Merge pull request #8849 from electron/to-data-url-scale-factor

Support scale factor in more NativeImage APIs

atom/common/api/atom_api_native_image.cc

@@ -12,7 +12,6 @@
 #include "atom/common/native_mate_converters/gfx_converter.h"
 #include "atom/common/native_mate_converters/gurl_converter.h"
 #include "atom/common/native_mate_converters/value_converter.h"
-#include "base/base64.h"
 #include "base/files/file_util.h"
 #include "base/strings/pattern.h"
 #include "base/strings/string_util.h"
@@ -21,6 +20,7 @@
 #include "net/base/data_url.h"
 #include "third_party/skia/include/core/SkPixelRef.h"
 #include "ui/base/layout.h"
+#include "ui/base/webui/web_ui_util.h"
 #include "ui/gfx/codec/jpeg_codec.h"
 #include "ui/gfx/codec/png_codec.h"
 #include "ui/gfx/geometry/size.h"
@@ -76,6 +76,15 @@ float GetScaleFactorFromPath(const base::FilePath& path) {
   return 1.0f;
 }
 
+// Get the scale factor from options object at the first argument
+float GetScaleFactorFromOptions(mate::Arguments* args) {
+  float scale_factor = 1.0f;
+  mate::Dictionary options;
+  if (args->GetNext(&options))
+    options.Get("scaleFactor", &scale_factor);
+  return scale_factor;
+}
+
 bool AddImageSkiaRep(gfx::ImageSkia* image,
                      const unsigned char* data,
                      size_t size,
@@ -230,21 +239,40 @@ HICON NativeImage::GetHICON(int size) {
 }
 #endif
 
-v8::Local<v8::Value> NativeImage::ToPNG(v8::Isolate* isolate) {
+v8::Local<v8::Value> NativeImage::ToPNG(mate::Arguments* args) {
+  float scale_factor = GetScaleFactorFromOptions(args);
+
+  if (scale_factor == 1.0f) {
+    // Use raw 1x PNG bytes when available
     scoped_refptr<base::RefCountedMemory> png = image_.As1xPNGBytes();
-  return node::Buffer::Copy(isolate,
+    if (png->size() > 0) {
-                            reinterpret_cast<const char*>(png->front()),
+      const char* data = reinterpret_cast<const char*>(png->front());
-                            static_cast<size_t>(png->size())).ToLocalChecked();
+      size_t size = png->size();
+      return node::Buffer::Copy(args->isolate(), data, size).ToLocalChecked();
+    }
+  }
+
+  const SkBitmap bitmap =
+      image_.AsImageSkia().GetRepresentation(scale_factor).sk_bitmap();
+  std::unique_ptr<std::vector<unsigned char>> encoded(
+      new std::vector<unsigned char>());
+  gfx::PNGCodec::EncodeBGRASkBitmap(bitmap, false, encoded.get());
+  const char* data = reinterpret_cast<char*>(encoded->data());
+  size_t size = encoded->size();
+  return node::Buffer::Copy(args->isolate(), data, size).ToLocalChecked();
 }
 
-v8::Local<v8::Value> NativeImage::ToBitmap(v8::Isolate* isolate) {
+v8::Local<v8::Value> NativeImage::ToBitmap(mate::Arguments* args) {
-  if (IsEmpty()) return node::Buffer::New(isolate, 0).ToLocalChecked();
+  float scale_factor = GetScaleFactorFromOptions(args);
 
-  const SkBitmap* bitmap = image_.ToSkBitmap();
+  const SkBitmap bitmap =
-  SkPixelRef* ref = bitmap->pixelRef();
+      image_.AsImageSkia().GetRepresentation(scale_factor).sk_bitmap();
-  return node::Buffer::Copy(isolate,
+  SkPixelRef* ref = bitmap.pixelRef();
+  if (!ref)
+    return node::Buffer::New(args->isolate(), 0).ToLocalChecked();
+  return node::Buffer::Copy(args->isolate(),
                             reinterpret_cast<const char*>(ref->pixels()),
-                            bitmap->getSafeSize()).ToLocalChecked();
+                            bitmap.getSafeSize()).ToLocalChecked();
 }
 
 v8::Local<v8::Value> NativeImage::ToJPEG(v8::Isolate* isolate, int quality) {
@@ -253,26 +281,34 @@ v8::Local<v8::Value> NativeImage::ToJPEG(v8::Isolate* isolate, int quality) {
   return node::Buffer::Copy(
       isolate,
       reinterpret_cast<const char*>(&output.front()),
-      static_cast<size_t>(output.size())).ToLocalChecked();
+      output.size()).ToLocalChecked();
 }
 
-std::string NativeImage::ToDataURL() {
+std::string NativeImage::ToDataURL(mate::Arguments* args) {
+  float scale_factor = GetScaleFactorFromOptions(args);
+
+  if (scale_factor == 1.0f) {
+    // Use raw 1x PNG bytes when available
     scoped_refptr<base::RefCountedMemory> png = image_.As1xPNGBytes();
-  std::string data_url;
+    if (png->size() > 0)
-  data_url.insert(data_url.end(), png->front(), png->front() + png->size());
+      return webui::GetPngDataUrl(png->front(), png->size());
-  base::Base64Encode(data_url, &data_url);
+  }
-  data_url.insert(0, "data:image/png;base64,");
+
-  return data_url;
+  return webui::GetBitmapDataUrl(
+      image_.AsImageSkia().GetRepresentation(scale_factor).sk_bitmap());
 }
 
-v8::Local<v8::Value> NativeImage::GetBitmap(v8::Isolate* isolate) {
+v8::Local<v8::Value> NativeImage::GetBitmap(mate::Arguments* args) {
-  if (IsEmpty()) return node::Buffer::New(isolate, 0).ToLocalChecked();
+  float scale_factor = GetScaleFactorFromOptions(args);
 
-  const SkBitmap* bitmap = image_.ToSkBitmap();
+  const SkBitmap bitmap =
-  SkPixelRef* ref = bitmap->pixelRef();
+      image_.AsImageSkia().GetRepresentation(scale_factor).sk_bitmap();
-  return node::Buffer::New(isolate,
+  SkPixelRef* ref = bitmap.pixelRef();
+  if (!ref)
+    return node::Buffer::New(args->isolate(), 0).ToLocalChecked();
+  return node::Buffer::New(args->isolate(),
                            reinterpret_cast<char*>(ref->pixels()),
-                           bitmap->getSafeSize(),
+                           bitmap.getSafeSize(),
                            &Noop,
                            nullptr).ToLocalChecked();
 }

atom/common/api/atom_api_native_image.h

@@ -70,10 +70,10 @@ class NativeImage : public mate::Wrappable<NativeImage> {
   ~NativeImage() override;
 
  private:
-  v8::Local<v8::Value> ToPNG(v8::Isolate* isolate);
+  v8::Local<v8::Value> ToPNG(mate::Arguments* args);
   v8::Local<v8::Value> ToJPEG(v8::Isolate* isolate, int quality);
-  v8::Local<v8::Value> ToBitmap(v8::Isolate* isolate);
+  v8::Local<v8::Value> ToBitmap(mate::Arguments* args);
-  v8::Local<v8::Value> GetBitmap(v8::Isolate* isolate);
+  v8::Local<v8::Value> GetBitmap(mate::Arguments* args);
   v8::Local<v8::Value> GetNativeHandle(
     v8::Isolate* isolate,
     mate::Arguments* args);
@@ -81,7 +81,7 @@ class NativeImage : public mate::Wrappable<NativeImage> {
                                    const base::DictionaryValue& options);
   mate::Handle<NativeImage> Crop(v8::Isolate* isolate,
                                  const gfx::Rect& rect);
-  std::string ToDataURL();
+  std::string ToDataURL(mate::Arguments* args);
   bool IsEmpty();
   gfx::Size GetSize();
   float GetAspectRatio();

docs/api/native-image.md

@@ -165,7 +165,10 @@ Process: [Main](../glossary.md#main-process), [Renderer](../glossary.md#renderer
 
 The following methods are available on instances of the `NativeImage` class:
 
-#### `image.toPNG()`
+#### `image.toPNG([options])`
+
+* `options` Object (optional)
+  * `scaleFactor` Double (optional) - Defaults to 1.0.
 
 Returns `Buffer` - A [Buffer][buffer] that contains the image's `PNG` encoded data.
 
@@ -175,16 +178,25 @@ Returns `Buffer` - A [Buffer][buffer] that contains the image's `PNG` encoded da
 
 Returns `Buffer` - A [Buffer][buffer] that contains the image's `JPEG` encoded data.
 
-#### `image.toBitmap()`
+#### `image.toBitmap([options])`
+
+* `options` Object (optional)
+  * `scaleFactor` Double (optional) - Defaults to 1.0.
 
 Returns `Buffer` - A [Buffer][buffer] that contains a copy of the image's raw bitmap pixel
 data.
 
-#### `image.toDataURL()`
+#### `image.toDataURL([options])`
+
+* `options` Object (optional)
+  * `scaleFactor` Double (optional) - Defaults to 1.0.
 
 Returns `String` - The data URL of the image.
 
-#### `image.getBitmap()`
+#### `image.getBitmap([options])`
+
+* `options` Object (optional)
+  * `scaleFactor` Double (optional) - Defaults to 1.0.
 
 Returns `Buffer` - A [Buffer][buffer] that contains the image's raw bitmap pixel data.
 

spec/api-native-image-spec.js

@@ -11,11 +11,15 @@ describe('nativeImage module', () => {
       assert.equal(empty.isEmpty(), true)
       assert.equal(empty.getAspectRatio(), 1)
       assert.equal(empty.toDataURL(), 'data:image/png;base64,')
+      assert.equal(empty.toDataURL({scaleFactor: 2.0}), 'data:image/png;base64,')
       assert.deepEqual(empty.getSize(), {width: 0, height: 0})
       assert.deepEqual(empty.getBitmap(), [])
+      assert.deepEqual(empty.getBitmap({scaleFactor: 2.0}), [])
       assert.deepEqual(empty.toBitmap(), [])
+      assert.deepEqual(empty.toBitmap({scaleFactor: 2.0}), [])
       assert.deepEqual(empty.toJPEG(100), [])
       assert.deepEqual(empty.toPNG(), [])
+      assert.deepEqual(empty.toPNG({scaleFactor: 2.0}), [])
 
       if (process.platform === 'darwin') {
         assert.deepEqual(empty.getNativeHandle(), [])
@@ -79,6 +83,60 @@ describe('nativeImage module', () => {
     })
   })
 
+  describe('toDataURL()', () => {
+    it('returns a PNG data URL', () => {
+      const imageA = nativeImage.createFromPath(path.join(__dirname, 'fixtures', 'assets', '1x1.png'))
+      assert.equal(imageA.toDataURL(), 'data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAAC0lEQVQYlWNgAAIAAAUAAdafFs0AAAAASUVORK5CYII=')
+      assert.equal(imageA.toDataURL({scaleFactor: 2.0}), 'data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAAC0lEQVQYlWNgAAIAAAUAAdafFs0AAAAASUVORK5CYII=')
+    })
+
+    it('returns a data URL at 1x scale factor by default', () => {
+      const imageA = nativeImage.createFromPath(path.join(__dirname, 'fixtures', 'assets', 'logo.png'))
+      const imageB = nativeImage.createFromBuffer(imageA.toPNG(), {
+        width: imageA.getSize().width,
+        height: imageA.getSize().height,
+        scaleFactor: 2.0
+      })
+      assert.deepEqual(imageB.getSize(), {width: 269, height: 95})
+
+      const imageC = nativeImage.createFromDataURL(imageB.toDataURL())
+      assert.deepEqual(imageC.getSize(), {width: 538, height: 190})
+      assert(imageB.toBitmap().equals(imageC.toBitmap()))
+    })
+
+    it('supports a scale factor', () => {
+      const imageA = nativeImage.createFromPath(path.join(__dirname, 'fixtures', 'assets', 'logo.png'))
+      const imageB = nativeImage.createFromDataURL(imageA.toDataURL({scaleFactor: 1.0}))
+      assert.deepEqual(imageB.getSize(), {width: 538, height: 190})
+      const imageC = nativeImage.createFromDataURL(imageA.toDataURL({scaleFactor: 2.0}))
+      assert.deepEqual(imageC.getSize(), {width: 538, height: 190})
+    })
+  })
+
+  describe('toPNG()', () => {
+    it('returns a buffer at 1x scale factor by default', () => {
+      const imageA = nativeImage.createFromPath(path.join(__dirname, 'fixtures', 'assets', 'logo.png'))
+      const imageB = nativeImage.createFromBuffer(imageA.toPNG(), {
+        width: imageA.getSize().width,
+        height: imageA.getSize().height,
+        scaleFactor: 2.0
+      })
+      assert.deepEqual(imageB.getSize(), {width: 269, height: 95})
+
+      const imageC = nativeImage.createFromBuffer(imageB.toPNG())
+      assert.deepEqual(imageC.getSize(), {width: 538, height: 190})
+      assert(imageB.toBitmap().equals(imageC.toBitmap()))
+    })
+
+    it('supports a scale factor', () => {
+      const imageA = nativeImage.createFromPath(path.join(__dirname, 'fixtures', 'assets', 'logo.png'))
+      const imageB = nativeImage.createFromBuffer(imageA.toPNG({scaleFactor: 1.0}))
+      assert.deepEqual(imageB.getSize(), {width: 538, height: 190})
+      const imageC = nativeImage.createFromBuffer(imageA.toPNG({scaleFactor: 2.0}), {scaleFactor: 2.0})
+      assert.deepEqual(imageC.getSize(), {width: 269, height: 95})
+    })
+  })
+
   describe('createFromPath(path)', () => {
     it('returns an empty image for invalid paths', () => {
       assert(nativeImage.createFromPath('').isEmpty())