How to get color from Button when background set as drawable

Question

I have a <Button/>

<Button
    android:id="@+id/btn"
    android:background="@drawable/btn_color"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content" />

Button background is set as android:background="@drawable/btn_color" where btn_color is

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="rectangle"
    android:padding="10dp">
    <solid android:color="#FF0000"/>
    <corners android:radius="10dp"/>
</shape>

I need to get the color #FF0000 of the button in my code. What I have tried is

val drawable = btn.getBackground().mutate() as GradientDrawable

How to get the color from this Drawable?

Test case `ColorDrawable buttonColor = (ColorDrawable) button.getBackground();` https://stackoverflow.com/a/13748610/7666442 — AskNilesh, Aug 31 '18 at 07:41
@NileshRathod it is giving exception that `GradientDrawable` cannot be cast to `ColorDrawable` — Prithvi Bhola, Aug 31 '18 at 07:48
You should use `ShapeDrawable` instead of `GradientDrawable ` — Muzammil Husnain, Aug 31 '18 at 08:02
@MuzammilHusnain can you please tell me more about how to use ShapeDrawable here — Prithvi Bhola, Aug 31 '18 at 08:08

Akaki Kapanadze · Answer 1 · 2018-08-31T12:55:18.650

0

Use:

val color = (btn.background as? GradientDrawable)?.color?.defaultColor

EDIT

but getColor() only available on API 24 and above. You should check Build.VERSION.SDK_INT >= Build.VERSION_CODES.N :

val color = if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
    (btn.background as? GradientDrawable)?.color?.defaultColor
} else null

edited Aug 31 '18 at 12:55

answered Aug 31 '18 at 08:13

Akaki Kapanadze

2,552
2
11
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It is throwing `java.lang.NoSuchMethodError : Method not found: MemberDescription(ownerInternalName = android/graphics/drawable/GradientDrawable, name = getColor, desc = ()Landroid/content/res/ColorStateList;, isStatic = false)` – Prithvi Bhola Aug 31 '18 at 11:06

score 0 · Answer 2 · answered Aug 31 '18 at 09:47

0

Try:

val color = (btn.background as? ShapeDrawable)?.paint.color

answered Aug 31 '18 at 09:47

Muzammil Husnain

1,218
1
10
24

`java.lang.ClassCastException: android.graphics.drawable.GradientDrawable cannot be cast to android.graphics.drawable.ShapeDrawable: Ljava/lang/ClassCastException;` exception is coming – Prithvi Bhola Aug 31 '18 at 11:04

score 0 · Answer 3 · answered Aug 31 '18 at 10:04

Why not convert the Drawable to Bitmap (link: How to convert a Drawable to a Bitmap?) and then get the Pixel at the center of it? Could not be the fastest way but one of the most compatible (because Gradient, Color or other type of Drawable are all flattened to a compatible Bitmap and you don't need to handle these differences)

How to get color from Button when background set as drawable

3 Answers3