I have LinearLayout and inside ListView ( multi select list) with attr width and height match_parent. I need to register OnTouchListener in LinearLayout but it seems that ListView steal event. How to solve this ?
You should make a custom layout extending LinearLayout like the following:
public class MyLayout extends LinearLayout {
#Override
public boolean onInterceptTouchEvent(MotionEvent ev) {
// do whatever you want with the event
// and return true so that children don't receive it
return true;
}
}
Related
I'm programming a custom ChipGroup class and in the layout I have a HorizontalScrollView and a Material ChipGroup inside. In my constructor I pass a boolean called "isScrollable" because I want it to be configurable the scrolling.
Is there a way to inactivate the scroll of the HorizontalScrollView if scrolling is configured as false?
You cannot disable the scrolling of a ScrollView. You would need to
extend to ScrollView and override the onTouchEvent method to return
false when some condition is matched.
The Gallery component scrolls
horizontally regardless of whether it is in a ScrollView or not - a
ScrollView provides only vertical scrolling (you need a
HorizontalScrollView for horizontal scrolling).
You seem to say you
have a problem with the image stretching itself -- this has nothing
to do with the ScrollView, you can change how an ImageView scales
with the android:scaleType property (XML) or the setScaleType method
for instance ScaleType.CENTER will not stretch your image and will center it at it's original size.
You could modify ScrollView as follows to disable scrolling:
class LockableScrollView extends ScrollView {
// true if we can scroll (not locked)
// false if we cannot scroll (locked)
private boolean mScrollable = true;
public void setScrollingEnabled(boolean enabled) {
mScrollable = enabled;
}
public boolean isScrollable() {
return mScrollable;
}
#Override
public boolean onTouchEvent(MotionEvent ev) {
switch (ev.getAction()) {
case MotionEvent.ACTION_DOWN:
// if we can scroll pass the event to the superclass
return mScrollable && super.onTouchEvent(ev);
default:
return super.onTouchEvent(ev);
}
}
#Override
public boolean onInterceptTouchEvent(MotionEvent ev) {
// Don't do anything with intercepted touch events if
// we are not scrollable
return mScrollable && super.onInterceptTouchEvent(ev);
}
}
then,
<com.mypackagename.LockableScrollView
android:id="#+id/QuranGalleryScrollView"
android:layout_height="fill_parent"
android:layout_width="fill_parent">
<Gallery android:id="#+id/Gallery"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:scrollbars="horizontal">
</Gallery>
</com.mypackagename.LockableScrollView>
in your XML file (just changed the ScrollView to your special LockableScrollView).
Then call
((LockableScrollView)findViewById(R.id.QuranGalleryScrollView)).setScrollingEnabled(false);
to disable scrolling of the view.
I have a list view whose item is a linearlayout which has a button as it's child view. I want the ontouchLIstener of the linearlayout to work. I don't want to use onInterceptTouchEvent. Is there a way a I can pass on the touch form the button to the parent listview. I tried this
- returning true from the button's onTouchListener
private View.OnTouchListener buttonListener = new View.OnTouchListener() {
#Override
public boolean onTouch(View view, MotionEvent motionEvent) {
Log.i(TAG, "Button On Touch");
return true;
}
};
But this does not work. It does not pass on the touch event to the linearlayout's onTouchListener.
There must be someway it should work.
The chain of events for a View group works like this - The dispatchEvent is called. Then dispatchEvent calls onInterceptTouchEvent. if it returns false, then the touch events are passed on to the children of the ViewGroup. If any of the children consume the event (in this case the button consumes the event) i.e if they return true then the motionevent is not passed on to other methods. Since the button is clickable it returns true in this case. If the onInterceptTouchEvent method returns true then the child views are not given the motion event and instead that ViewGroup's onTouchListener or onTouch method are called. Hence to pass on the touch event to the parent's (View Group) onTouchListener make sure to return true in the onInterceptTouchEvent method of the Parent (ViewGroup). You don't have to override onDispatchTouchEvent()
#Override
public boolean onInterceptTouchEvent(MotionEvent motionEvent) {
Log.i(TAG,"PARENT.onInterceptTouchEvent");
return true;
}
For more details about how the touch navigation is done, please see this stack post
Set your button clickable property to false, using:
button.setClickable(false);
Then in onTouch of button:
return false;
Note: This behavior is specific to button (and any other view that has clickable property set to true) that even if you return false from onTouch it will not propagate event to the parent and onClick method of the button will be called anyway.
EDIT: Another way is extending ListView class and overriding onInterceptTouch:
public class CustomListView extends ListView {
#Override
public boolean onInterceptTouchEvent(MotionEvent ev) {
// here you can listen for button touch events
}
}
I have a one RelativeLayout and this layout is having nearly 10 views in it.
I have set OnTouchListener to this Layout and doing some work in it and returning true.
this listener is working fine when I touch the layout where there are no View (mean on Empty area). If I touch on child views of this layout, this listener is not firing...
and from the documentation, I understood that we can override onInterceptTouchEvent() by extending ViewGroup (so here RelativeLayout) and handle touch events before child views consume this event...
this will do a trick, but I need to modify many xml files where I need this functionality by replacing RelativeLayout with my CustomRelativeLayout.
so my question is:
is there any way to handle touch event for RelativeLayout (ofcourse ViewGroup) before child views in RelativeLayout consumes event? I don't want to extend RelativeLayout...
Try to override
#Override
public boolean dispatchTouchEvent(MotionEvent ev) {
return super.dispatchTouchEvent(ev);
}
of Activity.
This method is the first that process touch events.
But in this case you need to work with current coordinates of views
While not necessarily being ideal, this works well for smaller layouts that won't have dynamic content.
In xml, set android:clickable="false" to all descendants of the ViewGroup in the layout (including nested ViewGroups and their children). Each child that gets clicked on will then propagate the click to its parent, eventually getting to the ViewGroup's default touch handlers. Make sure to set root ViewGroup, where you want to get the click events as android:clickable="true" or viewgroup.setClickable(true)
If you add views dynamically, make sure to call view.setClickable(false); before adding it to the view hierarchy.
Try add onTouchListener to RelativeLayout
RelativeLayout rl = (RelativeLayout) findViewById( R.id.relativeLauout );
rl.setOnTouchListener( new OnTouchListener() {
#Override
public boolean onTouch(View v, MotionEvent event) {
// do something
return false;
}
});
or use method onTouchEvent from Activity
#Override
public boolean onTouchEvent(MotionEvent event) {
// TODO Auto-generated method stub
return super.onTouchEvent(event);
}
Try to return false in the onTouchEvent() method of child views when processing ACTION_DOWN event. So the forwarding touch events will not be sent to child views, aka event not consumed.
You can simply set in your xml:
android:clickable="true"
edited for clarity
I feel like this question already has an answer, but I can't find one.
I have a ScrollView in my layout, and it contains a variety of clickable views.
Under a specific condition I would like to disable clicks and events for the ScrollView and ALL of its children.
The following have not been helpful:
ScrollView.setEnabled(false)
ScrollView.setClickable(false)
ScrollView.setOnTouchListener(null)
As well as:
(parent view of the ScrollView).requestDisallowInterceptTouchEvent()
I have created a custom ScrollView with the following code:
public class StoppableScrollView extends ScrollView
{
private static boolean stopped = false;
public StoppableScrollView(Context context)
{
super(context);
}
public StoppableScrollView(Context context, AttributeSet attrs)
{
super(context, attrs);
}
#Override
public boolean onInterceptTouchEvent(MotionEvent ev)
{
if(stopped)
{
return true;
}
else
{
super.onInterceptTouchEvent(ev);
return false;
}
}
#Override
public boolean onTouchEvent(MotionEvent ev)
{
if(stopped)
{
return true;
}
else
{
super.onTouchEvent(ev);
return false;
}
}
public static void setStopped(boolean inBool)
{
stopped = inBool;
}
public static boolean getStopped()
{
return stopped;
}
}
Using only onTouchEvent() will stop the scrolling, but not the clicking of child views.
Using only onInterceptTouchEvent() makes it such that when clicks work scrolling does not, and vice versa.
Using both onTouchEvent() and onInterceptTouchEvent() successfully stops unwanted clicks on child views when stopped is 'true' but it also disables scrolling regardless of the state of stopped.
Is there an easier way to get this behaviour, or is there a way to modify the StoppableScrollView class so that it will handle these touch events properly?
What probably should help is the following (because I had similar problems):
In the ScrollView you should do a RelativeLayout as Main Child (ScrollView does accept only 1 main child anyway). This RelativeLayout should of course of fill_parent in both directions.
At the really end of the RelativeLayout (after all other children), you could put now a LinearLayout with transparent background (#00FFFFFF) which has also fill_parent in both directions. This LinearLayout should have Visibility = View.GONE (by default)
Also you have to attach an empty OnClickListener to it. Now, because of zOrder if you make this LinearLayout Visibility = View.Visible it will catch all the events and avoid clicking the children above!
As scrollview allows immeditate one child say in my case i have linear layout.and in this linear layout i have other conreolls.
now our first task is to get this linear layout so what we can write is
LinearLayout l = (LinearLayout) scrollview.getChildAt(0);
now after getting this linear layour we can easily access other controlls placed inside it via this code and disable it.
for(int i =0; i<l.getChildCount(); i++)
{
Log.i(TAG,"child "+ l.getChildAt(i));
l.getChildAt(i).setEnabled(false);
}
I'm creating a custom widget by expanding LinearLayout. One of the elements in my custom widget is a linear layout, inflated from another layout. When I set the OnClickListener it is not responding. Can you please advise?
Thanks!
Instead of using setOnClickListener use setOnTouchListener
This code will work as a onclick event
YourLinearLayout.setOnTouchListener(new View.OnTouchListener() {
#Override
public boolean onTouch(View v, MotionEvent event) {
boolean returnValue = true;
if(event.getAction()==MotionEvent.ACTION_UP){ //on touch release
returnValue = false; //prevent default action on release
//do something here
}
return returnValue;
}
});
And then add this to your LinearLayout class to intercept child touch events
#Override
public boolean onInterceptTouchEvent(MotionEvent ev) {
return true; //will prevent child touch events
}
Have you declared the LinearLayout clickable?
You can do this either in the XML:
android:clickable="true"
or in Java code:
myLinearLayout.setClickable( true );
Also see the other StackOverflow thread on this question:
onClickListener on a LinearLayout
Make sure you put all childs inside LinearLayout to android:clickable="false". Than myLinearLayout.setClickable( true ) works for me.