scratch-vm/src/blocks/scratch3_data.js
2018-07-11 13:14:01 -04:00

248 lines
8.6 KiB
JavaScript

const Cast = require('../util/cast');
class Scratch3DataBlocks {
constructor (runtime) {
/**
* The runtime instantiating this block package.
* @type {Runtime}
*/
this.runtime = runtime;
}
/**
* Retrieve the block primitives implemented by this package.
* @return {object.<string, Function>} Mapping of opcode to Function.
*/
getPrimitives () {
return {
data_variable: this.getVariable,
data_setvariableto: this.setVariableTo,
data_changevariableby: this.changeVariableBy,
data_hidevariable: this.hideVariable,
data_showvariable: this.showVariable,
data_listcontents: this.getListContents,
data_addtolist: this.addToList,
data_deleteoflist: this.deleteOfList,
data_deletealloflist: this.deleteAllOfList,
data_insertatlist: this.insertAtList,
data_replaceitemoflist: this.replaceItemOfList,
data_itemoflist: this.getItemOfList,
data_itemnumoflist: this.getItemNumOfList,
data_lengthoflist: this.lengthOfList,
data_listcontainsitem: this.listContainsItem,
data_hidelist: this.hideList,
data_showlist: this.showList
};
}
getVariable (args, util) {
const variable = util.target.lookupOrCreateVariable(
args.VARIABLE.id, args.VARIABLE.name);
return variable.value;
}
setVariableTo (args, util) {
const variable = util.target.lookupOrCreateVariable(
args.VARIABLE.id, args.VARIABLE.name);
variable.value = args.VALUE;
}
changeVariableBy (args, util) {
const variable = util.target.lookupOrCreateVariable(
args.VARIABLE.id, args.VARIABLE.name);
const castedValue = Cast.toNumber(variable.value);
const dValue = Cast.toNumber(args.VALUE);
variable.value = castedValue + dValue;
}
changeMonitorVisibility (id, visible) {
// Send the monitor blocks an event like the flyout checkbox event.
// This both updates the monitor state and changes the isMonitored block flag.
this.runtime.monitorBlocks.changeBlock({
id: id, // Monitor blocks for variables are the variable ID.
element: 'checkbox', // Mimic checkbox event from flyout.
value: visible
}, this.runtime);
}
showVariable (args) {
this.changeMonitorVisibility(args.VARIABLE.id, true);
}
hideVariable (args) {
this.changeMonitorVisibility(args.VARIABLE.id, false);
}
showList (args) {
this.changeMonitorVisibility(args.LIST.id, true);
}
hideList (args) {
this.changeMonitorVisibility(args.LIST.id, false);
}
getListContents (args, util) {
const list = util.target.lookupOrCreateList(
args.LIST.id, args.LIST.name);
// If block is running for monitors, return copy of list as an array if changed.
if (util.thread.updateMonitor) {
// Return original list value if up-to-date, which doesn't trigger monitor update.
if (list._monitorUpToDate) return list.value;
// If value changed, reset the flag and return a copy to trigger monitor update.
// Because monitors use Immutable data structures, only new objects trigger updates.
list._monitorUpToDate = true;
return list.value.slice();
}
// Determine if the list is all single letters.
// If it is, report contents joined together with no separator.
// If it's not, report contents joined together with a space.
let allSingleLetters = true;
for (let i = 0; i < list.value.length; i++) {
const listItem = list.value[i];
if (!((typeof listItem === 'string') &&
(listItem.length === 1))) {
allSingleLetters = false;
break;
}
}
if (allSingleLetters) {
return list.value.join('');
}
return list.value.join(' ');
}
addToList (args, util) {
const list = util.target.lookupOrCreateList(
args.LIST.id, args.LIST.name);
if (list.value.length < Scratch3DataBlocks.LIST_ITEM_LIMIT) {
list.value.push(args.ITEM);
list._monitorUpToDate = false;
}
}
deleteOfList (args, util) {
const list = util.target.lookupOrCreateList(
args.LIST.id, args.LIST.name);
const index = Cast.toListIndex(args.INDEX, list.value.length);
if (index === Cast.LIST_INVALID) {
return;
} else if (index === Cast.LIST_ALL) {
list.value = [];
return;
}
list.value.splice(index - 1, 1);
list._monitorUpToDate = false;
}
deleteAllOfList (args, util) {
const list = util.target.lookupOrCreateList(
args.LIST.id, args.LIST.name);
list.value = [];
return;
}
insertAtList (args, util) {
const item = args.ITEM;
const list = util.target.lookupOrCreateList(
args.LIST.id, args.LIST.name);
const index = Cast.toListIndex(args.INDEX, list.value.length + 1);
if (index === Cast.LIST_INVALID) {
return;
}
const listLimit = Scratch3DataBlocks.LIST_ITEM_LIMIT;
if (index > listLimit) return;
list.value.splice(index - 1, 0, item);
if (list.value.length > listLimit) {
// If inserting caused the list to grow larger than the limit,
// remove the last element in the list
list.value.pop();
}
list._monitorUpToDate = false;
}
replaceItemOfList (args, util) {
const item = args.ITEM;
const list = util.target.lookupOrCreateList(
args.LIST.id, args.LIST.name);
const index = Cast.toListIndex(args.INDEX, list.value.length);
if (index === Cast.LIST_INVALID) {
return;
}
list.value.splice(index - 1, 1, item);
list._monitorUpToDate = false;
}
getItemOfList (args, util) {
const list = util.target.lookupOrCreateList(
args.LIST.id, args.LIST.name);
const index = Cast.toListIndex(args.INDEX, list.value.length);
if (index === Cast.LIST_INVALID) {
return '';
}
return list.value[index - 1];
}
getItemNumOfList (args, util) {
const item = args.ITEM;
const list = util.target.lookupOrCreateList(
args.LIST.id, args.LIST.name);
// Go through the list items one-by-one using Cast.compare. This is for
// cases like checking if 123 is contained in a list [4, 7, '123'] --
// Scratch considers 123 and '123' to be equal.
for (let i = 0; i < list.value.length; i++) {
if (Cast.compare(list.value[i], item) === 0) {
return i + 1;
}
}
// We don't bother using .indexOf() at all, because it would end up with
// edge cases such as the index of '123' in [4, 7, 123, '123', 9].
// If we use indexOf(), this block would return 4 instead of 3, because
// indexOf() sees the first occurence of the string 123 as the fourth
// item in the list. With Scratch, this would be confusing -- after all,
// '123' and 123 look the same, so one would expect the block to say
// that the first occurrence of '123' (or 123) to be the third item.
// Default to 0 if there's no match. Since Scratch lists are 1-indexed,
// we don't have to worry about this conflicting with the "this item is
// the first value" number (in JS that is 0, but in Scratch it's 1).
return 0;
}
lengthOfList (args, util) {
const list = util.target.lookupOrCreateList(
args.LIST.id, args.LIST.name);
return list.value.length;
}
listContainsItem (args, util) {
const item = args.ITEM;
const list = util.target.lookupOrCreateList(
args.LIST.id, args.LIST.name);
if (list.value.indexOf(item) >= 0) {
return true;
}
// Try using Scratch comparison operator on each item.
// (Scratch considers the string '123' equal to the number 123).
for (let i = 0; i < list.value.length; i++) {
if (Cast.compare(list.value[i], item) === 0) {
return true;
}
}
return false;
}
/**
* Type representation for list variables.
* @const {string}
*/
static get LIST_ITEM_LIMIT () {
return 200000;
}
}
module.exports = Scratch3DataBlocks;