Change out-parameter types in PDFiumEngine::GetRegion()

- Change `region` from a void* to a base::span<uint8_t>.
- Change `stride` from int to size_t.

Change-Id: Iebbb079915550111c357efdd4c0b892df4bd6443
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4991109
Code-Coverage: findit-for-me@appspot.gserviceaccount.com <findit-for-me@appspot.gserviceaccount.com>
Reviewed-by: Tom Sepez <tsepez@chromium.org>
Commit-Queue: Lei Zhang <thestig@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1217916}

pdf/pdfium/pdfium_engine.cc

@@ -3337,8 +3337,8 @@ void PDFiumEngine::DrawSelections(int progressive_index,
   int page_index = progressive_paints_[progressive_index].page_index();
   gfx::Rect dirty_in_screen = progressive_paints_[progressive_index].rect();
 
-  void* region = nullptr;
-  int stride;
+  base::span<uint8_t> region;
+  size_t stride;
   GetRegion(dirty_in_screen.origin(), image_data, region, stride);
 
   std::vector<gfx::Rect> highlighted_rects;
@@ -3402,14 +3402,16 @@ int PDFiumEngine::GetProgressiveIndex(int page_index) const {
 ScopedFPDFBitmap PDFiumEngine::CreateBitmap(const gfx::Rect& rect,
                                             bool has_alpha,
                                             SkBitmap& image_data) const {
-  void* region;
-  int stride;
+  base::span<uint8_t> region;
+  size_t stride;
   GetRegion(rect.origin(), image_data, region, stride);
-  if (!region)
+  if (region.empty()) {
     return nullptr;
+  }
+
   int format = has_alpha ? FPDFBitmap_BGRA : FPDFBitmap_BGRx;
-  return ScopedFPDFBitmap(
-      FPDFBitmap_CreateEx(rect.width(), rect.height(), format, region, stride));
+  return ScopedFPDFBitmap(FPDFBitmap_CreateEx(rect.width(), rect.height(),
+                                              format, region.data(), stride));
 }
 
 void PDFiumEngine::GetPDFiumRect(int page_index,
@@ -3483,15 +3485,16 @@ gfx::RectF PDFiumEngine::GetPageBoundingBox(int page_index) {
   return page->GetBoundingBox();
 }
 
-void PDFiumEngine::Highlight(void* buffer,
-                             int stride,
+void PDFiumEngine::Highlight(base::span<uint8_t> buffer,
+                             size_t stride,
                              const gfx::Rect& rect,
                              int color_red,
                              int color_green,
                              int color_blue,
                              std::vector<gfx::Rect>& highlighted_rects) const {
-  if (!buffer)
+  if (buffer.empty()) {
     return;
+  }
 
   gfx::Rect new_rect = rect;
   for (const auto& highlighted : highlighted_rects)
@@ -3512,6 +3515,7 @@ void PDFiumEngine::Highlight(void* buffer,
   int h = new_rect.height();
 
   for (int y = t; y < t + h; ++y) {
+    base::span<uint8_t> row = buffer.subspan(y * stride, stride);
     for (int x = l; x < l + w; ++x) {
       bool overlaps = false;
       for (size_t i : overlapping_rect_indices) {
@@ -3524,7 +3528,7 @@ void PDFiumEngine::Highlight(void* buffer,
       if (overlaps)
         continue;
 
-      uint8_t* pixel = static_cast<uint8_t*>(buffer) + y * stride + x * 4;
+      uint8_t* pixel = row.data() + x * 4;
       pixel[0] = static_cast<uint8_t>(pixel[0] * (color_blue / 255.0));
       pixel[1] = static_cast<uint8_t>(pixel[1] * (color_green / 255.0));
       pixel[2] = static_cast<uint8_t>(pixel[2] * (color_red / 255.0));
@@ -3714,29 +3718,28 @@ void PDFiumEngine::DrawPageShadow(const gfx::Rect& page_rc,
 
 void PDFiumEngine::GetRegion(const gfx::Point& location,
                              SkBitmap& image_data,
-                             void*& region,
-                             int& stride) const {
+                             base::span<uint8_t>& region,
+                             size_t& stride) const {
   if (image_data.isNull()) {
     DCHECK(plugin_size().IsEmpty());
     stride = 0;
-    region = nullptr;
     return;
   }
-  char* buffer = static_cast<char*>(image_data.getPixels());
+  uint8_t* buffer = static_cast<uint8_t*>(image_data.getPixels());
   stride = image_data.rowBytes();
 
   gfx::Point offset_location = location + page_offset_;
   // TODO: update this when we support BIDI and scrollbars can be on the left.
   if (!buffer ||
       !gfx::Rect(gfx::PointAtOffsetFromOrigin(page_offset_), plugin_size())
            .Contains(offset_location)) {
-    region = nullptr;
     return;
   }
 
-  buffer += location.y() * stride;
-  buffer += (location.x() + page_offset_.x()) * 4;
-  region = buffer;
+  base::span<uint8_t> buffer_span(buffer, image_data.height() * stride);
+  size_t x_offset = location.x() + page_offset_.x();
+  size_t offset = location.y() * stride + x_offset * 4;
+  region = buffer_span.subspan(offset);
 }
 
 void PDFiumEngine::OnSelectionTextChanged() {

pdf/pdfium/pdfium_engine.h

@@ -15,6 +15,7 @@
 
 #include "base/check.h"
 #include "base/containers/flat_map.h"
+#include "base/containers/span.h"
 #include "base/memory/raw_ptr.h"
 #include "base/memory/weak_ptr.h"
 #include "base/time/time.h"
@@ -519,8 +520,8 @@ class PDFiumEngine : public PDFEngine,
   // Given an image `buffer` with `stride`, highlights `rect`.
   // `highlighted_rects` contains the already highlighted rectangles and will be
   // updated to include `rect` if `rect` has not already been highlighted.
-  void Highlight(void* buffer,
-                 int stride,
+  void Highlight(base::span<uint8_t> buffer,
+                 size_t stride,
                  const gfx::Rect& rect,
                  int color_red,
                  int color_green,
@@ -549,8 +550,8 @@ class PDFiumEngine : public PDFEngine,
 
   void GetRegion(const gfx::Point& location,
                  SkBitmap& image_data,
-                 void*& region,
-                 int& stride) const;
+                 base::span<uint8_t>& region,
+                 size_t& stride) const;
 
   // Called when the selection changes.
   void OnSelectionTextChanged();