commit vendor

vendor/sabre/event/lib/EmitterTrait.php

@@ -0,0 +1,178 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Sabre\Event;
+
+/**
+ * Event Emitter Trait.
+ *
+ * This trait contains all the basic functions to implement an
+ * EventEmitterInterface.
+ *
+ * Using the trait + interface allows you to add EventEmitter capabilities
+ * without having to change your base-class.
+ *
+ * @copyright Copyright (C) fruux GmbH (https://fruux.com/)
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+trait EmitterTrait
+{
+    /**
+     * Subscribe to an event.
+     */
+    public function on(string $eventName, callable $callBack, int $priority = 100)
+    {
+        if (!isset($this->listeners[$eventName])) {
+            $this->listeners[$eventName] = [
+                true,  // If there's only one item, it's sorted
+                [$priority],
+                [$callBack],
+            ];
+        } else {
+            $this->listeners[$eventName][0] = false; // marked as unsorted
+            $this->listeners[$eventName][1][] = $priority;
+            $this->listeners[$eventName][2][] = $callBack;
+        }
+    }
+
+    /**
+     * Subscribe to an event exactly once.
+     */
+    public function once(string $eventName, callable $callBack, int $priority = 100)
+    {
+        $wrapper = null;
+        $wrapper = function () use ($eventName, $callBack, &$wrapper) {
+            $this->removeListener($eventName, $wrapper);
+
+            return \call_user_func_array($callBack, \func_get_args());
+        };
+
+        $this->on($eventName, $wrapper, $priority);
+    }
+
+    /**
+     * Emits an event.
+     *
+     * This method will return true if 0 or more listeners were successfully
+     * handled. false is returned if one of the events broke the event chain.
+     *
+     * If the continueCallBack is specified, this callback will be called every
+     * time before the next event handler is called.
+     *
+     * If the continueCallback returns false, event propagation stops. This
+     * allows you to use the eventEmitter as a means for listeners to implement
+     * functionality in your application, and break the event loop as soon as
+     * some condition is fulfilled.
+     *
+     * Note that returning false from an event subscriber breaks propagation
+     * and returns false, but if the continue-callback stops propagation, this
+     * is still considered a 'successful' operation and returns true.
+     *
+     * Lastly, if there are 5 event handlers for an event. The continueCallback
+     * will be called at most 4 times.
+     */
+    public function emit(string $eventName, array $arguments = [], callable $continueCallBack = null): bool
+    {
+        if (\is_null($continueCallBack)) {
+            foreach ($this->listeners($eventName) as $listener) {
+                $result = \call_user_func_array($listener, $arguments);
+                if (false === $result) {
+                    return false;
+                }
+            }
+        } else {
+            $listeners = $this->listeners($eventName);
+            $counter = \count($listeners);
+
+            foreach ($listeners as $listener) {
+                --$counter;
+                $result = \call_user_func_array($listener, $arguments);
+                if (false === $result) {
+                    return false;
+                }
+
+                if ($counter > 0) {
+                    if (!$continueCallBack()) {
+                        break;
+                    }
+                }
+            }
+        }
+
+        return true;
+    }
+
+    /**
+     * Returns the list of listeners for an event.
+     *
+     * The list is returned as an array, and the list of events are sorted by
+     * their priority.
+     *
+     * @return callable[]
+     */
+    public function listeners(string $eventName): array
+    {
+        if (!isset($this->listeners[$eventName])) {
+            return [];
+        }
+
+        // The list is not sorted
+        if (!$this->listeners[$eventName][0]) {
+            // Sorting
+            \array_multisort($this->listeners[$eventName][1], SORT_NUMERIC, $this->listeners[$eventName][2]);
+
+            // Marking the listeners as sorted
+            $this->listeners[$eventName][0] = true;
+        }
+
+        return $this->listeners[$eventName][2];
+    }
+
+    /**
+     * Removes a specific listener from an event.
+     *
+     * If the listener could not be found, this method will return false. If it
+     * was removed it will return true.
+     */
+    public function removeListener(string $eventName, callable $listener): bool
+    {
+        if (!isset($this->listeners[$eventName])) {
+            return false;
+        }
+        foreach ($this->listeners[$eventName][2] as $index => $check) {
+            if ($check === $listener) {
+                unset($this->listeners[$eventName][1][$index]);
+                unset($this->listeners[$eventName][2][$index]);
+
+                return true;
+            }
+        }
+
+        return false;
+    }
+
+    /**
+     * Removes all listeners.
+     *
+     * If the eventName argument is specified, all listeners for that event are
+     * removed. If it is not specified, every listener for every event is
+     * removed.
+     */
+    public function removeAllListeners(string $eventName = null)
+    {
+        if (!\is_null($eventName)) {
+            unset($this->listeners[$eventName]);
+        } else {
+            $this->listeners = [];
+        }
+    }
+
+    /**
+     * The list of listeners.
+     *
+     * @var array
+     */
+    protected $listeners = [];
+}