Add return value to FPDF_DeviceToPage().

Do the same for FPDF_PageToDevice(). Clean up the internal
implementation as well.

Change-Id: Ia207bfa779d144cb9f0310e768750ab10e603b8f
Reviewed-on: https://pdfium-review.googlesource.com/17370
Commit-Queue: Lei Zhang <thestig@chromium.org>
Reviewed-by: dsinclair <dsinclair@chromium.org>

3 files changed, 57 insertions, 54 deletions

diff --git a/fpdfsdk/fpdf_view.cpp b/fpdfsdk/fpdf_view.cpp
index f39d80cab0..f2fa43f369 100644
--- a/fpdfsdk/fpdf_view.cpp
+++ b/fpdfsdk/fpdf_view.cpp
@@ -731,41 +731,53 @@ FPDF_EXPORT unsigned long FPDF_CALLCONV FPDF_GetLastError() {
   return GetLastError();
 }
 
-FPDF_EXPORT void FPDF_CALLCONV FPDF_DeviceToPage(FPDF_PAGE page,
-                                                 int start_x,
-                                                 int start_y,
-                                                 int size_x,
-                                                 int size_y,
-                                                 int rotate,
-                                                 int device_x,
-                                                 int device_y,
-                                                 double* page_x,
-                                                 double* page_y) {
+FPDF_EXPORT FPDF_BOOL FPDF_CALLCONV FPDF_DeviceToPage(FPDF_PAGE page,
+                                                      int start_x,
+                                                      int start_y,
+                                                      int size_x,
+                                                      int size_y,
+                                                      int rotate,
+                                                      int device_x,
+                                                      int device_y,
+                                                      double* page_x,
+                                                      double* page_y) {
   if (!page || !page_x || !page_y)
-    return;
+    return false;
 
   UnderlyingPageType* pPage = UnderlyingFromFPDFPage(page);
   const FX_RECT rect(start_x, start_y, start_x + size_x, start_y + size_y);
-  pPage->DeviceToPage(rect, rotate, CFX_PointF(device_x, device_y), page_x,
-                      page_y);
+  Optional<CFX_PointF> pos =
+      pPage->DeviceToPage(rect, rotate, CFX_PointF(device_x, device_y));
+  if (!pos)
+    return false;
+
+  *page_x = pos->x;
+  *page_y = pos->y;
+  return true;
 }
 
-FPDF_EXPORT void FPDF_CALLCONV FPDF_PageToDevice(FPDF_PAGE page,
-                                                 int start_x,
-                                                 int start_y,
-                                                 int size_x,
-                                                 int size_y,
-                                                 int rotate,
-                                                 double page_x,
-                                                 double page_y,
-                                                 int* device_x,
-                                                 int* device_y) {
+FPDF_EXPORT FPDF_BOOL FPDF_CALLCONV FPDF_PageToDevice(FPDF_PAGE page,
+                                                      int start_x,
+                                                      int start_y,
+                                                      int size_x,
+                                                      int size_y,
+                                                      int rotate,
+                                                      double page_x,
+                                                      double page_y,
+                                                      int* device_x,
+                                                      int* device_y) {
   if (!page || !device_x || !device_y)
-    return;
+    return false;
 
   UnderlyingPageType* pPage = UnderlyingFromFPDFPage(page);
   const FX_RECT rect(start_x, start_y, start_x + size_x, start_y + size_y);
-  pPage->PageToDevice(rect, rotate, page_x, page_y, device_x, device_y);
+  Optional<CFX_PointF> pos = pPage->PageToDevice(rect, rotate, page_x, page_y);
+  if (!pos)
+    return false;
+
+  *device_x = FXSYS_round(pos->x);
+  *device_y = FXSYS_round(pos->y);
+  return true;
 }
 
 FPDF_EXPORT FPDF_BITMAP FPDF_CALLCONV FPDFBitmap_Create(int width,
diff --git a/fpdfsdk/fpdfxfa/cpdfxfa_page.cpp b/fpdfsdk/fpdfxfa/cpdfxfa_page.cpp
index d4a6d95574..8fea85d72b 100644
--- a/fpdfsdk/fpdfxfa/cpdfxfa_page.cpp
+++ b/fpdfsdk/fpdfxfa/cpdfxfa_page.cpp
@@ -126,34 +126,28 @@ float CPDFXFA_Page::GetPageHeight() const {
   return 0.0f;
 }
 
-void CPDFXFA_Page::DeviceToPage(const FX_RECT& rect,
-                                int rotate,
-                                const CFX_PointF& device_point,
-                                double* page_x,
-                                double* page_y) const {
+Optional<CFX_PointF> CPDFXFA_Page::DeviceToPage(
+    const FX_RECT& rect,
+    int rotate,
+    const CFX_PointF& device_point) const {
   if (!m_pPDFPage && !m_pXFAPageView)
-    return;
+    return {};
 
   CFX_PointF pos =
       GetDisplayMatrix(rect, rotate).GetInverse().Transform(device_point);
-  *page_x = pos.x;
-  *page_y = pos.y;
+  return pos;
 }
 
-void CPDFXFA_Page::PageToDevice(const FX_RECT& rect,
-                                int rotate,
-                                double page_x,
-                                double page_y,
-                                int* device_x,
-                                int* device_y) const {
+Optional<CFX_PointF> CPDFXFA_Page::PageToDevice(const FX_RECT& rect,
+                                                int rotate,
+                                                double page_x,
+                                                double page_y) const {
   if (!m_pPDFPage && !m_pXFAPageView)
-    return;
+    return {};
 
   CFX_Matrix page2device = GetDisplayMatrix(rect, rotate);
-  CFX_PointF pos = page2device.Transform(
+  return page2device.Transform(
       CFX_PointF(static_cast<float>(page_x), static_cast<float>(page_y)));
-  *device_x = FXSYS_round(pos.x);
-  *device_y = FXSYS_round(pos.y);
 }
 
 CFX_Matrix CPDFXFA_Page::GetDisplayMatrix(const FX_RECT& rect,
diff --git a/fpdfsdk/fpdfxfa/cpdfxfa_page.h b/fpdfsdk/fpdfxfa/cpdfxfa_page.h
index aef1b0b539..131e811b66 100644
--- a/fpdfsdk/fpdfxfa/cpdfxfa_page.h
+++ b/fpdfsdk/fpdfxfa/cpdfxfa_page.h
@@ -13,6 +13,7 @@
 #include "core/fxcrt/fx_system.h"
 #include "core/fxcrt/retain_ptr.h"
 #include "core/fxcrt/unowned_ptr.h"
+#include "third_party/base/optional.h"
 
 class CPDFXFA_Context;
 class CPDF_Dictionary;
@@ -38,17 +39,13 @@ class CPDFXFA_Page : public Retainable {
   float GetPageWidth() const;
   float GetPageHeight() const;
 
-  void DeviceToPage(const FX_RECT& rect,
-                    int rotate,
-                    const CFX_PointF& device_point,
-                    double* page_x,
-                    double* page_y) const;
-  void PageToDevice(const FX_RECT& rect,
-                    int rotate,
-                    double page_x,
-                    double page_y,
-                    int* device_x,
-                    int* device_y) const;
+  Optional<CFX_PointF> DeviceToPage(const FX_RECT& rect,
+                                    int rotate,
+                                    const CFX_PointF& device_point) const;
+  Optional<CFX_PointF> PageToDevice(const FX_RECT& rect,
+                                    int rotate,
+                                    double page_x,
+                                    double page_y) const;
 
   CFX_Matrix GetDisplayMatrix(const FX_RECT& rect, int iRotate) const;