servo/components/script/dom/channelmergernode.rs

/* 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::audionode::{AudioNode, MAX_CHANNEL_COUNT};
use dom::baseaudiocontext::BaseAudioContext;
use dom::bindings::codegen::Bindings::AudioNodeBinding::{ChannelCountMode, ChannelInterpretation};
use dom::bindings::codegen::Bindings::AudioNodeBinding::AudioNodeOptions;
use dom::bindings::codegen::Bindings::ChannelMergerNodeBinding::{self, ChannelMergerOptions};
use dom::bindings::error::{Error, Fallible};
use dom::bindings::reflector::reflect_dom_object;
use dom::bindings::root::DomRoot;
use dom::window::Window;
use dom_struct::dom_struct;
use servo_media::audio::channel_node::ChannelNodeOptions;
use servo_media::audio::node::AudioNodeInit;

#[dom_struct]
pub struct ChannelMergerNode {
    node: AudioNode,
}

impl ChannelMergerNode {
    #[allow(unrooted_must_root)]
    pub fn new_inherited(
        _: &Window,
        context: &BaseAudioContext,
        options: &ChannelMergerOptions,
    ) -> Fallible<ChannelMergerNode> {
        let mut node_options = AudioNodeOptions::empty();
        let count = options.parent.channelCount.unwrap_or(1);
        let mode = options.parent.channelCountMode.unwrap_or(ChannelCountMode::Explicit);
        let interpretation = options.parent.channelInterpretation.unwrap_or(ChannelInterpretation::Speakers);

        if count != 1 || mode != ChannelCountMode::Explicit {
            return Err(Error::InvalidState)
        }

        if options.numberOfInputs < 1 || options.numberOfInputs > MAX_CHANNEL_COUNT {
            return Err(Error::IndexSize)
        }

        node_options.channelCount = Some(count);
        node_options.channelCountMode = Some(mode);
        node_options.channelInterpretation = Some(interpretation);
        let node = AudioNode::new_inherited(
            AudioNodeInit::ChannelMergerNode(options.into()),
            context,
            &node_options,
            options.numberOfInputs, // inputs
            1, // outputs
        )?;
        Ok(ChannelMergerNode {
            node,
        })
    }

    #[allow(unrooted_must_root)]
    pub fn new(
        window: &Window,
        context: &BaseAudioContext,
        options: &ChannelMergerOptions,
    ) -> Fallible<DomRoot<ChannelMergerNode>> {
        let node = ChannelMergerNode::new_inherited(window, context, options)?;
        Ok(reflect_dom_object(Box::new(node), window, ChannelMergerNodeBinding::Wrap))
    }

    pub fn Constructor(
        window: &Window,
        context: &BaseAudioContext,
        options: &ChannelMergerOptions,
    ) -> Fallible<DomRoot<ChannelMergerNode>> {
        ChannelMergerNode::new(window, context, options)
    }
}

impl<'a> From<&'a ChannelMergerOptions> for ChannelNodeOptions {
    fn from(options: &'a ChannelMergerOptions) -> Self {
        Self {
            channels: options.numberOfInputs as u8,
        }
    }
}