Java tutorial
/* * Kontalk Android client * Copyright (C) 2017 Kontalk Devteam <devteam@kontalk.org> * 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. * This program 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 this program. If not, see <http://www.gnu.org/licenses/>. */ package org.kontalk.ui.view; import org.kontalk.R; import org.kontalk.data.Contact; import org.kontalk.data.Contact.ContactCallback; import android.content.Context; import android.graphics.drawable.Drawable; import android.os.Handler; import android.support.v4.content.ContextCompat; import android.util.AttributeSet; import android.widget.RelativeLayout; /** * A list item for avatar use. * @author Daniele Ricci */ public abstract class AvatarListItem extends RelativeLayout implements ContactCallback { protected CircleContactBadge mAvatarView; private Handler mHandler; static protected Drawable sDefaultContactImage; static protected Drawable sDefaultGroupImage; public AvatarListItem(Context context) { super(context); init(context); } public AvatarListItem(Context context, AttributeSet attrs) { super(context, attrs); init(context); } private void init(Context context) { mHandler = new Handler(); } private Drawable getDefaultContactImage() { if (sDefaultContactImage == null) sDefaultContactImage = ContextCompat.getDrawable(getContext(), R.drawable.ic_default_contact); return sDefaultContactImage; } private Drawable getDefaultGroupImage() { if (sDefaultGroupImage == null) sDefaultGroupImage = ContextCompat.getDrawable(getContext(), R.drawable.ic_default_group); return sDefaultGroupImage; } @Override protected void onFinishInflate() { super.onFinishInflate(); mAvatarView = (CircleContactBadge) findViewById(R.id.avatar); if (isInEditMode()) { mAvatarView.setImageDrawable(getDefaultContactImage()); mAvatarView.setVisibility(VISIBLE); } } protected void loadAvatar(Contact contact) { Drawable defaultIcon = isGroupChat() ? getDefaultGroupImage() : getDefaultContactImage(); if (contact != null) { // we mark this with the contact's hash code for the async avatar mAvatarView.setTag(contact.hashCode()); mAvatarView.assignContactUri(contact.getUri()); mAvatarView.setImageDrawable(defaultIcon); // laod avatar asynchronously contact.getAvatarAsync(getContext(), this); } else { mAvatarView.setTag(null); mAvatarView.setImageDrawable(defaultIcon); } } protected abstract boolean isGroupChat(); @Override public void avatarLoaded(final Contact contact, final Drawable avatar) { if (avatar != null) { if (mHandler.getLooper().getThread() != Thread.currentThread()) { mHandler.post(new Runnable() { public void run() { updateAvatar(contact, avatar); } }); } else { updateAvatar(contact, avatar); } } } void updateAvatar(Contact contact, Drawable avatar) { try { // be sure the contact is still the same // this is an insane workaround against race conditions Integer contactTag = (Integer) mAvatarView.getTag(); if (contactTag != null && contactTag == contact.hashCode()) mAvatarView.setImageDrawable(avatar); } catch (Exception e) { // we are deliberately ignoring any exception here // because an error here could happen only if something // weird is happening, e.g. user leaving the activity } } }