fix: make sure SVGCanvas get content is complete (#990)

skia-c/skia_c.cpp

@@ -687,6 +687,12 @@ extern "C"
     CANVAS_CAST->drawPicture(picture, MATRIX_CAST, PAINT_CAST);
   }
 
+  void skiac_canvas_destroy(skiac_canvas *c_canvas) {
+    if (c_canvas) {
+      delete CANVAS_CAST;
+    }
+  }
+
 
   // Paint
 
@@ -1741,19 +1747,13 @@ extern "C"
   void skiac_sk_w_stream_get(skiac_w_memory_stream *c_w_memory_stream, skiac_sk_data *sk_data, int width, int height)
   {
     auto stream = reinterpret_cast<SkDynamicMemoryWStream *>(c_w_memory_stream);
-    stream->write("</svg>", 6);
-    auto data = stream->detachAsData().release();
-
-    sk_data->data = reinterpret_cast<skiac_data *>(data);
-    sk_data->ptr = data->bytes();
-    sk_data->size = data->size();
-    auto string = new SkString("<?xml version=\"1.0\" encoding=\"utf-8\" ?>\n<svg xmlns=\"http://www.w3.org/2000/svg\" xmlns:xlink=\"http://www.w3.org/1999/xlink\" width=\"");
-    string->appendS32(width);
-    string->append("\" height=\"");
-    string->appendS32(height);
-    string->append("\">\n");
-    stream->write(string->c_str(), string->size());
-    stream->flush();
+    auto size = stream->bytesWritten();
+    auto data = SkData::MakeUninitialized(size);
+    stream->copyTo(data->writable_data());
+    auto data_ptr = data.release();
+    sk_data->data = reinterpret_cast<skiac_data *>(data_ptr);
+    sk_data->ptr = data_ptr->bytes();
+    sk_data->size = data_ptr->size();
   }
 
   void skiac_sk_w_stream_destroy(skiac_w_memory_stream *c_w_memory_stream)

skia-c/skia_c.hpp

@@ -362,6 +362,7 @@ extern "C"
   void skiac_canvas_write_pixels(skiac_canvas *c_canvas, int width, int height, uint8_t *pixels, size_t row_bytes, int x, int y);
   void skiac_canvas_write_pixels_dirty(skiac_canvas *c_canvas, int width, int height, uint8_t *pixels, size_t row_bytes, size_t length, float x, float y, float dirty_x, float dirty_y, float dirty_width, float dirty_height, uint8_t cs);
   void skiac_canvas_draw_picture(skiac_canvas *c_canvas, skiac_picture *c_picture, skiac_matrix *c_matrix, skiac_paint *c_paint);
+  void skiac_canvas_destroy(skiac_canvas *c_canvas);
 
   // Paint
   skiac_paint *skiac_paint_create();

src/lib.rs

@@ -592,9 +592,27 @@ impl<'scope> SVGCanvas<'scope> {
   }
 
   #[napi]
-  pub fn get_content(&self, env: Env) -> Result<BufferSlice> {
-    let svg_data_stream = self.ctx.context.stream.as_ref().unwrap();
+  pub fn get_content(&mut self, env: Env) -> Result<BufferSlice> {
+    let svg_data_stream = self
+      .ctx
+      .context
+      .stream
+      .take()
+      .ok_or_else(|| Error::new(Status::GenericFailure, "SVGCanvas has no stream"))?;
+    unsafe {
+      sk::ffi::skiac_canvas_destroy(self.ctx.context.surface.0);
+    };
     let svg_data = svg_data_stream.data(self.ctx.context.width, self.ctx.context.height);
+    let (surface, stream) = sk::Surface::new_svg(
+      self.ctx.context.width,
+      self.ctx.context.height,
+      self.ctx.context.surface.alpha_type(),
+      self.flag.into(),
+      ColorSpace::default(),
+    )
+    .ok_or_else(|| Error::new(Status::GenericFailure, "Failed to create surface"))?;
+    self.ctx.context.surface = surface;
+    self.ctx.context.stream = Some(stream);
     unsafe {
       BufferSlice::from_external(&env, svg_data.0.ptr, svg_data.0.size, svg_data, |_, d| {
         mem::drop(d)

src/sk.rs

@@ -495,6 +495,8 @@ pub mod ffi {
       paint: *mut skiac_paint,
     );
 
+    pub fn skiac_canvas_destroy(canvas: *mut skiac_canvas);
+
     pub fn skiac_paint_create() -> *mut skiac_paint;
 
     pub fn skiac_paint_clone(source: *mut skiac_paint) -> *mut skiac_paint;
@@ -2001,7 +2003,7 @@ impl Color {
 }
 
 #[repr(transparent)]
-pub struct Canvas(*mut ffi::skiac_canvas);
+pub struct Canvas(pub(crate) *mut ffi::skiac_canvas);
 
 impl Canvas {
   pub fn clear(&mut self) {