Find elements through the actor rather than the driver

"Actor::find" is a more robust way to look for elements, as it handles
some exceptions that may be thrown. Therefore, even if the elements are
not actually used and it is only checked whether they exist or not using
the actor is the preferred way when possible (and it also makes it
consistent with the rest of the acceptance tests).

Signed-off-by: Daniel Calviño Sánchez <danxuliu@gmail.com>

tests/acceptance/features/bootstrap/AppsManagementContext.php

@@ -45,6 +45,15 @@ class AppsManagementContext implements Context, ActorAwareInterface {
 				describedAs("Enable button in the app list for $app");
 	}
 
+	/**
+	 * @return Locator
+	 */
+	public static function enableButtonForAnyApp() {
+		return Locator::forThe()->button("Enable")->
+				descendantOf(self::appsList())->
+				describedAs("Enable button in the app list for any app");
+	}
+
 	/**
 	 * @return Locator
 	 */
@@ -63,6 +72,15 @@ class AppsManagementContext implements Context, ActorAwareInterface {
 				describedAs("Disable button in the app list for $app");
 	}
 
+	/**
+	 * @return Locator
+	 */
+	public static function disableButtonForAnyApp() {
+		return Locator::forThe()->button("Disable")->
+				descendantOf(self::appsList())->
+				describedAs("Disable button in the app list for any app");
+	}
+
 	/**
 	 * @return Locator
 	 */
@@ -195,16 +213,24 @@ class AppsManagementContext implements Context, ActorAwareInterface {
 	 * @Given /^I see that there are only disabled apps$/
 	 */
 	public function iSeeThatThereAreOnlyDisabledApps() {
-		$buttons = $this->actor->getSession()->getDriver()->find("//input[@value = 'Disable']");
-		PHPUnit\Framework\Assert::assertEmpty($buttons, 'Found disabled apps');
+		try {
+			$this->actor->find(self::disableButtonForAnyApp(), 2);
+
+			PHPUnit_Framework_Assert::fail("Found enabled apps");
+		} catch (NoSuchElementException $exception) {
+		}
 	}
 
 	/**
 	 * @Given /^I see that there are only enabled apps$/
 	 */
 	public function iSeeThatThereAreOnlyEnabledApps() {
-		$buttons = $this->actor->getSession()->getDriver()->find("//input[@value = 'Enable']");
-		PHPUnit\Framework\Assert::assertEmpty($buttons, 'Found disabled apps');
+		try {
+			$this->actor->find(self::enableButtonForAnyApp(), 2);
+
+			PHPUnit_Framework_Assert::fail("Found disabled apps");
+		} catch (NoSuchElementException $exception) {
+		}
 	}
 
 	/**