What is the best solution to implement mouse or load or select event in prism 4. I am adding double click event on dxgrid and looking for a best practice to implement this feature.
for eg : mouse click, loaded, selected
Thanks,
You would typically use Behaviors for that. Behaviors map specific events of your View to commands in your ViewModel.
Related
I am creating my own GUI in OpenTK.
I want to fire a mouse event when the cursor is, for example, in one of the GUI controls. How can I do that? Because now I'm just iterating through a list of items in the main class, and in the Opentk´s window´s MouseMove event I'm just checking if the mouse coordinates are within the "region" of the component I'm drawing.
This works for now, but I think it could be done in a better way. This way my code is unordered and in the main class, and I would rather have it in the specific component class.
What I would like is to have an event attached to each component of my GUI, so that I can define many events for one component.
I mean, I would like to have for example a button component where I can override or just use a method that fires when an event occurs. Same as OpenGL´s window where you can override events.
This is not a complete answer, because your question is quite broad, but I hope it helps.
In order to implement such a system, here are the core components for a potential design:
UI Components: Some kind of standard interface where different component types can define logic for interactions. Depending on the language, the most common approach is probably something like a parent class Component, with methods to be overridden. These would probably include things like:
Mouse Hover
Mouse Click (press / release)
Click drag
It will also likely need some additional associated information:
Some way to determine the component's location. Could be providing a bounding box, or perhaps a method that tests if a given point is within this component or not.
Information or functionality for drawing the component.
Display and layering settings (is it visible or hidden, should it draw on top of other components or behind).
UI Context: The context is a structure that defines the set of components that are existent in the UI. This could be something like a list structure of Components. In order to build your UI, you would add components to this context. The context will define some behaviour:
Managing components (add / remove / modify).
How to draw the entire context (for example, looping over each component and executing the draw functionality for each).
Handling of events (see next section)
Event Dispatch: To make your UI usable, you can insert an "adapter" layer that handles events from your windowing library (OpenTK) then translates them into usable events for your components and dispatches them. Here is an example of how this might work for a "click" event (pseudo-code):
function TK_Event_ClickPressed(point) {
for component in context {
if component.ContainsPoint(point) {
component.EventClickPressed()
}
}
}
This is actually the more tricky part of the design, in my opinion, because there are some tricky conventions around how component based UI works. You don't necessarily have to follow them, but they're important to be aware of at least because it is probably how people expect your UI to work:
After click press, click drag continues to occur until click release, even if the cursor leaves the component area.
"Actions" occur on click release.
Click release only takes action if the corresponding click press occurred on the same component.
The click release doesn't take any action if the cursor is no longer inside the component (leaving and re-entering the component before release still does the action, though).
You can only be actively clicking one component at a time (the one shown on top), even if multiple components overlap at that spot.
Assuming that you follow these conventions, this means that dispatching events is actually a bit more complicated than just checking if the event point was in a given component or not. You need to maintain some kind of state to keep track of whether the context is currently in a click or not, and which component, if any, is "consuming" the current click. That is, which component should be given the click release and drag events if they occur.
With these systems in place, you just need to create a window, create a UI context, register the adapter layer to the window to act on that context, set up the window to draw the context on frame, then use the context to add / remove / modify components in your program.
When i use the following to create a button
NSWindow.standardWindowButton(NSWindowButton.ZoomButton, forStyleMask: 0)
I get a button that doesn't react to mouse hover events. I can augment this by creating a container view with a NSTrackingArea and manually triggering the highlight method but it produces a clicked state.
Is there a way to somehow force the button into the expected behavior state without the darkened background?
I have been trying to avoid subclassing NSButton, but it seems like i may have to, and I'm just in a state of denial.
I could not get this working for the life of me so my solution was to write my own custom buttons. This works fine for me because my NSWindow is already custom so there wont be a clash of style.
https://gist.github.com/icodeforlove/a334884e59784b4c2567
Another viable solution is to use https://github.com/indragiek/INAppStoreWindow as #xhruso00 mentioned, but it seemed like overkill.
I've set up a jVectorMap and I want to change the behaviour of it slightly so that when a user hovers over a marker, the same behaviour as the default 'click' behaviour will happen.
Do any of you know how I could go about doing this? Thanks in advance!
Just like the onMarkerClick event, there is also an onMarkerOver event as listed in the documentation. http://jvectormap.com/documentation/javascript-api-v1/jvm-worldmap/
onMarkerOver - Will be called on marker mouse over event.
onMarkerClick - Will be called on marker click event.
So any functions you had currently executing on a click can be moved to the onRegionOver event and you should get the functionality you are looking for.
I want to build a simple forms designer in Cocoa and need to move controls around on a form using the mouse (click, hold, move around, release).
Do I need to inherit new classes from all control classes to intercept those events ? Is there a way to implement it generically for any control?
One way might be to have a single large custom view that fills all the space the controls will be in. Implement the necessary methods to implement mouse events in this view, doing hit detection on the control views and moving them around. This approach requires only 1 custom subclass of NSView, and you can use any views or controls you want to move around without subclassing them.
Write a custom view to contain the controls. Override -hitTest: to ignore the controls and return self instead. Then when you receive mouse events, figure out which control they apply to and move as appropriate.
I am trying to give a ListBox drag and drop ordering functionality and I have hit a wall. I got it to work when I specify the list box items in xaml but it does not work when I bind to a list it no longer works because the items are no longer of a listboxitem type.
I found this code http://blog.dobaginski.com/josh/?p=52 that allows me to get the underlying ListBoxItem but I can't get the mouse move event to fire.
I have went through other tutorials but have not been able to find one that deals with a ListBox. Has anyone done this with a ListBox.
The events I am using are SelectedChange, MouseMove, and LeftMouseButtonUp (I think that name is right). I am not using LeftMouseButtonDown because I couldn't get it to fire.
As far as i know you cannot get at the listbox item container when using data binding. YOu could in Beta 1.
You also cannot set a mouse event handler in the style, you must use a data template, just so you know.
You will likely have to use the mouse move event from a parent element, probably the UserControl or main layout control that hosts the listbox.
State changes and animations need to be in the style though so... you still cant get at the listbox item, just the element inside it in the data template.
Oh and if doing drag and drop HitTest is now protected so that will make the Drop harder.
since today you can download the final 2.0 version of Silverlight with some add ons, check the Scott's web log
I've been trying to do the same thing in WPF,
but have only found many buggy implementations.
One person has guided me towards the blog of Beatriz Costa,
and from what I remember she's one of those rare geniouses,
so I suggest you read that as well... I know I will
Blog of Beatriz Costa