AAPT2: Rename to match new style

Use Google3 naming style to match new
projects' and open source google projects' style.

Preferred to do this in a massive CL so as to avoid
style inconsistencies that plague legacy code bases.
This is a relatively NEW code base, may as well keep
it up to date.

Test: name/style refactor - existing tests pass
Change-Id: Ie80ecb78d46ec53efdfca2336bb57d96cbb7fb87
diff --git a/tools/aapt2/compile/NinePatch.cpp b/tools/aapt2/compile/NinePatch.cpp
index 8842eb7..eab5c97 100644
--- a/tools/aapt2/compile/NinePatch.cpp
+++ b/tools/aapt2/compile/NinePatch.cpp
@@ -15,14 +15,16 @@
  */
 
 #include "compile/Image.h"
-#include "util/StringPiece.h"
-#include "util/Util.h"
 
-#include <androidfw/ResourceTypes.h>
 #include <sstream>
 #include <string>
 #include <vector>
 
+#include "androidfw/ResourceTypes.h"
+
+#include "util/StringPiece.h"
+#include "util/Util.h"
+
 namespace aapt {
 
 // Colors in the format 0xAARRGGBB (the way 9-patch expects it).
@@ -36,7 +38,7 @@
 /**
  * Returns the alpha value encoded in the 0xAARRGBB encoded pixel.
  */
-static uint32_t getAlpha(uint32_t color);
+static uint32_t get_alpha(uint32_t color);
 
 /**
  * Determines whether a color on an ImageLine is valid.
@@ -53,19 +55,19 @@
    * Returns true if the color specified is a neutral color
    * (no padding, stretching, or optical bounds).
    */
-  virtual bool isNeutralColor(uint32_t color) const = 0;
+  virtual bool IsNeutralColor(uint32_t color) const = 0;
 
   /**
    * Returns true if the color is either a neutral color
    * or one denoting padding, stretching, or optical bounds.
    */
-  bool isValidColor(uint32_t color) const {
+  bool IsValidColor(uint32_t color) const {
     switch (color) {
       case kPrimaryColor:
       case kSecondaryColor:
         return true;
     }
-    return isNeutralColor(color);
+    return IsNeutralColor(color);
   }
 };
 
@@ -81,42 +83,43 @@
 //
 // class ImageLine {
 // public:
-//      virtual int32_t getLength() const = 0;
-//      virtual uint32_t getColor(int32_t idx) const = 0;
+//      virtual int32_t GetLength() const = 0;
+//      virtual uint32_t GetColor(int32_t idx) const = 0;
 // };
 //
 template <typename ImageLine>
-static bool fillRanges(const ImageLine* imageLine,
-                       const ColorValidator* colorValidator,
-                       std::vector<Range>* primaryRanges,
-                       std::vector<Range>* secondaryRanges, std::string* err) {
-  const int32_t length = imageLine->getLength();
+static bool FillRanges(const ImageLine* image_line,
+                       const ColorValidator* color_validator,
+                       std::vector<Range>* primary_ranges,
+                       std::vector<Range>* secondary_ranges,
+                       std::string* out_err) {
+  const int32_t length = image_line->GetLength();
 
-  uint32_t lastColor = 0xffffffffu;
+  uint32_t last_color = 0xffffffffu;
   for (int32_t idx = 1; idx < length - 1; idx++) {
-    const uint32_t color = imageLine->getColor(idx);
-    if (!colorValidator->isValidColor(color)) {
-      *err = "found an invalid color";
+    const uint32_t color = image_line->GetColor(idx);
+    if (!color_validator->IsValidColor(color)) {
+      *out_err = "found an invalid color";
       return false;
     }
 
-    if (color != lastColor) {
+    if (color != last_color) {
       // We are ending a range. Which range?
       // note: encode the x offset without the final 1 pixel border.
-      if (lastColor == kPrimaryColor) {
-        primaryRanges->back().end = idx - 1;
-      } else if (lastColor == kSecondaryColor) {
-        secondaryRanges->back().end = idx - 1;
+      if (last_color == kPrimaryColor) {
+        primary_ranges->back().end = idx - 1;
+      } else if (last_color == kSecondaryColor) {
+        secondary_ranges->back().end = idx - 1;
       }
 
       // We are starting a range. Which range?
       // note: encode the x offset without the final 1 pixel border.
       if (color == kPrimaryColor) {
-        primaryRanges->push_back(Range(idx - 1, length - 2));
+        primary_ranges->push_back(Range(idx - 1, length - 2));
       } else if (color == kSecondaryColor) {
-        secondaryRanges->push_back(Range(idx - 1, length - 2));
+        secondary_ranges->push_back(Range(idx - 1, length - 2));
       }
-      lastColor = color;
+      last_color = color;
     }
   }
   return true;
@@ -128,19 +131,19 @@
  */
 class HorizontalImageLine {
  public:
-  explicit HorizontalImageLine(uint8_t** rows, int32_t xOffset, int32_t yOffset,
+  explicit HorizontalImageLine(uint8_t** rows, int32_t xoffset, int32_t yoffset,
                                int32_t length)
-      : mRows(rows), mXOffset(xOffset), mYOffset(yOffset), mLength(length) {}
+      : rows_(rows), xoffset_(xoffset), yoffset_(yoffset), length_(length) {}
 
-  inline int32_t getLength() const { return mLength; }
+  inline int32_t GetLength() const { return length_; }
 
-  inline uint32_t getColor(int32_t idx) const {
-    return NinePatch::packRGBA(mRows[mYOffset] + (idx + mXOffset) * 4);
+  inline uint32_t GetColor(int32_t idx) const {
+    return NinePatch::PackRGBA(rows_[yoffset_] + (idx + xoffset_) * 4);
   }
 
  private:
-  uint8_t** mRows;
-  int32_t mXOffset, mYOffset, mLength;
+  uint8_t** rows_;
+  int32_t xoffset_, yoffset_, length_;
 
   DISALLOW_COPY_AND_ASSIGN(HorizontalImageLine);
 };
@@ -151,179 +154,180 @@
  */
 class VerticalImageLine {
  public:
-  explicit VerticalImageLine(uint8_t** rows, int32_t xOffset, int32_t yOffset,
+  explicit VerticalImageLine(uint8_t** rows, int32_t xoffset, int32_t yoffset,
                              int32_t length)
-      : mRows(rows), mXOffset(xOffset), mYOffset(yOffset), mLength(length) {}
+      : rows_(rows), xoffset_(xoffset), yoffset_(yoffset), length_(length) {}
 
-  inline int32_t getLength() const { return mLength; }
+  inline int32_t GetLength() const { return length_; }
 
-  inline uint32_t getColor(int32_t idx) const {
-    return NinePatch::packRGBA(mRows[mYOffset + idx] + (mXOffset * 4));
+  inline uint32_t GetColor(int32_t idx) const {
+    return NinePatch::PackRGBA(rows_[yoffset_ + idx] + (xoffset_ * 4));
   }
 
  private:
-  uint8_t** mRows;
-  int32_t mXOffset, mYOffset, mLength;
+  uint8_t** rows_;
+  int32_t xoffset_, yoffset_, length_;
 
   DISALLOW_COPY_AND_ASSIGN(VerticalImageLine);
 };
 
 class DiagonalImageLine {
  public:
-  explicit DiagonalImageLine(uint8_t** rows, int32_t xOffset, int32_t yOffset,
-                             int32_t xStep, int32_t yStep, int32_t length)
-      : mRows(rows),
-        mXOffset(xOffset),
-        mYOffset(yOffset),
-        mXStep(xStep),
-        mYStep(yStep),
-        mLength(length) {}
+  explicit DiagonalImageLine(uint8_t** rows, int32_t xoffset, int32_t yoffset,
+                             int32_t xstep, int32_t ystep, int32_t length)
+      : rows_(rows),
+        xoffset_(xoffset),
+        yoffset_(yoffset),
+        xstep_(xstep),
+        ystep_(ystep),
+        length_(length) {}
 
-  inline int32_t getLength() const { return mLength; }
+  inline int32_t GetLength() const { return length_; }
 
-  inline uint32_t getColor(int32_t idx) const {
-    return NinePatch::packRGBA(mRows[mYOffset + (idx * mYStep)] +
-                               ((idx + mXOffset) * mXStep) * 4);
+  inline uint32_t GetColor(int32_t idx) const {
+    return NinePatch::PackRGBA(rows_[yoffset_ + (idx * ystep_)] +
+                               ((idx + xoffset_) * xstep_) * 4);
   }
 
  private:
-  uint8_t** mRows;
-  int32_t mXOffset, mYOffset, mXStep, mYStep, mLength;
+  uint8_t** rows_;
+  int32_t xoffset_, yoffset_, xstep_, ystep_, length_;
 
   DISALLOW_COPY_AND_ASSIGN(DiagonalImageLine);
 };
 
 class TransparentNeutralColorValidator : public ColorValidator {
  public:
-  bool isNeutralColor(uint32_t color) const override {
-    return getAlpha(color) == 0;
+  bool IsNeutralColor(uint32_t color) const override {
+    return get_alpha(color) == 0;
   }
 };
 
 class WhiteNeutralColorValidator : public ColorValidator {
  public:
-  bool isNeutralColor(uint32_t color) const override {
+  bool IsNeutralColor(uint32_t color) const override {
     return color == kColorOpaqueWhite;
   }
 };
 
-inline static uint32_t getAlpha(uint32_t color) {
+inline static uint32_t get_alpha(uint32_t color) {
   return (color & 0xff000000u) >> 24;
 }
 
-static bool populateBounds(const std::vector<Range>& padding,
-                           const std::vector<Range>& layoutBounds,
-                           const std::vector<Range>& stretchRegions,
-                           const int32_t length, int32_t* paddingStart,
-                           int32_t* paddingEnd, int32_t* layoutStart,
-                           int32_t* layoutEnd, const StringPiece& edgeName,
-                           std::string* err) {
+static bool PopulateBounds(const std::vector<Range>& padding,
+                           const std::vector<Range>& layout_bounds,
+                           const std::vector<Range>& stretch_regions,
+                           const int32_t length, int32_t* padding_start,
+                           int32_t* padding_end, int32_t* layout_start,
+                           int32_t* layout_end, const StringPiece& edge_name,
+                           std::string* out_err) {
   if (padding.size() > 1) {
-    std::stringstream errStream;
-    errStream << "too many padding sections on " << edgeName << " border";
-    *err = errStream.str();
+    std::stringstream err_stream;
+    err_stream << "too many padding sections on " << edge_name << " border";
+    *out_err = err_stream.str();
     return false;
   }
 
-  *paddingStart = 0;
-  *paddingEnd = 0;
+  *padding_start = 0;
+  *padding_end = 0;
   if (!padding.empty()) {
     const Range& range = padding.front();
-    *paddingStart = range.start;
-    *paddingEnd = length - range.end;
-  } else if (!stretchRegions.empty()) {
+    *padding_start = range.start;
+    *padding_end = length - range.end;
+  } else if (!stretch_regions.empty()) {
     // No padding was defined. Compute the padding from the first and last
     // stretch regions.
-    *paddingStart = stretchRegions.front().start;
-    *paddingEnd = length - stretchRegions.back().end;
+    *padding_start = stretch_regions.front().start;
+    *padding_end = length - stretch_regions.back().end;
   }
 
-  if (layoutBounds.size() > 2) {
-    std::stringstream errStream;
-    errStream << "too many layout bounds sections on " << edgeName << " border";
-    *err = errStream.str();
+  if (layout_bounds.size() > 2) {
+    std::stringstream err_stream;
+    err_stream << "too many layout bounds sections on " << edge_name
+               << " border";
+    *out_err = err_stream.str();
     return false;
   }
 
-  *layoutStart = 0;
-  *layoutEnd = 0;
-  if (layoutBounds.size() >= 1) {
-    const Range& range = layoutBounds.front();
+  *layout_start = 0;
+  *layout_end = 0;
+  if (layout_bounds.size() >= 1) {
+    const Range& range = layout_bounds.front();
     // If there is only one layout bound segment, it might not start at 0, but
     // then it should
     // end at length.
     if (range.start != 0 && range.end != length) {
-      std::stringstream errStream;
-      errStream << "layout bounds on " << edgeName
-                << " border must start at edge";
-      *err = errStream.str();
+      std::stringstream err_stream;
+      err_stream << "layout bounds on " << edge_name
+                 << " border must start at edge";
+      *out_err = err_stream.str();
       return false;
     }
-    *layoutStart = range.end;
+    *layout_start = range.end;
 
-    if (layoutBounds.size() >= 2) {
-      const Range& range = layoutBounds.back();
+    if (layout_bounds.size() >= 2) {
+      const Range& range = layout_bounds.back();
       if (range.end != length) {
-        std::stringstream errStream;
-        errStream << "layout bounds on " << edgeName
-                  << " border must start at edge";
-        *err = errStream.str();
+        std::stringstream err_stream;
+        err_stream << "layout bounds on " << edge_name
+                   << " border must start at edge";
+        *out_err = err_stream.str();
         return false;
       }
-      *layoutEnd = length - range.start;
+      *layout_end = length - range.start;
     }
   }
   return true;
 }
 
-static int32_t calculateSegmentCount(const std::vector<Range>& stretchRegions,
+static int32_t CalculateSegmentCount(const std::vector<Range>& stretch_regions,
                                      int32_t length) {
-  if (stretchRegions.size() == 0) {
+  if (stretch_regions.size() == 0) {
     return 0;
   }
 
-  const bool startIsFixed = stretchRegions.front().start != 0;
-  const bool endIsFixed = stretchRegions.back().end != length;
+  const bool start_is_fixed = stretch_regions.front().start != 0;
+  const bool end_is_fixed = stretch_regions.back().end != length;
   int32_t modifier = 0;
-  if (startIsFixed && endIsFixed) {
+  if (start_is_fixed && end_is_fixed) {
     modifier = 1;
-  } else if (!startIsFixed && !endIsFixed) {
+  } else if (!start_is_fixed && !end_is_fixed) {
     modifier = -1;
   }
-  return static_cast<int32_t>(stretchRegions.size()) * 2 + modifier;
+  return static_cast<int32_t>(stretch_regions.size()) * 2 + modifier;
 }
 
-static uint32_t getRegionColor(uint8_t** rows, const Bounds& region) {
+static uint32_t GetRegionColor(uint8_t** rows, const Bounds& region) {
   // Sample the first pixel to compare against.
-  const uint32_t expectedColor =
-      NinePatch::packRGBA(rows[region.top] + region.left * 4);
+  const uint32_t expected_color =
+      NinePatch::PackRGBA(rows[region.top] + region.left * 4);
   for (int32_t y = region.top; y < region.bottom; y++) {
     const uint8_t* row = rows[y];
     for (int32_t x = region.left; x < region.right; x++) {
-      const uint32_t color = NinePatch::packRGBA(row + x * 4);
-      if (getAlpha(color) == 0) {
+      const uint32_t color = NinePatch::PackRGBA(row + x * 4);
+      if (get_alpha(color) == 0) {
         // The color is transparent.
         // If the expectedColor is not transparent, NO_COLOR.
-        if (getAlpha(expectedColor) != 0) {
+        if (get_alpha(expected_color) != 0) {
           return android::Res_png_9patch::NO_COLOR;
         }
-      } else if (color != expectedColor) {
+      } else if (color != expected_color) {
         return android::Res_png_9patch::NO_COLOR;
       }
     }
   }
 
-  if (getAlpha(expectedColor) == 0) {
+  if (get_alpha(expected_color) == 0) {
     return android::Res_png_9patch::TRANSPARENT_COLOR;
   }
-  return expectedColor;
+  return expected_color;
 }
 
-// Fills outColors with each 9-patch section's colour. If the whole section is
+// Fills out_colors with each 9-patch section's color. If the whole section is
 // transparent,
-// it gets the special TRANSPARENT colour. If the whole section is the same
-// colour, it is assigned
-// that colour. Otherwise it gets the special NO_COLOR colour.
+// it gets the special TRANSPARENT color. If the whole section is the same
+// color, it is assigned
+// that color. Otherwise it gets the special NO_COLOR color.
 //
 // Note that the rows contain the 9-patch 1px border, and the indices in the
 // stretch regions are
@@ -332,63 +336,63 @@
 // the indices must be offset by 1.
 //
 // width and height also include the 9-patch 1px border.
-static void calculateRegionColors(
-    uint8_t** rows, const std::vector<Range>& horizontalStretchRegions,
-    const std::vector<Range>& verticalStretchRegions, const int32_t width,
-    const int32_t height, std::vector<uint32_t>* outColors) {
-  int32_t nextTop = 0;
+static void CalculateRegionColors(
+    uint8_t** rows, const std::vector<Range>& horizontal_stretch_regions,
+    const std::vector<Range>& vertical_stretch_regions, const int32_t width,
+    const int32_t height, std::vector<uint32_t>* out_colors) {
+  int32_t next_top = 0;
   Bounds bounds;
-  auto rowIter = verticalStretchRegions.begin();
-  while (nextTop != height) {
-    if (rowIter != verticalStretchRegions.end()) {
-      if (nextTop != rowIter->start) {
+  auto row_iter = vertical_stretch_regions.begin();
+  while (next_top != height) {
+    if (row_iter != vertical_stretch_regions.end()) {
+      if (next_top != row_iter->start) {
         // This is a fixed segment.
         // Offset the bounds by 1 to accommodate the border.
-        bounds.top = nextTop + 1;
-        bounds.bottom = rowIter->start + 1;
-        nextTop = rowIter->start;
+        bounds.top = next_top + 1;
+        bounds.bottom = row_iter->start + 1;
+        next_top = row_iter->start;
       } else {
         // This is a stretchy segment.
         // Offset the bounds by 1 to accommodate the border.
-        bounds.top = rowIter->start + 1;
-        bounds.bottom = rowIter->end + 1;
-        nextTop = rowIter->end;
-        ++rowIter;
+        bounds.top = row_iter->start + 1;
+        bounds.bottom = row_iter->end + 1;
+        next_top = row_iter->end;
+        ++row_iter;
       }
     } else {
       // This is the end, fixed section.
       // Offset the bounds by 1 to accommodate the border.
-      bounds.top = nextTop + 1;
+      bounds.top = next_top + 1;
       bounds.bottom = height + 1;
-      nextTop = height;
+      next_top = height;
     }
 
-    int32_t nextLeft = 0;
-    auto colIter = horizontalStretchRegions.begin();
-    while (nextLeft != width) {
-      if (colIter != horizontalStretchRegions.end()) {
-        if (nextLeft != colIter->start) {
+    int32_t next_left = 0;
+    auto col_iter = horizontal_stretch_regions.begin();
+    while (next_left != width) {
+      if (col_iter != horizontal_stretch_regions.end()) {
+        if (next_left != col_iter->start) {
           // This is a fixed segment.
           // Offset the bounds by 1 to accommodate the border.
-          bounds.left = nextLeft + 1;
-          bounds.right = colIter->start + 1;
-          nextLeft = colIter->start;
+          bounds.left = next_left + 1;
+          bounds.right = col_iter->start + 1;
+          next_left = col_iter->start;
         } else {
           // This is a stretchy segment.
           // Offset the bounds by 1 to accommodate the border.
-          bounds.left = colIter->start + 1;
-          bounds.right = colIter->end + 1;
-          nextLeft = colIter->end;
-          ++colIter;
+          bounds.left = col_iter->start + 1;
+          bounds.right = col_iter->end + 1;
+          next_left = col_iter->end;
+          ++col_iter;
         }
       } else {
         // This is the end, fixed section.
         // Offset the bounds by 1 to accommodate the border.
-        bounds.left = nextLeft + 1;
+        bounds.left = next_left + 1;
         bounds.right = width + 1;
-        nextLeft = width;
+        next_left = width;
       }
-      outColors->push_back(getRegionColor(rows, bounds));
+      out_colors->push_back(GetRegionColor(rows, bounds));
     }
   }
 }
@@ -397,12 +401,12 @@
 // alpha value begins
 // (on both sides).
 template <typename ImageLine>
-static void findOutlineInsets(const ImageLine* imageLine, int32_t* outStart,
-                              int32_t* outEnd) {
-  *outStart = 0;
-  *outEnd = 0;
+static void FindOutlineInsets(const ImageLine* image_line, int32_t* out_start,
+                              int32_t* out_end) {
+  *out_start = 0;
+  *out_end = 0;
 
-  const int32_t length = imageLine->getLength();
+  const int32_t length = image_line->GetLength();
   if (length < 3) {
     return;
   }
@@ -413,179 +417,181 @@
   const int32_t mid2 = length / 2;
   const int32_t mid1 = mid2 + (length % 2);
 
-  uint32_t maxAlpha = 0;
-  for (int32_t i = 0; i < mid1 && maxAlpha != 0xff; i++) {
-    uint32_t alpha = getAlpha(imageLine->getColor(i));
-    if (alpha > maxAlpha) {
-      maxAlpha = alpha;
-      *outStart = i;
+  uint32_t max_alpha = 0;
+  for (int32_t i = 0; i < mid1 && max_alpha != 0xff; i++) {
+    uint32_t alpha = get_alpha(image_line->GetColor(i));
+    if (alpha > max_alpha) {
+      max_alpha = alpha;
+      *out_start = i;
     }
   }
 
-  maxAlpha = 0;
-  for (int32_t i = length - 1; i >= mid2 && maxAlpha != 0xff; i--) {
-    uint32_t alpha = getAlpha(imageLine->getColor(i));
-    if (alpha > maxAlpha) {
-      maxAlpha = alpha;
-      *outEnd = length - (i + 1);
+  max_alpha = 0;
+  for (int32_t i = length - 1; i >= mid2 && max_alpha != 0xff; i--) {
+    uint32_t alpha = get_alpha(image_line->GetColor(i));
+    if (alpha > max_alpha) {
+      max_alpha = alpha;
+      *out_end = length - (i + 1);
     }
   }
   return;
 }
 
 template <typename ImageLine>
-static uint32_t findMaxAlpha(const ImageLine* imageLine) {
-  const int32_t length = imageLine->getLength();
-  uint32_t maxAlpha = 0;
-  for (int32_t idx = 0; idx < length && maxAlpha != 0xff; idx++) {
-    uint32_t alpha = getAlpha(imageLine->getColor(idx));
-    if (alpha > maxAlpha) {
-      maxAlpha = alpha;
+static uint32_t FindMaxAlpha(const ImageLine* image_line) {
+  const int32_t length = image_line->GetLength();
+  uint32_t max_alpha = 0;
+  for (int32_t idx = 0; idx < length && max_alpha != 0xff; idx++) {
+    uint32_t alpha = get_alpha(image_line->GetColor(idx));
+    if (alpha > max_alpha) {
+      max_alpha = alpha;
     }
   }
-  return maxAlpha;
+  return max_alpha;
 }
 
 // Pack the pixels in as 0xAARRGGBB (as 9-patch expects it).
-uint32_t NinePatch::packRGBA(const uint8_t* pixel) {
+uint32_t NinePatch::PackRGBA(const uint8_t* pixel) {
   return (pixel[3] << 24) | (pixel[0] << 16) | (pixel[1] << 8) | pixel[2];
 }
 
-std::unique_ptr<NinePatch> NinePatch::create(uint8_t** rows,
+std::unique_ptr<NinePatch> NinePatch::Create(uint8_t** rows,
                                              const int32_t width,
                                              const int32_t height,
-                                             std::string* err) {
+                                             std::string* out_err) {
   if (width < 3 || height < 3) {
-    *err = "image must be at least 3x3 (1x1 image with 1 pixel border)";
+    *out_err = "image must be at least 3x3 (1x1 image with 1 pixel border)";
     return {};
   }
 
-  std::vector<Range> horizontalPadding;
-  std::vector<Range> horizontalOpticalBounds;
-  std::vector<Range> verticalPadding;
-  std::vector<Range> verticalOpticalBounds;
-  std::vector<Range> unexpectedRanges;
-  std::unique_ptr<ColorValidator> colorValidator;
+  std::vector<Range> horizontal_padding;
+  std::vector<Range> horizontal_layout_bounds;
+  std::vector<Range> vertical_padding;
+  std::vector<Range> vertical_layout_bounds;
+  std::vector<Range> unexpected_ranges;
+  std::unique_ptr<ColorValidator> color_validator;
 
   if (rows[0][3] == 0) {
-    colorValidator = util::make_unique<TransparentNeutralColorValidator>();
-  } else if (packRGBA(rows[0]) == kColorOpaqueWhite) {
-    colorValidator = util::make_unique<WhiteNeutralColorValidator>();
+    color_validator = util::make_unique<TransparentNeutralColorValidator>();
+  } else if (PackRGBA(rows[0]) == kColorOpaqueWhite) {
+    color_validator = util::make_unique<WhiteNeutralColorValidator>();
   } else {
-    *err = "top-left corner pixel must be either opaque white or transparent";
+    *out_err =
+        "top-left corner pixel must be either opaque white or transparent";
     return {};
   }
 
   // Private constructor, can't use make_unique.
-  auto ninePatch = std::unique_ptr<NinePatch>(new NinePatch());
+  auto nine_patch = std::unique_ptr<NinePatch>(new NinePatch());
 
-  HorizontalImageLine topRow(rows, 0, 0, width);
-  if (!fillRanges(&topRow, colorValidator.get(),
-                  &ninePatch->horizontalStretchRegions, &unexpectedRanges,
-                  err)) {
+  HorizontalImageLine top_row(rows, 0, 0, width);
+  if (!FillRanges(&top_row, color_validator.get(),
+                  &nine_patch->horizontal_stretch_regions, &unexpected_ranges,
+                  out_err)) {
     return {};
   }
 
-  if (!unexpectedRanges.empty()) {
-    const Range& range = unexpectedRanges[0];
-    std::stringstream errStream;
-    errStream << "found unexpected optical bounds (red pixel) on top border "
-              << "at x=" << range.start + 1;
-    *err = errStream.str();
+  if (!unexpected_ranges.empty()) {
+    const Range& range = unexpected_ranges[0];
+    std::stringstream err_stream;
+    err_stream << "found unexpected optical bounds (red pixel) on top border "
+               << "at x=" << range.start + 1;
+    *out_err = err_stream.str();
     return {};
   }
 
-  VerticalImageLine leftCol(rows, 0, 0, height);
-  if (!fillRanges(&leftCol, colorValidator.get(),
-                  &ninePatch->verticalStretchRegions, &unexpectedRanges, err)) {
+  VerticalImageLine left_col(rows, 0, 0, height);
+  if (!FillRanges(&left_col, color_validator.get(),
+                  &nine_patch->vertical_stretch_regions, &unexpected_ranges,
+                  out_err)) {
     return {};
   }
 
-  if (!unexpectedRanges.empty()) {
-    const Range& range = unexpectedRanges[0];
-    std::stringstream errStream;
-    errStream << "found unexpected optical bounds (red pixel) on left border "
-              << "at y=" << range.start + 1;
+  if (!unexpected_ranges.empty()) {
+    const Range& range = unexpected_ranges[0];
+    std::stringstream err_stream;
+    err_stream << "found unexpected optical bounds (red pixel) on left border "
+               << "at y=" << range.start + 1;
     return {};
   }
 
-  HorizontalImageLine bottomRow(rows, 0, height - 1, width);
-  if (!fillRanges(&bottomRow, colorValidator.get(), &horizontalPadding,
-                  &horizontalOpticalBounds, err)) {
+  HorizontalImageLine bottom_row(rows, 0, height - 1, width);
+  if (!FillRanges(&bottom_row, color_validator.get(), &horizontal_padding,
+                  &horizontal_layout_bounds, out_err)) {
     return {};
   }
 
-  if (!populateBounds(horizontalPadding, horizontalOpticalBounds,
-                      ninePatch->horizontalStretchRegions, width - 2,
-                      &ninePatch->padding.left, &ninePatch->padding.right,
-                      &ninePatch->layoutBounds.left,
-                      &ninePatch->layoutBounds.right, "bottom", err)) {
+  if (!PopulateBounds(horizontal_padding, horizontal_layout_bounds,
+                      nine_patch->horizontal_stretch_regions, width - 2,
+                      &nine_patch->padding.left, &nine_patch->padding.right,
+                      &nine_patch->layout_bounds.left,
+                      &nine_patch->layout_bounds.right, "bottom", out_err)) {
     return {};
   }
 
-  VerticalImageLine rightCol(rows, width - 1, 0, height);
-  if (!fillRanges(&rightCol, colorValidator.get(), &verticalPadding,
-                  &verticalOpticalBounds, err)) {
+  VerticalImageLine right_col(rows, width - 1, 0, height);
+  if (!FillRanges(&right_col, color_validator.get(), &vertical_padding,
+                  &vertical_layout_bounds, out_err)) {
     return {};
   }
 
-  if (!populateBounds(verticalPadding, verticalOpticalBounds,
-                      ninePatch->verticalStretchRegions, height - 2,
-                      &ninePatch->padding.top, &ninePatch->padding.bottom,
-                      &ninePatch->layoutBounds.top,
-                      &ninePatch->layoutBounds.bottom, "right", err)) {
+  if (!PopulateBounds(vertical_padding, vertical_layout_bounds,
+                      nine_patch->vertical_stretch_regions, height - 2,
+                      &nine_patch->padding.top, &nine_patch->padding.bottom,
+                      &nine_patch->layout_bounds.top,
+                      &nine_patch->layout_bounds.bottom, "right", out_err)) {
     return {};
   }
 
   // Fill the region colors of the 9-patch.
-  const int32_t numRows =
-      calculateSegmentCount(ninePatch->horizontalStretchRegions, width - 2);
-  const int32_t numCols =
-      calculateSegmentCount(ninePatch->verticalStretchRegions, height - 2);
-  if ((int64_t)numRows * (int64_t)numCols > 0x7f) {
-    *err = "too many regions in 9-patch";
+  const int32_t num_rows =
+      CalculateSegmentCount(nine_patch->horizontal_stretch_regions, width - 2);
+  const int32_t num_cols =
+      CalculateSegmentCount(nine_patch->vertical_stretch_regions, height - 2);
+  if ((int64_t)num_rows * (int64_t)num_cols > 0x7f) {
+    *out_err = "too many regions in 9-patch";
     return {};
   }
 
-  ninePatch->regionColors.reserve(numRows * numCols);
-  calculateRegionColors(rows, ninePatch->horizontalStretchRegions,
-                        ninePatch->verticalStretchRegions, width - 2,
-                        height - 2, &ninePatch->regionColors);
+  nine_patch->region_colors.reserve(num_rows * num_cols);
+  CalculateRegionColors(rows, nine_patch->horizontal_stretch_regions,
+                        nine_patch->vertical_stretch_regions, width - 2,
+                        height - 2, &nine_patch->region_colors);
 
   // Compute the outline based on opacity.
 
   // Find left and right extent of 9-patch content on center row.
-  HorizontalImageLine midRow(rows, 1, height / 2, width - 2);
-  findOutlineInsets(&midRow, &ninePatch->outline.left,
-                    &ninePatch->outline.right);
+  HorizontalImageLine mid_row(rows, 1, height / 2, width - 2);
+  FindOutlineInsets(&mid_row, &nine_patch->outline.left,
+                    &nine_patch->outline.right);
 
   // Find top and bottom extent of 9-patch content on center column.
-  VerticalImageLine midCol(rows, width / 2, 1, height - 2);
-  findOutlineInsets(&midCol, &ninePatch->outline.top,
-                    &ninePatch->outline.bottom);
+  VerticalImageLine mid_col(rows, width / 2, 1, height - 2);
+  FindOutlineInsets(&mid_col, &nine_patch->outline.top,
+                    &nine_patch->outline.bottom);
 
-  const int32_t outlineWidth =
-      (width - 2) - ninePatch->outline.left - ninePatch->outline.right;
-  const int32_t outlineHeight =
-      (height - 2) - ninePatch->outline.top - ninePatch->outline.bottom;
+  const int32_t outline_width =
+      (width - 2) - nine_patch->outline.left - nine_patch->outline.right;
+  const int32_t outline_height =
+      (height - 2) - nine_patch->outline.top - nine_patch->outline.bottom;
 
   // Find the largest alpha value within the outline area.
-  HorizontalImageLine outlineMidRow(
-      rows, 1 + ninePatch->outline.left,
-      1 + ninePatch->outline.top + (outlineHeight / 2), outlineWidth);
-  VerticalImageLine outlineMidCol(
-      rows, 1 + ninePatch->outline.left + (outlineWidth / 2),
-      1 + ninePatch->outline.top, outlineHeight);
-  ninePatch->outlineAlpha =
-      std::max(findMaxAlpha(&outlineMidRow), findMaxAlpha(&outlineMidCol));
+  HorizontalImageLine outline_mid_row(
+      rows, 1 + nine_patch->outline.left,
+      1 + nine_patch->outline.top + (outline_height / 2), outline_width);
+  VerticalImageLine outline_mid_col(
+      rows, 1 + nine_patch->outline.left + (outline_width / 2),
+      1 + nine_patch->outline.top, outline_height);
+  nine_patch->outline_alpha =
+      std::max(FindMaxAlpha(&outline_mid_row), FindMaxAlpha(&outline_mid_col));
 
   // Assuming the image is a round rect, compute the radius by marching
   // diagonally from the top left corner towards the center.
-  DiagonalImageLine diagonal(rows, 1 + ninePatch->outline.left,
-                             1 + ninePatch->outline.top, 1, 1,
-                             std::min(outlineWidth, outlineHeight));
-  int32_t topLeft, bottomRight;
-  findOutlineInsets(&diagonal, &topLeft, &bottomRight);
+  DiagonalImageLine diagonal(rows, 1 + nine_patch->outline.left,
+                             1 + nine_patch->outline.top, 1, 1,
+                             std::min(outline_width, outline_height));
+  int32_t top_left, bottom_right;
+  FindOutlineInsets(&diagonal, &top_left, &bottom_right);
 
   /* Determine source radius based upon inset:
    *     sqrt(r^2 + r^2) = sqrt(i^2 + i^2) + r
@@ -593,15 +599,15 @@
    *     (sqrt(2) - 1) * r = sqrt(2) * i
    *     r = sqrt(2) / (sqrt(2) - 1) * i
    */
-  ninePatch->outlineRadius = 3.4142f * topLeft;
-  return ninePatch;
+  nine_patch->outline_radius = 3.4142f * top_left;
+  return nine_patch;
 }
 
-std::unique_ptr<uint8_t[]> NinePatch::serializeBase(size_t* outLen) const {
+std::unique_ptr<uint8_t[]> NinePatch::SerializeBase(size_t* outLen) const {
   android::Res_png_9patch data;
-  data.numXDivs = static_cast<uint8_t>(horizontalStretchRegions.size()) * 2;
-  data.numYDivs = static_cast<uint8_t>(verticalStretchRegions.size()) * 2;
-  data.numColors = static_cast<uint8_t>(regionColors.size());
+  data.numXDivs = static_cast<uint8_t>(horizontal_stretch_regions.size()) * 2;
+  data.numYDivs = static_cast<uint8_t>(vertical_stretch_regions.size()) * 2;
+  data.numColors = static_cast<uint8_t>(region_colors.size());
   data.paddingLeft = padding.left;
   data.paddingRight = padding.right;
   data.paddingTop = padding.top;
@@ -609,8 +615,8 @@
 
   auto buffer = std::unique_ptr<uint8_t[]>(new uint8_t[data.serializedSize()]);
   android::Res_png_9patch::serialize(
-      data, (const int32_t*)horizontalStretchRegions.data(),
-      (const int32_t*)verticalStretchRegions.data(), regionColors.data(),
+      data, (const int32_t*)horizontal_stretch_regions.data(),
+      (const int32_t*)vertical_stretch_regions.data(), region_colors.data(),
       buffer.get());
   // Convert to file endianness.
   reinterpret_cast<android::Res_png_9patch*>(buffer.get())->deviceToFile();
@@ -619,32 +625,32 @@
   return buffer;
 }
 
-std::unique_ptr<uint8_t[]> NinePatch::serializeLayoutBounds(
-    size_t* outLen) const {
-  size_t chunkLen = sizeof(uint32_t) * 4;
-  auto buffer = std::unique_ptr<uint8_t[]>(new uint8_t[chunkLen]);
+std::unique_ptr<uint8_t[]> NinePatch::SerializeLayoutBounds(
+    size_t* out_len) const {
+  size_t chunk_len = sizeof(uint32_t) * 4;
+  auto buffer = std::unique_ptr<uint8_t[]>(new uint8_t[chunk_len]);
   uint8_t* cursor = buffer.get();
 
-  memcpy(cursor, &layoutBounds.left, sizeof(layoutBounds.left));
-  cursor += sizeof(layoutBounds.left);
+  memcpy(cursor, &layout_bounds.left, sizeof(layout_bounds.left));
+  cursor += sizeof(layout_bounds.left);
 
-  memcpy(cursor, &layoutBounds.top, sizeof(layoutBounds.top));
-  cursor += sizeof(layoutBounds.top);
+  memcpy(cursor, &layout_bounds.top, sizeof(layout_bounds.top));
+  cursor += sizeof(layout_bounds.top);
 
-  memcpy(cursor, &layoutBounds.right, sizeof(layoutBounds.right));
-  cursor += sizeof(layoutBounds.right);
+  memcpy(cursor, &layout_bounds.right, sizeof(layout_bounds.right));
+  cursor += sizeof(layout_bounds.right);
 
-  memcpy(cursor, &layoutBounds.bottom, sizeof(layoutBounds.bottom));
-  cursor += sizeof(layoutBounds.bottom);
+  memcpy(cursor, &layout_bounds.bottom, sizeof(layout_bounds.bottom));
+  cursor += sizeof(layout_bounds.bottom);
 
-  *outLen = chunkLen;
+  *out_len = chunk_len;
   return buffer;
 }
 
-std::unique_ptr<uint8_t[]> NinePatch::serializeRoundedRectOutline(
-    size_t* outLen) const {
-  size_t chunkLen = sizeof(uint32_t) * 6;
-  auto buffer = std::unique_ptr<uint8_t[]>(new uint8_t[chunkLen]);
+std::unique_ptr<uint8_t[]> NinePatch::SerializeRoundedRectOutline(
+    size_t* out_len) const {
+  size_t chunk_len = sizeof(uint32_t) * 6;
+  auto buffer = std::unique_ptr<uint8_t[]>(new uint8_t[chunk_len]);
   uint8_t* cursor = buffer.get();
 
   memcpy(cursor, &outline.left, sizeof(outline.left));
@@ -659,12 +665,12 @@
   memcpy(cursor, &outline.bottom, sizeof(outline.bottom));
   cursor += sizeof(outline.bottom);
 
-  *((float*)cursor) = outlineRadius;
-  cursor += sizeof(outlineRadius);
+  *((float*)cursor) = outline_radius;
+  cursor += sizeof(outline_radius);
 
-  *((uint32_t*)cursor) = outlineAlpha;
+  *((uint32_t*)cursor) = outline_alpha;
 
-  *outLen = chunkLen;
+  *out_len = chunk_len;
   return buffer;
 }
 
@@ -677,16 +683,16 @@
              << " r=" << bounds.right << " b=" << bounds.bottom;
 }
 
-::std::ostream& operator<<(::std::ostream& out, const NinePatch& ninePatch) {
+::std::ostream& operator<<(::std::ostream& out, const NinePatch& nine_patch) {
   return out << "horizontalStretch:"
-             << util::joiner(ninePatch.horizontalStretchRegions, " ")
+             << util::Joiner(nine_patch.horizontal_stretch_regions, " ")
              << " verticalStretch:"
-             << util::joiner(ninePatch.verticalStretchRegions, " ")
-             << " padding: " << ninePatch.padding
-             << ", bounds: " << ninePatch.layoutBounds
-             << ", outline: " << ninePatch.outline
-             << " rad=" << ninePatch.outlineRadius
-             << " alpha=" << ninePatch.outlineAlpha;
+             << util::Joiner(nine_patch.vertical_stretch_regions, " ")
+             << " padding: " << nine_patch.padding
+             << ", bounds: " << nine_patch.layout_bounds
+             << ", outline: " << nine_patch.outline
+             << " rad=" << nine_patch.outline_radius
+             << " alpha=" << nine_patch.outline_alpha;
 }
 
 }  // namespace aapt