When a Component derivative is in a scrollable Container after pointerPressed and some scrolling the pointerReleased is never called.
Is this a bug or a feature - and why do You think that way?
There is a special case for buttons which you can leverage by deriving buttons. Events are delivered to the component where they occur. If a release occurs outside of the component it's sent to the component where it occurred as we don't track the original component.
For buttons there is a special pressed and not released case. This will detect such a button in the pointer release code and deliver the event to it.
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I am trying to use a parent component to control animations in a child Canvas element. Specifically I want an animation to happen when a user inputs a correct answer.
It works until the user changes the state in the parent component, and then it no longer works.
I've made a stripped-back, minimal version of my code here to show my issue: https://codesandbox.io/s/epic-leaf-08jqvy?file=/src/App.js
My desired behaviour is that the red box bounces when a user clicks submit. That happens if they don't type anything in the input box, but as soon as you enter anything into there - changing state and re-rendering the component - the button no longer triggers the animation in the Canvas child component.
As far as I can tell, the issue is to do with changing the state when inputing text. If I make a version where the input is just assigned to a variable, it works fine, but I need to be able to use state and re-render other parts of it.
I have put a console.log in the jump() function, so I can see that it is being called, but no animation is taking place in the canvas.
I assume that what's happening is that everything is being re-rendered when the state changes, and so the useRef is no longer tracking to the right thing.
Things I've tried:
putting the canvas in a memoized component to prevent it from re-rendering
using eventlisteners to see if I can trigger the animations in other ways - keydown ones work, but I need the user to be able to type, so I tried other ones (like hashchange or audio.play) but neither of those worked.
You can see the thing I'm actually trying to build here: https://papaya-platypus-86565f.netlify.app/play Basically users answer questions and an animation plays depending on whether they're right or wrong, to give it a game-y feel.
Thanks!
I like your red box as well as your reasoning. Yes, the input state changing on keystroke is causing the entire App component to re-render. Note that your App.js component has a lot going on (all good stuff), such as your Box class instantiation, your canvas instantiation, etc.
The key is to break your components into smaller parts, particularly separating stateful components from non-stateful components. We don't want your canvas re-mounting on every input change, so we make them sibling components!
Here's a working example of your code, just in smaller components:
https://codesandbox.io/s/strange-julien-d3n4zm
I hope this helps.
Is there a native MUI event for when the pre-selection value changes in a MUI:Select component?
For example, here is my MUI:Select component with 3 options:
I would like an event for when 'Public', 'Restricted' or 'Private' is pre-selected (but not actually selected; i.e. before the onChange() event), either with a mouse-over event or a keyboard up/down event. This is because I have a tooltip card that needs to change dynamically for the user as they interact with the options.
Using this example https://codesandbox.io/s/3iv96 as a guide, I implemented a bespoke solution by capturing the mouse-over event and extracting the text value. I just realized I have forgotten to handle key up/down.
So the question becomes whether I have just missed the obvious, or do I need to roll my own component by wrapping MUI:Select and publishing the events I need.
Looks like out of the box this isn't supported.
Looking at this thread https://github.com/JedWatson/react-select/issues/745 it has to be done manually.
I'm using react FullCalendar component and I need to change the background color of an event as it becomes the "CurrentEvent" (when the now indicator is over it).
I'm able to do that when I load the screen, but I also need to do it when the screen is open and the "current event" changes as the time passes.
The way I was thinking about doing that is by using any callback indicating this situation and then changing the style, but I'm not finding any callback that points out this situation.
Any ideas? Thank you.
I have implemented code in focusGained that in some cases may cause the component (a container I have set to be focusable) which just received that focus to be removed from the screen, and replaced in the container by another component. This will also cause a redraw of the screen to show the changed component.
This does work but I have a bit of a problem, in that the next component in the container also gains focus and so my code removes/replaces it also. I assume this is because on the redraw, that component now occupies the same space where the tap originally occurred.
If the last component in the container was originally selected, then the replacement component is itself given focus and so it is removed and replaced.
Any ideas on what I may have miscoded or anything I can do to avoid the second focusGained call?
I doubt you did something wrong. If we remove the component with the focus we'll find the next available one. The replace method doesn't take focus into consideration but can't grant focus to a component that isn't physically here yet so it's granted to the next component. Not much to do here.
You can requstFocus() after the transition completes to fix the order manually.
I'd like derive a class from Button to add an initial delay and interval which shall be used as long as the button is touched for repeated action.
At first thought this seems to be simple enough but the method com.codename1.ui.Button.setState(int) cannot be overridden because it has package access only. Is that for a good reason?
I noticed, that Button calls actionPerformed on pointerReleased. My Button descendant should call actionPerformed repeatedly but not wen the parent container of the Button is beeing scrolled. This would hopefully just correspond with the Button state STATE_PRESSED, right?
If I understand correctly what you mean then I'd just start a timer on the pressed method and then repeatedly call super.pressed & super.released whenever the timer elapses.