I've got a big headache and spent a few hours to solve my problem withou any reasonable results.
I use a custom adapter (extending ArrayAdapter) to show listview items. This adapter implements OnTouchListener. There's also a background selector which color is changing when an item is touched and OnItemClickListener in ListViewActivity.
What I need is capture touch events (all of them, not only ACTION_DOWN) in the adapter. When onTouch returns false, the consecutive events (ACTION_CANCEL, ACTION_UP etc.) aren't captured. On the other hand returning true stops dispatching all other events (e.g. click) so that the ListViewActivity's onItemClick is never triggered.
I tried hard to find any working solution in SO and other resources, but with no success.
One idea was not worry about click events and background. I may set the background programatically and trigger click event the same way when the onTouch action is ACTION_UP, but view.performClick() does nothing (view is the 1st argument of onTouch method).
[EDIT]
To make it clear, I want to handle touch events in the adapter beacuse I need the textview in the item to marquee when the user touches it. Thus, in onTouch, when the action equals ACTION_DOWN, I assign true to setSelected property of the textview and, consequently, false when ACTION_CANCEL or ACTION_UP.
Any suggestions?
Thanks in advance.
Related
I need to create a click event, that's not being consumed, so that an underlying adapter receives the touch event.
I cant use an OnClickListener, because that would consume the event.
I tried my best with OnTouchListener, but if I return true the event gets consumed and if I return false the listener only registers ACTION_DOWN events.
How can I react on a click, but if its not a click the adapter will receive the move?
EDIT:
I'm using a lorentzos.swipecards SwipeFlingAdapterView, which uses touch-move-events. I put a layout over half of the view of the items of the adapter, which need to react on click events. But I either can't implement the click event, since I can't catch two events in a row without consuming them, or I can't have the SwipeFlingAdapterView react on the touch-move-event, since I, well, consumed it in the click event.
Don't know what sourcecode to share, since I tried many different ways and nothing works.
I know this got asked often, but all solutions(, I found,) don't work for me.
What I have is a CardView with an OnClickListener making a Toast (#toast1).
Inside the CardView there are multiple views as also a WebView.
As mentioned elsewhere, to pass through the click through the WebView to the CardView I have done following:
Set android:clickable="false" in WebView XML
insert following under CardView.setOnClickListener(...)
WebView.setOnTouchListener( (view, event) -> true);
I also replaced the lambda with an anonymous method, to see if its just this. No change.
What happens now is:
At the border and over the other views, the clickListener is triggered and the toast appears
Over the webView the clickListener isn't triggered.
Also put a toast (#toast2) in touchLstener of WebView before returning true, and it gets triggered.
What I expect:
Click will passed through WebView
With #toast2 added: First show #toast2 then #toast1
What is a bit confusing, that in documentation of OnTouchListener, the return is following:
True if the listener has consumed the event, false otherwise.
For me that means:
true: Don't pass click to below views, as listener consumed it
false: Pass click to below views, as listener didn't consumed it
But setting to false didn't change anything.
First of all I would suggest you to get familiar with android touch handling system - you can find a really good description in this answer. To sum it up: touch event propagation starts on top level of hierarchy, but actual handling of the touch event starts on the lowest level of view hierarchy. As for solution of your problem I may suggest to sublcass the parent of your WebView and override onInterceptTouchEvent in the following way:
#Override
public boolean onInterceptTouchEvent(MotionEvent e) {
return true;
}
This will instruct this parent view to intercept all touch events that would otherwise go to its children views, thus limiting the first level of touch processing to this view.
This doesn't seem like a typical view layout which I'm having trouble with.
I have two listViews.
Each listView has touchListener
(whose purpose is to synchronize scrolling by calling dispatchTouchEvent() to another listView)
ListView also has onItemClickListener to handle clicks on the row of listView.
Everything works as intended up to here.
I'd like to add another clickListener to subview-group of the listView's row to handle click event on the subview.
After attaching this clickListener, I see listView's scroll doesn't always work.
I suspect its because the clickListener of this child view is inspecting touch events (to see if its indeed a click) before the parent(listView)'s touchListener.
I can think of two workarounds to this problem.
attach touchListener instead of clickListener to child, and make it return false for all touch event except FINGER_UP event.
on FINGER_UP event, I execute the method which I initially had in onClickListener
public boolean onInterceptTouchEvent (MotionEvent ev)
Implement this method to intercept all touch screen motion events. This allows you to watch events as they are dispatched to your children, and take ownership of the current gesture at any point.
(ok... I'm confused, I thought touch events goes to child views first and propagate to parents if children don't handle the touches..)
.. How do I implement the method 1?
.. Please help me to figure out #2 as well and to grasp the touch delivery mechanism.
EDIT -
This is where I add OnClickListener to my subview.
viewHolder.layout_author.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
Intent profileIntent = new Intent(ImageListAdapter.this.activity, ProfileActivity.class);
profileIntent.putExtra("JsonUser", jsonAlbumImage.jsonUser);
ImageListAdapter.this.activity.startActivity(profileIntent);
}
});
I'd like to add another clickListener to subview-group of the listView's row to handle click event on the subview.
You simply need to write a custom adapter and assign the OnClickListener in getView(). You can look at the question: Android GridView Button Click Handler for example code.
Also awhile back I answered Android. Scrolling 2 listviews together did you use a similar approach to synchronize your ListViews? When I combine both of the answers, my app functions the way you want. I hope this helps.
I have a listView. In that listView i have implemented onTouchListener. Every things work fine, but when list is Scrolling , on tapping on the list , the list should stop(like normal android listView).No action can be done while scrolling like stopping the scroll.This happen because of the onTouchListener. I am returning false from onTouchListener. I don't know why this behavior happens?Can any one help.
try returning super.onTouchListener, or true, when you don't want to consume the event (i'm thinking you implemented gestures). returning false means you're discarding the TouchEvent, and you don't want to do that if you want to stop the scroll.
I need to differentiate between programmatically scrolling a list view and manually scrolling a list view. I am not quite sure how to do it. Any idea ?
Thanks.
I guess a way would be to do something like add onscrollchanged listener and onTouch listener to the listview. And keep a boolean like fromUser.
In the onTouch listener you can set the flag to true on MotionEvent.ActionDown. When the MotionEvent is ActionUp you can set the flag to false.
So whenever the scroll listener is fired you can check the flag and see whether its from the user or not.