const EventEmitter = require('events');
const log = require('./util/log');
const Runtime = require('./engine/runtime');
const sb2 = require('./serialization/sb2');
const sb3 = require('./serialization/sb3');
const StringUtil = require('./util/string-util');
const loadCostume = require('./import/load-costume.js');
const loadSound = require('./import/load-sound.js');
const RESERVED_NAMES = ['_mouse_', '_stage_', '_edge_', '_myself_', '_random_'];
/**
* Handles connections between blocks, stage, and extensions.
* @constructor
*/
class VirtualMachine extends EventEmitter {
constructor () {
super();
/**
* VM runtime, to store blocks, I/O devices, sprites/targets, etc.
* @type {!Runtime}
*/
this.runtime = new Runtime();
/**
* The "currently editing"/selected target ID for the VM.
* Block events from any Blockly workspace are routed to this target.
* @type {!string}
*/
this.editingTarget = null;
// Runtime emits are passed along as VM emits.
this.runtime.on(Runtime.SCRIPT_GLOW_ON, glowData => {
this.emit(Runtime.SCRIPT_GLOW_ON, glowData);
});
this.runtime.on(Runtime.SCRIPT_GLOW_OFF, glowData => {
this.emit(Runtime.SCRIPT_GLOW_OFF, glowData);
});
this.runtime.on(Runtime.BLOCK_GLOW_ON, glowData => {
this.emit(Runtime.BLOCK_GLOW_ON, glowData);
});
this.runtime.on(Runtime.BLOCK_GLOW_OFF, glowData => {
this.emit(Runtime.BLOCK_GLOW_OFF, glowData);
});
this.runtime.on(Runtime.PROJECT_RUN_START, () => {
this.emit(Runtime.PROJECT_RUN_START);
});
this.runtime.on(Runtime.PROJECT_RUN_STOP, () => {
this.emit(Runtime.PROJECT_RUN_STOP);
});
this.runtime.on(Runtime.VISUAL_REPORT, visualReport => {
this.emit(Runtime.VISUAL_REPORT, visualReport);
});
this.runtime.on(Runtime.TARGETS_UPDATE, () => {
this.emitTargetsUpdate();
});
this.runtime.on(Runtime.MONITORS_UPDATE, monitorList => {
this.emit(Runtime.MONITORS_UPDATE, monitorList);
});
this.blockListener = this.blockListener.bind(this);
this.flyoutBlockListener = this.flyoutBlockListener.bind(this);
this.monitorBlockListener = this.monitorBlockListener.bind(this);
this.variableListener = this.variableListener.bind(this);
}
/**
* Start running the VM - do this before anything else.
*/
start () {
this.runtime.start();
}
/**
* "Green flag" handler - start all threads starting with a green flag.
*/
greenFlag () {
this.runtime.greenFlag();
}
/**
* Set whether the VM is in "turbo mode."
* When true, loops don't yield to redraw.
* @param {boolean} turboModeOn Whether turbo mode should be set.
*/
setTurboMode (turboModeOn) {
this.runtime.turboMode = !!turboModeOn;
}
/**
* Set whether the VM is in 2.0 "compatibility mode."
* When true, ticks go at 2.0 speed (30 TPS).
* @param {boolean} compatibilityModeOn Whether compatibility mode is set.
*/
setCompatibilityMode (compatibilityModeOn) {
this.runtime.setCompatibilityMode(!!compatibilityModeOn);
}
/**
* Stop all threads and running activities.
*/
stopAll () {
this.runtime.stopAll();
}
/**
* Clear out current running project data.
*/
clear () {
this.runtime.dispose();
this.editingTarget = null;
this.emitTargetsUpdate();
}
/**
* Get data for playground. Data comes back in an emitted event.
*/
getPlaygroundData () {
const instance = this;
// Only send back thread data for the current editingTarget.
const threadData = this.runtime.threads.filter(thread => thread.target === instance.editingTarget);
// Remove the target key, since it's a circular reference.
const filteredThreadData = JSON.stringify(threadData, (key, value) => {
if (key === 'target') return;
return value;
}, 2);
this.emit('playgroundData', {
blocks: this.editingTarget.blocks,
threads: filteredThreadData
});
}
/**
* Post I/O data to the virtual devices.
* @param {?string} device Name of virtual I/O device.
* @param {object} data Any data object to post to the I/O device.
*/
postIOData (device, data) {
if (this.runtime.ioDevices[device]) {
this.runtime.ioDevices[device].postData(data);
}
}
/**
* Load a project from a Scratch 2.0 JSON representation.
* @param {?string} json JSON string representing the project.
* @return {!Promise} Promise that resolves after targets are installed.
*/
loadProject (json) {
// @todo: Handle other formats, e.g., Scratch 1.4, Scratch 3.0.
return this.fromJSON(json);
}
/**
* Load a project from the Scratch web site, by ID.
* @param {string} id - the ID of the project to download, as a string.
*/
downloadProjectId (id) {
const storage = this.runtime.storage;
if (!storage) {
log.error('No storage module present; cannot load project: ', id);
return;
}
const vm = this;
const promise = storage.load(storage.AssetType.Project, id);
promise.then(projectAsset => {
vm.loadProject(projectAsset.decodeText());
});
}
/**
* @returns {string} Project in a Scratch 3.0 JSON representation.
*/
saveProjectSb3 () {
// @todo: Handle other formats, e.g., Scratch 1.4, Scratch 2.0.
return this.toJSON();
}
/**
* Export project as a Scratch 3.0 JSON representation.
* @return {string} Serialized state of the runtime.
*/
toJSON () {
return JSON.stringify(sb3.serialize(this.runtime));
}
/**
* Load a project from a Scratch JSON representation.
* @param {string} json JSON string representing a project.
* @returns {Promise} Promise that resolves after the project has loaded
*/
fromJSON (json) {
// Clear the current runtime
this.clear();
// Validate & parse
if (typeof json !== 'string') {
log.error('Failed to parse project. Non-string supplied to fromJSON.');
return;
}
json = JSON.parse(json);
if (typeof json !== 'object') {
log.error('Failed to parse project. JSON supplied to fromJSON is not an object.');
return;
}
// Establish version, deserialize, and load into runtime
// @todo Support Scratch 1.4
// @todo This is an extremely naïve / dangerous way of determining version.
// See `scratch-parser` for a more sophisticated validation
// methodology that should be adapted for use here
let deserializer;
if ((typeof json.meta !== 'undefined') && (typeof json.meta.semver !== 'undefined')) {
deserializer = sb3;
} else {
deserializer = sb2;
}
return deserializer.deserialize(json, this.runtime).then(targets => {
this.clear();
for (let n = 0; n < targets.length; n++) {
if (targets[n] !== null) {
this.runtime.targets.push(targets[n]);
targets[n].updateAllDrawableProperties();
}
}
// Select the first target for editing, e.g., the first sprite.
if (this.runtime.targets.length > 1) {
this.editingTarget = this.runtime.targets[1];
} else {
this.editingTarget = this.runtime.targets[0];
}
// Update the VM user's knowledge of targets and blocks on the workspace.
this.emitTargetsUpdate();
this.emitWorkspaceUpdate();
this.runtime.setEditingTarget(this.editingTarget);
});
}
/**
* Add a single sprite from the "Sprite2" (i.e., SB2 sprite) format.
* @param {string} json JSON string representing the sprite.
* @returns {Promise} Promise that resolves after the sprite is added
*/
addSprite2 (json) {
// Validate & parse
if (typeof json !== 'string') {
log.error('Failed to parse sprite. Non-string supplied to addSprite2.');
return;
}
json = JSON.parse(json);
if (typeof json !== 'object') {
log.error('Failed to parse sprite. JSON supplied to addSprite2 is not an object.');
return;
}
// Select new sprite.
return sb2.deserialize(json, this.runtime, true).then(targets => {
this.runtime.targets.push(targets[0]);
this.editingTarget = targets[0];
this.editingTarget.updateAllDrawableProperties();
// Update the VM user's knowledge of targets and blocks on the workspace.
this.emitTargetsUpdate();
this.emitWorkspaceUpdate();
this.runtime.setEditingTarget(this.editingTarget);
});
}
/**
* Add a costume to the current editing target.
* @param {string} md5ext - the MD5 and extension of the costume to be loaded.
* @param {!object} costumeObject Object representing the costume.
* @property {int} skinId - the ID of the costume's render skin, once installed.
* @property {number} rotationCenterX - the X component of the costume's origin.
* @property {number} rotationCenterY - the Y component of the costume's origin.
* @property {number} [bitmapResolution] - the resolution scale for a bitmap costume.
*/
addCostume (md5ext, costumeObject) {
loadCostume(md5ext, costumeObject, this.runtime).then(() => {
this.editingTarget.addCostume(costumeObject);
this.editingTarget.setCostume(
this.editingTarget.sprite.costumes.length - 1
);
});
}
/**
* Rename a costume on the current editing target.
* @param {int} costumeIndex - the index of the costume to be renamed.
* @param {string} newName - the desired new name of the costume (will be modified if already in use).
*/
renameCostume (costumeIndex, newName) {
this.editingTarget.renameCostume(costumeIndex, newName);
this.emitTargetsUpdate();
}
/**
* Delete a costume from the current editing target.
* @param {int} costumeIndex - the index of the costume to be removed.
*/
deleteCostume (costumeIndex) {
this.editingTarget.deleteCostume(costumeIndex);
}
/**
* Add a sound to the current editing target.
* @param {!object} soundObject Object representing the costume.
* @returns {?Promise} - a promise that resolves when the sound has been decoded and added
*/
addSound (soundObject) {
return loadSound(soundObject, this.runtime).then(() => {
this.editingTarget.addSound(soundObject);
this.emitTargetsUpdate();
});
}
/**
* Rename a sound on the current editing target.
* @param {int} soundIndex - the index of the sound to be renamed.
* @param {string} newName - the desired new name of the sound (will be modified if already in use).
*/
renameSound (soundIndex, newName) {
this.editingTarget.renameSound(soundIndex, newName);
this.emitTargetsUpdate();
}
/**
* Get a sound buffer from the audio engine.
* @param {int} soundIndex - the index of the sound to be got.
* @return {AudioBuffer} the sound's audio buffer.
*/
getSoundBuffer (soundIndex) {
const id = this.editingTarget.sprite.sounds[soundIndex].soundId;
if (id && this.runtime && this.runtime.audioEngine) {
return this.runtime.audioEngine.getSoundBuffer(id);
}
return null;
}
/**
* Update a sound buffer.
* @param {int} soundIndex - the index of the sound to be updated.
* @param {AudioBuffer} newBuffer - new audio buffer for the audio engine.
*/
updateSoundBuffer (soundIndex, newBuffer) {
const id = this.editingTarget.sprite.sounds[soundIndex].soundId;
if (id && this.runtime && this.runtime.audioEngine) {
this.runtime.audioEngine.updateSoundBuffer(id, newBuffer);
}
this.emitTargetsUpdate();
}
/**
* Delete a sound from the current editing target.
* @param {int} soundIndex - the index of the sound to be removed.
*/
deleteSound (soundIndex) {
this.editingTarget.deleteSound(soundIndex);
}
/**
* Get an SVG string from the renderer.
* @param {int} costumeIndex - the index of the sound to be got.
* @return {string} the costume's SVG string, or null if it's not an SVG costume.
*/
getCostumeSvg (costumeIndex) {
const id = this.editingTarget.sprite.costumes[costumeIndex].assetId;
if (id && this.runtime && this.runtime.storage &&
this.runtime.storage.get(id).dataFormat === 'svg') {
return this.runtime.storage.get(id).decodeText();
}
return null;
}
/**
* Update a costume with the given SVG
* @param {int} costumeIndex - the index of the costume to be updated.
* @param {string} svg - new SVG for the renderer.
*/
updateSvg (costumeIndex, svg) {
const costume = this.editingTarget.sprite.costumes[costumeIndex];
if (costume && this.runtime && this.runtime.renderer) {
const rotationCenter = [
costume.rotationCenterX / costume.bitmapResolution,
costume.rotationCenterY / costume.bitmapResolution
];
this.runtime.renderer.updateSVGSkin(costume.skinId, svg, rotationCenter);
}
// TODO: Also update storage in addition to renderer. Without storage, if you switch
// costumes and switch back, you will lose your changes in the paint editor.
// TODO: emitTargetsUpdate if we need to update the storage ID on the updated costume;
}
/**
* Add a backdrop to the stage.
* @param {string} md5ext - the MD5 and extension of the backdrop to be loaded.
* @param {!object} backdropObject Object representing the backdrop.
* @property {int} skinId - the ID of the backdrop's render skin, once installed.
* @property {number} rotationCenterX - the X component of the backdrop's origin.
* @property {number} rotationCenterY - the Y component of the backdrop's origin.
* @property {number} [bitmapResolution] - the resolution scale for a bitmap backdrop.
*/
addBackdrop (md5ext, backdropObject) {
loadCostume(md5ext, backdropObject, this.runtime).then(() => {
const stage = this.runtime.getTargetForStage();
stage.sprite.costumes.push(backdropObject);
stage.setCostume(stage.sprite.costumes.length - 1);
});
}
/**
* Rename a sprite.
* @param {string} targetId ID of a target whose sprite to rename.
* @param {string} newName New name of the sprite.
*/
renameSprite (targetId, newName) {
const target = this.runtime.getTargetById(targetId);
if (target) {
if (!target.isSprite()) {
throw new Error('Cannot rename non-sprite targets.');
}
const sprite = target.sprite;
if (!sprite) {
throw new Error('No sprite associated with this target.');
}
if (newName && RESERVED_NAMES.indexOf(newName) === -1) {
const names = this.runtime.targets
.filter(runtimeTarget => runtimeTarget.isSprite() && runtimeTarget.id !== target.id)
.map(runtimeTarget => runtimeTarget.sprite.name);
sprite.name = StringUtil.unusedName(newName, names);
}
this.emitTargetsUpdate();
} else {
throw new Error('No target with the provided id.');
}
}
/**
* Delete a sprite and all its clones.
* @param {string} targetId ID of a target whose sprite to delete.
*/
deleteSprite (targetId) {
const target = this.runtime.getTargetById(targetId);
const targetIndexBeforeDelete = this.runtime.targets.map(t => t.id).indexOf(target.id);
if (target) {
if (!target.isSprite()) {
throw new Error('Cannot delete non-sprite targets.');
}
const sprite = target.sprite;
if (!sprite) {
throw new Error('No sprite associated with this target.');
}
const currentEditingTarget = this.editingTarget;
for (let i = 0; i < sprite.clones.length; i++) {
const clone = sprite.clones[i];
this.runtime.stopForTarget(sprite.clones[i]);
this.runtime.disposeTarget(sprite.clones[i]);
// Ensure editing target is switched if we are deleting it.
if (clone === currentEditingTarget) {
const nextTargetIndex = Math.min(this.runtime.targets.length - 1, targetIndexBeforeDelete);
this.setEditingTarget(this.runtime.targets[nextTargetIndex].id);
}
}
// Sprite object should be deleted by GC.
this.emitTargetsUpdate();
} else {
throw new Error('No target with the provided id.');
}
}
/**
* Set the audio engine for the VM/runtime
* @param {!AudioEngine} audioEngine The audio engine to attach
*/
attachAudioEngine (audioEngine) {
this.runtime.attachAudioEngine(audioEngine);
}
/**
* Set the renderer for the VM/runtime
* @param {!RenderWebGL} renderer The renderer to attach
*/
attachRenderer (renderer) {
this.runtime.attachRenderer(renderer);
}
/**
* Set the storage module for the VM/runtime
* @param {!ScratchStorage} storage The storage module to attach
*/
attachStorage (storage) {
this.runtime.attachStorage(storage);
}
/**
* Handle a Blockly event for the current editing target.
* @param {!Blockly.Event} e Any Blockly event.
*/
blockListener (e) {
if (this.editingTarget) {
this.editingTarget.blocks.blocklyListen(e, this.runtime);
}
}
/**
* Handle a Blockly event for the flyout.
* @param {!Blockly.Event} e Any Blockly event.
*/
flyoutBlockListener (e) {
this.runtime.flyoutBlocks.blocklyListen(e, this.runtime);
}
/**
* Handle a Blockly event for the flyout to be passed to the monitor container.
* @param {!Blockly.Event} e Any Blockly event.
*/
monitorBlockListener (e) {
// Filter events by type, since monitor blocks only need to listen to these events.
// Monitor blocks shouldn't be destroyed when flyout blocks are deleted.
if (['create', 'change'].indexOf(e.type) !== -1) {
this.runtime.monitorBlocks.blocklyListen(e, this.runtime);
}
}
/**
* Handle a Blockly event for the variable map.
* @param {!Blockly.Event} e Any Blockly event.
*/
variableListener (e) {
// Filter events by type, since blocks only needs to listen to these
// var events.
if (['var_create', 'var_rename', 'var_delete'].indexOf(e.type) !== -1) {
this.runtime.getTargetForStage().blocks.blocklyListen(e,
this.runtime);
}
}
/**
* Set an editing target. An editor UI can use this function to switch
* between editing different targets, sprites, etc.
* After switching the editing target, the VM may emit updates
* to the list of targets and any attached workspace blocks
* (see `emitTargetsUpdate` and `emitWorkspaceUpdate`).
* @param {string} targetId Id of target to set as editing.
*/
setEditingTarget (targetId) {
// Has the target id changed? If not, exit.
if (targetId === this.editingTarget.id) {
return;
}
const target = this.runtime.getTargetById(targetId);
if (target) {
this.editingTarget = target;
// Emit appropriate UI updates.
this.emitTargetsUpdate();
this.emitWorkspaceUpdate();
this.runtime.setEditingTarget(target);
}
}
/**
* Repopulate the workspace with the blocks of the current editingTarget. This
* allows us to get around bugs like gui#413.
*/
refreshWorkspace () {
if (this.editingTarget) {
this.emitWorkspaceUpdate();
this.runtime.setEditingTarget(this.editingTarget);
}
}
/**
* Emit metadata about available targets.
* An editor UI could use this to display a list of targets and show
* the currently editing one.
*/
emitTargetsUpdate () {
this.emit('targetsUpdate', {
// [[target id, human readable target name], ...].
targetList: this.runtime.targets
.filter(
// Don't report clones.
target => !target.hasOwnProperty('isOriginal') || target.isOriginal
).map(
target => target.toJSON()
),
// Currently editing target id.
editingTarget: this.editingTarget ? this.editingTarget.id : null
});
}
/**
* Emit an Blockly/scratch-blocks compatible XML representation
* of the current editing target's blocks.
*/
emitWorkspaceUpdate () {
const variableMap = Object.assign({},
this.runtime.getTargetForStage().variables,
this.editingTarget.variables
);
const variables = Object.keys(variableMap).map(k => variableMap[k]);
const xmlString = `<xml xmlns="http://www.w3.org/1999/xhtml">
<variables>
${variables.map(v => v.toXML()).join()}
</variables>
${this.editingTarget.blocks.toXML()}
</xml>`;
this.emit('workspaceUpdate', {xml: xmlString});
}
/**
* Get a target id for a drawable id. Useful for interacting with the renderer
* @param {int} drawableId The drawable id to request the target id for
* @returns {?string} The target id, if found. Will also be null if the target found is the stage.
*/
getTargetIdForDrawableId (drawableId) {
const target = this.runtime.getTargetByDrawableId(drawableId);
if (target && target.hasOwnProperty('id') && target.hasOwnProperty('isStage') && !target.isStage) {
return target.id;
}
return null;
}
/**
* Put a target into a "drag" state, during which its X/Y positions will be unaffected
* by blocks.
* @param {string} targetId The id for the target to put into a drag state
*/
startDrag (targetId) {
const target = this.runtime.getTargetById(targetId);
if (target) {
target.startDrag();
this.setEditingTarget(target.id);
}
}
/**
* Remove a target from a drag state, so blocks may begin affecting X/Y position again
* @param {string} targetId The id for the target to remove from the drag state
*/
stopDrag (targetId) {
const target = this.runtime.getTargetById(targetId);
if (target) target.stopDrag();
}
/**
* Post/edit sprite info for the current editing target.
* @param {object} data An object with sprite info data to set.
*/
postSpriteInfo (data) {
this.editingTarget.postSpriteInfo(data);
}
}
module.exports = VirtualMachine;