Good Morning,
I have a list of items with a prev. & next button. When the user is at the start of the list the prev button is disabled. Clicking next takes them to the next record and my click handler sets the prev button enabled true. However in the emulator it doesn't show the button enabled. Clicking next moves me to the third record and again the handler sets the prev button enabled but this time it does become enabled in the emulator. I'm grasping at straw here but do I need to invalidate and redraw or something?? I don't understand why such an elementary task is not working.
In XML:
<Button
android:id="#+id/btn_PrevLift"
...
android:enabled="false"
android:onClick="btn_PrevLiftClick" />
In the handler code:
private void UpdateNavButtonStatus(int z)
{
...
btn_Next.setEnabled(true);
btn_Prev.setEnabled(true);
....
}
No just to show you how little I know about what I'm doing how come when I look at the variable values in Eclipse debug I can't see the enabled property in any state???
More Info
Very odd to me at least. If I move from using XML defined event handlers to programatically defined as below it works great!!!???
btn_Nxt.setOnClickListener(new OnClickListener()
{
public void onClick(View v)
{
//Call helper methods etc...
}
});
I think I have it but not sure exactly why
So when I was trying to get a handle on my Button objects I was using the View.findViewById(etc). When I changed from XML to the programatically declared event handler I used ViewGroup.findViewById. Reverting back to xml if I use the ViewGroup I get a "different" handle that seems to work...????
Ok,so what you can do is declare a variable count and on the click f button next increment the value of count..and on the click of Back button decrement the value of count and give the condition that while count<0 the task of the back button is done else nothing
I have identified the problem and of course the problem is me. I was enabling the button and then the ListView was updating to the next record. Of course my enabled button was one behind so it appeared that when I clicked a second time the button suddenly enable but that is not the case. When I clicked a second time we moved to record three and showed button for record two which was enabled.
See my buttons were part of my ListView and new buttons were being drawn for each record. OOHHHH it makes so much sense now how everything was behaving.
Anyway I moved the buttons off the ListView layout so they remain constant as the user navigates through the records.
Related
What is the equivalent of GetKey for buttons. In my android game when user press and holds the button , i want player to move right but it only moves for one time when i press the button.But when i get input from a keyboard with GetKey function , it moves until i stop holding that button. I want to use my button like GetKey.I tried to add a event trigger pointer down component into my button but it is not working.What should i do?
public void moveRight(){
rigidbody2D.velocity = new Vector2(moveSpeed,rigidbody2D.velocity.y);
}
void Update () {
if(Input.GetKeyDown (KeyCode.Space)){
rigidbody2D.velocity = new Vector2(rigidbody2D.velocity.x, jumpHigh);
}
if (Input.GetKey (KeyCode.A)) {
rigidbody2D.velocity = new Vector2(-moveSpeed,rigidbody2D.velocity.y);
}
if (Input.GetKey (KeyCode.D)) {
rigidbody2D.velocity = new Vector2(moveSpeed,rigidbody2D.velocity.y);
}
}
they are absolutely same but i don't understand why its not working continously.
Update method is the key, i know this but i don't know how to get information about is a button pressed in Update method.Stuck help.
Well, we have two different parts of Unity3D API here.
Let's split it up into pieces:
Input.GetKey
As stated in API docs, Input.GetKey just checks if certain key is pressed:
Returns true while the user holds down the key identified by name. Think auto fire.
If you check it every frame, (Update() is executed every frame) you re-check if button is pressed and if so, proceed with velocity change.
EventTrigger
EventTriggers are a little different. They actually bind a delegate (UnityAction to be precise) you pass to them and trigger it as callbacks on given EventTriggerType fired. So if you bind to OnPointerDown() with your moveRight(), it will fire when pointer goes down over GameObject. If you keep the button pressed, it won't fire again because actual event of pointer going down has already happened and it already fired appropriate trigger you passed to it. Pointer is actually not going down right now. It's pressed.
It all goes down to the fact that one part checks every frame if button is pressed while the other one fires when button press happens.
I have recieved code for an android application
unfortunately , the person who wrote the program is unreachable.
my problem is, in a certain activity there is a button but I can't find the listener for that button. it's like it doesn't exist and yet the app is running ok with that button.
the button is a button to move next . i have searched all sources for the button id but couldn't find it. only found it in the layout xml. how is that possible?
I have tried debugging it , and while I press that button the code jumps to the other activity's class so I can't seem to find what happens when I press that button!
the thing is there is a bug that happens as soon as I press the button (some global variable changes) and so I need to analyze what is happening when the button is pressed.
any help would be appreciated
You can specify a click listener method in XML with
android:onClick="methodName"
and the corresponding
public void methodName(View view)
in your activity will get invoked.
Check the android xml, where that button has been defined in. It will have an onClick property associated with that button, where a method name would have been mentioned. So as soon as the button is clicked, that method will be called automatically.
We can use button without listener, for Example in Layout file:
<Button
android:id="#+id/test"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentRight="true"
android:layout_alignRight="#+id/ported"
android:layout_below="#+id/ported"
android:onclick="test" />
You can get called this method in activity whenever you pressed that test button
public void test(View view)
{
// Your code
}
i have button in my first activity called Start.
Now when i click on this button it takes 1 to 2 seconds to load the next activity, now at that time the user clicks on the start button multiple times so what happens is that the next activity will open multiple times.
How to overcome this? Is there any way that even if the user clicks on the Start button multiple times open the activity only once.
Your Options:
On click, disable the button and display a ProgressDialog to the user.
Use the Intent flag FLAG_ACTIVITY_SINGLE_TOP to ensure only one activity is maintained on the stack. Documentation
Use the qualifer launchMode=singleInstance in your AndroidManifest.xml so only one instance of your Activity is allowed at a time. Documentation
I would recommend the first, because it can show the user your application is still working even if it takes a few seconds to do the necessary processing to begin your Activity.
You can put the launch mode of your 2nd activity as "Single Instance" in your manifest file.
Don't use anything like a launchMode or Intent flags. They are used for different purposes.
Description here
What you have to do is:
Show a progress dialog to clearly show the user that an
action(calling 2nd Activity) is in progress. This was user will not
try to click the button multiple times
Simply disable the button's click listener after 1st click. This is not
recommended because user might not be able to know whether he/she
clicked the button. Also this is the case where user tends to click
the button multiple times.
I have buttons in my app that do various things. A problem i am running into is that a button can be pressed multiple times before what that button does is enabled/processed/calculated.
Example
when i press a button { an integer should have 1 added to it unless it is at it maximum value.
when i press a button { a dialog should show (only once).
in either case if i press slowly i have no problems, but if i press rapidly the integer will pass its maximum or multiple dialogs will show.
Can someone point me in the right direction to deal with this.
It sounds as though you could simply set a boolean value when the button handler is entered to signify that the task is being performed. If you enter the function and the value is already true then simply return (or just disable the button until the operation is complete).
I don't know a lot about android, and I don't know if you have the task running in a different thread or if multiple clicks are being queued up, in which case the boolean wouldn't help as it would all be happening in serial. In that case, as I suggested earlier, just disable the button while the task is in progress (probably a good idea in any case).
I would suggest disabling is not that user friendly, i see the user is selecting button and has a lot of time in between before the next operation happens and tats why he ends up clicking multiple times. In this case as soon as soon capture the click you can show circular progress dialog , that shows user something is in happening and he wont be able to click button also.
Dismiss the dialog once you have set the counter
or second case about to open the dialog ProgressDialog dialog = ProgressDialog.show(MyActivity.this, "",
"Loading. Please wait...", true); then dialog.dismiss() once ur done
I want to be able to press a button on my program and hold it down (without releasing) to increment a variable. Problem I am having right now is when I conduct the long button press it only runs once, until I release and press again.
First I want to find out if there is a way to do this without having to use the OnTouchListener, and just using the OnLongClick. Is there a way to check the value of the button? For example.. buttondown=true; Conduct a whileloop to increment until the button is released.
Second, I don't want the updates to be delayed, because the incremented value is being drawn as the user holds down the button.
Basically I am doing something like this:
btn_resume.setOnLongClickListener(new OnLongClickListener() {
public boolean onLongClick(View v) {
..code..
return true;
}
});
OnLongClick will only be called once per press. It isn't going to work for your purpose.
If I understood your question correct this can be achieved using a OnLongClickListener.
Check http://developer.android.com/reference/android/view/View.html#setOnTouchListener(android.view.View.OnTouchListener)
OnTouchListener provides a more granular handling of touch events, e.g. KeyDown, KeyUp
I think you can use OnLongClickListener for increment/decrement. But once the long press is done for the button, the longpress has to be canceled or reset for the next long press of the same button.