Merge r230088 - Web Automation: clipToViewport is ignored for element…

… screenshots

https://bugs.webkit.org/show_bug.cgi?id=184158
<rdar://problem/39014307>

Reviewed by Timothy Hatcher.

In §19.2 Take Element Screenshot, step 5.2 says that we should clip
the element screenshot rect with the visible viewport rect. We don't
do that right now even though we pass over clipToViewport.

* WebProcess/Automation/WebAutomationSessionProxy.cpp:
(WebKit::snapshotRectForScreenshot):
Clip the rect to viewport if needed.

(WebKit::WebAutomationSessionProxy::takeScreenshot):
This scrollIntoView is misplaced; by this point we have already done
the math to figure out the screenshot rect. Move it before computing the rect.

Source/WebKit/ChangeLog

@@ -1,3 +1,23 @@
+2018-03-29  Brian Burg  <bburg@apple.com>
+
+        Web Automation: clipToViewport is ignored for element screenshots
+        https://bugs.webkit.org/show_bug.cgi?id=184158
+        <rdar://problem/39014307>
+
+        Reviewed by Timothy Hatcher.
+
+        In §19.2 Take Element Screenshot, step 5.2 says that we should clip
+        the element screenshot rect with the visible viewport rect. We don't
+        do that right now even though we pass over clipToViewport.
+
+        * WebProcess/Automation/WebAutomationSessionProxy.cpp:
+        (WebKit::snapshotRectForScreenshot):
+        Clip the rect to viewport if needed.
+
+        (WebKit::WebAutomationSessionProxy::takeScreenshot):
+        This scrollIntoView is misplaced; by this point we have already done
+        the math to figure out the screenshot rect. Move it before computing the rect.
+
 2018-03-29  Carlos Eduardo Ramalho  <cadubentzen@gmail.com>
 
         [WPE] Floating point exception in WebEventFactory::createWebWheelEvent

Source/WebKit/WebProcess/Automation/WebAutomationSessionProxy.cpp

@@ -663,12 +663,20 @@ void WebAutomationSessionProxy::selectOptionElement(uint64_t pageID, uint64_t fr
 
 static WebCore::IntRect snapshotRectForScreenshot(WebPage& page, WebCore::Element* element, bool clipToViewport)
 {
+    auto* frameView = page.mainFrameView();
+    if (!frameView)
+        return { };
+
     if (element) {
         if (!element->renderer())
             return { };
 
         WebCore::LayoutRect topLevelRect;
-        return WebCore::snappedIntRect(element->renderer()->paintingRootRect(topLevelRect));
+        WebCore::IntRect elementRect = WebCore::snappedIntRect(element->renderer()->paintingRootRect(topLevelRect));
+        if (clipToViewport)
+            elementRect.intersect(frameView->visibleContentRect());
+
+        return elementRect;
     }
 
     if (auto* frameView = page.mainFrameView())
@@ -705,16 +713,16 @@ void WebAutomationSessionProxy::takeScreenshot(uint64_t pageID, uint64_t frameID
         }
     }
 
+    if (coreElement && scrollIntoViewIfNeeded)
+        coreElement->scrollIntoViewIfNeeded(false);
+
     String screenshotErrorType = Inspector::Protocol::AutomationHelpers::getEnumConstantValue(Inspector::Protocol::Automation::ErrorMessage::ScreenshotError);
     WebCore::IntRect snapshotRect = snapshotRectForScreenshot(*page, coreElement, clipToViewport);
     if (snapshotRect.isEmpty()) {
         WebProcess::singleton().parentProcessConnection()->send(Messages::WebAutomationSession::DidTakeScreenshot(callbackID, handle, screenshotErrorType), 0);
         return;
     }
 
-    if (coreElement && scrollIntoViewIfNeeded)
-        coreElement->scrollIntoViewIfNeeded(false);
-
     RefPtr<WebImage> image = page->scaledSnapshotWithOptions(snapshotRect, 1, SnapshotOptionsShareable);
     if (!image) {
         WebProcess::singleton().parentProcessConnection()->send(Messages::WebAutomationSession::DidTakeScreenshot(callbackID, handle, screenshotErrorType), 0);