I am developing a quiz application using LWUIT where users can choose from different types of quizzes.
The user has the choice of taking a timed quiz or an untimed quiz. In a timed quiz, a count down timer will be displayed on top of the screen and the test will automatically be submitted when the timer ends.
How should I implement this in LWUIT? I am looking for an approach which will tackle this problem elegantly. Would really appreciate your comments and feedback.
Thanks ,
Nikhil.
The best way is to use an animation, just implement the Animation interface and use Form.registerAnimated(). Always return false from the animate() method and within it just update your UI based on the current time.
This is a superior approach to using the java.util.Timer API because the animation is invoked within the LWUIT EDT thread and not within a separate thread so you can just change the GUI without fear of a race condition.
Related
I'm Oliver, a noob of web animation,these two days I'm trying to do gsap marquee side project, I build 500 dom boxes as the sandbox url:
https://codesandbox.io/s/gsap-marquee-test-6zx2d?file=/src/App.js&fbclid=IwAR1tbmloHRXHUBHKG5FjBGDAx0TFd9sTkBJfSwpye8CQteO-TO8FNi1w4mw
and I have few question:
1.I used setTimeout to seperate each box as a unique timeline animation,so that the single box animation could go to another line immediately after finished last line, instead of waiting the other 499 boxs finished in the same line if I use property stagger.
This method would produce 500 timeline instances,it seems not a good idea, are there any methods could produce the same animation in one or few timeline?
2.If I do such animation in canvas,the browser render effciency would be better?
You should avoid using setTimeout with GSAP as it's best to use GSAP to control the timing of things.
In this situation, you can probably make use of GSAP's staggers. You should also learn about the position parameter of GSAP's timelines. If you use one (or both, depending on the exact effect that you need) of these you should be able to avoid creating so many timelines.
Additionally, your animation is not responsive. You probably want to make use of functional properties (where your properties of a tween are functions, not just hard numbers) with timeline invalidation to make it responsive.
I also highly recommend going through the most common GSAP mistakes article as you're making some of them.
As for using canvas for rendering your boxes, it probably depends on what your boxes are like. In most cases it'd probably be faster to use canvas, yes. But the slow part of animating these boxes is not anything related to the animation functionality itself, per se. It's related to render speed. In general it's faster to render a bunch of objects to canvas than it is to render a bunch of DOM elements.
I am trying to design an activity diagram for an image editing application. Let's say that the application has one adjustment to edit an image. that's brightness. When the user opens the application he can change the brightness again and again. Then finally save it. That's really not a loop. but it's a repetitive process. How can I represent such a process. I have found stack answers for looping through documents and for loops. But didn't found a matching scenario for like this.
Thank you!
Oh, but why do you say it is not a loop? It is.
Sorry, no reasonable drawing tool at hand, so this will be textual
Let's look at a pseudocode:
open app (image as attribute)
while decide to continue to brighten the image do
brighten the image
loop
As you can see you do loop and your condition to loop or finish it depends on the decision to brighten or finish working with the app.
The brightening itself can be more complex (e.g. may have some selection of settings like level or method of brightening, it may even have the ability to break the brightenin or undoing) but it is still the loop.
Out of this solution to represent a loop you can use options 2 and 3 easily.
UI Control such as LISTVIEW or Tree or ... comes with model that is observable.
When one make a change to that model, I suppose JavaFX knows how to refresh it automatically in the display.
However my question here is as follows:
Is it the intent way, that someone who wants to update and not replace this model, do so in a background thread with a platform.runlater.
In other words, one has some serious computation to do, and needs to to update an ObservableList as a result. Is it the intended way, to do the heavy work in a background thread and at the end of it, run the update in a platform run later?
I'm asking this because this is what I have been doing so far without problem. But from my reading here and there, in particular in
http://docs.oracle.com/javase/8/javafx/api/javafx/concurrent/Task.html
It seems that some other mechanism shall be used. One should rather return a full list instead of updating the observable list.
But this works only if things comes from the GUI. In case the update is triggered from the back end, there is no way to do so.
The solution that I have used so far, was always to hold a reference to the observable list and updating it by means of platform.Runlater.
Is there any other way ?
The link you give has an example (the PartialResultsTask) that does as you describe: it updates an existing ObservableList as it progresses via a call to Platform.runLater(). So this is clearly a supported way of doing things.
For updating from the back end (i.e. from a class unaware that the data are being used in a UI), you'd really have to post some code for anyone to be able to help. But you might have a look at the techniques used in this article. While he doesn't actually update lists from the backend in the examples there, the same strategy could be used to do so.
So i'm making a little game in which a player can wander around a map and collect things, but may also come across randomly moving bots. I'm trying to make it so that if the player and standing next to the bot and click's 'fight' the bot loses health.
The only way I can think of doing this is by making an ActionListener in the bot class. So I'm trying to make an 'if' statement like, if the Player is on a nextdoor tile, and clicks 'fight', the bot will lose health. However I've never used an ActionListener and despite looking at lots of examples I still don't understand them.
The bot's coordinates on the map are 'ycord' and 'xcord' and the player is represented by 'P'.
Is there a way of saying this...
if(map[ycord+1][xcord].equals("P") && 'fightbutton' is pressed){
bot.health--;
Thanks a lot!
I think you should not use an ActionListener. ActionListeners need to be "registered" on the instance that creates actions, in your case players. So every bot would need to register an ActionListener on every player, which (in my opinion) is a bit messy.
Instead, I would simply create a hitBy(Player) method on Bot which is executed by some superior Game instance. A fighting player would do something like game.madeHit(this) and the game searches for close-by bots and then executes bot.hitBy(player). This can be done by simply iterating over a list containing all bots; this list should be available in Game.
I'm kind of a UI buff - every "screen" in my game should transition in/out when it appears or disappears. Because my game is simple in terms of resources, I thought I'd just make each "screen" a CCLayer and define a function for the transitions, leaving everything in memory. It's turning out to be more complicated than I expected.
I think I have two main problems right now:
1) Each "screen" is a CCLayer. This looks fine, but I can't seem to stop receiving touch events, even when they are inactive. Child sprites do not seem to respect the isTouchEnabled property, so I'm hitting invisible buttons all the time.
2) I wrote a custom button class that is basically a sprite with a few separate textures for states. It uses the CCTargetedTouchDelegate protocol. I'm thinking this is a big part of the above problem.
I'm not quite clear on the CCMenu stuff. Is there a tutorial or documentation out there that better explains its designed purpose and how to use it? The documentation for cocos2d doesn't talk at all about what each class does, which makes it much, much harder to properly use the library. Also, when should I use a scene instead of layers? Can I write custom transitions?
I found that if you have multiple layers in a single scene for menus, such as for a main menu (simpler to have a layer for load game, new game, etc. than an entire scene) that if you add all of you buttons as children of the layer; then to stop them from receiving touches, simply move the layer off screen when not in use. Heres an example.
[loadLayer setPosition:CGPointMake(-1000,-1000)];
[settingsLayer setPosition:CGPointMake(-1000,-1000)];
[menuLayer setPosition:CGPointMake(0,0)];
And each time you select a button that would take you to say the load game layer just reverse it for the right layer.
[loadLayer setPosition:CGPointMake(0,0)];
[settingsLayer setPosition:CGPointMake(-1000,-1000)];
[menuLayer setPosition:CGPointMake(-1000,-1000)];
It's more convenient to use CCScenes for menus. All of the children of an inactive CCScene will not receive touch events, so you don't have to manage that behavior. CCScenes also have built-in transitions like a crossfade, but if you're like me, you'll probably just want to run an action to make the scene transition out, then call CCDirector:replaceScene.