import defaultValue from "../Core/defaultValue.js";
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import defined from "../Core/defined.js";
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import DeveloperError from "../Core/DeveloperError.js";
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import Event from "../Core/Event.js";
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import knockout from "../ThirdParty/knockout.js";
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/**
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* Create a Command from a given function, for use with ViewModels.
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*
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* A Command is a function with an extra <code>canExecute</code> observable property to determine
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* whether the command can be executed. When executed, a Command function will check the
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* value of <code>canExecute</code> and throw if false. It also provides events for when
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* a command has been or is about to be executed.
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*
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* @function
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*
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* @param {Function} func The function to execute.
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* @param {Boolean} [canExecute=true] A boolean indicating whether the function can currently be executed.
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*/
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function createCommand(func, canExecute) {
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//>>includeStart('debug', pragmas.debug);
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if (!defined(func)) {
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throw new DeveloperError("func is required.");
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}
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//>>includeEnd('debug');
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canExecute = defaultValue(canExecute, true);
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var beforeExecute = new Event();
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var afterExecute = new Event();
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function command() {
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//>>includeStart('debug', pragmas.debug);
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if (!command.canExecute) {
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throw new DeveloperError("Cannot execute command, canExecute is false.");
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}
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//>>includeEnd('debug');
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var commandInfo = {
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args: arguments,
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cancel: false,
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};
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var result;
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beforeExecute.raiseEvent(commandInfo);
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if (!commandInfo.cancel) {
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result = func.apply(null, arguments);
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afterExecute.raiseEvent(result);
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}
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return result;
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}
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command.canExecute = canExecute;
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knockout.track(command, ["canExecute"]);
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Object.defineProperties(command, {
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beforeExecute: {
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value: beforeExecute,
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},
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afterExecute: {
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value: afterExecute,
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},
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});
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return command;
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}
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export default createCommand;
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