If none of these nodes have handlers to handle the event, then the event reaches the root node and finally the process will be completed. If any of the nodes in the event dispatch chain has a handler registered for the generated event, it will be executed. In the event bubbling phase, the event is travelled from the target node to the stage node (bottom to top). If none of the nodes in the dispatch chain has a filter for the event generated, then it is passed to the target node and finally the target node processes the event. If any of these nodes has a filter registered for the generated event, it will be executed. This event travels to all nodes in the dispatch chain (from top to bottom). Event Capturing PhaseĪfter the construction of the event dispatch chain, the root node of the application dispatches the event. It is the path from the stage to the source Node.įollowing is the event dispatch chain for the event generated, when we click on the play button in the above scenario. Whenever an event is generated, the default/initial route of the event is determined by construction of an Event Dispatch chain. Whenever an event is generated, JavaFX undergoes the following phases. 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.
#Javafx imageviewer onmouseclick event code
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.
#Javafx imageviewer onmouseclick event software
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. In JavaFX, we can develop GUI applications, web applications and graphical applications.
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