, try to return the hash that is specified as xt (exact topci)
			String xt = getQueryParameter(rawTorrentUri, "xt");
			if (xt != null && !xt.equals("")) {
				return xt;
			}
		}

		if (rawTorrentUri.isHierarchical()) {
			String path = rawTorrentUri.getPath();
			if (path != null) {
				if (path.contains("/")) {
					path = path.substring(path.lastIndexOf("/"));
				}
				return path;
			}
		}

		// No idea what to do with this; return as is
		return rawTorrentUri.toString();
	}

	private static String getQueryParameter(Uri uri, String parameter) {
		int start = uri.toString().indexOf(parameter + "=");
		if (start >= 0) {
			int begin = start + (parameter + "=").length();
			int end = uri.toString().indexOf("&", begin);
			return uri.toString().substring(begin, end >= 0 ? end : uri.toString().length());
		}
		return null;
	}

}