Make it easier to test changes to a .icon file.

ui/gfx/paint_vector_icon.cc

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ui/gfx/paint_vector_icon.h"
 
 #include <map>
 
 #include "base/lazy_instance.h"
+#include "base/strings/string_number_conversions.h"
+#include "base/strings/string_split.h"
 #include "ui/gfx/canvas.h"
 #include "ui/gfx/image/canvas_image_source.h"
 #include "ui/gfx/vector_icon_types.h"
 #include "ui/gfx/vector_icons2.h"
 
 namespace gfx {
 
 namespace {
 
-class VectorIconSource : public CanvasImageSource {
- public:
-  VectorIconSource(VectorIconId id, size_t dip_size, SkColor color)
-      : CanvasImageSource(
-            gfx::Size(static_cast<int>(dip_size), static_cast<int>(dip_size)),
-            false),
-        id_(id),
-        color_(color) {}
+// Translates a string such as "MOVE_TO" into a command such as MOVE_TO.
+CommandType CommandFromString(const std::string& source) {
+#define RETURN_IF_IS(command) \
+  if (source == #command)     \
+    return command;
 
-  ~VectorIconSource() override {}
+  RETURN_IF_IS(MOVE_TO);
+  RETURN_IF_IS(R_MOVE_TO);
+  RETURN_IF_IS(R_LINE_TO);
+  RETURN_IF_IS(H_LINE_TO);
+  RETURN_IF_IS(R_H_LINE_TO);
+  RETURN_IF_IS(V_LINE_TO);
+  RETURN_IF_IS(R_V_LINE_TO);
+  RETURN_IF_IS(CUBIC_TO);
+  RETURN_IF_IS(R_CUBIC_TO);
+  RETURN_IF_IS(CIRCLE);
+  RETURN_IF_IS(CLOSE);
+  RETURN_IF_IS(END);
+#undef RETURN_IF_IS

[sky, 2015/08/03 15:27:49]

It would be nice if this generated a compile error when the command set changed.

[Evan Stade, 2015/08/03 17:19:37]

I agree, but the only way I can think to do that is to invert the check, turn it
into a switch statement, and add a loop. This doesn't seem very elegant, and
since this code is only used for debugging, it breaking periodically doesn't
seem that problematic.

 
-  // CanvasImageSource:
-  void Draw(gfx::Canvas* canvas) override {
-    PaintVectorIcon(canvas, id_, size_.width(), color_);
+  NOTREACHED();
+  return CLOSE;
+}
+
+std::vector<PathElement> PathFromSource(const std::string& source) {
+  std::vector<PathElement> path;
+  std::vector<std::string> pieces = base::SplitString(
+      source, "\n ,f", base::TRIM_WHITESPACE, base::SPLIT_WANT_NONEMPTY);
+  for (const auto& piece : pieces) {
+    double value;
+    if (base::StringToDouble(piece, &value))
+      path.push_back(PathElement(SkDoubleToScalar(value)));
+    else
+      path.push_back(PathElement(CommandFromString(piece)));
   }
+  return path;
+}
 
- private:
-  const VectorIconId id_;
-  const SkColor color_;
-
-  DISALLOW_COPY_AND_ASSIGN(VectorIconSource);
-};
-
-// This class caches vector icons (as ImageSkia) so they don't have to be drawn
-// more than once. This also guarantees the backing data for the images returned
-// by CreateVectorIcon will persist in memory until program termination.
-class VectorIconCache {
- public:
-  VectorIconCache() {}
-  ~VectorIconCache() {}
-
-  ImageSkia GetOrCreateIcon(VectorIconId id, size_t dip_size, SkColor color) {
-    IconDescription description(id, dip_size, color);
-    auto iter = images_.find(description);
-    if (iter != images_.end())
-      return iter->second;
-
-    ImageSkia icon(
-        new VectorIconSource(id, dip_size, color),
-        gfx::Size(static_cast<int>(dip_size), static_cast<int>(dip_size)));
-    images_.insert(std::make_pair(description, icon));
-    return icon;
-  }
-
- private:
-  struct IconDescription {
-    IconDescription(VectorIconId id, size_t dip_size, SkColor color)
-        : id(id), dip_size(dip_size), color(color) {}
-
-    bool operator<(const IconDescription& other) const {
-      if (id != other.id)
-        return id < other.id;
-      if (dip_size != other.dip_size)
-        return dip_size < other.dip_size;
-      return color < other.color;
-    }
-
-    VectorIconId id;
-    size_t dip_size;
-    SkColor color;
-  };
-
-  std::map<IconDescription, ImageSkia> images_;
-
-  DISALLOW_COPY_AND_ASSIGN(VectorIconCache);
-};
-
-static base::LazyInstance<VectorIconCache> g_icon_cache =
-    LAZY_INSTANCE_INITIALIZER;
-
-}  // namespace
-
-void PaintVectorIcon(Canvas* canvas,
-                     VectorIconId id,
-                     size_t dip_size,
-                     SkColor color) {
-  DCHECK(VectorIconId::VECTOR_ICON_NONE != id);
-  const PathElement* path_elements = GetPathForVectorIcon(id);
+void PaintPath(Canvas* canvas,
+               const PathElement* path_elements,
+               size_t dip_size,
+               SkColor color) {
   SkPath path;
   path.setFillType(SkPath::kEvenOdd_FillType);
   if (dip_size != kReferenceSizeDip) {
     SkScalar scale = SkIntToScalar(dip_size) / SkIntToScalar(kReferenceSizeDip);
     canvas->sk_canvas()->scale(scale, scale);
   }
 
   for (size_t i = 0; path_elements[i].type != END; i++) {
     switch (path_elements[i].type) {
       case MOVE_TO: {
@@ skipping 93 matching lines @@
     }
   }
 
   SkPaint paint;
   paint.setStyle(SkPaint::kFill_Style);
   paint.setAntiAlias(true);
   paint.setColor(color);
   canvas->DrawPath(path, paint);
 }
 
+class VectorIconSource : public CanvasImageSource {
+ public:
+  VectorIconSource(VectorIconId id, size_t dip_size, SkColor color)
+      : CanvasImageSource(
+            gfx::Size(static_cast<int>(dip_size), static_cast<int>(dip_size)),
+            false),
+        id_(id),
+        color_(color) {}
+
+  VectorIconSource(const std::string& definition,
+                   size_t dip_size,
+                   SkColor color)
+      : CanvasImageSource(
+            gfx::Size(static_cast<int>(dip_size), static_cast<int>(dip_size)),
+            false),
+        id_(VectorIconId::VECTOR_ICON_NONE),
+        path_(PathFromSource(definition)),
+        color_(color) {}
+
+  ~VectorIconSource() override {}
+
+  // CanvasImageSource:
+  void Draw(gfx::Canvas* canvas) override {
+    if (path_.empty())
+      PaintVectorIcon(canvas, id_, size_.width(), color_);
+    else
+      PaintPath(canvas, path_.data(), size_.width(), color_);
+  }
+
+ private:
+  const VectorIconId id_;
+  const std::vector<PathElement> path_;
+  const SkColor color_;
+
+  DISALLOW_COPY_AND_ASSIGN(VectorIconSource);
+};
+
+// This class caches vector icons (as ImageSkia) so they don't have to be drawn
+// more than once. This also guarantees the backing data for the images returned
+// by CreateVectorIcon will persist in memory until program termination.
+class VectorIconCache {
+ public:
+  VectorIconCache() {}
+  ~VectorIconCache() {}
+
+  ImageSkia GetOrCreateIcon(VectorIconId id, size_t dip_size, SkColor color) {
+    IconDescription description(id, dip_size, color);
+    auto iter = images_.find(description);
+    if (iter != images_.end())
+      return iter->second;
+
+    ImageSkia icon(
+        new VectorIconSource(id, dip_size, color),
+        gfx::Size(static_cast<int>(dip_size), static_cast<int>(dip_size)));
+    images_.insert(std::make_pair(description, icon));
+    return icon;
+  }
+
+ private:
+  struct IconDescription {
+    IconDescription(VectorIconId id, size_t dip_size, SkColor color)
+        : id(id), dip_size(dip_size), color(color) {}
+
+    bool operator<(const IconDescription& other) const {
+      if (id != other.id)
+        return id < other.id;
+      if (dip_size != other.dip_size)
+        return dip_size < other.dip_size;
+      return color < other.color;
+    }
+
+    VectorIconId id;
+    size_t dip_size;
+    SkColor color;
+  };
+
+  std::map<IconDescription, ImageSkia> images_;
+
+  DISALLOW_COPY_AND_ASSIGN(VectorIconCache);
+};
+
+static base::LazyInstance<VectorIconCache> g_icon_cache =
+    LAZY_INSTANCE_INITIALIZER;
+
+}  // namespace
+
+void PaintVectorIcon(Canvas* canvas,
+                     VectorIconId id,
+                     size_t dip_size,
+                     SkColor color) {
+  DCHECK(VectorIconId::VECTOR_ICON_NONE != id);
+  PaintPath(canvas, GetPathForVectorIcon(id), dip_size, color);
+}
+
 ImageSkia CreateVectorIcon(VectorIconId id, size_t dip_size, SkColor color) {
   return g_icon_cache.Get().GetOrCreateIcon(id, dip_size, color);
 }
 
+ImageSkia CreateVectorIconFromSource(const std::string& source,
+                                     size_t dip_size,
+                                     SkColor color) {
+  return ImageSkia(
+      new VectorIconSource(source, dip_size, color),
+      gfx::Size(static_cast<int>(dip_size), static_cast<int>(dip_size)));
+}
+
 }  // namespace gfx