1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
|
// Copyright 2013 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
/**
* @fileoverview Rendering for iframed most visited thumbnails.
*/
window.addEventListener('DOMContentLoaded', function() {
'use strict';
fillMostVisited(document.location, function(params, data) {
function logEvent(eventName) {
chrome.embeddedSearch.newTabPage.logEvent(eventName);
}
function logImpression(tileIndex, provider) {
chrome.embeddedSearch.newTabPage.logImpression(tileIndex, provider);
}
function showDomainElement() {
logEvent(NTP_LOGGING_EVENT_TYPE.NTP_THUMBNAIL_ERROR);
var link = createMostVisitedLink(
params, data.url, data.title, undefined, data.ping, data.provider);
var domain = document.createElement('div');
domain.textContent = data.domain;
link.appendChild(domain);
document.body.appendChild(link);
}
// Called on intentionally empty tiles for which the visuals are handled
// externally by the page itself.
function showEmptyTile() {
var link = createMostVisitedLink(
params, data.url, data.title, undefined, data.ping, data.provider);
document.body.appendChild(link);
logEvent(NTP_LOGGING_EVENT_TYPE.NTP_EXTERNAL_TILE);
}
function createAndAppendThumbnail(isVisible) {
var image = new Image();
image.onload = function() {
var shadow = document.createElement('span');
shadow.classList.add('shadow');
var link = createMostVisitedLink(
params, data.url, data.title, undefined, data.ping, data.provider);
link.appendChild(shadow);
link.appendChild(image);
// We add 'position: absolute' in anticipation that there could be more
// than one thumbnail. This will superpose the elements.
link.style.position = 'absolute';
document.body.appendChild(link);
};
if (!isVisible) {
image.style.visibility = 'hidden';
}
return image;
}
// Log an impression if we know the position of the tile.
if (isFinite(params.pos) && data.provider) {
logImpression(parseInt(params.pos, 10), data.provider);
}
if (data.thumbnailUrl) {
var image = createAndAppendThumbnail(true);
// If a backup thumbnail URL was provided, preload it in case the first
// thumbnail errors. The backup thumbnail is always preloaded so that the
// server can't gain knowledge on the local thumbnail DB by specifying a
// second URL that is only sometimes fetched.
if (data.thumbnailUrl2) {
var image2 = createAndAppendThumbnail(false);
var imageFailed = false;
var image2Failed = false;
image2.onerror = function() {
image2Failed = true;
image2.style.visibility = 'hidden';
if (imageFailed) {
showDomainElement();
}
};
image2.src = data.thumbnailUrl2;
// The first thumbnail's onerror function will swap the visibility of
// the two thumbnails.
image.onerror = function() {
logEvent(NTP_LOGGING_EVENT_TYPE.NTP_FALLBACK_THUMBNAIL_USED);
imageFailed = true;
image.style.visibility = 'hidden';
if (image2Failed) {
showDomainElement();
} else {
image2.style.visibility = 'visible';
}
};
logEvent(NTP_LOGGING_EVENT_TYPE.NTP_FALLBACK_THUMBNAIL_REQUESTED);
} else {
image.onerror = showDomainElement;
}
image.src = data.thumbnailUrl;
logEvent(NTP_LOGGING_EVENT_TYPE.NTP_THUMBNAIL_ATTEMPT);
} else if (data.domain) {
showDomainElement();
} else {
showEmptyTile();
}
});
});
|
