Comparing two drawables in android

Question

How to compare two drawables, I am doing like this but not having any success

public void MyClick(View view)
{
 Drawable fDraw = view.getBackground();
 Drawable sDraw = getResources().getDrawable(R.drawable.twt_hover);

  if(fDraw.equals(sDraw))
  {
   //Not coming
  }
}

http://stackoverflow.com/questions/27463737/compatibility-of-getcontext-and-getresource-between-5-0-and-lower — user3201520, Feb 08 '15 at 04:47
If you are writing tests with Robolectric and the goal is to determine if the correct drawable was loaded, see this answer: https://stackoverflow.com/questions/18008044/assert-imageview-was-loaded-with-specific-drawable-resource-id — yuval, Jan 28 '21 at 01:42

score 150 · Accepted Answer · edited Jan 10 '18 at 13:05

150

Update https://stackoverflow.com/a/36373569/1835650

getConstantState() works not well

~~There is another way to compare:~~

mRememberPwd.getDrawable().getConstantState().equals
            (getResources().getDrawable(R.drawable.login_checked).getConstantState());

mRemeberPwd is an ImageView in this example. If you're using a TextView, use getBackground().getConstantState instead.

edited Jan 10 '18 at 13:05

TeeTracker

7,064
8
40
46

answered Dec 20 '12 at 03:46

Mejonzhan

2,374
1
20
30

3

This solution works and its better as it avoids converting Drawable into Bitmap and compare. – Braj Aug 09 '13 at 11:34
2

Not always: WallpaperManager.getInstance(this).getFastDrawable().getConstantState() is null. – paulgavrikov Nov 29 '13 at 00:28
Sorry for late accepting this as answer and changing my own answer as this seems better option (and more upvotes also :) ). So checking this as answer. – Roshan Jha Feb 20 '14 at 11:47
8

This code works great on devices lower than 5.0 but im getting errors using it on a 5.0 device, can anyone confirm this method works or not on android 5.0 or higher – Phil3992 Dec 17 '14 at 14:18
This will not work in Android 5.0 and higher. You should never rely on constant state equality. – alanv Dec 17 '14 at 18:48
Did you got any solution for 5.0 version? – Parag Chauhan Jan 26 '15 at 11:38
Any solution for SDK 21+? – Amio.io Feb 05 '15 at 20:34
have you got any solution for 5.0 for comparing drawables ? – Richa Mar 11 '15 at 05:47
Else we can do it by imageView.getBackground().getConstantState.equals(getResources().getDrawable(R.drawable.resource_id).getConstantState()) – Abdul Gaffar Jan 13 '17 at 06:14
this method is crashing the app on android v5.1.1, any alternatives? – Akay Nov 13 '17 at 14:11
It works not well with vector, the update is for generic cases. – TeeTracker Jan 10 '18 at 13:19
"Calling Drawable#mutate() on a Drawable should typically create a new ConstantState for that Drawable." What about those non-typical cases? This answer is a flaky hack. – John Glen Jun 06 '22 at 00:22

score 44 · Answer 2 · answered Jul 22 '15 at 11:41

Relying on getConstantState() alone can result in false negatives.

The approach I've taken is to try comparing the ConstantState in the first instance, but fall back on a Bitmap comparison if that check fails.

This should work in all cases (including images which aren't resources) but note that it is memory hungry.

public static boolean areDrawablesIdentical(Drawable drawableA, Drawable drawableB) {
    Drawable.ConstantState stateA = drawableA.getConstantState();
    Drawable.ConstantState stateB = drawableB.getConstantState();
    // If the constant state is identical, they are using the same drawable resource.
    // However, the opposite is not necessarily true.
    return (stateA != null && stateB != null && stateA.equals(stateB))
            || getBitmap(drawableA).sameAs(getBitmap(drawableB));
}

public static Bitmap getBitmap(Drawable drawable) {
    Bitmap result;
    if (drawable instanceof BitmapDrawable) {
        result = ((BitmapDrawable) drawable).getBitmap();
    } else {
        int width = drawable.getIntrinsicWidth();
        int height = drawable.getIntrinsicHeight();
        // Some drawables have no intrinsic width - e.g. solid colours.
        if (width <= 0) {
            width = 1;
        }
        if (height <= 0) {
            height = 1;
        }

        result = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
        Canvas canvas = new Canvas(result);
        drawable.setBounds(0, 0, canvas.getWidth(), canvas.getHeight());
        drawable.draw(canvas);
    }
    return result;
}

This is 100% true and needs more upvotes! People, please test your code with known Drawables before immediately relying on `getConstantState()` comparison — avalancha, Nov 09 '15 at 11:00
Good findings! But according to the documentation of BitmapDrawable.getBitmap(), getBitmap() may be null so you might want to check this as well — PhilLab, Jun 16 '17 at 16:25
This answer is true and I have checked that after debugging several hours with the coding of only getConstantState(). — Raghav Satyadev, Jul 11 '17 at 09:37
To be safe, `setBounds` and `draw` on a copy instead of the original https://stackoverflow.com/a/25462223/1916449 — arekolek, Mar 26 '18 at 21:00
This doesn't work with tinted BitmapDrawables (see setTintMode / setTint / setTintList). The bitmaps can be identical byte for byte but with different tint properties. Because the Android SDK does not provide any getters for the tint properties, there may not be a way to make it work with tinted drawables. — Theo, Jan 30 '19 at 23:15
The docs say "Calling Drawable#mutate() on a Drawable should typically create a new ConstantState for that Drawable." In the non-typical cases, you will get a false positive. — John Glen, Jun 06 '22 at 00:24

score 15 · Answer 3 · edited Feb 03 '12 at 09:18

15

My question was for just comparing two drawables, I tried but could not get any method that directly compare two drawables,however for my solution i changed drawable to bitmap and then comparing two bitmaps and that is working.

Bitmap bitmap = ((BitmapDrawable)fDraw).getBitmap();
Bitmap bitmap2 = ((BitmapDrawable)sDraw).getBitmap();

if(bitmap == bitmap2)
    {
        //Code blcok
    }

edited Feb 03 '12 at 09:18

MKJParekh

34,073
11
87
98

answered Feb 03 '12 at 08:54

Roshan Jha

2,091
1
21
30

thats what I was suggesting you, to compare drawable according to type of drawable. – jeet Feb 03 '12 at 09:04
1

You might also want to compare bitmaps like this: http://stackoverflow.com/a/7696320/317889 – HGPB Apr 12 '13 at 15:05
3

This is very heavy, so consider recycling Bitmaps or you will end up in a OutOfMemoryError! – paulgavrikov Nov 29 '13 at 00:27
2

Why can you compare Bitmaps with pointer equality (==)? I'd expect Bitmap.equals() to be needed. – Ellen Spertus Feb 28 '14 at 22:55
@espertus You are right. I used same in question for drawable objects dont know why turned to == for bitmap object in answer. Any ways thanks for pointing out this basic. – Roshan Jha Mar 01 '14 at 05:30
@espertus Can you tell, which would be prefer here as both == and .equals working here. – Roshan Jha Mar 01 '14 at 05:41
@espertus Because == seems cheaper than .equals – Roshan Jha Mar 01 '14 at 06:00
== tests that the same object is returned; .equals() generally detects that the two values have the same hash code, although it is sometimes overridden in implementations. They may be equivalent in this case -- I don't know -- but they shouldn't be assumed to be in every case. In any case, I'm glad you found something that works for the case you need. – Ellen Spertus Mar 01 '14 at 17:10

tohid · Answer 4 · 2015-05-13T15:28:23.827

10

for SDK 21+

this works in SDK -21

mRememberPwd.getDrawable().getConstantState().equals
        (getResources().getDrawable(R.drawable.login_checked).getConstantState())

for SDK +21 android 5. set drawable id to imageview with tag

img.setTag(R.drawable.xxx);

and compare like this

if ((Integer) img.getTag() == R.drawable.xxx)
{
....your code
}

this solution is for who want to compare drawable id of imageview with id of drawable.xxx.

edited May 13 '15 at 15:28

answered May 13 '15 at 15:22

tohid

119
1
7

Actually this works but I'm kind of shocked why there is no other possibility T_T! – novas1r1 Jun 27 '17 at 12:54

waqaslam · Answer 5 · 2012-02-03T08:17:01.987

4

perhaps try it in this way:

public void MyClick(View view)
{
 Drawable fDraw = view.getBackground();
 Drawable sDraw = getResources().getDrawable(R.drawable.twt_hover);

  if(fDraw.hashCode() == sDraw.hashCode())
  {
   //Not coming
  }
}

or prepare a method which takes two drawable arguments and return boolean. In that method you may convert drawable into bytes and compare,

public boolean compareDrawable(Drawable d1, Drawable d2){
    try{
        Bitmap bitmap1 = ((BitmapDrawable)d1).getBitmap();
        ByteArrayOutputStream stream1 = new ByteArrayOutputStream();
        bitmap1.compress(Bitmap.CompressFormat.JPEG, 100, stream1);
        stream1.flush();
        byte[] bitmapdata1 = stream1.toByteArray();
        stream1.close();

        Bitmap bitmap2 = ((BitmapDrawable)d2).getBitmap();
        ByteArrayOutputStream stream2 = new ByteArrayOutputStream();
        bitmap2.compress(Bitmap.CompressFormat.JPEG, 100, stream2);
        stream2.flush();
        byte[] bitmapdata2 = stream2.toByteArray();
        stream2.close();

        return bitmapdata1.equals(bitmapdata2);
    }
    catch (Exception e) {
        // TODO: handle exception
    }
    return false;
}

edited Feb 03 '12 at 08:17

answered Feb 03 '12 at 07:47

waqaslam

67,549
16
165
178

check the updated answer. if still doesn't work then check your drawables. Or try passing same drawables to verify the functionality of code – waqaslam Feb 03 '12 at 08:18
yes, after not getting success I am thinking same for converting drawables to bitmap and then to byte,let me try that one,thank you for your efforts – Roshan Jha Feb 03 '12 at 08:33
not working,did you test it? might be there is something wrong,cant we directly compare two drawables? – Roshan Jha Feb 03 '12 at 08:47
did you try it passing same drawable for `e.g R.drawable.abc` as both parameters? – waqaslam Feb 03 '12 at 08:49
hello waqas,check your method once again and then tell again whether it is working or not,might be possible that I am doing something wrong but that did not work,but then it changes definition of my question that how to compare two drawables.Changing drawable to bitmap and then bytes will then compare bitmap and bytes thats not my requirement.if we check drawable methods then there is method .equals(object) so I thought it should work directly,but it did not.Well you can check my answer below I am converting drawable to bitmap and then comparing two bitmaps and it is working. – Roshan Jha Feb 03 '12 at 08:58

score 3 · Answer 6 · answered Apr 08 '15 at 14:56

3

The solution for Android 5:

 if(image.getDrawable().getConstantState().equals(image.getContext().getDrawable(R.drawable.something).getConstantState()))

answered Apr 08 '15 at 14:56

Tiago Santos

489
5
16

score 3 · Answer 7 · answered Mar 31 '17 at 04:00

3

getDrawable(int) is Now Deprecated. Use getDrawable(context,R.drawable.yourimageid)

To Compare Two Backgrounds

Boolean Condition1=v.getBackground().getConstantState().equals(
ContextCompat.getDrawable(getApplicationContext(),R.drawable.***).getConstantState());

answered Mar 31 '17 at 04:00

RAJESH KUMAR ARUMUGAM

1,560
21
35

2

This worked like a charm to fix an odd bug on Android 5. In my code, the actual drawable was returned with `context.getResources().getDrawable(R.drawable.***)` on Android 6+ but wasn't on Android 5. With this little change I can compare background drawables across all Android versions flawlessly – Jose_GD Dec 10 '18 at 15:44

score 3 · Answer 8 · answered Jun 19 '17 at 14:33

Ok, I think I've found the ultimate solution for this. Because of AppCompat and friends, the drawable provided is sometimes inflated in different forms so it's not enough to do getResources().getBitmap(R.drawable.my_awesome_drawable).

So, in order to get a drawable instance of the same type and form as provided by the view one can do this:

public static Drawable drawableFrom(View view, @DrawableRes int drawableId) {
    Context context = view.getContext();
    try {
        View dummyView = view.getClass().getConstructor(Context.class).newInstance(context);
        dummyView.setBackgroundResource(drawableId);
        return dummyView.getBackground();
    } catch (Exception e) {
      return ResourcesCompat.getDrawable(context.getResources(), drawableId, null);
    }
}

This is useful when doing tests. However, I would not recommend doing this in production. If you need to, extra caching would be desirable to avoid doing too much reflection.

For Expresso tests you can use this quite nicely:

onView(withDrawable(R.drawable.awesome_drawable))
  .check(matches(isDisplayed()));

or

onView(withId(R.id.view_id))
  .check(matches(withDrawable(R.drawable.awesome_drawable)));

Before you'll have to declare this helper class:

public class CustomMatchers {

  public static Matcher<View> withDrawable(@DrawableRes final int drawableId) {
     return new DrawableViewMatcher(drawableId);
  }
  private static class DrawableViewMatcher extends TypeSafeMatcher<View> {

     private final int expectedId;
     private String resourceName;

     private enum DrawableExtractionPolicy {
        IMAGE_VIEW {
          @Override
          Drawable findDrawable(View view) {
             return view instanceof ImageView ? ((ImageView) view).getDrawable() : null;
          }
        },
        TEXT_VIEW_COMPOUND {
          @Override
          Drawable findDrawable(View view) {
             return view instanceof TextView ? findFirstCompoundDrawable((TextView) view) : null;
          }
        },
        BACKGROUND {
          @Override
          Drawable findDrawable(View view) {
             return view.getBackground();
          }
        };

        @Nullable
        private static Drawable findFirstCompoundDrawable(TextView view) {
          for (Drawable drawable : view.getCompoundDrawables()) {
             if (drawable != null) {
                return drawable;
             }
          }
          return null;
        }

        abstract Drawable findDrawable(View view);

     }

     private DrawableViewMatcher(@DrawableRes int expectedId) {
        this.expectedId = expectedId;
     }

     @Override
     protected boolean matchesSafely(View view) {
        resourceName = resources(view).getResourceName(expectedId);
        return haveSameState(actualDrawable(view), expectedDrawable(view));
     }

     private boolean haveSameState(Drawable actual, Drawable expected) {
        return actual != null && expected != null && areEqual(expected.getConstantState(), actual.getConstantState());
     }

     private Drawable actualDrawable(View view) {
        for (DrawableExtractionPolicy policy : DrawableExtractionPolicy.values()) {
          Drawable drawable = policy.findDrawable(view);
          if (drawable != null) {
             return drawable;
          }
        }
        return null;
     }

     private boolean areEqual(Object first, Object second) {
        return first == null ? second == null : first.equals(second);
     }

     private Drawable expectedDrawable(View view) {
        return drawableFrom(view, expectedId);
     }

     private static Drawable drawableFrom(View view, @DrawableRes int drawableId) {
        Context context = view.getContext();
        try {
          View dummyView = view.getClass().getConstructor(Context.class).newInstance(context);
          dummyView.setBackgroundResource(drawableId);
          return dummyView.getBackground();
        } catch (Exception e) {
          return ResourcesCompat.getDrawable(context.getResources(), drawableId, null);
        }
     }

     @NonNull
     private Resources resources(View view) {
        return view.getContext().getResources();
     }

     @Override
     public void describeTo(Description description) {
        description.appendText("with drawable from resource id: ");
        description.appendValue(expectedId);
        if (resourceName != null) {
          description.appendValueList("[", "", "]", resourceName);
        }
     }
  }

}

score 3 · Answer 9 · answered Mar 02 '20 at 12:49

3

Compare 2 drawable:

drawable1.constantState == drawable2.constantState
            || drawable1.toBitmap().sameAs(drawable2.toBitmap())

If you can not find Drawable.toBitmap(...) here is it Drawable.kt

answered Mar 02 '20 at 12:49

Benny

2,233
1
22
27

sdk 31, im using this `toBitmap().sameAs` to compare checkbox checked or unchecked based on two drawables.. – Nurkartiko Dec 05 '21 at 03:37

score 2 · Answer 10 · answered Apr 24 '12 at 13:25

2

Use getTag() and setTag() for comparison

answered Apr 24 '12 at 13:25

Pooja Akshantal

49
2

score 0 · Answer 11 · answered Mar 21 '18 at 13:17

I already answered on the similar topic here: Get the ID of a drawable in ImageView. The approach is based on tagging a view with a specified resource id in the custom LayoutInflater. Whole process is automated by a simple library TagView.

As a result, you can compare two drawables just by their ids:

TagViewUtils.getTag(view, ViewTag.VIEW_BACKGROUND.id) == R.drawable.twt_hover

score 0 · Answer 12 · answered Jan 24 '20 at 15:29

Expanding on the answer from @vaughandroid the following Matcher works for a Vector Drawable that is tinted. You have to provide the tint that was used for the Drawable.

public static Matcher<View> compareVectorDrawables(final int imageId, final int tintId) {
        return new TypeSafeMatcher<View>() {

        @Override
        protected boolean matchesSafely(View target) {
            if (!(target instanceof ImageView)) {
                return false;
            }
            ImageView imageView = (ImageView) target;
            if (imageId < 0) {
                return imageView.getDrawable() == null;
            }
            Resources resources = target.getContext().getResources();
            Drawable expectedDrawable = resources.getDrawable(imageId, null);
            if (expectedDrawable == null) {
                return false;
            }

            Drawable imageDrawable = imageView.getDrawable();
            ColorFilter imageColorFilter = imageDrawable.getColorFilter();

            expectedDrawable.setColorFilter(imageColorFilter);
            expectedDrawable.setTintList(target.getResources()
                    .getColorStateList(tintId, null));

            boolean areSame = areDrawablesIdentical(imageDrawable, expectedDrawable);
            return areSame;
        }

        public boolean areDrawablesIdentical(Drawable drawableA, Drawable drawableB) {
            Drawable.ConstantState stateA = drawableA.getConstantState();
            Drawable.ConstantState stateB = drawableB.getConstantState();
            // If the constant state is identical, they are using the same drawable resource.
            // However, the opposite is not necessarily true.
            return (stateA != null && stateB != null && stateA.equals(stateB))
                    || getBitmap(drawableA).sameAs(getBitmap(drawableB));
        }

        public Bitmap getBitmap(Drawable drawable) {
            Bitmap result;
            if (drawable instanceof BitmapDrawable) {
                result = ((BitmapDrawable) drawable).getBitmap();
            } else {
                int width = drawable.getIntrinsicWidth();
                int height = drawable.getIntrinsicHeight();
                // Some drawables have no intrinsic width - e.g. solid colours.
                if (width <= 0) {
                    width = 1;
                }
                if (height <= 0) {
                    height = 1;
                }

                result = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
                Canvas canvas = new Canvas(result);
                drawable.setBounds(0, 0, canvas.getWidth(), canvas.getHeight());
                drawable.draw(canvas);
            }
            return result;
        }

        @Override
        public void describeTo(Description description) {

        }
    };
}

score 0 · Answer 13 · answered Dec 20 '22 at 19:53

a usefull method collected from GitHub copilot:

fun compareTwoDrawable(drawable1: Drawable, drawable2: Drawable): Boolean {
   val bitmap1 = (drawable1 as BitmapDrawable).bitmap
   val bitmap2 = (drawable2 as BitmapDrawable).bitmap
   return bitmap1.sameAs(bitmap2)
}

Addon.mahesh · Answer 14 · 2014-02-20T12:59:18.210

-1

if You want to directly compare two drawable then use following code

Drawable fDraw = getResources().getDrawable(R.drawable.twt_hover);

Drawable sDraw = getResources().getDrawable(R.drawable.twt_hover);

if (fDraw.getConstantState().equals(sDraw.getConstantState())) {
    //write your code.
} else {
    //write your code.
}

edited Feb 20 '14 at 12:59

answered Feb 20 '14 at 11:19

Addon.mahesh

107
5

score -2 · Answer 15 · answered Feb 03 '12 at 07:48

-2

When you are using equals() method it is used to compare the contents. you should try == for comparing two objects.

public void MyClick(View view)
{
 Drawable fDraw = view.getBackground();
 Drawable sDraw = getResources().getDrawable(R.drawable.twt_hover);

  if( fDraw == sDraw )
  {
   // Coming
  }
}

answered Feb 03 '12 at 07:48

Lucifer

29,392
25
90
143

then it may be possible that they are not ==, they are != – Lucifer Feb 03 '12 at 08:06
but they refer to same image from resources – Roshan Jha Feb 03 '12 at 08:36
I just need to check whether they are equal or not?not any method available for that? – Roshan Jha Feb 03 '12 at 09:04
ya, i got your requirement, please come to chat room – Lucifer Feb 03 '12 at 09:08
1

== Compares if this is the same object, which it isn't n 99.99999999% of the time. – paulgavrikov Nov 29 '13 at 00:25

Comparing two drawables in android

15 Answers15

Linked

Related