[iOS] Added WebState's CreateFullPagePDF Public API

Generates a PDF of the webView and invokes the callback with the NSData of the PDF or nil if a PDF couldn't be generated.

The WebState calls the WebController that will invoke WKWebViewUtility's CreateFullPagePDF with the current webView. The callback is passed though at each step.

Bug: 1103777
Change-Id: I3b83082937849e2851f6ceb1954b91cc0bc242ae
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2295784
Commit-Queue: Julian Mentasti-Meza <jmentasti@google.com>
Reviewed-by: Eugene But <eugenebut@chromium.org>
Reviewed-by: Sebastien Lalancette <seblalancette@chromium.org>
Cr-Commit-Position: refs/heads/master@{#790411}

ios/web/public/test/fakes/test_web_state.h

@@ -91,6 +91,7 @@ class TestWebState : public WebState {
   void SetHasOpener(bool has_opener) override;
   bool CanTakeSnapshot() const override;
   void TakeSnapshot(const gfx::RectF& rect, SnapshotCallback callback) override;
+  void CreateFullPagePdf(base::OnceCallback<void(NSData*)> callback) override;
 
   // Setters for test data.
   void SetBrowserState(BrowserState* browser_state);

ios/web/public/test/fakes/test_web_state.mm

@@ -458,4 +458,9 @@ void TestWebState::TakeSnapshot(const gfx::RectF& rect,
   std::move(callback).Run(gfx::Image([[UIImage alloc] init]));
 }
 
+void TestWebState::CreateFullPagePdf(
+    base::OnceCallback<void(NSData*)> callback) {
+  std::move(callback).Run([[NSData alloc] init]);
+}
+
 }  // namespace web

ios/web/public/web_state.h

@@ -369,6 +369,11 @@ class WebState : public base::SupportsUserData {
   virtual void TakeSnapshot(const gfx::RectF& rect,
                             SnapshotCallback callback) = 0;
 
+  // Creates PDF representation of the web page and invokes the |callback| with
+  // the NSData of the PDF or nil if a PDF couldn't be generated.
+  virtual void CreateFullPagePdf(
+      base::OnceCallback<void(NSData*)> callback) = 0;
+
   // Adds and removes observers for page navigation notifications. The order in
   // which notifications are sent to observers is undefined. Clients must be
   // sure to remove the observer before they go away.

ios/web/web_state/ui/crw_web_controller.h

@@ -178,6 +178,11 @@ class WebStateImpl;
 - (void)takeSnapshotWithRect:(CGRect)rect
                   completion:(void (^)(UIImage* snapshot))completion;
 
+// Creates PDF representation of the web page and invokes the |completion| with
+// the NSData of the PDF or nil if a PDF couldn't be generated.
+- (void)createFullPagePDFWithCompletion:
+    (void (^)(NSData* PDFDocumentData))completion;
+
 // Creates a web view if it's not yet created. Returns the web view.
 - (WKWebView*)ensureWebViewCreated;
 

ios/web/web_state/ui/crw_web_controller.mm

@@ -6,6 +6,7 @@
 
 #import <WebKit/WebKit.h>
 
+#include "base/bind.h"
 #import "base/ios/block_types.h"
 #include "base/ios/ios_util.h"
 #include "base/json/string_escape.h"
@@ -860,6 +861,10 @@ typedef void (^ViewportStateCompletion)(const web::PageViewportState*);
                   }];
 }
 
+- (void)createFullPagePDFWithCompletion:(void (^)(NSData*))completionBlock {
+  web::CreateFullPagePdf(self.webView, base::BindOnce(completionBlock));
+}
+
 #pragma mark - CRWTouchTrackingDelegate (Public)
 
 - (void)touched:(BOOL)touched {

ios/web/web_state/web_state_impl.h

@@ -229,6 +229,7 @@ class WebStateImpl : public WebState,
   void SetHasOpener(bool has_opener) override;
   bool CanTakeSnapshot() const override;
   void TakeSnapshot(const gfx::RectF& rect, SnapshotCallback callback) override;
+  void CreateFullPagePdf(base::OnceCallback<void(NSData*)> callback) override;
   void AddObserver(WebStateObserver* observer) override;
   void RemoveObserver(WebStateObserver* observer) override;
   void CloseWebState() override;

ios/web/web_state/web_state_impl.mm

@@ -804,6 +804,18 @@ void WebStateImpl::TakeSnapshot(const gfx::RectF& rect,
                              }];
 }
 
+void WebStateImpl::CreateFullPagePdf(
+    base::OnceCallback<void(NSData*)> callback) {
+  // Move the callback to a __block pointer, which will be in scope as long
+  // as the callback is retained.
+  __block base::OnceCallback<void(NSData*)> callback_for_block =
+      std::move(callback);
+  [web_controller_
+      createFullPagePDFWithCompletion:^(NSData* pdf_document_data) {
+        std::move(callback_for_block).Run(pdf_document_data);
+      }];
+}
+
 void WebStateImpl::OnNavigationStarted(web::NavigationContextImpl* context) {
   // Navigation manager loads internal URLs to restore session history and
   // create back-forward entries for WebUI. Do not trigger external callbacks.

ios/web/web_state/web_state_unittest.mm

@@ -217,6 +217,39 @@ TEST_F(WebStateTest, Snapshot) {
   });
 }
 
+// Tests that the create PDF method retuns an PDF of a rendered html page of the
+// appropriate size.
+TEST_F(WebStateTest, CreateFullPagePdf) {
+  CGFloat kSaveAreaTopInset =
+      UIApplication.sharedApplication.keyWindow.safeAreaInsets.top;
+
+  ASSERT_TRUE(LoadHtml("<html><div style='background-color:#FF0000; width:50%; "
+                       "height:100%;'></div></html>"));
+  [[[UIApplication sharedApplication] keyWindow]
+      addSubview:web_state()->GetView()];
+  // The subview is added but not immediately painted, so a small delay is
+  // necessary.
+  base::test::ios::SpinRunLoopWithMinDelay(base::TimeDelta::FromSecondsD(0.2));
+
+  __block NSData* callback_data = nil;
+  web_state()->CreateFullPagePdf(base::BindOnce(^(NSData* pdf_document_data) {
+    callback_data = [pdf_document_data copy];
+  }));
+
+  ASSERT_TRUE(callback_data);
+
+  CGPDFDocumentRef pdf = CGPDFDocumentCreateWithProvider(
+      CGDataProviderCreateWithCFData((CFDataRef)callback_data));
+  CGSize pdf_size =
+      CGPDFPageGetBoxRect(CGPDFDocumentGetPage(pdf, 1), kCGPDFMediaBox).size;
+
+  EXPECT_EQ(pdf_size.height,
+            UIScreen.mainScreen.bounds.size.height - kSaveAreaTopInset);
+  EXPECT_EQ(pdf_size.width, [[UIScreen mainScreen] bounds].size.width);
+
+  CGPDFDocumentRelease(pdf);
+}
+
 // Tests that message sent from main frame triggers the ScriptCommandCallback
 // with |is_main_frame| = true.
 TEST_F(WebStateTest, MessageFromMainFrame) {