Bug 753595 - Add a getScreenshot call to mozbrowser. r=jlebar

d2862405 · Dale Harvey · a3172ed2 · d2862405 · d2862405 · d2862405
Commit d2862405 authored 12 years ago by Dale Harvey
--- a/dom/base/BrowserElementChild.js
+++ b/dom/base/BrowserElementChild.js
@@ -75,6 +75,9 @@ BrowserElementChild.prototype = {
                     this._iconChangedHandler.bind(this),
                     /* useCapture = */ true,
                     /* wantsUntrusted = */ false);
+
+    addMessageListener("browser-element-api:get-screenshot",
+                       this._recvGetScreenshot.bind(this));
  },

  _titleChangedHandler: function(e) {
@@ -110,6 +113,22 @@ BrowserElementChild.prototype = {
    }
  },

+  _recvGetScreenshot: function(data) {
+    debug("Received getScreenshot message: (" + data.json.id + ")");
+    var canvas = content.document
+      .createElementNS("http://www.w3.org/1999/xhtml", "canvas");
+    var ctx = canvas.getContext("2d");
+    canvas.mozOpaque = true;
+    canvas.height = content.innerHeight;
+    canvas.width = content.innerWidth;
+    ctx.drawWindow(content, 0, 0, content.innerWidth,
+                   content.innerHeight, "rgb(255,255,255)");
+    sendAsyncMsg('got-screenshot', {
+      id: data.json.id,
+      screenshot: canvas.toDataURL("image/png")
+    });
+  },
+
  // The docShell keeps a weak reference to the progress listener, so we need
  // to keep a strong ref to it ourselves.
  _progressListener: {

--- a/dom/base/BrowserElementParent.js
+++ b/dom/base/BrowserElementParent.js
@@ -7,6 +7,8 @@
 let Cu = Components.utils;
 let Ci = Components.interfaces;
 let Cc = Components.classes;
+
+Cu.import("resource://gre/modules/Services.jsm");
 Cu.import("resource://gre/modules/XPCOMUtils.jsm");

 const NS_PREFBRANCH_PREFCHANGE_TOPIC_ID = "nsPref:changed";
@@ -52,6 +54,9 @@ BrowserElementParent.prototype = {

    this._initialized = true;

+    this._screenshotListeners = {};
+    this._screenshotReqCounter = 0;
+
    var os = Cc["@mozilla.org/observer-service;1"].getService(Ci.nsIObserverService);
    os.addObserver(this, 'remote-browser-frame-shown', /* ownsWeak = */ true);
    os.addObserver(this, 'in-process-browser-frame-shown', /* ownsWeak = */ true);
@@ -101,6 +106,11 @@ BrowserElementParent.prototype = {
    addMessageListener("titlechange", this._fireEventFromMsg);
    addMessageListener("iconchange", this._fireEventFromMsg);
    addMessageListener("get-mozapp-manifest-url", this._sendMozAppManifestURL);
+    mm.addMessageListener('browser-element-api:got-screenshot',
+                          this._recvGotScreenshot.bind(this));
+
+    XPCNativeWrapper.unwrap(frameElement).getScreenshot =
+      this._getScreenshot.bind(this, mm, frameElement);

    mm.loadFrameScript("chrome://global/content/BrowserElementChild.js",
                       /* allowDelayedLoad = */ true);
@@ -139,6 +149,21 @@ BrowserElementParent.prototype = {
    return frameElement.getAttribute('mozapp');
  },

+  _recvGotScreenshot: function(data) {
+    var req = this._screenshotListeners[data.json.id];
+    delete this._screenshotListeners[data.json.id];
+    Services.DOMRequest.fireSuccess(req, data.json.screenshot);
+  },
+
+  _getScreenshot: function(mm, frameElement) {
+    let id = 'req_' + this._screenshotReqCounter++;
+    let req = Services.DOMRequest
+      .createRequest(frameElement.ownerDocument.defaultView);
+    this._screenshotListeners[id] = req;
+    mm.sendAsyncMessage('browser-element-api:get-screenshot', {id: id});
+    return req;
+  },
+
  observe: function(subject, topic, data) {
    switch(topic) {
    case 'app-startup':

--- a/dom/tests/mochitest/browser-frame/Makefile.in
+++ b/dom/tests/mochitest/browser-frame/Makefile.in
@@ -55,6 +55,7 @@ _TEST_FILES = \
 		test_browserFrame6.html \
 		test_browserFrame7.html \
 		test_browserFrame8.html \
+		test_browserFrame9.html \
 		$(NULL)

 libs:: $(_TEST_FILES)

--- a/dom/tests/mochitest/browser-frame/test_browserFrame9.html
+++ b/dom/tests/mochitest/browser-frame/test_browserFrame9.html
+<!DOCTYPE HTML>
+<html>
+<!--
+https://bugzilla.mozilla.org/show_bug.cgi?id=753595
+-->
+<head>
+  <title>Test for Bug 753595</title>
+  <script type="application/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+  <script type="application/javascript" src="browserFrameHelpers.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css"/>
+</head>
+<body>
+<a target="_blank" href="https://bugzilla.mozilla.org/show_bug.cgi?id=753595">Mozilla Bug 753595</a>
+
+<!--
+   Test the getScreenshot property for mozbrowser
+-->
+
+<script type="application/javascript;version=1.7">
+
+"use strict";
+
+SimpleTest.waitForExplicitFinish();
+
+function runTest() {
+
+  browserFrameHelpers.setEnabledPref(true);
+  browserFrameHelpers.addToWhitelist();
+
+  var iframe1 = document.createElement('iframe');
+  iframe1.mozbrowser = true;
+  document.body.appendChild(iframe1);
+
+  var screenshots = [];
+  var numLoaded = 0;
+
+  function screenshotLoaded(e) {
+    screenshots.push(e.target.result);
+    if (screenshots.length === 1) {
+      iframe1.src = 'data:text/html,<html>' +
+        '<body style="background:blue">hello</body></html>';
+    }
+    else if (screenshots.length === 2) {
+      ok(screenshots[0] !== 'data:,', 'First Screenshot is not blank');
+      ok(screenshots[0] !== screenshots[1], 'Screenshots differ');
+      SimpleTest.finish();
+    }
+  }
+
+  function iframeLoadedHandler() {
+    numLoaded++;
+    // Ignore the first loaded event, that is fired on creation of
+    // the iframe
+    if (numLoaded === 2) {
+      iframe1.getScreenshot().onsuccess = screenshotLoaded;
+    } else if (numLoaded === 3) {
+      iframe1.getScreenshot().onsuccess = screenshotLoaded;
+    }
+  }
+
+  iframe1.addEventListener('mozbrowserloadend', iframeLoadedHandler);
+
+  iframe1.src = 'data:text/html,<html>' +
+      '<body style="background:green">hello</body></html>';
+}
+
+addEventListener('load', function() { SimpleTest.executeSoon(runTest); });
+
+</script>
+
+</body>
+</html>