FlexGantt

If you are developing a UI framework for JavaFX, then please make it a habit to always split your custom controls into a control class and a skin class. Coming from Swing myself this was not obvious to me right away. Swing also uses an MVC concept and delegates the actual component rendering to a UI delegate, but people extending Swing mostly subclassed one of its controls and added extensions / modifications to the subclass. Only very few frameworks actually worked with the UI delegates (e.g. MacWidgets). I have the luxury of being able to compare the implementation of [...]

When working on FlexCalendarFX I got to the point where I had to define a set of colors to visualize the controls for different calendars in different colors. And not just one color per calendar but several: a background and a text color for deselected / selected / hover states. The  colors were used in several places but for the sake of brevity I only focus on the visual calendar entries in the day view of FlexCalendarFX. The two screenshots below show the same entry, first deselected, then selected. What is important to notice is that these are not completely different [...]

Picking the right colors for your user interface elements is always a great challenge, but it is even more challenging when you develop reusable framework controls where you as a developer have no control over the look and feel of the application using them. While you might always add elements on top of the default gray background the developers embedding your controls  might have more of a gothic tendency and use a black background. All of a sudden the nice colors your picked clash with the rest of the application. To tackle this problem the best way I found while working on FlexGanttFX and FlexCalendarFX [...]

Even in this time of total NSA surveillance it is still a good idea to implement your JavaFX controls with observability in mind. This is easy to achieve in JavaFX especially compared to Swing. The Old Days Coming from Swing I was used to spending a lot of energy and time on making custom controls observable. It usually required adding methods to add and remove listeners of a certain type. This listener type was a new interface, the single method of that interface accepted a new event object. To send this event object the control had to "fire" it [...]

When developing custom controls for JavaFX I would highly recommend to follow in the footsteps of  the core JavaFX controls and to make the API of your controls as final as possible and to put the "final" keyword in front of all your method declarations. Example In FlexGanttFX I have a lot of code that looks like this: public final Activity getActivityAt(double x, double y) { ... } public final Row getRowAt(double y) { ... } public final void setShowLinks(boolean show) { ... }   Why? When you design a control you have a specific behaviour of the control in [...]