If you click on the play button, the source will be the mouse, the target node will be the play button and the type of the event generated is the mouse click. Type − Type of the occurred event in case of mouse event – mouse pressed, mouse released are the type of events.Īssume that we have an application which has a Circle, Stop and Play Buttons inserted using a group object as follows − In the above scenario, mouse is the source of the event. Source − The source from which the event is generated will be the source of the event. A target can be a window, scene, and a node. Target − The node on which an event occurred. JavaFX provides handlers and filters to handle events. This mechanism has the code which is known as an event handler that is executed when an event occurs. It includes actions like window hiding, window shown, window hidden, window showing, etc.Įvent Handling is the mechanism that controls the event and decides what should happen, if an event occurs. It is represented by the class named WindowEvent. Window Event − This is an event related to window showing/hiding actions. It includes actions like drag entered, drag dropped, drag entered target, drag exited target, drag over, etc. It is represented by the class named DragEvent. This event includes actions like key pressed, key released and key typed.ĭrag Event − This is an input event which occurs when the mouse is dragged. It is represented by the class named KeyEvent. Key Event − This is an input event that indicates the key stroke occurred on a node. It includes actions like mouse clicked, mouse pressed, mouse released, mouse moved, mouse entered target, mouse exited target, etc. It is represented by the class named MouseEvent. Mouse Event − This is an input event that occurs when a mouse is clicked. JavaFX provides a wide variety of events. The class named Event of the package javafx.event is the base class for an event.Īn instance of any of its subclass is an event. JavaFX provides support to handle a wide varieties of events. The operating system interruptions, hardware or software failure, timer expiry, operation completion are the example of background events. For example, clicking on a button, moving the mouse, entering a character through keyboard, selecting an item from list, scrolling the page, etc.īackground Events − Those events that don't require the interaction of end-user are known as background events. They are generated as consequences of a person interacting with the graphical components in a Graphical User Interface. The events can be broadly classified into the following two categories −įoreground Events − Those events which require the direct interaction of a user. In such applications, whenever a user interacts with the application (nodes), an event is said to have been occurred.įor example, clicking on a button, moving the mouse, entering a character through keyboard, selecting an item from list, scrolling the page are the activities that causes an event to happen. From the EventHandler interface, we can see that we need to implement the handle method, so we define EventHandlers like so: EventHandler handler = new EventHandler() else if (zoomBar.In JavaFX, we can develop GUI applications, web applications and graphical applications. So to listen to events we need to create EventHandlers for the type of event we want to listen to. onMouse, all key event listeners begin with. Handily they are prefixed by what event they listen for, so all mouse event listeners begin with. The Node class has a wide range of event listeners for the different types of events. To see the other types of events JavaFX offers, they are all subclasses of the InputEvent class. To begin, there are a few API documentation pages that I recommend being familiar with – the Node class (the class that you set event handlers on), the EventHandler interface (what you set on nodes), and the two most obvious types of InputEvent s – the MouseEvent and KeyEvent classes (the events to be handled). I had a lot of fun playing with mouse events while building our PageFlow PDF Viewing mode in JavaFX, so thought it worth writing a quick tutorial and sharing what I have learned. He oversees the BuildVu product strategy and roadmap in addition to spending lots of time writing code. Leon Atherton Leon is a developer at IDRsolutions and product manager for BuildVu.
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