How to retrieve drawable from attributes reference

Question

I defined theme and style inside my app. icons (drawable) are defined using reference in style file as

<attr name="myicon" format="reference" />

and style as

<style name="CustomTheme" parent="android:Theme.Holo">
    <item name="myicon">@drawable/ajout_produit_light</item>

I need to retrieve the drawable programmatically to use the good image in a dialogfragment. If I make like

mydialog.setIcon(R.style.myicon);

I get an id equals to 0, so no image

I tried to use something like

int[] attrs = new int[] { R.drawable.myicon};
TypedArray ta = getActivity().getApplication().getTheme().obtainStyledAttributes(attrs);
Drawable mydrawable = ta.getDrawable(0);
mTxtTitre.setCompoundDrawables(mydrawable, null, null, null);

I tried different things like that but result is always 0 or null :-/

How I can I do this ?

score 22 · Answer 1 · edited May 23 '17 at 12:25

22

I found the solution on Access resource defined in theme and attrs.xml android

TypedArray a = getTheme().obtainStyledAttributes(R.style.AppTheme, new int[] {R.attr.homeIcon});     
int attributeResourceId = a.getResourceId(0, 0);
Drawable drawable = getResources().getDrawable(attributeResourceId);

edited May 23 '17 at 12:25

Community

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answered Mar 11 '13 at 13:23

arnouf

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Don't forget to call a.recycle – Cheok Yan Cheng Mar 15 '16 at 17:07
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For anyone else that was wondering: `a.recycle()` will signal that the allocated memory is no longer in use and the data associated with `a` can be returned to the memory pool immediately instead of waiting for garbage collection. As answered [here](http://stackoverflow.com/questions/7252839/what-is-the-use-of-recycle-method-in-typedarray) – Prof Mar 04 '17 at 23:44

score 20 · Answer 2 · edited Mar 04 '20 at 09:16

20

Kotlin solution:

val typedValue = TypedValue()
context.theme.resolveAttribute(R.attr.yourAttr, typedValue, true)
val imageResId = typedValue.resourceId
val drawable = ContextCompat.getDrawable(context, imageResId) ?: throw IllegalArgumentException("Cannot load drawable $imageResId")

edited Mar 04 '20 at 09:16

wbk727

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answered Aug 27 '19 at 19:03

Sevastyan Savanyuk

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How can this be used in a `Fragment`? – wbk727 Mar 03 '20 at 23:37
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Single line solution: `val drawable = ContextCompat.getDrawable(context, TypedValue().apply { context.theme.resolveAttribute(R.attr.myIcon, this, true) }.resourceId)` – Peter Keefe Apr 01 '20 at 13:34
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@PeterKeefe `.apply` makes code less readable and should be used carefully. Kotlin is not about conciseness, it is about readability. – Sevastyan Savanyuk Apr 02 '20 at 20:36

Bruno Bieri · Answer 3 · 2022-01-24T07:47:14.187

With the assumption your context (activity) is themed the way you want it, you can use resolveAttribute on the theme:

TypedValue themedValue = new TypedValue();
this.getTheme().resolveAttribute(R.attr.your_attribute, themedValue, true);
myView.setBackgroundResource(themedValue.resourceId);

So in your case it would look something like this:

TypedValue themedValue = new TypedValue();
this.getTheme().resolveAttribute(R.attr.myicon, themedValue, true);
Drawable mydrawable = AppCompatResources.getDrawable(this, themedValue.resourceId);
mTxtTitre.setCompoundDrawables(mydrawable, null, null, null);

In the examples this would be your activity. If you're not in an activity get a valid context.

score -1 · Answer 4 · answered Mar 11 '13 at 13:26

It would seem as though you are trying to set the icon of your myDialog using a resource and are trying to access it through R.style but your other code segment leads me to believe that you have the resource located in R.drawable

With that in mind you should be able to get the effect you want with myDialog.setIcon(R.drawable.myicon);

How to retrieve drawable from attributes reference

4 Answers4