iOS: Add FindElementAtPoint to context_menu.js.

FindElementAtPoint asynchronously returns the DOM element details using
postMessage which can be used to communicate with the native app from
any document frame.

Bug: 228355
Cq-Include-Trybots: master.tryserver.chromium.mac:ios-simulator-cronet;master.tryserver.chromium.mac:ios-simulator-full-configs
Change-Id: I52c6e08f168824f0f458b97965e627d75a93ffa6
Reviewed-on: https://chromium-review.googlesource.com/918404
Commit-Queue: Mike Dougherty <michaeldo@chromium.org>
Reviewed-by: Eugene But <eugenebut@chromium.org>
Cr-Commit-Position: refs/heads/master@{#537914}

ios/web/public/test/js_test_util.h

@@ -8,6 +8,8 @@
 #import <Foundation/Foundation.h>
 #import <WebKit/WebKit.h>
 
+#include "base/compiler_specific.h"
+
 @class CRWJSInjectionManager;
 @class CRWJSInjectionReceiver;
 
@@ -35,6 +37,12 @@ id ExecuteJavaScript(WKWebView* web_view,
 // Fails if there was an error during script execution.
 id ExecuteJavaScript(WKWebView* web_view, NSString* script);
 
+// Synchronously loads |html| into |web_view|. Returns true is successful or
+// false if the |web_view| never finishes loading.
+bool LoadHtml(WKWebView* web_view,
+              NSString* html,
+              NSURL* base_url) WARN_UNUSED_RESULT;
+
 }  // namespace web
 
 #endif  // IOS_WEB_PUBLIC_TEST_JS_TEST_UTIL_H_

ios/web/public/test/js_test_util.mm

@@ -17,6 +17,10 @@
 #error "This file requires ARC support."
 #endif
 
+using testing::kWaitForJSCompletionTimeout;
+using testing::kWaitForPageLoadTimeout;
+using testing::WaitUntilConditionOrTimeout;
+
 namespace web {
 
 id ExecuteJavaScript(CRWJSInjectionManager* manager, NSString* script) {
@@ -29,10 +33,9 @@ id ExecuteJavaScript(CRWJSInjectionManager* manager, NSString* script) {
              completed = true;
            }];
 
-  BOOL success = testing::WaitUntilConditionOrTimeout(
-      testing::kWaitForJSCompletionTimeout, ^{
-        return completed;
-      });
+  BOOL success = WaitUntilConditionOrTimeout(kWaitForJSCompletionTimeout, ^{
+    return completed;
+  });
   // Log stack trace to provide some context.
   EXPECT_TRUE(success)
       << "CRWJSInjectionManager failed to complete javascript execution.\n"
@@ -64,10 +67,9 @@ id ExecuteJavaScript(WKWebView* web_view,
                block_error = [script_error copy];
                completed = true;
              }];
-  BOOL success = testing::WaitUntilConditionOrTimeout(
-      testing::kWaitForJSCompletionTimeout, ^{
-        return completed;
-      });
+  BOOL success = WaitUntilConditionOrTimeout(kWaitForJSCompletionTimeout, ^{
+    return completed;
+  });
   // Log stack trace to provide some context.
   EXPECT_TRUE(success) << "WKWebView failed to complete javascript execution.\n"
                        << base::SysNSStringToUTF8([[NSThread callStackSymbols]
@@ -78,5 +80,13 @@ id ExecuteJavaScript(WKWebView* web_view,
   return result;
 }
 
+bool LoadHtml(WKWebView* web_view, NSString* html, NSURL* base_url) {
+  [web_view loadHTMLString:html baseURL:base_url];
+
+  return WaitUntilConditionOrTimeout(kWaitForPageLoadTimeout, ^{
+    return !web_view.loading;
+  });
+}
+
 }  // namespace web
 

ios/web/web_state/context_menu_constants.h

@@ -8,10 +8,16 @@
 #import <Foundation/Foundation.h>
 
 // Contains keys present in dictionary returned by __gCrWeb.getElementFromPoint
-// JS API.
+// and __gCrWeb.findElementAtPoint JS APIs.
 
 namespace web {
 
+// Required in findElementAtPoint response. (Not used by getElementFromPoint.)
+// Represents a unique string request ID that is passed through directly from a
+// call to findElementAtPoint to the response dictionary. The request ID should
+// be used to correlate a response with a previous call to findElementAtPoint.
+extern NSString* const kContextMenuElementRequestID;
+
 // Optional key. Represents element's href attribute if present or parent's href
 // if element is an image.
 extern NSString* const kContextMenuElementHyperlink;

ios/web/web_state/context_menu_constants.mm

@@ -10,6 +10,7 @@
 
 namespace web {
 
+NSString* const kContextMenuElementRequestID = @"requestID";
 NSString* const kContextMenuElementHyperlink = @"href";
 NSString* const kContextMenuElementSource = @"src";
 NSString* const kContextMenuElementTitle = @"title";

ios/web/web_state/js/resources/context_menu.js

@@ -11,6 +11,44 @@ goog.provide('__crWeb.contextMenu');
 /** Beginning of anonymous object */
 (function() {
 
+/**
+ * Finds the url of the image or link under the selected point. Sends the
+ * found element (or an empty object if no links or images are found) back to
+ * the application by posting a 'FindElementResultHandler' message.
+ * The object returned in the message is an object of the form {
+ *     requestID,  // identifier as passed to this function
+ *     href,  // URL of the link under the point
+ *     innerText,  // innerText of the link, if the selected element is a link
+ *     src,  // src of the image, if the selected element is an image
+ *     title,  // title of the image, if the selected
+ *     referrerPolicy
+ *   }
+ *   where:
+ *     <ul>
+ *     <li>requestID is the value of the identifier passed to this function.
+ *     <li>href, innerText are set if the selected element is a link.
+ *     <li>src, title are set if the selected element is an image.
+ *     <li>href is also set if the selected element is an image with a link.
+ *     <li>referrerPolicy is the referrer policy to use for navigations away
+ *         from the current page.
+ *     </ul>
+ * @param {string} identifier An identifier which be returned in the result
+ *                 dictionary of this request.
+ * @param {number} x Horizontal center of the selected point in web view
+ *                 coordinates.
+ * @param {number} y Vertical center of the selected point in web view
+ *                 coordinates.
+ * @param {number} webViewWidth the width of web view.
+ * @param {number} webViewHeight the height of web view.
+ */
+__gCrWeb['findElementAtPoint'] =
+    function(requestID, x, y, webViewWidth, webViewHeight) {
+      var scale = getPageWidth() / webViewWidth;
+      var result = getElementFromPointInPageCoordinates(x * scale, y * scale);
+      result.requestID = requestID;
+      __gCrWeb.common.sendWebKitMessage('FindElementResultHandler', result);
+    };
+
 /**
  * Returns the url of the image or link under the selected point. Returns an
  * empty object if no links or images are found.