91 lines
2.5 KiB
JavaScript
91 lines
2.5 KiB
JavaScript
|
import inherits from 'inherits-browser';
|
||
|
|
|
||
|
|
import CommandInterceptor from '../../command/CommandInterceptor';
|
||
|
|
|
||
|
|
/**
|
||
|
|
* @typedef {import('../../core/EventBus').default} EventBus
|
||
|
|
*/
|
||
|
|
|
||
|
|
/**
|
||
|
|
* A basic provider that may be extended to implement modeling rules.
|
||
|
|
*
|
||
|
|
* Extensions should implement the init method to actually add their custom
|
||
|
|
* modeling checks. Checks may be added via the #addRule(action, fn) method.
|
||
|
|
*
|
||
|
|
* @param {EventBus} eventBus
|
||
|
|
*/
|
||
|
|
export default function RuleProvider(eventBus) {
|
||
|
|
CommandInterceptor.call(this, eventBus);
|
||
|
|
|
||
|
|
this.init();
|
||
|
|
}
|
||
|
|
|
||
|
|
RuleProvider.$inject = [ 'eventBus' ];
|
||
|
|
|
||
|
|
inherits(RuleProvider, CommandInterceptor);
|
||
|
|
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Adds a modeling rule for the given action, implemented through
|
||
|
|
* a callback function.
|
||
|
|
*
|
||
|
|
* The function will receive the modeling specific action context
|
||
|
|
* to perform its check. It must return `false` to disallow the
|
||
|
|
* action from happening or `true` to allow the action.
|
||
|
|
*
|
||
|
|
* A rule provider may pass over the evaluation to lower priority
|
||
|
|
* rules by returning return nothing (or <code>undefined</code>).
|
||
|
|
*
|
||
|
|
* @example
|
||
|
|
*
|
||
|
|
* ResizableRules.prototype.init = function() {
|
||
|
|
*
|
||
|
|
* \/**
|
||
|
|
* * Return `true`, `false` or nothing to denote
|
||
|
|
* * _allowed_, _not allowed_ and _continue evaluating_.
|
||
|
|
* *\/
|
||
|
|
* this.addRule('shape.resize', function(context) {
|
||
|
|
*
|
||
|
|
* var shape = context.shape;
|
||
|
|
*
|
||
|
|
* if (!context.newBounds) {
|
||
|
|
* // check general resizability
|
||
|
|
* if (!shape.resizable) {
|
||
|
|
* return false;
|
||
|
|
* }
|
||
|
|
*
|
||
|
|
* // not returning anything (read: undefined)
|
||
|
|
* // will continue the evaluation of other rules
|
||
|
|
* // (with lower priority)
|
||
|
|
* return;
|
||
|
|
* } else {
|
||
|
|
* // element must have minimum size of 10*10 points
|
||
|
|
* return context.newBounds.width > 10 && context.newBounds.height > 10;
|
||
|
|
* }
|
||
|
|
* });
|
||
|
|
* };
|
||
|
|
*
|
||
|
|
* @param {string|Array<string>} actions the identifier for the modeling action to check
|
||
|
|
* @param {number} [priority] the priority at which this rule is being applied
|
||
|
|
* @param {Function} fn the callback function that performs the actual check
|
||
|
|
*/
|
||
|
|
RuleProvider.prototype.addRule = function(actions, priority, fn) {
|
||
|
|
|
||
|
|
var self = this;
|
||
|
|
|
||
|
|
if (typeof actions === 'string') {
|
||
|
|
actions = [ actions ];
|
||
|
|
}
|
||
|
|
|
||
|
|
actions.forEach(function(action) {
|
||
|
|
|
||
|
|
self.canExecute(action, priority, function(context, action, event) {
|
||
|
|
return fn(context);
|
||
|
|
}, true);
|
||
|
|
});
|
||
|
|
};
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Implement this method to add new rules during provider initialization.
|
||
|
|
*/
|
||
|
|
RuleProvider.prototype.init = function() {};
|