Implement Canvas pixel manipulation

components/script/dom/imagedata.rs

@@ -0,0 +1,87 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+use dom::bindings::codegen::Bindings::ImageDataBinding;
+use dom::bindings::codegen::Bindings::ImageDataBinding::ImageDataMethods;
+use dom::bindings::global::GlobalRef;
+use dom::bindings::js::{JSRef, Temporary};
+use dom::bindings::utils::{Reflector, reflect_dom_object};
+use geom::size::Size2D;
+use js::jsapi::{JSContext, JSObject};
+use js::jsfriendapi::bindgen::{JS_NewUint8ClampedArray, JS_GetUint8ClampedArrayData};
+use libc::uint8_t;
+use std::vec::Vec;
+use collections::slice;
+use std::ptr;
+
+#[dom_struct]
+#[allow(raw_pointer_derive)]
+pub struct ImageData {
+    reflector_: Reflector,
+    width: u32,
+    height: u32,
+    data: *mut JSObject,
+}
+
+impl ImageData {
+    #[allow(unsafe_blocks)]
+    fn new_inherited(width: u32, height: u32, data: Option<Vec<u8>>, global: GlobalRef) -> ImageData {
+        unsafe {
+            let cx = global.get_cx();
+            let js_object: *mut JSObject = JS_NewUint8ClampedArray(cx, width * height * 4);
+
+            if let Some(vec) = data {
+                let js_object_data: *mut uint8_t = JS_GetUint8ClampedArrayData(js_object, cx);
+                ptr::copy_nonoverlapping_memory(js_object_data, vec.as_ptr(), vec.len())
+            }
+
+            ImageData {
+                reflector_: Reflector::new(),
+                width: width,
+                height: height,
+                data: js_object,
+            }
+        }
+    }
+
+    pub fn new(global: GlobalRef, width: u32, height: u32, data: Option<Vec<u8>>) -> Temporary<ImageData> {
+        reflect_dom_object(box ImageData::new_inherited(width, height, data, global),
+                           global, ImageDataBinding::Wrap)
+    }
+}
+
+pub trait ImageDataHelpers {
+    fn get_data_array(self, global: &GlobalRef) -> Vec<u8>;
+    fn get_size(&self) -> Size2D<i32>;
+}
+
+impl<'a> ImageDataHelpers for JSRef<'a, ImageData> {
+    #[allow(unsafe_blocks)]
+    fn get_data_array(self, global: &GlobalRef) -> Vec<u8> {
+        unsafe {
+            let cx = global.get_cx();
+            let data: *const uint8_t = JS_GetUint8ClampedArrayData(self.Data(cx), cx) as *const uint8_t;
+            let len = self.Width() * self.Height() * 4;
+            slice::from_raw_parts(data, len as uint).to_vec()
+        }
+    }
+
+    fn get_size(&self) -> Size2D<i32> {
+        Size2D(self.Width() as i32, self.Height() as i32)
+    }
+}
+
+impl<'a> ImageDataMethods for JSRef<'a, ImageData> {
+    fn Width(self) -> u32 {
+        self.width
+    }
+
+    fn Height(self) -> u32 {
+        self.height
+    }
+
+    fn Data(self, _: *mut JSContext) -> *mut JSObject {
+        self.data
+    }
+}