Two years ago, when I was developing an application for the iPhone, I used the following built-in system method on all of my buttons:
[button setExclusiveTouch:YES];
Essentially, if you had many buttons on screen, this method insured that the application wouldn't be permitted do crazy things when several button events firing at the same time as any new button press would cancel all others.
problematic: ButtonA and ButtonB are available. Each button has a mouse up event which fire a specific animated (tweened) reorganization/layout of the UI. If both button's events are fired at the same time, their events will likely conflict, causing a strange new layout, perhaps a runtime error.
solution: Application buttons cancel any current pending mouse up events when said button enters mouse down.
private function mouseDownEventHandler(evt:MouseEvent):void
{
//if other buttons are currently in a mouse down state ready to fire
//a mouse up event, cancel them all here.
}
It's simple to manually handle this if there are only a few buttons on stage, but managing buttons becomes more and more complicated / bug-prone if there are several / many buttons available.
Is there a convenience method available in AIR specifically for this functionality?
I'm not aware of such thing.
I guess your best bet would be creating your own Button class where you handle mouse down, set a static flag and prevent reaction if that flag has been already set up by other instance of the same class.
In pseudo-code:
class MyButton
{
private static var pressed : Boolean = false;
function mouseDown(evt : MouseEvent)
{
if(!pressed)
{
pressed = true;
// Do your thing
}
}
}
Just remember to set pressed to false on mouse up and you should be good to go.
HTH,
J
Related
How do I make it look like a button was pressed using C# code? If I can actually push the button (play the animation and activate the events associated with the button press) with code that would be even better.
Playing the animation is pretty easy, using the Visual State Manager:
private async void PretendToClickButton()
{
VisualStateManager.GoToState(myButton, "Pressed", true);
await Task.Delay(250);
VisualStateManager.GoToState(myButton, "Normal", true);
}
You can play with the delay as you see fit.
Programmatically raising the event is not possible; you just have to call the handler method(s) directly (which assumes you the code that handles the event).
[Edit: You could subclass Button and provide your own mechanism for simulating the Click event, but that makes the XAML a wee bit trickier]
I am almost done with an Engineering Internship where a group and I were assigned a project involving hardware and programming. Our project was an old-style arcade box Tower Defense Game with a theme of Stopping Global Warming.
After following a nicely made tutorial, we have completed our game except for one thing: in the tutorial's game you select a tower by clicking a button with the mouse, however for our purposes we need it so the user presses a keyboard button to select the tower (we already got it so when you press a button on the arcade box and it presses a key).
Below is the code section that I believe contains the code that needs to be changed. I have tried fiddling with KeyboardEvent.KEY_DOWN, however to no avail.
In case everything above made no sense, I need to make the event listener listen for the "w" key to be pressed, and then select the Fire Tower.
setupGame();
// Initialise the UI event listeners.
mcGameUI.btnBuildFireTower.addEventListener(KeyboardEvent.KEY_DOWN, clickTowerFire);
mcGameUI.btnBuildFireTower.addEventListener(MouseEvent.ROLL_OVER, showTowerFireHelp);
mcGameUI.btnBuildFireTower.addEventListener(MouseEvent.ROLL_OUT, clearHelp);
Thank you!!!!
Keyboard events need to be listened for on an object which has focus. Fortunately, the stage always has focus, so it's a good idea to attach your keyboard event listeners there, e.g.
stage.addEventListener(KeyboardEvent.KEY_DOWN, clickTowerFire);
If you want to add actions based on a specific key press, you can use the keyCode property that is attached to the KeyboardEvent:
function clickTowerFire(event:KeyboardEvent):void
{
if(event.keyCode === 87) // W
{
// Your existing code here.
}
}
I'm working on something similar to the Angry Birds "rollout" for options, etc., but I'm running into a fairly substantial problem.
The rollout itself is just a toggle button, with several other buttons added to the display list that move when you touch the toggle button. Each of these buttons is a class that extends Sprite and contains individual methods for touch events, begin, end and out. When these buttons get initialized (NOT instantiated), the touch begin listener is added. Something like this:
public function Initialize():void
{
this.addEventListener(TouchEvent.TOUCH_BEGIN, OnTouchBegin, false, int.MAX_VALUE);
}
private function OnTouchBegin(e:TouchEvent):void
{
this.removeEventListener(TouchEvent.TOUCH_BEGIN, OnTouchBegin);
this.addEventListener(TouchEvent.TOUCH_END, OnTouchRelease, false, int.MAX_VALUE);
this.addEventListener(TouchEvent.TOUCH_OUT, OnTouchOut, false, int.MAX_VALUE);
}
private function OnTouchRelease(e:TouchEvent):void
{
this.addEventListener(TouchEvent.TOUCH_BEGIN, OnTouchBegin, false, int.MAX_VALUE);
this.removeEventListener(TouchEvent.TOUCH_END, OnTouchRelease);
this.removeEventListener(TouchEvent.TOUCH_OUT, OnTouchOut);
}
private function OnTouchOut(e:TouchEvent):void
{
this.addEventListener(TouchEvent.TOUCH_BEGIN, OnTouchBegin, false, int.MAX_VALUE);
this.removeEventListener(TouchEvent.TOUCH_END, OnTouchRelease);
this.removeEventListener(TouchEvent.TOUCH_OUT, OnTouchOut);
}
Then, when these buttons get hidden from the screen, a method is called to remove any of the listeners that are currently active on them:
public function Deactivate():void
{
this.removeEventListener(TouchEvent.TOUCH_OUT, OnTouchOut);
this.removeEventListener(TouchEvent.TOUCH_END, OnTouchRelease);
this.removeEventListener(TouchEvent.TOUCH_BEGIN, OnTouchBegin);
}
This is just for the standard button functionality (up/down texture and sound), on top of this, when I make the game, in my rollout class, I have an additional method that will add another event listener for custom logic that should occur when the button is touched (the button itself is created elsewhere).
public function AddRolloutButton(listener:Function):void
{
if (listener != null)
{
_buttons[index].addEventListener(TouchEvent.TOUCH_BEGIN, listener);
}
The buttons in the rollout itself are removed from the display list until they are to be shown. When the rollout is closed, the buttons are deactivated (removed from display list and the 3 button listeners within the button class are removed).
Everything works perfectly fine the very first time I open and close the rollout. After that, the event dispatching system just inexplicably dies. Every single InteractiveObject on the screen, regardless of position or type, becomes unusable. I traced out whether or not the listeners were still there on the rollout toggle button, and it was. I also confirmed that the rollout button itself was the only thing on the display list.
What I've noticed is that if I comment out the listener removal in the deactivate method of the button for the touch begin listener, or pass in null for the listener method in the AddRolloutButton method, everything works just fine. The issue seems to stem from having multiple listeners of the same type on the rollout buttons, and then removing one or all of them.
If anyone has any ideas of just what is going on, that would be very helpful. I was under the impression that adding multiple listeners of the same type to an InteractiveObject was perfectly valid.
UPDATE:
It appears that only TouchEvents get broken by this issue I'm having. I just tried using a mouse click listener on the stage after opening and closing the rollout, and that still works. So, only touch events are getting broken, if that helps at all.
Seems like there is something going wrong in your AddRolloutButton method. Are you sure you are assigning the correct listener function?
In your example the listener:Function argument should be equal to _buttons[index]. OnTouchBegin.
Or, since whatever class that owns the AddRolloutButton method seems to be in control of the buttons, you could potentially scrap the listener argument altogether since you know what method that needs to be triggered.
For example like this:
public function AddRolloutButton():void {
var currentButton:MyButtonClass = _buttons[index] as MyButtonClass;
currentButton.addEventListener(TouchEvent.TOUCH_BEGIN, currentButton.OnTouchBegin);
[...]
}
However, what you could do is to never remove the TouchEvent.TOUCH_BEGIN in the Deactivate function. The touch events will never be triggered when the DisplayObject isn't on the Display List. This means you don't have to worry about adding the listener every time you want to add the button to the Display List again.
If you set the listener to use a weak reference it will not hinder the button from being garbage collected when it's not needed anymore. To make your event listener use a weak reference, set the fifth argument of the addEventListener method to true.
addEventListener(type:String, listener:Function, useCapture:Boolean = false, priority:int = 0, useWeakReference:Boolean = false):void
public function Initialize():void {
this.addEventListener(TouchEvent.TOUCH_BEGIN, OnTouchBegin, false, int.MAX_VALUE, true);
}
Do you call the Initialize method again at some point after closing the rollout?
From your code it looks as though you remove all of the event listeners in Deactivate and then never add the TouchEvent.TOUCH_BEGIN listener again.
I'm not sure what you're trying to accomplish by removing the event listeners. Since the Button has a reference to the callback, it has a reference to that callback whether the listeners are attached or not. Are you thinking that adding a listener creates a reference from the callback to the button? It doesn't--the reverse is true.
If you really want to have the Button release the callback when it is removed from the display list, then it can't hold that reference after it removes the listeners. Consider using something like Supervising Presenter or a RobotLegs Mediator to manage those dependencies.
I seriously doubt that the entire event system is being borked by what you're doing.
I'd be more inclined to believe that this:
if (listener != null)
{
_buttons[index].addEventListener(TouchEvent.TOUCH_BEGIN, listener);
}
is failing, either because the button that's referenced is not the one that's actually on stage, or because listener is null..
I have seen times where adding and removing events with priorities can cause things to fail, but typically this is with events that aren't propagating on the display list.
One way that you can test this is simply to listen to the main document or the stage for touch events and see if you're getting those events. If the entire event system is borked, you won't get them, but if your listener logic is wrong, you will.
You may also want to check the willTrigger property on the button and event.
I'm implementing an FLV video player based on Flex 3 and I would like to add a feature similar to YouTube player.
I want the progress bar to display both the video displaying progress, but also the video loaded status. How can I implement this behaviour?
Using 2 progress bars on top of each other? I'm also using Flex mx: VideoDisplay component, do I need to change this?
yes you should place two bars ontop of each other in the background you place the laodingbar and in the Front you place the current position bar.
But finally this is a bit more work than it looks to make it fully functional...
I would create a new class implementing all bar/slider functionality.
The laoder is only listening on update(val) to set its new value on percentage.
The playingbar will need some functionality on click and mousedown/mousemove for seeking AND the update function to be set again, including an event to trigger seek in the player aftern userinteraction.
Then you bind the loading bar update to the progress event of the player
All events can be found here
//setting up loadingbar
player.addEventListener(ProgressEvent.PROGRESS,slider_update);
//function to update the slider
private function slider_update(E:ProgressEvent):void{
var percentage:float = 0;
if(E.bytesTotal != 0){
E.bytesLoaded/E.bytesTotal
}
slider.update(percentage)
}
With the current playbar its allmost the same
//listens to statechanges of the player to handle updates for cur-pos
player.addEventListener(VideoEvent.PLAYHEAD_UPDATE, checkStatechange);
private function checkStatechange(E:VideoEvent):void{
if(player.totalTime!=0){
timeSlider.update(E.playheadTime/E.totalTime);
};
continue with binds on click to set seek immediatly - to mouseDown and the move to make the scrolling on video possible...
actually for the seek with mousedown the mousemove should be listening on stage so the mouseUp otherwise the user has to stay on the loadingbar while seeking this is in most cases allmost impossible to handle ;)
-have fun
}
I have a DisplayObject docked at the top of my interface that displays debug information (frames per second, etc.) and is translucent with an alpha of 60%.
I would like to interact with items under this surface, such that when the mouse rolls over it, it dims to 10% alpha, and mouse events pass through it to the underlying objects.
Normally, I have this debug info panel's mouseEnabled and mouseChildren properties set to false, so objects under it receive mouse events.
The problem is that in order to hide it when the mouse rolls over it, it needs to have mouseEnabled set to true. However, if mouseEnabled is true, the mouse events are not picked up by objects underneath it.
As far as I know, I can't selectively enable mouseEvents, so it's either going to receive them all or none of them. That means that I'd have to handle and forward ALL events, if I took that approach.
I really wish the mouseEnabled property had a "peek" mode or something, so that it could receive the events if it is on top, but also allow them to pass through to objects underneath.
If a DisplayObject has mouseEnabled=true it means that its events will be sent to its container not to whateve is underneath the object. So this solution will not work. The best solution would be to reroute events from it manually using getObjectsUnderPoint as described here.
I've been using this approach for years in multi-touch apps. With multiple touch points I don't see any processor overhead. And you got only one cursor.
I feel your pain. Unfortunately, I don't know of a way to enable/disable specific mouse events. You could get creative with the solution though. For instance, maybe try adding a MOUSE_MOVE listener to your stage and track the coordinates of the mouse. Then, if the stageX,stageY of the mouse is in the area of your panel, set the visibility. You might also be able to use getObjectsUnderPoint() to determine which objects are under the mouse. But, my guess is that it would get a little intense on the processor to run that on each frame iteration.
I believe you are looking for mouseEnabled = false
But another last ditch attempt you can do is on mouse over move it to the other side of the screen.
One approach you can take, although not ideal, is to add an enter frame listener and check the mouse position every frame. something along the lines of:
stage.addEventListener(Event.ENTER_FRAME, onEnterFrame);
private function onEnterFrame(e:Event):void {
if(mouseX > width || mouseY > height){
//hide stats
}
}
I'm assuming you have this display hierarchy:
Debug Window
Debug Control 1
Debug Control 2
...
Overlay
Why not make the overlay a mask on DebugWindow and have your mouseEvents attached to DebugWindow itself? See this page for some inspiration: http://blog.shaperstudio.com/2010/11/as3-inverse-mask/
I had this same problem.. i made function to check is mouse over certain object:
public function isMouseOverObject(mPos: Point, pObject:DisplayObject, pContainer:DisplayObjectContainer) {
var under_objects:Array = pContainer.getObjectsUnderPoint(mPos);
var is_under:Boolean = false;
for (var i:int = 0; i < under_objects.length; i++) {
if (under_objects[i] == pObject) {
is_under = true;
break;
}
}
return is_under;
}