JavaFX: Creating custom controls – the right way. JavaFX: Creating custom controls – the right way Is is quite difficult to create custom controls in JavaFX that perform like they should. This is the result of lack of documentation, unavailability of source code and a not-so-good API… I struggled with that issue for two days. And finally I think I understood the hole concept.
I wrote about that process in this blog some days ago. If you are just looking for a template, continue here. Here is a small drawing that visualizes the relevant methods/fields related to custom controls: width/height The width and height are set by the container. LayoutBounds The layoutBounds are calculated automatically based on the values of width/height of the control. Attention: The layoutBounds do not depend on the layoutBounds of the node created by the Skin! This might be counter-intuitive. BoundsInLocal The boundsInLocal are bound to the boundsInLocal of the node created by the skin. GetMin/Pref/MaxWidth/height Which methods to extend? This is *really* necessary. JavaFX and custom controls. There are two ways how a custom control/node can be created. The simple way is to extend CustomNode. Then everything should work as expected. The second possibility is to extend Control, Skin and Behaviour. This is the better way if you want to support different skins.
And of course it seems to be the more MVC-like approach. Problems with the *bounds* Implementing a new control seems to be very straight forward. If placing the control within a Stack, the control sticks to the upper left corner. But boundsInLocal seems to be okay… Finding the reason.. So what can we do? Okay, let’s find out on our own. Step 1: Simple Control without any Skin I created a control and I did not set a skin. As expected, the layoutBounds and the boundsInLocal where both set to (0/0/0/0). Step 2: Simple Control with an empty Skin I now set a skin in create() of my Control. The layoutBounds are initially set to (0/0/100/50)! Conclusion: There exist hard coded default values for each control (100/50). JavaFX: Building custom controls. One of the big criticisms leveled at JavaFX presently is its lack of controls (or components if you come from the Swing world).
This was addressed to some degree in JavaFX 1.2, but there are still many controls missing, and some of the controls in the latest release have relatively basic API’s at this point. Certainly this will improve in future releases, but I thought I’d try to simply explain the process you need to go through to build your own controls. Who knows, you might be able to sell them if you get them good enough.
In JavaFX, there are three classes that you should become familiar with: Control, Skin and Behavior. Simply put, the Control class should be used to maintain state. I’ll jump right into a demo now. Firstly, the control itself simply has a text variable to store the buttons text. JavaFX 1.3: Template for custom controls. Utility Classes for Building JavaFX Application. Overview of Basic Features. TabbedPane V.3. JavaFX Scrollbar.