commit 639cab1bffe5a5dfbe22a31fae25604d04aa9bc3
Author: Gregory Eremin <g@erem.in>
Date:   Fri Jun 27 00:09:54 2014 +0700

    Initial commit

diff --git a/background.js b/background.js
new file mode 100644
index 0000000..4887bbc
--- /dev/null
+++ b/background.js
@@ -0,0 +1,262 @@
+(function() {
+    var SHOW_TIMEOUT = 1000,
+        LOAD_TIMEOUT = SHOW_TIMEOUT / 4,
+        STORAGE = {};
+
+    var links = document.getElementsByTagName('a');
+    for (var i = 0; i < links.length; i++) {
+        var el = links[i],
+            href = el.getAttribute('href');
+
+        // Skipping elements that has no href and anchor links
+        if (href === null || href[0] === '#') {
+            continue;
+        }
+
+        STORAGE[i] = {};
+        (function(i) {
+            var el = links[i];
+
+            el.addEventListener('mouseover', function(e) {
+                log('The mouse is OVER!');
+
+                if (STORAGE[i].result === undefined) {
+                    STORAGE[i].load_timeout = after(LOAD_TIMEOUT, function() {
+                        STORAGE[i].xhr = loadPageInfo(el.href, function(res) {
+                            log('Result loaded:', res);
+                            STORAGE[i].result = res;
+                            delete STORAGE[i].xhr;
+
+                            var tt = document.getElementById('whats-there-tooltip');
+                            if (tt === null) {
+                                showTooltip(el, STORAGE[i].result, STORAGE[i].e);
+                            }
+                        });
+                    });
+                }
+
+                STORAGE[i].show_timeout = after(SHOW_TIMEOUT, function() {
+                    log('Time for result!');
+                    if (STORAGE[i].result !== undefined) {
+                        showTooltip(el, STORAGE[i].result, STORAGE[i].e);
+                    }
+                });
+            });
+
+            el.addEventListener('mouseout', function(e) {
+                hideTooltip();
+                log('The mouse is OUT!');
+
+                if (STORAGE[i].xhr !== undefined) {
+                    STORAGE[i].xhr.abort();
+                    log('XHR aborted!');
+                }
+                window.clearTimeout(STORAGE[i].load_timeout);
+                window.clearTimeout(STORAGE[i].show_timeout);
+            });
+
+            el.addEventListener('mousemove', function(e) {
+                STORAGE[i].e = e;
+            });
+        })(i);
+    }
+
+    function showTooltip(el, info, e) {
+        var tt = document.getElementById('whats-there-tooltip');
+        if (tt !== null) {
+            // Don't show a tooltip if there's one already
+            return;
+        }
+
+        if (info.title === undefined && info.description === undefined) {
+            // Don't show a tooltip if there's no title nor descriptions for the page
+            return;
+        }
+
+        var tt = document.createElement('div'),
+            body = document.getElementsByTagName('body')[0],
+            bounds = el.getBoundingClientRect();
+
+        tt.setAttribute('class', 'whats-there-tooltip');
+        tt.setAttribute('id', 'whats-there-tooltip');
+
+        if (info.image_url !== undefined) {
+            var div = document.createElement('div');
+            div.setAttribute('class', 'whats-there-img');
+            div.style.backgroundImage = 'url(' + info.image_url + ')';
+            tt.appendChild(div);
+        }
+
+        if (info.title !== undefined) {
+            var div = document.createElement('div');
+            div.setAttribute('class', 'whats-there-title');
+            div.innerText = info.title;
+            tt.appendChild(div);
+        }
+
+        if (info.description !== undefined) {
+            var div = document.createElement('div');
+            div.setAttribute('class', 'whats-there-description');
+            div.innerText = info.description;
+            tt.appendChild(div);
+        }
+
+        var site_name;
+        if (info.site_name === undefined) {
+            site_name = info.host;
+        } else {
+            site_name = info.site_name + ' (' + info.host + ')';
+        }
+        var div = document.createElement('div');
+        div.setAttribute('class', 'whats-there-site');
+        div.innerText = site_name;
+        tt.appendChild(div);
+
+        body.appendChild(tt);
+        moveTooltip(e);
+    }
+
+    function hideTooltip() {
+        var tt = document.getElementById('whats-there-tooltip');
+        if (tt !== null) {
+            tt.parentNode.removeChild(tt);
+        }
+    }
+
+    function moveTooltip(e) {
+        var tt = document.getElementById('whats-there-tooltip'),
+            tt_width = tt.clientWidth,
+            tt_height = tt.clientHeight,
+            w_width = window.innerWidth,
+            w_height = window.innerHeight,
+            s_top = document.documentElement.scrollTop,
+            s_left = document.documentElement.scrollLeft,
+            e_top = e.clientY,
+            e_left = e.clientX;
+
+        var tt_top = s_top + e_top - tt_height - 20,
+            tt_left = s_left + e_left - tt_width / 2;
+
+        // Vertical positioning fix
+        if (tt_top < 10) {
+            tt_top = 10;
+
+            if (e_left > w_width / 2) {
+                tt_left = s_left + e_left - tt_width - 20;
+            } else {
+                tt_left = s_left + e_left + 20;
+            }
+        } else {
+            // Horizontal positioning fixes
+            if (e_left - tt_width / 2 - 10 < s_left) {
+                tt_left = 10;
+            } else if (tt_left + tt_width + 10 > w_width) {
+                tt_left = w_width - tt_width - 10;
+            }
+        }
+
+        tt.style.top = tt_top + 'px';
+        tt.style.left = tt_left + 'px';
+    }
+
+    function loadPageInfo(url, callback) {
+        var xhr = new XMLHttpRequest();
+
+        xhr.onreadystatechange = function() {
+            if (this.readyState === this.HEADERS_RECEIVED) {
+                var ct = this.getResponseHeader('Content-Type');
+
+                // Aborting page load if it's not HTML
+                if (ct === null || ct.indexOf('text/html') != 0) {
+                    this.abort();
+                }
+            } else if (this.readyState === this.DONE && this.status === 200) {
+                var result = parseTags(this.responseText),
+                    tokens = url.split('/');
+
+                result.protocol = tokens[0];
+                result.host = tokens[2];
+                if (result.image_url !== undefined) {
+                    result.image_url = makeAbsoluteURL(url, result.image_url);
+                }
+
+                callback(result);
+            }
+        }
+
+        xhr.open('GET', url, true);
+        xhr.send(null);
+
+        return xhr;
+    }
+
+    function parseTags(html) {
+        var parser = new DOMParser(),
+            result = {};
+
+        var doc = parser.parseFromString(html, 'text/html');
+
+        var title = doc.getElementsByTagName('title')[0];
+        if (title !== undefined) {
+            result.title = title.innerText;
+        }
+
+        var tags = doc.getElementsByTagName('meta');
+        for (var i = 0; i < tags.length; i++) {
+            var el = tags[i],
+                name = el.getAttribute('name'),
+                property = el.getAttribute('property'),
+                content = el.getAttribute('content'),
+                has_content = (content !== null && content.length > 0);
+
+            if (property === 'og:title' && has_content) {
+                result.title = content;
+            } else if (name === 'description' && has_content) {
+                result.description = content;
+            } else if (property === 'og:description' && has_content) {
+                result.description = content;
+            } else if (property === 'og:image' && has_content) {
+                result.image_url = content;
+            } else if (property === 'og:site_name' && has_content) {
+                result.site_name = content;
+            }
+        }
+
+        return result;
+    }
+
+    function makeAbsoluteURL(page_url, link_url) {
+        var tokens = link_url.split('/'),
+            page = document.createElement('a'),
+            link = document.createElement('a');
+
+        page.href = page_url;
+        link.href = link_url;
+
+        if ((tokens[0] === 'http:' || tokens[0] === 'https:') && tokens[1] === '') {
+            // Assuming it's an absolute URL already
+            return link_url;
+        } else if (link_url.slice(0, 2) === '//') {
+            // Relative protocol
+            return page.protocol + link_url;
+        } else {
+            return [
+                page.protocol,
+                '//',
+                page.host,
+                link.pathname,
+                link.search
+            ].join('')
+        }
+    }
+
+    function after(timeout, func) {
+        return window.setTimeout(func, timeout);
+    }
+
+    function log() {
+        if (false && console) {
+            console.log.apply(console, arguments);
+        }
+    }
+})();
diff --git a/manifest.json b/manifest.json
new file mode 100644
index 0000000..3d0ef6c
--- /dev/null
+++ b/manifest.json
@@ -0,0 +1,20 @@
+{
+    "manifest_version": 2,
+
+    "name": "Whats There",
+    "description": "Shows nice link previews based on the page's Open Graph tags",
+    "version": "1.0",
+
+    "permissions": [
+        "http://*/*",
+        "https://*/*"
+    ],
+    "content_scripts": [
+        {
+            "all_frames": true,
+            "js": [ "background.js" ],
+            "css": [ "tooltip.css" ],
+            "matches": [ "\u003Call_urls>" ]
+        }
+    ]
+}
diff --git a/resources/aviasales.jpg b/resources/aviasales.jpg
new file mode 100644
index 0000000..cd9076d
Binary files /dev/null and b/resources/aviasales.jpg differ
diff --git a/resources/playground.html b/resources/playground.html
new file mode 100644
index 0000000..19cdc29
--- /dev/null
+++ b/resources/playground.html
@@ -0,0 +1,41 @@
+<!doctype html>
+<html>
+<head>
+    <title>Playground</title>
+    <meta charset="utf8">
+    <style type="text/css">
+        a { position: absolute; }
+
+        #l1{ top: 20px; left: 20px; }
+        #l2{ top: 120px; left: 20px; }
+        #l3{ top: 220px; left: 20px; }
+        #l4{ top: 320px; left: 20px; }
+        #l5{ top: 420px; left: 20px; }
+        #l6{ top: 420px; left: 320px; }
+
+        #r1{ top: 20px; right: 20px; }
+        #r2{ top: 120px; right: 20px; }
+        #r3{ top: 220px; right: 20px; }
+        #r4{ top: 320px; right: 20px; }
+        #r5{ top: 420px; right: 20px; }
+        #r6{ top: 520px; right: 20px; }
+        #r7{ top: 520px; right: 320px; }
+    </style>
+</head>
+<body>
+    <a id="l1" href="http://localhots.xxx/">localhots.xxx</a>
+    <a id="l2" href="http://erem.in/">erem.in</a>
+    <a id="l3" href="https://www.facebook.com/">facebook.com</a>
+    <a id="l4">bad link</a>
+    <a id="l5" href="../../..">wtf</a>
+    <a id="l6" href="http://www.aviasales.ru/">aviasales.ru</a>
+
+    <a id="r1" href="https://twitter.com/">twitter.com</a>
+    <a id="r2" href="https://github.com/">github.com</a>
+    <a id="r3" href="https://www.travelpayouts.com/">travelpayouts.com</a>
+    <a id="r4" href="http://hotellook.ru/">hotellook.ru</a>
+    <a id="r5" href="http://www.jetradar.com/">jetradar.com</a>
+    <a id="r6" href="http://www.youtube.com/">youtube.com</a>
+    <a id="r7" href="http://habrahabr.ru/">habrahabr.ru</a>
+</body>
+</html>
diff --git a/resources/themes_demo.html b/resources/themes_demo.html
new file mode 100644
index 0000000..1148f82
--- /dev/null
+++ b/resources/themes_demo.html
@@ -0,0 +1,47 @@
+<!doctype html>
+<html>
+<head>
+    <title>Themes Demo</title>
+    <meta charset="utf8">
+    <style type="text/css">
+        .whats-there-img {
+            background-image: url(aviasales.jpg);
+        }
+        #tt1 { left: 20px; top: 20px; }
+        #tt2 { left: 20px; top: 190px; }
+        #tt3 { left: 20px; top: 360px; }
+        #tt4 { left: 450px; top: 20px; }
+        #tt5 { left: 450px; top: 190px; }
+    </style>
+</head>
+<body>
+    <div class="whats-there-tooltip" id="tt1">
+        <div class="whats-there-img"></div>
+        <div class="whats-there-title">Дешевые авиабилеты онлайн. Поиск билетов на самолет по 728 авиакомпаниям, включая low-cost - Aviasales</div>
+        <div class="whats-there-description">Aviasales.ru помогает найти авиабилеты дешево. Мы ищем билеты на самолет по ведущим российским и зарубежным авиакассам. С помощью нашего поиска вы найдете лучшие цены на авиабилеты. Мы не продаем авиабилеты, мы помогаем вам найти лучшее предложение.</div>
+        <div class="whats-there-site">Aviasales.ru (aviasales.ru)</div>
+    </div>
+
+    <div class="whats-there-tooltip" id="tt2">
+        <div class="whats-there-title">Дешевые авиабилеты онлайн. Поиск билетов на самолет по 728 авиакомпаниям, включая low-cost - Aviasales</div>
+        <div class="whats-there-description">Aviasales.ru помогает найти авиабилеты дешево. Мы ищем билеты на самолет по ведущим российским и зарубежным авиакассам. С помощью нашего поиска вы найдете лучшие цены на авиабилеты. Мы не продаем авиабилеты, мы помогаем вам найти лучшее предложение.</div>
+        <div class="whats-there-site">Aviasales.ru (aviasales.ru)</div>
+    </div>
+
+    <div class="whats-there-tooltip" id="tt3">
+        <div class="whats-there-img"></div>
+        <div class="whats-there-title">Дешевые авиабилеты онлайн. Поиск билетов на самолет по 728 авиакомпаниям, включая low-cost - Aviasales</div>
+        <div class="whats-there-site">Aviasales.ru (aviasales.ru)</div>
+    </div>
+
+    <div class="whats-there-tooltip" id="tt4">
+        <div class="whats-there-title">Дешевые авиабилеты онлайн. Поиск билетов на самолет по 728 авиакомпаниям, включая low-cost - Aviasales</div>
+        <div class="whats-there-site">Aviasales.ru (aviasales.ru)</div>
+    </div>
+
+    <div class="whats-there-tooltip" id="tt5">
+        <div class="whats-there-description">Aviasales.ru помогает найти авиабилеты дешево. Мы ищем билеты на самолет по ведущим российским и зарубежным авиакассам. С помощью нашего поиска вы найдете лучшие цены на авиабилеты. Мы не продаем авиабилеты, мы помогаем вам найти лучшее предложение.</div>
+        <div class="whats-there-site">Aviasales.ru (aviasales.ru)</div>
+    </div>
+</body>
+</html>
diff --git a/tooltip.css b/tooltip.css
new file mode 100644
index 0000000..7845be5
--- /dev/null
+++ b/tooltip.css
@@ -0,0 +1,63 @@
+.whats-there-tooltip
+{
+    font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif;
+    font-size: 14px;
+    line-height: 18px;
+
+    position: absolute;
+    z-index: 999999;
+
+    overflow: hidden;
+
+    width: 400px;
+
+    border-width: 1px;
+    border-style: solid;
+    border-color: #ccc;
+    border-radius: 5px;
+    background-color: #fff;
+    box-shadow: 0 1px 3px 1px rgba(0, 0, 0, .2);
+}
+.whats-there-img
+{
+    float: left;
+
+    width: 150px;
+    height: 150px;
+    margin-right: 10px;
+
+    background-repeat: no-repeat;
+    background-position: center center;
+    background-size: auto 100%;
+}
+.whats-there-title
+{
+    font-weight: 600;
+
+    overflow: hidden;
+
+    height: 18px;
+    margin: 5px 10px;
+
+    white-space: nowrap;
+    text-overflow: ellipsis;
+}
+.whats-there-description
+{
+    font-size: 13px;
+    line-height: 16px;
+
+    overflow: hidden;
+
+    height: 94px;
+    margin: 5px 10px;
+
+    color: #666;
+}
+.whats-there-site
+{
+    overflow: hidden;
+
+    height: 18px;
+    margin: 5px 10px;
+}