electron/atom/renderer/lib/web-view.coffee
2014-10-25 16:04:16 +08:00

544 lines
19 KiB
CoffeeScript

v8Util = process.atomBinding 'v8_util'
guestViewInternal = require './guest-view-internal'
webFrame = require 'web-frame'
remote = require 'remote'
# ID generator.
nextId = 0
getNextId = -> ++nextId
# FIXME
# Discarded after Chrome 39
PLUGIN_METHOD_ATTACH = '-internal-attach'
# Attributes.
WEB_VIEW_ATTRIBUTE_ALLOWTRANSPARENCY = 'allowtransparency'
WEB_VIEW_ATTRIBUTE_AUTOSIZE = 'autosize'
WEB_VIEW_ATTRIBUTE_MAXHEIGHT = 'maxheight'
WEB_VIEW_ATTRIBUTE_MAXWIDTH = 'maxwidth'
WEB_VIEW_ATTRIBUTE_MINHEIGHT = 'minheight'
WEB_VIEW_ATTRIBUTE_MINWIDTH = 'minwidth'
WEB_VIEW_ATTRIBUTE_PARTITION = 'partition'
AUTO_SIZE_ATTRIBUTES = [
WEB_VIEW_ATTRIBUTE_AUTOSIZE,
WEB_VIEW_ATTRIBUTE_MAXHEIGHT,
WEB_VIEW_ATTRIBUTE_MAXWIDTH,
WEB_VIEW_ATTRIBUTE_MINHEIGHT,
WEB_VIEW_ATTRIBUTE_MINWIDTH,
]
# Error messages.
ERROR_MSG_ALREADY_NAVIGATED =
'The object has already navigated, so its partition cannot be changed.'
ERROR_MSG_CANNOT_INJECT_SCRIPT = '<webview>: ' +
'Script cannot be injected into content until the page has loaded.'
ERROR_MSG_CONTENTWINDOW_NOT_AVAILABLE = '<webview>: ' +
'contentWindow is not available at this time. It will become available ' +
'when the page has finished loading.'
ERROR_MSG_INVALID_PARTITION_ATTRIBUTE = 'Invalid partition attribute.'
# Represents the state of the storage partition.
class Partition
constructor: ->
@validPartitionId = true
@persistStorage = false
@storagePartitionId = ''
toAttribute: ->
return '' unless @validPartitionId
(if @persistStorage then 'persist:' else '') + @storagePartitionId
fromAttribute: (value, hasNavigated) ->
result = {}
if hasNavigated
result.error = ERROR_MSG_ALREADY_NAVIGATED
return result
value ?= ''
LEN = 'persist:'.length
if value.substr(0, LEN) == 'persist:'
value = value.substr LEN
unless value
@validPartitionId = false
result.error = ERROR_MSG_INVALID_PARTITION_ATTRIBUTE
return result
@persistStorage = true
else
@persistStorage = false
@storagePartitionId = value
result
# Represents the internal state of the WebView node.
class WebView
constructor: (@webviewNode) ->
v8Util.setHiddenValue @webviewNode, 'internal', this
@attached = false
@pendingGuestCreation = false
@elementAttached = false
@beforeFirstNavigation = true
@contentWindow = null
@validPartitionId = true
# Used to save some state upon deferred attachment.
# If <object> bindings is not available, we defer attachment.
# This state contains whether or not the attachment request was for
# newwindow.
@deferredAttachState = null
# on* Event handlers.
@on = {}
@browserPluginNode = @createBrowserPluginNode()
shadowRoot = @webviewNode.createShadowRoot()
@partition = new Partition()
@setupWebViewSrcAttributeMutationObserver()
@setupFocusPropagation()
@setupWebviewNodeProperties()
@viewInstanceId = getNextId()
guestViewInternal.registerEvents this, @viewInstanceId
shadowRoot.appendChild @browserPluginNode
createBrowserPluginNode: ->
# We create BrowserPlugin as a custom element in order to observe changes
# to attributes synchronously.
browserPluginNode = new WebView.BrowserPlugin()
v8Util.setHiddenValue browserPluginNode, 'internal', this
browserPluginNode
getGuestInstanceId: ->
@guestInstanceId
# Resets some state upon reattaching <webview> element to the DOM.
reset: ->
# If guestInstanceId is defined then the <webview> has navigated and has
# already picked up a partition ID. Thus, we need to reset the initialization
# state. However, it may be the case that beforeFirstNavigation is false BUT
# guestInstanceId has yet to be initialized. This means that we have not
# heard back from createGuest yet. We will not reset the flag in this case so
# that we don't end up allocating a second guest.
if @guestInstanceId
guestViewInternal.destroyGuest @guestInstanceId
@guestInstanceId = undefined
@beforeFirstNavigation = true
@validPartitionId = true
@partition.validPartitionId = true
@contentWindow = null
@internalInstanceId = 0
# Sets the <webview>.request property.
setRequestPropertyOnWebViewNode: (request) ->
Object.defineProperty @webviewNode, 'request', value: request, enumerable: true
setupFocusPropagation: ->
unless @webviewNode.hasAttribute 'tabIndex'
# <webview> needs a tabIndex in order to be focusable.
# TODO(fsamuel): It would be nice to avoid exposing a tabIndex attribute
# to allow <webview> to be focusable.
# See http://crbug.com/231664.
@webviewNode.setAttribute 'tabIndex', -1
@webviewNode.addEventListener 'focus', (e) =>
# Focus the BrowserPlugin when the <webview> takes focus.
@browserPluginNode.focus()
@webviewNode.addEventListener 'blur', (e) =>
# Blur the BrowserPlugin when the <webview> loses focus.
@browserPluginNode.blur()
# Validation helper function for executeScript() and insertCSS().
validateExecuteCodeCall: ->
throw new Error(ERROR_MSG_CANNOT_INJECT_SCRIPT) unless @guestInstanceId
setupAutoSizeProperties: ->
for attributeName in AUTO_SIZE_ATTRIBUTES
this[attributeName] = @webviewNode.getAttribute attributeName
Object.defineProperty @webviewNode, attributeName,
get: => this[attributeName]
set: (value) => @webviewNode.setAttribute attributeName, value
enumerable: true
setupWebviewNodeProperties: ->
@setupAutoSizeProperties()
Object.defineProperty @webviewNode, WEB_VIEW_ATTRIBUTE_ALLOWTRANSPARENCY,
get: => @allowtransparency
set: (value) =>
@webviewNode.setAttribute WEB_VIEW_ATTRIBUTE_ALLOWTRANSPARENCY, value
enumerable: true
# We cannot use {writable: true} property descriptor because we want a
# dynamic getter value.
Object.defineProperty @webviewNode, 'contentWindow',
get: =>
return @contentWindow if @contentWindow?
window.console.error ERROR_MSG_CONTENTWINDOW_NOT_AVAILABLE
# No setter.
enumerable: true
Object.defineProperty @webviewNode, 'partition',
get: => @partition.toAttribute()
set: (value) =>
result = @partition.fromAttribute value, @hasNavigated()
throw result.error if result.error?
@webviewNode.setAttribute 'partition', value
enumerable: true
@src = @webviewNode.getAttribute 'src'
Object.defineProperty @webviewNode, 'src',
get: => @src
set: (value) => @webviewNode.setAttribute 'src', value
# No setter.
enumerable: true
# The purpose of this mutation observer is to catch assignment to the src
# attribute without any changes to its value. This is useful in the case
# where the webview guest has crashed and navigating to the same address
# spawns off a new process.
setupWebViewSrcAttributeMutationObserver: ->
@srcAndPartitionObserver = new MutationObserver (mutations) =>
for mutation in mutations
oldValue = mutation.oldValue
newValue = @webviewNode.getAttribute mutation.attributeName
return if oldValue isnt newValue
@handleWebviewAttributeMutation mutation.attributeName, oldValue, newValue
params =
attributes: true,
attributeOldValue: true,
attributeFilter: ['src', 'partition']
@srcAndPartitionObserver.observe @webviewNode, params
# This observer monitors mutations to attributes of the <webview> and
# updates the BrowserPlugin properties accordingly. In turn, updating
# a BrowserPlugin property will update the corresponding BrowserPlugin
# attribute, if necessary. See BrowserPlugin::UpdateDOMAttribute for more
# details.
handleWebviewAttributeMutation: (name, oldValue, newValue) ->
if name in AUTO_SIZE_ATTRIBUTES
this[name] = newValue
return unless @guestInstanceId
# Convert autosize attribute to boolean.
autosize = @webviewNode.hasAttribute WEB_VIEW_ATTRIBUTE_AUTOSIZE
guestViewInternal.setAutoSize @guestInstanceId,
enableAutoSize: autosize,
min:
width: parseInt @minwidth || 0
height: parseInt @minheight || 0
max:
width: parseInt @maxwidth || 0
height: parseInt @maxheight || 0
else if name is WEB_VIEW_ATTRIBUTE_ALLOWTRANSPARENCY
# We treat null attribute (attribute removed) and the empty string as
# one case.
oldValue ?= ''
newValue ?= ''
return if oldValue is newValue
@allowtransparency = newValue != ''
return unless @guestInstanceId
guestViewInternal.setAllowTransparency @guestInstanceId, @allowtransparency
else if name is 'src'
# We treat null attribute (attribute removed) and the empty string as
# one case.
oldValue ?= ''
newValue ?= ''
# Once we have navigated, we don't allow clearing the src attribute.
# Once <webview> enters a navigated state, it cannot be return back to a
# placeholder state.
if newValue == '' and oldValue != ''
# src attribute changes normally initiate a navigation. We suppress
# the next src attribute handler call to avoid reloading the page
# on every guest-initiated navigation.
@ignoreNextSrcAttributeChange = true
@webviewNode.setAttribute 'src', oldValue
@src = newValue
if @ignoreNextSrcAttributeChange
# Don't allow the src mutation observer to see this change.
@srcAndPartitionObserver.takeRecords()
@ignoreNextSrcAttributeChange = false
return
result = {}
@parseSrcAttribute result
throw result.error if result.error?
else if name is 'partition'
# Note that throwing error here won't synchronously propagate.
@partition.fromAttribute newValue, @hasNavigated()
handleBrowserPluginAttributeMutation: (name, oldValue, newValue) ->
# FIXME
# internalbindings => internalInstanceid after Chrome 39
if name is 'internalbindings' and !oldValue and !!newValue
@browserPluginNode.removeAttribute 'internalbindings'
# FIXME
# @internalInstanceId = parseInt newValue
if !!@guestInstanceId and @guestInstanceId != 0
isNewWindow = if @deferredAttachState then @deferredAttachState.isNewWindow else false
params = @buildAttachParams isNewWindow
# FIXME
# guestViewInternalNatives.AttachGuest
# @internalInstanceId,
# @guestInstanceId,
# params,
# (w) => @contentWindow = w
@browserPluginNode[PLUGIN_METHOD_ATTACH] @guestInstanceId, params
onSizeChanged: (webViewEvent) ->
newWidth = webViewEvent.newWidth
newHeight = webViewEvent.newHeight
node = @webviewNode
width = node.offsetWidth
height = node.offsetHeight
# Check the current bounds to make sure we do not resize <webview>
# outside of current constraints.
if node.hasAttribute(WEB_VIEW_ATTRIBUTE_MAXWIDTH) and
node[WEB_VIEW_ATTRIBUTE_MAXWIDTH]
maxWidth = node[WEB_VIEW_ATTRIBUTE_MAXWIDTH]
else
maxWidth = width
if node.hasAttribute(WEB_VIEW_ATTRIBUTE_MINWIDTH) and
node[WEB_VIEW_ATTRIBUTE_MINWIDTH]
minWidth = node[WEB_VIEW_ATTRIBUTE_MINWIDTH]
else
minWidth = width
minWidth = maxWidth if minWidth > maxWidth
if node.hasAttribute(WEB_VIEW_ATTRIBUTE_MAXHEIGHT) and
node[WEB_VIEW_ATTRIBUTE_MAXHEIGHT]
maxHeight = node[WEB_VIEW_ATTRIBUTE_MAXHEIGHT]
else
maxHeight = height
if node.hasAttribute(WEB_VIEW_ATTRIBUTE_MINHEIGHT) and
node[WEB_VIEW_ATTRIBUTE_MINHEIGHT]
minHeight = node[WEB_VIEW_ATTRIBUTE_MINHEIGHT]
else
minHeight = height
minHeight = maxHeight if minHeight > maxHeight
if not @webviewNode.hasAttribute WEB_VIEW_ATTRIBUTE_AUTOSIZE or
(newWidth >= minWidth and
newWidth <= maxWidth and
newHeight >= minHeight and
newHeight <= maxHeight)
node.style.width = newWidth + 'px'
node.style.height = newHeight + 'px'
# Only fire the DOM event if the size of the <webview> has actually
# changed.
@dispatchEvent webViewEvent
# Returns if <object> is in the render tree.
isPluginInRenderTree: ->
# FIXME
# !!@internalInstanceId && @internalInstanceId != 0
'function' == typeof this.browserPluginNode[PLUGIN_METHOD_ATTACH]
hasNavigated: ->
not @beforeFirstNavigation
parseSrcAttribute: (result) ->
unless @partition.validPartitionId
result.error = ERROR_MSG_INVALID_PARTITION_ATTRIBUTE
return
@src = @webviewNode.getAttribute 'src'
return unless @src
unless @guestInstanceId?
if @beforeFirstNavigation
@beforeFirstNavigation = false
@createGuest()
return
# Navigate to |this.src|.
remote.getGuestWebContents(@guestInstanceId).loadUrl @src
parseAttributes: ->
return unless @elementAttached
hasNavigated = @hasNavigated()
attributeValue = @webviewNode.getAttribute 'partition'
result = @partition.fromAttribute attributeValue, hasNavigated
@parseSrcAttribute result
createGuest: ->
return if @pendingGuestCreation
storagePartitionId =
@webviewNode.getAttribute(WEB_VIEW_ATTRIBUTE_PARTITION) or
@webviewNode[WEB_VIEW_ATTRIBUTE_PARTITION]
params = storagePartitionId: storagePartitionId
guestViewInternal.createGuest 'webview', params, (guestInstanceId) =>
@pendingGuestCreation = false
unless @elementAttached
guestViewInternal.destroyGuest guestInstanceId
return
@attachWindow guestInstanceId, false
@pendingGuestCreation = true
dispatchEvent: (webViewEvent) ->
@webviewNode.dispatchEvent webViewEvent
# Adds an 'on<event>' property on the webview, which can be used to set/unset
# an event handler.
setupEventProperty: (eventName) ->
propertyName = 'on' + eventName.toLowerCase()
Object.defineProperty @webviewNode, propertyName,
get: => @on[propertyName]
set: (value) =>
if @on[propertyName]
@webviewNode.removeEventListener eventName, @on[propertyName]
@on[propertyName] = value
if value
@webviewNode.addEventListener eventName, value
enumerable: true
# Updates state upon loadcommit.
onLoadCommit: (@baseUrlForDataUrl, @currentEntryIndex, @entryCount, @processId, url, isTopLevel) ->
oldValue = @webviewNode.getAttribute 'src'
newValue = url
if isTopLevel and (oldValue != newValue)
# Touching the src attribute triggers a navigation. To avoid
# triggering a page reload on every guest-initiated navigation,
# we use the flag ignoreNextSrcAttributeChange here.
this.ignoreNextSrcAttributeChange = true
this.webviewNode.setAttribute 'src', newValue
onAttach: (storagePartitionId) ->
@webviewNode.setAttribute 'partition', storagePartitionId
@partition.fromAttribute storagePartitionId, this.hasNavigated()
buildAttachParams: (isNewWindow) ->
allowtransparency: @allowtransparency || false
autosize: @webviewNode.hasAttribute WEB_VIEW_ATTRIBUTE_AUTOSIZE
instanceId: @viewInstanceId
maxheight: parseInt @maxheight || 0
maxwidth: parseInt @maxwidth || 0
minheight: parseInt @minheight || 0
minwidth: parseInt @minwidth || 0
# We don't need to navigate new window from here.
src: if isNewWindow then undefined else @src
# If we have a partition from the opener, that will also be already
# set via this.onAttach().
storagePartitionId: @partition.toAttribute()
userAgentOverride: @userAgentOverride
attachWindow: (guestInstanceId, isNewWindow) ->
@guestInstanceId = guestInstanceId
params = @buildAttachParams isNewWindow
unless @isPluginInRenderTree()
@deferredAttachState = isNewWindow: isNewWindow
return true
@deferredAttachState = null
# FIXME
# guestViewInternalNatives.AttachGuest @internalInstanceId, @guestInstanceId, params, (w) => @contentWindow = w
@browserPluginNode[PLUGIN_METHOD_ATTACH] @guestInstanceId, params
# Registers browser plugin <object> custom element.
registerBrowserPluginElement = ->
proto = Object.create HTMLObjectElement.prototype
proto.createdCallback = ->
@setAttribute 'type', 'application/browser-plugin'
@setAttribute 'id', 'browser-plugin-' + getNextId()
# The <object> node fills in the <webview> container.
@style.width = '100%'
@style.height = '100%'
proto.attributeChangedCallback = (name, oldValue, newValue) ->
internal = v8Util.getHiddenValue this, 'internal'
return unless internal
internal.handleBrowserPluginAttributeMutation name, oldValue, newValue
proto.attachedCallback = ->
# Load the plugin immediately.
unused = this.nonExistentAttribute
WebView.BrowserPlugin = webFrame.registerEmbedderCustomElement 'browserplugin',
extends: 'object', prototype: proto
delete proto.createdCallback
delete proto.attachedCallback
delete proto.detachedCallback
delete proto.attributeChangedCallback
# Registers <webview> custom element.
registerWebViewElement = ->
proto = Object.create HTMLObjectElement.prototype
proto.createdCallback = ->
new WebView(this)
proto.attributeChangedCallback = (name, oldValue, newValue) ->
internal = v8Util.getHiddenValue this, 'internal'
return unless internal
internal.handleWebviewAttributeMutation name, oldValue, newValue
proto.detachedCallback = ->
internal = v8Util.getHiddenValue this, 'internal'
return unless internal
internal.elementAttached = false
internal.reset()
proto.attachedCallback = ->
internal = v8Util.getHiddenValue this, 'internal'
return unless internal
unless internal.elementAttached
internal.elementAttached = true
internal.parseAttributes()
# Public-facing API methods.
methods = [
"getUrl"
"getTitle"
"isLoading"
"isWaitingForResponse"
"stop"
"reload"
"reloadIngoringCache"
"canGoBack"
"canGoForward"
"canGoToOffset"
"goBack"
"goForward"
"goToIndex"
"goToOffset"
"isCrashed"
"setUserAgent"
"executeJavaScript"
"insertCSS"
"send"
]
# Forward proto.foo* method calls to WebView.foo*.
createHandler = (m) ->
(args...) ->
internal = v8Util.getHiddenValue this, 'internal'
remote.getGuestWebContents(internal.guestInstanceId)[m] args...
proto[m] = createHandler m for m in methods
window.WebView = webFrame.registerEmbedderCustomElement 'webview',
prototype: proto
# Delete the callbacks so developers cannot call them and produce unexpected
# behavior.
delete proto.createdCallback
delete proto.attachedCallback
delete proto.detachedCallback
delete proto.attributeChangedCallback
useCapture = true
listener = (event) ->
return if document.readyState == 'loading'
registerBrowserPluginElement()
registerWebViewElement()
window.removeEventListener event.type, listener, useCapture
window.addEventListener 'readystatechange', listener, true