I have a class A and class B.
A is the object (as a character) and B is the rendering class which have the aim to show A.
I am looking for a way to detect when A is pressed, with normal InputProcessor I can't because it detect touch in the entire screen, I only want detect touch over the object. If I check touch position and "A" position it doesn't work because the object is moving and the values aren't so precise
How to solve?
Related
I want to implement touch listener that detects
Click/tap on chess piece in order to select ot
Swipe/move of chess piece immediately.
How to do it?
Unfortunately, I am not sure what you mean by a "chess piece", but let's assume that the board is a view in the background, and inside you have inner views which are chess pieces.
To achieve the select/unselect given piece effect you should add a simple View.OnClickListener interface to your view. Each of your pieces should have a view class and some data connected to it (like a position, a type of piece, id, etc.). After clicking the piece update the state of some global variable, for example, selectedPiece with an ID assigned to a given piece. You should also change the UI of a given piece, for example change the border to show the selected piece to a user. Then after clicking a new field for moving the piece you should update the UI by moving your piece view to an appropriate position. Also, the data of a piece or a game should be updated - depending on the place of storing the pieces' positions.
For this you should implement the drag&drop feature which is described here: https://www.tutorialspoint.com/android/android_drag_and_drop.html. You should determine the places where the user can move a piece and in case of dropping the piece in the wrong place, cancel the move and go with the piece to a start position.
Basic response to touch events using event.x and event.y works:
https://developer.android.com/develop/ui/views/graphics/opengl/touch
https://suragch.medium.com/how-touch-events-are-delivered-in-android-eee3b607b038
...more info:
Android Touch Listener
I am developing an app in which I need to implement object movement following by users finger touch/drag. My object is at the bottom of the screen and it can move horizontal only. I have no idea about Gesture control or Object movement in Android.
Also, the object should maintain its state, for example if user stops dragging the object it should appear to its last position only.
I need to sort this out, any help would be appreciable.
Thanks
are you looking for this:
https://www.youtube.com/watch?v=hdxdTkdNkVs
than have a look on this:
https://github.com/fouady/SpotifyTray-Android
Let's say
-I have a button that listens to a "tap" event, and directs to a function that does something.
-I put an ImageRact that covers the button. One layer up.
When I click on the cover image just above the area the buttons lies behind , the event function STILL executes.
How do I avoid this?
example:
local function hidebg()
display.remove(logo3)
logo3=nil
end
local logo2= display.newImage("logo.png")
logo2.x=display.contentCenterX
logo2.y=280
logo2.width=200
logo2.height=74
logo2:addEventListener("tap", hidebg)
local cover =display.newImageRect("NEW GAME A.png", 480,320)
cover.x=display.contentCenterX/2
cover.y=display.contentCenterY/2
The hidebg() function is still executed although the "logo2" is covered by "cover" image.
I know I could make the button isVisible=false and solve the problem, but I have dozens of buttons in different groups in different layers, and I wonder how to do it in a smart way. Maybe somehow disable a whole group? I don't know.
There are 2 ways that you can disable that button in your project.
1) Just create a listener to cover as below and return true as follows:
function coverPressed()
return true;
end
cover:addEventListener("tap",coverPressed)
2) Check if cover exists, and then remove the listener of logo2 as:
logo2:removeEventListener("tap", hidebg)
Keep Coding............ 😃
Control Touch Propagation
The reason that this problem can be solved by adding a touch event listener that returns true to the masking DisplayObject, as suggested in the accepted answer, is that this handles or halts the propagation of the touch. Having been handled by the masking object, the touch will never reach the listener on the button located further down in the display hierarchy (or further back, if you prefer).
This is explained in the Corona SDK documentation on tap/touch propagation:
When the user touches the screen, the event is dispatched to the display hierarchy. Only those display objects that intersect the touch location on the screen will receive the event.
Tap and touch events propagate through these objects in a particular order. By default, the first object to receive the event is the front-most display object in the display hierarchy that intersects the touch location. The next object to receive the event is the next object back in the hierarchy that intersects the touch location, and so on.
Tap and touch events propagate until they are "handled." This means that if you have multiple objects overlaying each other in the display hierarchy, and a tap or touch event listener has been applied to each, the event will propagate through all of these objects. However, you can stop propagation to the next underlying object by telling Corona that the event has been handled. This is as simple as returning true [emphasis mine] from the event listener — this stops the propagation cycle and prevents any underlying objects from responding to the hit event.
Change Widget Properties
If your button is from the widget.* library, you can achieve the same result more simply by disabling it and making it invisible:
button:setEnabled( false )
button.isVisible = false
By the way, the advantage of using isVisible (rather than changing alpha) is that you don't need to keep track of the alpha value before hiding the button. If you later do button.isVisible = true, the ButtonWidget will have the same alpha value as before.
In my application, I save data in my sqlite db a variable number of notes composed of: (IDNote,title,body, date of creation, owner of note, icon_name). When i save and query the DB, my data are all ok, so my question is, Is possible to implement GestureDetection for moving and restore a single icon that correspond at a single note ? Because a found an example but all the icons are moved, but i want to move only one icon at time simulating all the gesture of the icons of Desktop computer.
Thanks in advance.
Marco
Set an OnTouchListener on the view that holds your icon. This listener is called when an ACTION_DOWN event on the view is caught.
Here register it somewhere as the 'currently dragged object'. Make sure onTouch() returns false, so the event is propagated further to your views parent.
This parent is responsible for checking whether a view has been registered as the 'currently dragged object'. Also, it has to call your Gesturedetector, which in onScroll will do the actual scrolling and moving.
This is just an idea, tell how it went!
Is there a way to detect a click from MotionEvents in Android? To be more specific, I need a way to distinct two kind of events: movement and click (I'm more interested in the latter).
For example, this kind of behavior can be observed in MapView component: if you drag the map just a little - it does not move (I would call this a click), however if movement distance is bigger the map starts to move as well (I would call this movement). Is there a standard threshold (global parameter) or other method to distinct these two actions?
You can implement an OnGestureListener. onSingleTapUp() will be called for a click type event and onScroll() will be called for a movement type event.