Implement FORM_OnFocus() API.

Given a point, if there is an annotation at the point, give if focus if
it is not focus already. If there is no annotation at the point, then
remove the focus from the focused annotation.

BUG=chromium:754594

Change-Id: Iec3070472bbbfbad9d86e517f25da560f82efd4e
Reviewed-on: https://pdfium-review.googlesource.com/12530
Commit-Queue: Lei Zhang <thestig@chromium.org>
Reviewed-by: dsinclair <dsinclair@chromium.org>

10 files changed, 177 insertions, 1 deletions

diff --git a/fpdfsdk/cpdfsdk_pageview.cpp b/fpdfsdk/cpdfsdk_pageview.cpp
index 2155b5d3d8..5bdd720596 100644
--- a/fpdfsdk/cpdfsdk_pageview.cpp
+++ b/fpdfsdk/cpdfsdk_pageview.cpp
@@ -259,6 +259,17 @@ void CPDFSDK_PageView::ReplaceSelection(const CFX_WideString& text) {
   }
 }
 
+bool CPDFSDK_PageView::OnFocus(const CFX_PointF& point, uint32_t nFlag) {
+  CPDFSDK_Annot::ObservedPtr pAnnot(GetFXWidgetAtPoint(point));
+  if (!pAnnot) {
+    m_pFormFillEnv->KillFocusAnnot(nFlag);
+    return false;
+  }
+
+  m_pFormFillEnv->SetFocusAnnot(&pAnnot);
+  return true;
+}
+
 bool CPDFSDK_PageView::OnLButtonDown(const CFX_PointF& point, uint32_t nFlag) {
   CPDFSDK_Annot::ObservedPtr pAnnot(GetFXWidgetAtPoint(point));
   if (!pAnnot) {
diff --git a/fpdfsdk/cpdfsdk_pageview.h b/fpdfsdk/cpdfsdk_pageview.h
index c23aaa7988..00e90d73e8 100644
--- a/fpdfsdk/cpdfsdk_pageview.h
+++ b/fpdfsdk/cpdfsdk_pageview.h
@@ -64,6 +64,7 @@ class CPDFSDK_PageView final : public CPDF_Page::View {
   CFX_WideString GetSelectedText();
   void ReplaceSelection(const CFX_WideString& text);
 
+  bool OnFocus(const CFX_PointF& point, uint32_t nFlag);
   bool OnLButtonDown(const CFX_PointF& point, uint32_t nFlag);
   bool OnLButtonUp(const CFX_PointF& point, uint32_t nFlag);
 #ifdef PDF_ENABLE_XFA
diff --git a/fpdfsdk/fpdfformfill.cpp b/fpdfsdk/fpdfformfill.cpp
index b36c1dff23..1b5cc483a8 100644
--- a/fpdfsdk/fpdfformfill.cpp
+++ b/fpdfsdk/fpdfformfill.cpp
@@ -291,6 +291,17 @@ FPDF_EXPORT FPDF_BOOL FPDF_CALLCONV FORM_OnMouseMove(FPDF_FORMHANDLE hHandle,
   return pPageView->OnMouseMove(CFX_PointF(page_x, page_y), modifier);
 }
 
+FPDF_EXPORT FPDF_BOOL FPDF_CALLCONV FORM_OnFocus(FPDF_FORMHANDLE hHandle,
+                                                 FPDF_PAGE page,
+                                                 int modifier,
+                                                 double page_x,
+                                                 double page_y) {
+  CPDFSDK_PageView* pPageView = FormHandleToPageView(hHandle, page);
+  if (!pPageView)
+    return false;
+  return pPageView->OnFocus(CFX_PointF(page_x, page_y), modifier);
+}
+
 FPDF_EXPORT FPDF_BOOL FPDF_CALLCONV FORM_OnLButtonDown(FPDF_FORMHANDLE hHandle,
                                                        FPDF_PAGE page,
                                                        int modifier,
diff --git a/fpdfsdk/fpdfview_c_api_test.c b/fpdfsdk/fpdfview_c_api_test.c
index 5bad9c8e7b..6f84f353aa 100644
--- a/fpdfsdk/fpdfview_c_api_test.c
+++ b/fpdfsdk/fpdfview_c_api_test.c
@@ -181,6 +181,7 @@ int CheckPDFiumCApi() {
     CHK(FORM_DoDocumentAAction);
     CHK(FORM_DoPageAAction);
     CHK(FORM_OnMouseMove);
+    CHK(FORM_OnFocus);
     CHK(FORM_OnLButtonDown);
     CHK(FORM_OnLButtonUp);
 #ifdef PDF_ENABLE_XFA
diff --git a/public/fpdf_formfill.h b/public/fpdf_formfill.h
index 6a90140097..bf385b3539 100644
--- a/public/fpdf_formfill.h
+++ b/public/fpdf_formfill.h
@@ -1242,6 +1242,29 @@ FPDF_EXPORT FPDF_BOOL FPDF_CALLCONV FORM_OnMouseMove(FPDF_FORMHANDLE hHandle,
                                                      double page_y);
 
 /**
+ * Function: FORM_OnFocus
+ *          This function focuses the form annotation at a given point. If the
+ *          annotation at the point already has focus, nothing happens. If there
+ *          is no annotation at the point, remove form focus.
+ * Parameters:
+ *          hHandle     -   Handle to the form fill module. Returned by
+ *                          FPDFDOC_InitFormFillEnvironment.
+ *          page        -   Handle to the page. Returned by FPDF_LoadPage.
+ *          modifier    -   Indicates whether various virtual keys are down.
+ *          page_x      -   Specifies the x-coordinate of the cursor in PDF user
+ *                          space.
+ *          page_y      -   Specifies the y-coordinate of the cursor in PDF user
+ *                          space.
+ * Return Value:
+ *          TRUE if there is an annotation at the given point and it has focus.
+ **/
+FPDF_EXPORT FPDF_BOOL FPDF_CALLCONV FORM_OnFocus(FPDF_FORMHANDLE hHandle,
+                                                 FPDF_PAGE page,
+                                                 int modifier,
+                                                 double page_x,
+                                                 double page_y);
+
+/**
  * Function: FORM_OnLButtonDown
  *          You can call this member function when the user presses the left
  *mouse button.
diff --git a/samples/pdfium_test.cc b/samples/pdfium_test.cc
index 31235f0eff..b94b674286 100644
--- a/samples/pdfium_test.cc
+++ b/samples/pdfium_test.cc
@@ -965,6 +965,14 @@ void SendPageEvents(FPDF_FORMHANDLE form,
       } else {
         fprintf(stderr, "mousemove: bad args\n");
       }
+    } else if (tokens[0] == "focus") {
+      if (tokens.size() == 3) {
+        int x = atoi(tokens[1].c_str());
+        int y = atoi(tokens[2].c_str());
+        FORM_OnFocus(form, page, 0, x, y);
+      } else {
+        fprintf(stderr, "focus: bad args\n");
+      }
     } else {
       fprintf(stderr, "Unrecognized event: %s\n", tokens[0].c_str());
     }
diff --git a/testing/resources/javascript/mouse_events.evt b/testing/resources/javascript/mouse_events.evt
new file mode 100644
index 0000000000..57105063e4
--- /dev/null
+++ b/testing/resources/javascript/mouse_events.evt
@@ -0,0 +1,19 @@
+# Mouse in, mouse out.
+mousemove,125,225
+mousemove,125,100
+# Mouse in, click in field.
+mousemove,125,225
+mousedown,left,125,225
+mouseup,left,125,225
+# Mouse out, click elsewhere.
+# This should trigger an On Blur event. (Bug 881)
+mousemove,125,100
+mousedown,left,125,100
+mouseup,left,125,100
+# Mouse in, focus.
+mousemove,125,225
+focus,125,225
+# Mouse out, unfocus.
+# This should trigger an On Blur event. (Bug 881)
+mousemove,125,100
+focus,125,100
diff --git a/testing/resources/javascript/mouse_events.in b/testing/resources/javascript/mouse_events.in
new file mode 100644
index 0000000000..a72162add3
--- /dev/null
+++ b/testing/resources/javascript/mouse_events.in
@@ -0,0 +1,92 @@
+{{header}}
+{{object 1 0}} <<
+  /Type /Catalog
+  /Pages 2 0 R
+  /AcroForm 4 0 R
+>>
+endobj
+{{object 2 0}} <<
+  /Type /Pages
+  /Count 1
+  /Kids [
+    3 0 R
+  ]
+>>
+endobj
+% Page number 0.
+{{object 3 0}} <<
+  /Type /Page
+  /Parent 2 0 R
+  /Resources <<
+    /Font <</F1 20 0 R>>
+  >>
+  /Annots [ 5 0 R ]
+  /Contents [21 0 R]
+  /MediaBox [0 0 612 792]
+>>
+% Forms
+{{object 4 0}} <<
+  /Fields [5 0 R]
+>>
+% Field with actions:
+% Cursor enter: E
+% Cursor exit: X
+% Mouse down: D
+% Mouse up: U
+% Focus: Fo
+% Blur: Bl
+{{object 5 0}} <<
+ /FT /Tx
+ /T (MyField)
+ /Type /Annot
+ /Subtype /Widget
+ /Rect [100 200 150 250]
+ /AA <<
+   /E 10 0 R
+   /X 11 0 R
+   /D 12 0 R
+   /U 13 0 R
+   /Fo 14 0 R
+   /Bl 15 0 R
+ >>
+>>
+{{object 10 0}} <<
+  /Type /Action
+  /S /JavaScript
+  /JS (app.alert\("enter"\);)
+>>
+endobj
+{{object 11 0}} <<
+  /Type /Action
+  /S /JavaScript
+  /JS (app.alert\("exit"\);)
+>>
+endobj
+{{object 12 0}} <<
+  /Type /Action
+  /S /JavaScript
+  /JS (app.alert\("down"\);)
+>>
+endobj
+{{object 13 0}} <<
+  /Type /Action
+  /S /JavaScript
+  /JS (app.alert\("up"\);)
+>>
+endobj
+{{object 14 0}} <<
+  /Type /Action
+  /S /JavaScript
+  /JS (app.alert\("focus"\);)
+>>
+endobj
+{{object 15 0}} <<
+  /Type /Action
+  /S /JavaScript
+  /JS (app.alert\("blur"\);)
+>>
+endobj
+{{xref}}
+{{trailer}}
+{{startxref}}
+%%EOF
diff --git a/testing/resources/javascript/mouse_events_expected.txt b/testing/resources/javascript/mouse_events_expected.txt
new file mode 100644
index 0000000000..3d9b8b6071
--- /dev/null
+++ b/testing/resources/javascript/mouse_events_expected.txt
@@ -0,0 +1,10 @@
+Alert: enter
+Alert: exit
+Alert: enter
+Alert: down
+Alert: focus
+Alert: up
+Alert: exit
+Alert: enter
+Alert: focus
+Alert: exit
diff --git a/testing/tools/test_runner.py b/testing/tools/test_runner.py
index 9524b7459b..86e05636ab 100644
--- a/testing/tools/test_runner.py
+++ b/testing/tools/test_runner.py
@@ -115,7 +115,7 @@ class TestRunner:
     txt_path = os.path.join(self.working_dir, input_root + '.txt')
 
     with open(txt_path, 'w') as outfile:
-      cmd_to_run = [self.pdfium_test_path, pdf_path]
+      cmd_to_run = [self.pdfium_test_path, '--send-events', pdf_path]
       subprocess.check_call(cmd_to_run, stdout=outfile)
 
     cmd = [sys.executable, self.text_diff_path, expected_txt_path, txt_path]