/***************************************************************************
* Copyright 2006-2016 by Christian Ihle *
* contact@kouchat.net *
* *
* This file is part of KouChat. *
* *
* KouChat is free software; you can redistribute it and/or modify *
* it under the terms of the GNU Lesser General Public License as *
* published by the Free Software Foundation, either version 3 of *
* the License, or (at your option) any later version. *
* *
* KouChat 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 *
* Lesser General Public License for more details. *
* *
* You should have received a copy of the GNU Lesser General Public *
* License along with KouChat. *
* If not, see <http://www.gnu.org/licenses/>. *
***************************************************************************/
package net.usikkert.kouchat.android.controller;
import net.usikkert.kouchat.android.component.LinkMovementMethodWithSelectSupport;
import android.text.NoCopySpan;
import android.text.Spannable;
import android.widget.ScrollView;
import android.widget.TextView;
/**
* Reusable functionality for controllers.
*
* @author Christian Ihle
*/
public class ControllerUtils {
/** Number of milliseconds in a second. */
public static final int ONE_SECOND = 1000;
/**
* Scrolls to the last line of text in a text view.
*
* @param textView The text view to scroll.
* @param scrollView The surrounding scroll view.
*/
public void scrollTextViewToBottom(final TextView textView, final ScrollView scrollView) {
scrollView.post(new Runnable() {
@Override
public void run() {
scrollView.smoothScrollTo(0, scrollView.getBottom() + textView.getHeight());
}
});
}
/**
* Makes sure the links you click on opens in the browser.
*
* @param textView The text view to activate link clicking on.
*/
public void makeLinksClickable(final TextView textView) {
textView.setMovementMethod(LinkMovementMethodWithSelectSupport.getInstance());
}
/**
* Removes spans with references to the text view.
*
* <p>There are several spans that are added to the text here and there, like:</p>
*
* <ul>
* <li>android.text.DynamicLayout$ChangeWatcher</li>
* <li>android.widget.TextView$ChangeWatcher</li>
* <li>android.widget.Editor$EasyEditSpanController</li>
* </ul>
*
* <p>These spans are of type {@link NoCopySpan}, and are not important to the text or how it's shown.
* Since they are inner classes, they keep a reference to their parent, like a {@link TextView}.
* And that references a context, which is usually an activity.</p>
*
* <p>If the text was garbage collected, then this would still not be a problem, but often it's not.
* The reason is that some of these lines are cached by the TextLine class, including all the spans.
* So to give the text view and the activity a chance to be garbage collected, then these spans must be
* removed.</p>
*
* @param textView The text view with the text to remove references from.
*/
public void removeReferencesToTextViewFromText(final TextView textView) {
final Spannable text = (Spannable) textView.getText();
final NoCopySpan[] noCopySpans = text.getSpans(0, text.length(), NoCopySpan.class);
for (final NoCopySpan noCopySpan : noCopySpans) {
text.removeSpan(noCopySpan);
}
}
}