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android – ListView item background via custom selector

Posted by: admin March 11, 2020 Leave a comment

Questions:

Is it possible to apply a custom background to each Listview item via the list selector?

The default selector specifies @android:color/transparent for the state_focused="false" case, but changing this to some custom drawable doesn’t affect items that aren’t selected. Romain Guy seems to suggest in this answer that this is possible.

I’m currently achieving the same affect by using a custom background on each view and hiding it when the item is selected/focused/whatever so the selector is shown, but it’d be more elegant to have this all defined in one place.

For reference, this is the selector I’m using to try and get this working:

<selector xmlns:android="http://schemas.android.com/apk/res/android">

    <item android:state_focused="false"
        android:drawable="@drawable/list_item_gradient" />

    <!-- Even though these two point to the same resource, have two states so the drawable will invalidate itself when coming out of pressed state. -->
    <item android:state_focused="true" android:state_enabled="false"
        android:state_pressed="true"
        android:drawable="@drawable/list_selector_background_disabled" />
    <item android:state_focused="true" android:state_enabled="false"
        android:drawable="@drawable/list_selector_background_disabled" />

    <item android:state_focused="true" android:state_pressed="true"
        android:drawable="@drawable/list_selector_background_transition" />
    <item android:state_focused="false" android:state_pressed="true"
        android:drawable="@drawable/list_selector_background_transition" />

    <item android:state_focused="true"
        android:drawable="@drawable/list_selector_background_focus" />

</selector>

And this is how I’m setting the selector:

<ListView
    android:id="@android:id/list"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:listSelector="@drawable/list_selector_background" />    

Thanks in advance for any help!

How to&Answers:

I’ve been frustrated by this myself and finally solved it. As Romain Guy hinted to, there’s another state, "android:state_selected", that you must use. Use a state drawable for the background of your list item, and use a different state drawable for listSelector of your list:

list_row_layout.xml:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="?android:attr/listPreferredItemHeight"
    android:background="@drawable/listitem_background"
    >
...
</LinearLayout>

listitem_background.xml:

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:state_selected="true" android:drawable="@color/android:transparent" />
    <item android:drawable="@drawable/listitem_normal" />
</selector>

layout.xml that includes the ListView:

...
<ListView 
   android:layout_width="fill_parent"
   android:layout_height="wrap_content"
   android:listSelector="@drawable/listitem_selector"
   />
...

listitem_selector.xml:

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:state_pressed="true" android:drawable="@drawable/listitem_pressed" />
    <item android:state_focused="true" android:drawable="@drawable/listitem_selected" />
</selector>

Answer:

The solution by dglmtn doesn’t work when you have a 9-patch drawable with padding as background. Strange things happen, I don’t even want to talk about it, if you have such a problem, you know them.

Now, If you want to have a listview with different states and 9-patch drawables (it would work with any drawables and colors, I think) you have to do 2 things:

  1. Set the selector for the items in the list.
  2. Get rid of the default selector for the list.

What you should do is first set the row_selector.xml:

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android" >
    <item android:state_enabled="true" 
     android:state_pressed="true" android:drawable="@drawable/list_item_bg_pressed" />
    <item android:state_enabled="true"
     android:state_focused="true" android:drawable="@drawable/list_item_bg_focused" />
    <item android:state_enabled="true"
     android:state_selected="true" android:drawable="@drawable/list_item_bg_focused" />
    <item
     android:drawable="@drawable/list_item_bg_normal" />
</selector>

Don’t forget the android:state_selected. It works like android:state_focused for the list, but it’s applied for the list item.

Now apply the selector to the items (row.xml):

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:orientation="horizontal"
android:background="@drawable/row_selector"
>
...
</RelativeLayout>

Make a transparent selector for the list:

<ListView
    android:id="@+id/android:list"
    ...
    android:listSelector="@android:color/transparent"
    />

This should do the thing.

Answer:

Never ever use a “background color” for your listview rows…

this will block every selector action (was my problem!)

good luck!

Answer:

The article “Why is my list black? An Android optimization” in the Android Developers Blog has a thorough explanation of why the list background turns black when scrolling. Simple answer: set cacheColorHint on your list to transparent (#00000000).

Answer:

It’s enough,if you put in list_row_layout.xml:

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:gravity="center_vertical"
android:background="@drawable/listitem_background">... </LinearLayout>

listitem_selector.xml:

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:drawable="@color/dark" android:state_pressed="true" />
    <item android:drawable="@color/dark" android:state_focused="true" />
    <item android:drawable="@android:color/white" />
</selector>

Answer:

instead of:

android:drawable="@color/transparent" 

write

android:drawable="@android:color/transparent"

Answer:

You can write a theme:

<pre>

    android:name=".List10" android:theme="@style/Theme"

theme.xml

<style name="Theme" parent="android:Theme">
        <item name="android:listViewStyle">@style/MyListView</item>
</style>

styles.xml

 <style name="MyListView" parent="@android:style/Widget.ListView">
<item name="android:listSelector">@drawable/my_selector</item>

my_selector is your want to custom selector
I am sorry i donot know how to write my code

Answer:

I’m not sure how to achieve your desired effect through the selector itself — after all, by definition, there is one selector for the whole list.

However, you can get control on selection changes and draw whatever you want. In this sample project, I make the selector transparent and draw a bar on the selected item.

Answer:

I always use the same method and it works every time, every where:
I simply use a selector like this

<item android:state_activated="true"  android:color="@color/your_selected_color" />
<item android:state_pressed="true" android:color="@color/your_pressed_color" />
<item android:color="@color/your_normal_color"></item>

and set on the ListView (THIS IS VERY IMPORTANT TO MAKE IT WORKING) the attribute

android:choiceMode="singleChoice"

for the textColor just put in the color folder(IMPORTANT, not drawable folder!) a selector like this

<item android:state_activated="true"  android:color="@color/your_selected_textColor" />
<item android:state_pressed="true" android:color="@color/your_pressed_textColor" />
<item android:color="@color/your_normal_textColor"></item>

this a sample row template

<ImageView
    android:id="@+skinMenu/lblIcon"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:gravity="center_horizontal"
    android:src="@drawable/menu_catalog" />

<TextView
    android:id="@+skinMenu/lblTitle"
    style="@style/superlabelStyle"
    android:layout_width="wrap_content"
    android:layout_height="match_parent"
    android:layout_marginLeft="20dp"
    android:gravity="center_vertical"
    android:text="test menu testo"
    android:textColor="@color/menu_textcolor_selector"
    android:textSize="20dp"
    android:textStyle="bold" />

everything showld work without tedious workarounds. hope this help

Answer:

FrostWire Team over here.

All the selector crap api doesn’t work as expected. After trying all the solutions presented in this thread to no good, we just solved the problem at the moment of inflating the ListView Item.

  1. Make sure your item keeps it’s state, we did it as a member variable of the MenuItem (boolean selected)

  2. When you inflate, ask if the underlying item is selected, if so, just set the drawable resource that you want as the background (be it a 9patch or whatever). Make sure your adapter is aware of this and that it calls notifyDataChanged() when something has been selected.

        @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        View rowView = convertView;
        if (rowView == null) {
            LayoutInflater inflater = act.getLayoutInflater();
            rowView = inflater.inflate(R.layout.slidemenu_listitem, null);
            MenuItemHolder viewHolder = new MenuItemHolder();
            viewHolder.label = (TextView) rowView.findViewById(R.id.slidemenu_item_label);
            viewHolder.icon = (ImageView) rowView.findViewById(R.id.slidemenu_item_icon);
            rowView.setTag(viewHolder);
        }
    
        MenuItemHolder holder = (MenuItemHolder) rowView.getTag();
        String s = items[position].label;
        holder.label.setText(s);
        holder.icon.setImageDrawable(items[position].icon);
    
        //Here comes the magic
        rowView.setSelected(items[position].selected);
    
        rowView.setBackgroundResource((rowView.isSelected()) ? R.drawable.slidemenu_item_background_selected : R.drawable.slidemenu_item_background);
    
        return rowView;
    }
    

It’d be really nice if the selectors would actually work, in theory it’s a nice and elegant solution, but it seems like it’s broken. KISS.