Only create widgets if really needed.

Currently the GetWidget call will create a backing widget for a control behind
the scenes if it doesn't exist. This can cause more work to be done then needed
as we may need to create the page and any supporting structures. This created
structure will then be torn down as we don't need it anymore once we're done
with the widget.

For the instances where setting the value on the widget will have no effect (as
we'll destroy it anyway) we can tell GetWidget() to not create the widget and
return without doing any work.

BUG=pdfium:632709

Review-Url: https://codereview.chromium.org/2251453002

2 files changed, 37 insertions, 24 deletions

diff --git a/fpdfsdk/javascript/Field.cpp b/fpdfsdk/javascript/Field.cpp
index 852888179a..20c41c6a19 100644
--- a/fpdfsdk/javascript/Field.cpp
+++ b/fpdfsdk/javascript/Field.cpp
@@ -262,7 +262,7 @@ void Field::UpdateFormControl(CPDFSDK_Document* pDocument,
   ASSERT(pFormControl);
 
   CPDFSDK_InterForm* pForm = pDocument->GetInterForm();
-  CPDFSDK_Widget* pWidget = pForm->GetWidget(pFormControl);
+  CPDFSDK_Widget* pWidget = pForm->GetWidget(pFormControl, false);
 
   if (pWidget) {
     if (bResetAP) {
@@ -292,10 +292,12 @@ void Field::UpdateFormControl(CPDFSDK_Document* pDocument,
 }
 
 CPDFSDK_Widget* Field::GetWidget(CPDFSDK_Document* pDocument,
-                                 CPDF_FormControl* pFormControl) {
+                                 CPDF_FormControl* pFormControl,
+                                 bool createIfNeeded) {
   CPDFSDK_InterForm* pInterForm =
       static_cast<CPDFSDK_InterForm*>(pDocument->GetInterForm());
-  return pInterForm ? pInterForm->GetWidget(pFormControl) : nullptr;
+  return pInterForm ? pInterForm->GetWidget(pFormControl, createIfNeeded)
+                    : nullptr;
 }
 
 FX_BOOL Field::ValueIsOccur(CPDF_FormField* pFormField,
@@ -403,7 +405,7 @@ FX_BOOL Field::borderStyle(IJS_Context* cc,
       return FALSE;
 
     CPDFSDK_Widget* pWidget =
-        GetWidget(m_pDocument, GetSmartFieldControl(pFormField));
+        GetWidget(m_pDocument, GetSmartFieldControl(pFormField), false);
     if (!pWidget)
       return FALSE;
 
@@ -459,7 +461,7 @@ void Field::SetBorderStyle(CPDFSDK_Document* pDocument,
       FX_BOOL bSet = FALSE;
       for (int i = 0, sz = pFormField->CountControls(); i < sz; ++i) {
         if (CPDFSDK_Widget* pWidget =
-                GetWidget(pDocument, pFormField->GetControl(i))) {
+                GetWidget(pDocument, pFormField->GetControl(i), false)) {
           if (pWidget->GetBorderStyle() != nBorderStyle) {
             pWidget->SetBorderStyle(nBorderStyle);
             bSet = TRUE;
@@ -473,7 +475,8 @@ void Field::SetBorderStyle(CPDFSDK_Document* pDocument,
         return;
       if (CPDF_FormControl* pFormControl =
               pFormField->GetControl(nControlIndex)) {
-        if (CPDFSDK_Widget* pWidget = GetWidget(pDocument, pFormControl)) {
+        if (CPDFSDK_Widget* pWidget =
+                GetWidget(pDocument, pFormControl, false)) {
           if (pWidget->GetBorderStyle() != nBorderStyle) {
             pWidget->SetBorderStyle(nBorderStyle);
             UpdateFormControl(pDocument, pFormControl, TRUE, TRUE, TRUE);
@@ -1208,7 +1211,7 @@ FX_BOOL Field::display(IJS_Context* cc,
     ASSERT(pFormField);
     CPDFSDK_InterForm* pInterForm = m_pDocument->GetInterForm();
     CPDFSDK_Widget* pWidget =
-        pInterForm->GetWidget(GetSmartFieldControl(pFormField));
+        pInterForm->GetWidget(GetSmartFieldControl(pFormField), true);
     if (!pWidget)
       return FALSE;
 
@@ -1246,7 +1249,8 @@ void Field::SetDisplay(CPDFSDK_Document* pDocument,
         CPDF_FormControl* pFormControl = pFormField->GetControl(i);
         ASSERT(pFormControl);
 
-        if (CPDFSDK_Widget* pWidget = pInterForm->GetWidget(pFormControl)) {
+        if (CPDFSDK_Widget* pWidget =
+                pInterForm->GetWidget(pFormControl, true)) {
           uint32_t dwFlag = pWidget->GetFlags();
           switch (number) {
             case 0:
@@ -1287,7 +1291,8 @@ void Field::SetDisplay(CPDFSDK_Document* pDocument,
         return;
       if (CPDF_FormControl* pFormControl =
               pFormField->GetControl(nControlIndex)) {
-        if (CPDFSDK_Widget* pWidget = pInterForm->GetWidget(pFormControl)) {
+        if (CPDFSDK_Widget* pWidget =
+                pInterForm->GetWidget(pFormControl, true)) {
           uint32_t dwFlag = pWidget->GetFlags();
           switch (number) {
             case 0:
@@ -1525,7 +1530,7 @@ FX_BOOL Field::hidden(IJS_Context* cc,
     ASSERT(pFormField);
     CPDFSDK_InterForm* pInterForm = m_pDocument->GetInterForm();
     CPDFSDK_Widget* pWidget =
-        pInterForm->GetWidget(GetSmartFieldControl(pFormField));
+        pInterForm->GetWidget(GetSmartFieldControl(pFormField), false);
     if (!pWidget)
       return FALSE;
 
@@ -1552,7 +1557,7 @@ void Field::SetHidden(CPDFSDK_Document* pDocument,
       FX_BOOL bSet = FALSE;
       for (int i = 0, sz = pFormField->CountControls(); i < sz; ++i) {
         if (CPDFSDK_Widget* pWidget =
-                pInterForm->GetWidget(pFormField->GetControl(i))) {
+                pInterForm->GetWidget(pFormField->GetControl(i), false)) {
           uint32_t dwFlags = pWidget->GetFlags();
 
           if (b) {
@@ -1580,7 +1585,8 @@ void Field::SetHidden(CPDFSDK_Document* pDocument,
         return;
       if (CPDF_FormControl* pFormControl =
               pFormField->GetControl(nControlIndex)) {
-        if (CPDFSDK_Widget* pWidget = pInterForm->GetWidget(pFormControl)) {
+        if (CPDFSDK_Widget* pWidget =
+                pInterForm->GetWidget(pFormControl, false)) {
           uint32_t dwFlags = pWidget->GetFlags();
 
           if (b) {
@@ -1696,7 +1702,8 @@ FX_BOOL Field::lineWidth(IJS_Context* cc,
     if (!pFormField->CountControls())
       return FALSE;
 
-    CPDFSDK_Widget* pWidget = pInterForm->GetWidget(pFormField->GetControl(0));
+    CPDFSDK_Widget* pWidget =
+        pInterForm->GetWidget(pFormField->GetControl(0), false);
     if (!pWidget)
       return FALSE;
 
@@ -1720,7 +1727,8 @@ void Field::SetLineWidth(CPDFSDK_Document* pDocument,
         CPDF_FormControl* pFormControl = pFormField->GetControl(i);
         ASSERT(pFormControl);
 
-        if (CPDFSDK_Widget* pWidget = pInterForm->GetWidget(pFormControl)) {
+        if (CPDFSDK_Widget* pWidget =
+                pInterForm->GetWidget(pFormControl, false)) {
           if (number != pWidget->GetBorderWidth()) {
             pWidget->SetBorderWidth(number);
             bSet = TRUE;
@@ -1734,7 +1742,8 @@ void Field::SetLineWidth(CPDFSDK_Document* pDocument,
         return;
       if (CPDF_FormControl* pFormControl =
               pFormField->GetControl(nControlIndex)) {
-        if (CPDFSDK_Widget* pWidget = pInterForm->GetWidget(pFormControl)) {
+        if (CPDFSDK_Widget* pWidget =
+                pInterForm->GetWidget(pFormControl, false)) {
           if (number != pWidget->GetBorderWidth()) {
             pWidget->SetBorderWidth(number);
             UpdateFormControl(pDocument, pFormControl, TRUE, TRUE, TRUE);
@@ -1965,7 +1974,7 @@ FX_BOOL Field::print(IJS_Context* cc,
         FX_BOOL bSet = FALSE;
         for (int i = 0, sz = pFormField->CountControls(); i < sz; ++i) {
           if (CPDFSDK_Widget* pWidget =
-                  pInterForm->GetWidget(pFormField->GetControl(i))) {
+                  pInterForm->GetWidget(pFormField->GetControl(i), false)) {
             uint32_t dwFlags = pWidget->GetFlags();
             if (bVP)
               dwFlags |= ANNOTFLAG_PRINT;
@@ -1986,7 +1995,8 @@ FX_BOOL Field::print(IJS_Context* cc,
           return FALSE;
         if (CPDF_FormControl* pFormControl =
                 pFormField->GetControl(m_nFormControlIndex)) {
-          if (CPDFSDK_Widget* pWidget = pInterForm->GetWidget(pFormControl)) {
+          if (CPDFSDK_Widget* pWidget =
+                  pInterForm->GetWidget(pFormControl, true)) {
             uint32_t dwFlags = pWidget->GetFlags();
             if (bVP)
               dwFlags |= ANNOTFLAG_PRINT;
@@ -2006,7 +2016,7 @@ FX_BOOL Field::print(IJS_Context* cc,
   } else {
     CPDF_FormField* pFormField = FieldArray[0];
     CPDFSDK_Widget* pWidget =
-        pInterForm->GetWidget(GetSmartFieldControl(pFormField));
+        pInterForm->GetWidget(GetSmartFieldControl(pFormField), true);
     if (!pWidget)
       return FALSE;
 
@@ -2118,7 +2128,7 @@ FX_BOOL Field::rect(IJS_Context* cc,
     CPDF_FormField* pFormField = FieldArray[0];
     CPDFSDK_InterForm* pInterForm = m_pDocument->GetInterForm();
     CPDFSDK_Widget* pWidget =
-        pInterForm->GetWidget(GetSmartFieldControl(pFormField));
+        pInterForm->GetWidget(GetSmartFieldControl(pFormField), true);
     if (!pWidget)
       return FALSE;
 
@@ -2152,7 +2162,8 @@ void Field::SetRect(CPDFSDK_Document* pDocument,
         CPDF_FormControl* pFormControl = pFormField->GetControl(i);
         ASSERT(pFormControl);
 
-        if (CPDFSDK_Widget* pWidget = pInterForm->GetWidget(pFormControl)) {
+        if (CPDFSDK_Widget* pWidget =
+                pInterForm->GetWidget(pFormControl, false)) {
           CFX_FloatRect crRect = rect;
 
           CPDF_Page* pPDFPage = pWidget->GetPDFPage();
@@ -2176,7 +2187,8 @@ void Field::SetRect(CPDFSDK_Document* pDocument,
         return;
       if (CPDF_FormControl* pFormControl =
               pFormField->GetControl(nControlIndex)) {
-        if (CPDFSDK_Widget* pWidget = pInterForm->GetWidget(pFormControl)) {
+        if (CPDFSDK_Widget* pWidget =
+                pInterForm->GetWidget(pFormControl, false)) {
           CFX_FloatRect crRect = rect;
 
           CPDF_Page* pPDFPage = pWidget->GetPDFPage();
@@ -3250,7 +3262,7 @@ FX_BOOL Field::setFocus(IJS_Context* cc,
   CPDFSDK_InterForm* pInterForm = m_pDocument->GetInterForm();
   CPDFSDK_Widget* pWidget = nullptr;
   if (nCount == 1) {
-    pWidget = pInterForm->GetWidget(pFormField->GetControl(0));
+    pWidget = pInterForm->GetWidget(pFormField->GetControl(0), false);
   } else {
     CPDFDoc_Environment* pEnv = m_pDocument->GetEnv();
     UnderlyingPageType* pPage = UnderlyingFromFPDFPage(
@@ -3261,7 +3273,7 @@ FX_BOOL Field::setFocus(IJS_Context* cc,
             m_pDocument->GetPageView(pPage, true)) {
       for (int32_t i = 0; i < nCount; i++) {
         if (CPDFSDK_Widget* pTempWidget =
-                pInterForm->GetWidget(pFormField->GetControl(i))) {
+                pInterForm->GetWidget(pFormField->GetControl(i), false)) {
           if (pTempWidget->GetPDFPage() == pCurPageView->GetPDFPage()) {
             pWidget = pTempWidget;
             break;
diff --git a/fpdfsdk/javascript/Field.h b/fpdfsdk/javascript/Field.h
index 5697865b7c..3d1b0ff876 100644
--- a/fpdfsdk/javascript/Field.h
+++ b/fpdfsdk/javascript/Field.h
@@ -425,7 +425,8 @@ class Field : public CJS_EmbedObj {
                                 FX_BOOL bRefresh);
 
   static CPDFSDK_Widget* GetWidget(CPDFSDK_Document* pDocument,
-                                   CPDF_FormControl* pFormControl);
+                                   CPDF_FormControl* pFormControl,
+                                   bool createIfNeeded);
   static std::vector<CPDF_FormField*> GetFormFields(
       CPDFSDK_Document* pDocument,
       const CFX_WideString& csFieldName);