![]() This description appears in the Add Event Handler window when the event is selected. When you create an event definition, you can enter a description for it in the Description field on the Advanced (gear) tab of the Inspector. You can easily add a matching event definition by right-clicking on the event you have implemented and choosing "Create Event Definition from Event". If you want the event handler to still be available to additional subclasses, you need to create a new event definition in the subclass (matching the name and parameters) and then call it in from event handler you implemented. Note that when you implement an event handler, it no longer appears in subclasses. Positions a Modal Dialog in the center of. Use the buttons on the right hand side to use the Windows API on TargetWindows. The built-in control classes all contain a wide variety of event handlers (such as Opening), all of which work in this manner. This example Xojo project shows how to work around this by using the Windows API to position dialog windows, while falling back to the default Xojo Framework methods on other platforms. Since you are not overridden the Save method, your code circumvents the possible issue shown above. Add those event handlers and implement them as needed. When you create a subclass, you will see that it has two Event Handlers you can add to it: PreSave and PostSave. In the Save method on the super class, you then call PreSave at the beginning and PostSave at the end. With events, you create two event definitions on the super class: PreSave and PostSave. If you forget to call Super.Save then your overridden method won't actually save! But if you do this with events, then there is no room for error. This works but it relies on you defining and implementing everything properly. ![]() They are shared versions of computed properties. Shared Computed Properties work exactly like you expect. (For information about constructors and destructors, see the section Constructors and Destructors.) When you access it, it gives you the current number of instances of the class. Each time you create or destroy an instance of the class, you can increment the value of the shared property in its constructor and decrement it in its destructor. For example, if you are using an instance of a class to keep track of items (e.g., persons, merchandise, sales transactions, and so forth) you can use a shared property as a counter. Generally speaking, shared properties are an advanced feature that you only need in special cases. It is important to understand that if you change the value of a shared property, the change is available to every usage of the shared property. In many ways, a public shared property works like a protected module property. A shared property can be accessed from anywhere its scope allows. ![]() Xojo 0 0 1094 Set the Position of your Mouse. Reporting bugs and making feature requestsĪ shared property (sometimes called a Class Property) is like a "regular" property, except it belongs to the class, not an instance of the class. Xojo 0 0 1149 Set the number of visible items in a ComboBox.How to extend layers or create new ones, using specific entry points for doing so. The following tutorials cover how to create plugins for Leaflet, and are intended only for developers experienced in JavaScript:Īn overview of Leaflet’s classes, class inheritance, and conventions. Leaflet can help you display images, videos and SVG elements somewhere on the map. How the default map panes work to display overlays on top of tiles, and how to override that. ![]() How to integrate with WMS and TMS services from professional GIS software. In the animation above, the Web app was running on a Raspberry Pi 400. News websites will love this.Ī tutorial on how to manage groups of layers and use the layer switching control.Ī primer on L.CRS.Simple, how to make maps with no concept of “latitude” or “longitude”. You can test a Xojo Web app by running it in debug mode, in much the same way that I showed in the previous blog post. In this tutorial, you’ll learn how to create and interact with map vectors created from GeoJSON objects.Ī case study of creating a colorful interactive choropleth map of US States Population Density with GeoJSON and some custom controls. In this pretty tutorial, you’ll learn how to easily define your own icons for use by the markers you put on the map.Ī guide to basic Leaflet accessibility - make your maps usable to persons of a wide range of abilities. In this tutorial, you’ll learn how to create a fullscreen map tuned for mobile devices like iPhone, iPad or Android phones, and how to easily detect and use the current user location. Every tutorial here comes with step-by-step code explanation and is easy enough even for beginner JavaScript developers.Ī simple step-by-step guide that will quickly get you started with Leaflet basics, including setting up a Leaflet map (with OpenStreetMap tiles) on your page, working with markers, polylines and popups, and dealing with events.
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