Java tutorial
/* Copyright 2017 Andrew Dawson * * This file is a part of Tusky. * * This program 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. * * Tusky 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 Tusky; if not, * see <http://www.gnu.org/licenses>. */ package com.keylesspalace.tusky.util; import android.content.ActivityNotFoundException; import android.content.Context; import android.content.Intent; import android.net.Uri; import android.preference.PreferenceManager; import android.provider.Browser; import android.support.annotation.Nullable; import android.support.customtabs.CustomTabsIntent; import android.support.v4.content.ContextCompat; import android.text.SpannableStringBuilder; import android.text.Spanned; import android.text.TextPaint; import android.text.method.LinkMovementMethod; import android.text.style.ClickableSpan; import android.text.style.URLSpan; import android.util.Log; import android.view.View; import android.widget.TextView; import com.keylesspalace.tusky.R; import com.keylesspalace.tusky.entity.Status; import com.keylesspalace.tusky.interfaces.LinkListener; import java.net.URI; import java.net.URISyntaxException; public class LinkHelper { private static String getDomain(String urlString) { URI uri; try { uri = new URI(urlString); } catch (URISyntaxException e) { return ""; } String host = uri.getHost(); if (host.startsWith("www.")) { return host.substring(4); } else { return host; } } /** * Finds links, mentions, and hashtags in a piece of text and makes them clickable, associating * them with callbacks to notify when they're clicked. * * @param view the returned text will be put in * @param content containing text with mentions, links, or hashtags * @param mentions any '@' mentions which are known to be in the content * @param listener to notify about particular spans that are clicked */ public static void setClickableText(TextView view, Spanned content, @Nullable Status.Mention[] mentions, final LinkListener listener) { SpannableStringBuilder builder = new SpannableStringBuilder(content); URLSpan[] urlSpans = content.getSpans(0, content.length(), URLSpan.class); for (URLSpan span : urlSpans) { int start = builder.getSpanStart(span); int end = builder.getSpanEnd(span); int flags = builder.getSpanFlags(span); CharSequence text = builder.subSequence(start, end); if (text.charAt(0) == '#') { final String tag = text.subSequence(1, text.length()).toString(); ClickableSpan newSpan = new ClickableSpan() { @Override public void onClick(View widget) { listener.onViewTag(tag); } @Override public void updateDrawState(TextPaint ds) { super.updateDrawState(ds); ds.setUnderlineText(false); } }; builder.removeSpan(span); builder.setSpan(newSpan, start, end, flags); } else if (text.charAt(0) == '@' && mentions != null && mentions.length > 0) { String accountUsername = text.subSequence(1, text.length()).toString(); /* There may be multiple matches for users on different instances with the same * username. If a match has the same domain we know it's for sure the same, but if * that can't be found then just go with whichever one matched last. */ String id = null; for (Status.Mention mention : mentions) { if (mention.localUsername.equalsIgnoreCase(accountUsername)) { id = mention.id; if (mention.url.contains(getDomain(span.getURL()))) { break; } } } if (id != null) { final String accountId = id; ClickableSpan newSpan = new ClickableSpan() { @Override public void onClick(View widget) { listener.onViewAccount(accountId); } @Override public void updateDrawState(TextPaint ds) { super.updateDrawState(ds); ds.setUnderlineText(false); } }; builder.removeSpan(span); builder.setSpan(newSpan, start, end, flags); } } else { ClickableSpan newSpan = new CustomURLSpan(span.getURL()); builder.removeSpan(span); builder.setSpan(newSpan, start, end, flags); } } view.setText(builder); view.setLinksClickable(true); view.setMovementMethod(LinkMovementMethod.getInstance()); } /** * Opens a link, depending on the settings, either in the browser or in a custom tab * * @param url a string containing the url to open * @param context context */ public static void openLink(String url, Context context) { Uri uri = Uri.parse(url); boolean useCustomTabs = PreferenceManager.getDefaultSharedPreferences(context).getBoolean("customTabs", false); if (useCustomTabs) { openLinkInCustomTab(uri, context); } else { openLinkInBrowser(uri, context); } } /** * opens a link in the browser via Intent.ACTION_VIEW * * @param uri the uri to open * @param context context */ public static void openLinkInBrowser(Uri uri, Context context) { Intent intent = new Intent(Intent.ACTION_VIEW, uri); intent.putExtra(Browser.EXTRA_APPLICATION_ID, context.getPackageName()); try { context.startActivity(intent); } catch (ActivityNotFoundException e) { Log.w("URLSpan", "Actvity was not found for intent, " + intent.toString()); } } /** * tries to open a link in a custom tab * falls back to browser if not possible * * @param uri the uri to open * @param context context */ public static void openLinkInCustomTab(Uri uri, Context context) { boolean lightTheme = PreferenceManager.getDefaultSharedPreferences(context).getBoolean("lightTheme", false); int toolbarColor = ContextCompat.getColor(context, lightTheme ? R.color.custom_tab_toolbar_light : R.color.custom_tab_toolbar_dark); CustomTabsIntent.Builder builder = new CustomTabsIntent.Builder(); builder.setToolbarColor(toolbarColor); CustomTabsIntent customTabsIntent = builder.build(); try { String packageName = CustomTabsHelper.getPackageNameToUse(context); //If we cant find a package name, it means theres no browser that supports //Chrome Custom Tabs installed. So, we fallback to the webview if (packageName == null) { openLinkInBrowser(uri, context); } else { customTabsIntent.intent.setPackage(packageName); customTabsIntent.launchUrl(context, uri); } } catch (ActivityNotFoundException e) { Log.w("URLSpan", "Activity was not found for intent, " + customTabsIntent.toString()); } } }