1 files changed, 217 insertions, 0 deletions
diff --git a/toolkit/components/extensions/ext-browser-content.js b/toolkit/components/extensions/ext-browser-content.js
new file mode 100644
index 000000000..e14ca50d6
--- /dev/null
+++ b/toolkit/components/extensions/ext-browser-content.js
@@ -0,0 +1,217 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+const {classes: Cc, interfaces: Ci, utils: Cu, results: Cr} = Components;
+
+Cu.import("resource://gre/modules/ExtensionUtils.jsm");
+Cu.import("resource://gre/modules/XPCOMUtils.jsm");
+
+XPCOMUtils.defineLazyModuleGetter(this, "clearTimeout",
+                                  "resource://gre/modules/Timer.jsm");
+XPCOMUtils.defineLazyModuleGetter(this, "NetUtil",
+                                  "resource://gre/modules/NetUtil.jsm");
+XPCOMUtils.defineLazyModuleGetter(this, "require",
+                                  "resource://devtools/shared/Loader.jsm");
+XPCOMUtils.defineLazyModuleGetter(this, "setTimeout",
+                                  "resource://gre/modules/Timer.jsm");
+
+XPCOMUtils.defineLazyGetter(this, "colorUtils", () => {
+  return require("devtools/shared/css/color").colorUtils;
+});
+
+const {
+  stylesheetMap,
+} = ExtensionUtils;
+
+/* globals addMessageListener, content, docShell, sendAsyncMessage */
+
+// Minimum time between two resizes.
+const RESIZE_TIMEOUT = 100;
+
+const BrowserListener = {
+  init({allowScriptsToClose, fixedWidth, maxHeight, maxWidth, stylesheets}) {
+    this.fixedWidth = fixedWidth;
+    this.stylesheets = stylesheets || [];
+
+    this.maxWidth = maxWidth;
+    this.maxHeight = maxHeight;
+
+    this.oldBackground = null;
+
+    if (allowScriptsToClose) {
+      content.QueryInterface(Ci.nsIInterfaceRequestor)
+             .getInterface(Ci.nsIDOMWindowUtils)
+             .allowScriptsToClose();
+    }
+
+    addEventListener("DOMWindowCreated", this, true);
+    addEventListener("load", this, true);
+    addEventListener("DOMContentLoaded", this, true);
+    addEventListener("DOMWindowClose", this, true);
+    addEventListener("MozScrolledAreaChanged", this, true);
+  },
+
+  destroy() {
+    removeEventListener("DOMWindowCreated", this, true);
+    removeEventListener("load", this, true);
+    removeEventListener("DOMContentLoaded", this, true);
+    removeEventListener("DOMWindowClose", this, true);
+    removeEventListener("MozScrolledAreaChanged", this, true);
+  },
+
+  receiveMessage({name, data}) {
+    if (name === "Extension:InitBrowser") {
+      this.init(data);
+    }
+  },
+
+  handleEvent(event) {
+    switch (event.type) {
+      case "DOMWindowCreated":
+        if (event.target === content.document) {
+          let winUtils = content.QueryInterface(Ci.nsIInterfaceRequestor)
+                                .getInterface(Ci.nsIDOMWindowUtils);
+
+          for (let url of this.stylesheets) {
+            winUtils.addSheet(stylesheetMap.get(url), winUtils.AGENT_SHEET);
+          }
+        }
+        break;
+
+      case "DOMWindowClose":
+        if (event.target === content) {
+          event.preventDefault();
+
+          sendAsyncMessage("Extension:DOMWindowClose");
+        }
+        break;
+
+      case "DOMContentLoaded":
+        if (event.target === content.document) {
+          sendAsyncMessage("Extension:BrowserContentLoaded", {url: content.location.href});
+          this.handleDOMChange(true);
+        }
+        break;
+
+      case "load":
+        if (event.target.contentWindow === content) {
+          // For about:addons inline <browsers>, we currently receive a load
+          // event on the <browser> element, but no load or DOMContentLoaded
+          // events from the content window.
+          sendAsyncMessage("Extension:BrowserContentLoaded", {url: content.location.href});
+        } else if (event.target !== content.document) {
+          break;
+        }
+
+        // We use a capturing listener, so we get this event earlier than any
+        // load listeners in the content page. Resizing after a timeout ensures
+        // that we calculate the size after the entire event cycle has completed
+        // (unless someone spins the event loop, anyway), and hopefully after
+        // the content has made any modifications.
+        Promise.resolve().then(() => {
+          this.handleDOMChange(true);
+        });
+
+        // Mutation observer to make sure the panel shrinks when the content does.
+        new content.MutationObserver(this.handleDOMChange.bind(this)).observe(
+          content.document.documentElement, {
+            attributes: true,
+            characterData: true,
+            childList: true,
+            subtree: true,
+          });
+        break;
+
+      case "MozScrolledAreaChanged":
+        this.handleDOMChange();
+        break;
+    }
+  },
+
+  // Resizes the browser to match the preferred size of the content (debounced).
+  handleDOMChange(ignoreThrottling = false) {
+    if (ignoreThrottling && this.resizeTimeout) {
+      clearTimeout(this.resizeTimeout);
+      this.resizeTimeout = null;
+    }
+
+    if (this.resizeTimeout == null) {
+      this.resizeTimeout = setTimeout(() => {
+        try {
+          if (content) {
+            this._handleDOMChange("delayed");
+          }
+        } finally {
+          this.resizeTimeout = null;
+        }
+      }, RESIZE_TIMEOUT);
+
+      this._handleDOMChange();
+    }
+  },
+
+  _handleDOMChange(detail) {
+    let doc = content.document;
+
+    let body = doc.body;
+    if (!body || doc.compatMode === "BackCompat") {
+      // In quirks mode, the root element is used as the scroll frame, and the
+      // body lies about its scroll geometry, and returns the values for the
+      // root instead.
+      body = doc.documentElement;
+    }
+
+
+    let result;
+    if (this.fixedWidth) {
+      // If we're in a fixed-width area (namely a slide-in subview of the main
+      // menu panel), we need to calculate the view height based on the
+      // preferred height of the content document's root scrollable element at the
+      // current width, rather than the complete preferred dimensions of the
+      // content window.
+
+      // Compensate for any offsets (margin, padding, ...) between the scroll
+      // area of the body and the outer height of the document.
+      let getHeight = elem => elem.getBoundingClientRect(elem).height;
+      let bodyPadding = getHeight(doc.documentElement) - getHeight(body);
+
+      let height = Math.ceil(body.scrollHeight + bodyPadding);
+
+      result = {height, detail};
+    } else {
+      let background = doc.defaultView.getComputedStyle(body).backgroundColor;
+      let bgColor = colorUtils.colorToRGBA(background);
+      if (bgColor.a !== 1) {
+        // Ignore non-opaque backgrounds.
+        background = null;
+      }
+
+      if (background !== this.oldBackground) {
+        sendAsyncMessage("Extension:BrowserBackgroundChanged", {background});
+      }
+      this.oldBackground = background;
+
+
+      // Adjust the size of the browser based on its content's preferred size.
+      let {contentViewer} = docShell;
+      let ratio = content.devicePixelRatio;
+
+      let w = {}, h = {};
+      contentViewer.getContentSizeConstrained(this.maxWidth * ratio,
+                                              this.maxHeight * ratio,
+                                              w, h);
+
+      let width = Math.ceil(w.value / ratio);
+      let height = Math.ceil(h.value / ratio);
+
+      result = {width, height, detail};
+    }
+
+    sendAsyncMessage("Extension:BrowserResized", result);
+  },
+};
+
+addMessageListener("Extension:InitBrowser", BrowserListener);