I have a linear layout that has several views within it. These views may have click listeners already associated with them when they are added to the layout. I want to disable all click listeners for children of this linear layout and have only one listener at the top level.
As a variant you may go through all child views and make them not clickable.
you can do that through the xml by adding the options focusable and clickable with false as values to the child views and with true values to the parent.
Another option would be using the same OnClickListener for parent and child views.
Related
I am new to Android Development, so what is meant by child in the below paragraph....
A ScrollView is a FrameLayout, meaning you should place one child in
it containing the entire contents to scroll; this child may itself be
a layout manager with a complex hierarchy of objects. A child that is
often used is a LinearLayout in a vertical orientation, presenting a
vertical array of top-level items that the user can scroll through.
https://developer.android.com/reference/android/widget/ScrollView.html
In android (and most other technologies), views can have subviews, aka "children". Most views can have children and can be a child of a parent view. It's kind of like a "tree".
The most obvious feature of being a child of some other view is that the child moves with the parent view. Another feature is that the child is in the coordinate space of the parent view.
Your paragraph here basically says you can only put one child view in ScrollView and it is usually a LinearLayout. But don't be fooled! This child can have its own child views.
Gaurav i think this is what you looking for, you need to use only one LinearLayout tag inside ScrollView tag, if you are using more than one LinearLayout than it will show error. If you want to use more LinearLayout tag you can use them inside LinearLayout tag which is inside ScrollView tag. May be this will help you.
You need to understand the general concept of child and parent . Simply you can think of the real life relation between parent and child.on the hierarchy parents are toplevel and child is below.so when you come to android layout parent is container and child is the content.
I have on LinearLayout (I'll call it the parent) with inside an other LinearLayout (the child)
When I listen to a click on the child layout, I'd like to make the clickable animation on the parent and not only on the child.
How can I make that?
Thank you
One way to do it is to add a OnClickListener to the parent layout and then add the attribute android:duplicateParentState="true" to the inner layout. That way, when you press/click on the inner layout, the parent layout will also receive the event and process any animations and if it was being actioned directly.
I have a child linearlayout created programmatically and added on a parent linearlayour programmatically.
parentlayout.addView(childlayout)
But, the I want to add again the child layout to another linearlayout, it returns an error, is it possible? What is the best way to do that?
Create another instance of the same class, and set the same properties. I mean Inflate your View again if needed. Because A single View cannot be a child of two ViewGroup parents.
Each view can have only one parent possible.
So you can not add same child to another linear layout.
What you can do is make another instance, apply same properties which you given to previous child. and then add this instance to the parent view.
I have a LinearLayout that acts like a container for views.
I'm inflating a different layout programatically and adding an OnClickListener and adding it in my LinearLayout.
What I want to achieve is to have the option to disable those OnClickListener on those views that I've inflated and added to my LinearLayout.
Can I just disable the OnClickListener on the parent LinearLayout to disable as well all the other child's OnClickListener?
Setting the parent LinearLayout click listener to null doesn't work though, any ideas?
THanks.
You can put the onClickListener as null to the views for which you don't want to add the listener instead of setting the listener as null to the parent layout.
There is a LinearLayout with a lot of child elements. When a user touches any of those child elements, the same method will be invoked. In order not to implement the same onClickListener for each element, I implemented the onClickListener for the parent LinearLayout ONLY.
Now, when I click anywhere within the parent layout's borders, the desired method is being invoked just as I have implemented the listener for all child elements.
Q: Can I rely that anytime I implement onClickListener for the parent, all of its child elements will react to the click event?
Q: What would happen if any child element has its own onClickListener? Would there be a collision or clicking on that element would fire its own click event only?
You answered your first question with your second question. A clickEvent will be delivered to the lowest child element in the layout hierarchy. If this element does not have an onClick behaviour it will pass the event up to its parent until the event gets handled.
Therefore you can treat the LinearLayout as one single block for your onClick behaviour.
If you create another clickable element inside the layout be sure to make it big enough to reduce the chance of the user missing the correct item.