Improve <webview> autosize:

chrome/renderer/resources/extensions/web_view.js

 // Copyright (c) 2012 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.
 
 // Shim that simulates a <webview> tag via Mutation Observers.
 //
 // The actual tag is implemented via the browser plugin. The internals of this
 // are hidden via Shadow DOM.
 
 'use strict';
 
 var eventBindings = require('event_bindings');
 var DocumentNatives = requireNative('document_natives');
 var messagingNatives = requireNative('messaging_natives');
 var WebRequestEvent = require('webRequestInternal').WebRequestEvent;
 var webRequestSchema =
     requireNative('schema_registry').GetSchema('webRequest');
 var webView = require('binding').Binding.create('webview').generate();
 
 // This secret enables hiding <webview> private members from the outside scope.
 // Outside of this file, |secret| is inaccessible. The only way to access the
 // <webview> element's internal members is via the |secret|. Since it's only
 // accessible by code here (and in web_view_experimental), only <webview>'s
 // API can access it and not external developers.
 var secret = {};
 
+var WEB_VIEW_ATTRIBUTE_MAXHEIGHT = 'maxheight';
+var WEB_VIEW_ATTRIBUTE_MAXWIDTH = 'maxwidth';
+var WEB_VIEW_ATTRIBUTE_MINHEIGHT = 'minheight';
+var WEB_VIEW_ATTRIBUTE_MINWIDTH = 'minwidth';
+
 /** @type {Array.<string>} */
-var WEB_VIEW_ATTRIBUTES = ['name', 'src', 'partition', 'autosize', 'minheight',
-    'minwidth', 'maxheight', 'maxwidth'];
+var WEB_VIEW_ATTRIBUTES = [
+    'name',
+    'src',
+    'partition',
+    'autosize',
+    WEB_VIEW_ATTRIBUTE_MINHEIGHT,
+    WEB_VIEW_ATTRIBUTE_MINWIDTH,
+    WEB_VIEW_ATTRIBUTE_MAXHEIGHT,
+    WEB_VIEW_ATTRIBUTE_MAXWIDTH
+];
 
 var webViewInstanceIdCounter = 0;
 
 var createEvent = function(name) {
   var eventOpts = {supportsListeners: true, supportsFilters: true};
   return new eventBindings.Event(name, undefined, eventOpts);
 };
 
 var WEB_VIEW_EXT_EVENTS = {
   'close': {
@@ skipping 67 matching lines @@
       'requestMethod',
       'url',
       'userGesture'
     ]
   },
   'responsive': {
     evt: createEvent('webview.onResponsive'),
     fields: ['processId']
   },
   'sizechanged': {
+    customHandler: function(webview, event, webviewEvent) {
+      var node = webview.webviewNode_;

[Fady Samuel, 2013/08/28 19:14:38]

Could you please move all this code to a helper method in WebViewInternal? It
would be nice to keep WEB_VIEW_EXT_EVENTS as succinct as possible to allow us
and any future <webview> developers to understand what events are supported by
<webview> at a glance.

+
+      // Check the current bounds to make sure we do not resize <webview>
+      // outside of current constraints.
+      var minWidth = 0;
+      if (node.hasAttribute(WEB_VIEW_ATTRIBUTE_MINWIDTH) &&
+          node[WEB_VIEW_ATTRIBUTE_MINWIDTH]) {
+        minWidth = node[WEB_VIEW_ATTRIBUTE_MINWIDTH];
+      }
+      var maxWidth;
+      if (node.hasAttribute(WEB_VIEW_ATTRIBUTE_MAXWIDTH) &&
+          node[WEB_VIEW_ATTRIBUTE_MAXWIDTH]) {
+        maxWidth = node[WEB_VIEW_ATTRIBUTE_MAXWIDTH];
+      } else {
+        maxWidth = node.offsetWidth;
+      }
+      if (minWidth > maxWidth) {
+        minWidth = maxWidth;
+      }
+
+      var minHeight = 0;
+      if (node.hasAttribute(WEB_VIEW_ATTRIBUTE_MINHEIGHT) &&
+          node[WEB_VIEW_ATTRIBUTE_MINHEIGHT]) {
+        minHeight = node[WEB_VIEW_ATTRIBUTE_MINHEIGHT];
+      }
+      var maxHeight;
+      if (node.hasAttribute(WEB_VIEW_ATTRIBUTE_MAXHEIGHT) &&
+          node[WEB_VIEW_ATTRIBUTE_MAXHEIGHT]) {
+        maxHeight = node[WEB_VIEW_ATTRIBUTE_MAXHEIGHT];
+      } else {
+        maxHeight = node.offsetHeight;
+      }
+      if (minHeight > maxHeight) {
+        minHeight = maxHeight;
+      }
+
+      if (webviewEvent.newWidth >= minWidth &&
+          webviewEvent.newWidth <= maxWidth &&
+          webviewEvent.newHeight >= minHeight &&
+          webviewEvent.newHeight <= maxHeight) {
+        webview.webviewNode_.style.width = webviewEvent.newWidth + 'px';
+        webview.webviewNode_.style.height = webviewEvent.newHeight + 'px';
+      }
+      webview.webviewNode_.dispatchEvent(webviewEvent);
+    },
     evt: createEvent('webview.onSizeChanged'),
     fields: ['oldHeight', 'oldWidth', 'newHeight', 'newWidth']
   },
   'unresponsive': {
     evt: createEvent('webview.onUnresponsive'),
     fields: ['processId']
   }
 };
 
 // Implemented when the experimental API is available.
@@ skipping 677 matching lines @@
 
 /**
  * Implemented when the experimental API is available.
  * @private
  */
 WebViewInternal.prototype.maybeAttachWebRequestEventToWebview_ = function() {};
 
 exports.webView = webView;
 exports.WebViewInternal = WebViewInternal;
 exports.CreateEvent = createEvent;