LeakCanary report leak in InputMethodManager

Question

I am trying to figure it out a leak in my app but I am not sure were this comes from.

LeakCanary is telling me that I can ignore it. Is that right?

01-06 12:04:56.580 6935-9159/com.mypackage D/LeakCanary: * LEAK CAN BE IGNORED.
01-06 12:04:56.580 6935-9159/com.mypackage D/LeakCanary: * com.mypackage.ui.map.MapComponentFragment has leaked:
01-06 12:04:56.580 6935-9159/com.mypackage D/LeakCanary: * GC ROOT android.view.inputmethod.InputMethodManager$1.this$0 (anonymous class extends com.android.internal.view.IInputMethodClient$Stub)
01-06 12:04:56.580 6935-9159/com.mypackage D/LeakCanary: * references android.view.inputmethod.InputMethodManager.mCurRootView
01-06 12:04:56.580 6935-9159/com.mypackage D/LeakCanary: * references com.android.internal.policy.impl.PhoneWindow$DecorView.mContext
01-06 12:04:56.580 6935-9159/com.mypackage D/LeakCanary: * references com.mypackage.ui.MainActivity.mFragments
01-06 12:04:56.580 6935-9159/com.mypackage D/LeakCanary: * references android.app.FragmentManagerImpl.mAdded
01-06 12:04:56.580 6935-9159/com.mypackage D/LeakCanary: * references java.util.ArrayList.array
01-06 12:04:56.580 6935-9159/com.mypackage D/LeakCanary: * references array java.lang.Object[].[0]
01-06 12:04:56.580 6935-9159/com.mypackage D/LeakCanary: * leaks com.mypackage.ui.map.MapComponentFragment instance
01-06 12:04:56.580 6935-9159/com.mypackage D/LeakCanary: * Reference Key: 0790f013-1c87-4d5f-8c10-db277187e3ce
01-06 12:04:56.580 6935-9159/com.mypackage D/LeakCanary: * Device: samsung samsung SM-N910C treltexx
01-06 12:04:56.580 6935-9159/com.mypackage D/LeakCanary: * Android Version: 5.1.1 API: 22 LeakCanary: 1.4-SNAPSHOT 2714152
01-06 12:04:56.580 6935-9159/com.mypackage D/LeakCanary: * Durations: watch=5085ms, gc=149ms, heap dump=2562ms, analysis=10313ms

There were several leaks caused by this fragment, but I fix them. This one I can't make it disappear.

Any clue?

EDIT

One more thing, if I want to ignore it this should be enough?

.instanceField("android.view.inputmethod.InputMethodManager", "mCurRootView")

But is still showing up in LeakCanary

Apparently this leak is in AndroidExcludeRef but still being reported. https://github.com/square/leakcanary/issues/322

There are various solutions or workarounds: https://issuetracker.google.com/issues/37043700#comment17 https://issuetracker.google.com/issues/36950938 https://stackoverflow.com/questions/5038158/main-activity-is-not-garbage-collected — Mr-IDE, Jan 14 '18 at 13:08

boiledwater · Answer 1 · 2018-03-13T08:28:59.147

/**
 * call this method in activity onDestroy() method.
*/
public static void fixInputMethod(Context context) {
    if (context == null) {
        return;
    }
    InputMethodManager inputMethodManager = null;
    try {
        inputMethodManager = (InputMethodManager) context.getSystemService(Context.INPUT_METHOD_SERVICE);
    } catch (Throwable th) {
        th.printStackTrace();
    }
    if (inputMethodManager == null) {
        return;
    }
    Field[] declaredFields = inputMethodManager.getClass().getDeclaredFields();
    for (Field declaredField : declaredFields) {
        try {
            if (!declaredField.isAccessible()) {
                declaredField.setAccessible(true);
            }
            Object obj = declaredField.get(inputMethodManager);
            if (obj == null || !(obj instanceof View)) {
                continue;
            }
            View view = (View) obj;
            if (view.getContext() == context) {
                declaredField.set(inputMethodManager, null);
            } else {
                continue;
            }
        } catch (Throwable th) {
            th.printStackTrace();
        }
    }
}

score 3 · Answer 2 · answered Jan 06 '16 at 11:25

3

Yup, you can ignore this leak.

Check for example this issue: https://github.com/square/leakcanary/issues/256

answered Jan 06 '16 at 11:25

Sandro Machado

9,921
4
36
57

the weird thing is when I do ignore I get others like this. Always coming from this fragment – Marcel Jan 06 '16 at 12:30
It is a bug from the Android framework and probably is already reported (and fixed in the next releases of Android). So you cannot do something about the issue, so you should ignore it. – Sandro Machado Jan 06 '16 at 12:34
I understood that, but still feels weird that when I ignore this one I get a new one from a listener in a button... – Marcel Jan 06 '16 at 12:50
And that have the TAG `LEAK CAN BE IGNORED.`? – Sandro Machado Jan 06 '16 at 13:49
I found the reasons of others but I can't ignore this one. Seams that the PhoneWindows is keeping the reference to the activity even after this one is destroyed. How can avoid getting this leak. (see my update question) – Marcel Jan 06 '16 at 17:24

humble_wolf · Answer 3 · 2022-04-05T04:46:12.693

2

Yes, you can ignore this leak. A hacky solution for solving above leak which will work for all versions is here

EDIT April 2022:-

The Author of medium story deleted it but the solution was around using a transparent activity as an exit activity.

edited Apr 05 '22 at 04:46

answered Mar 04 '17 at 07:22

humble_wolf

1,497
19
26

1

But this solution has a side effect of messing up the "screenshot" of your app, when the Recent Apps button is pressed. Your app screenshot will appear as a blank black (or white) screen, instead of showing the actual screen content. This is despite the DummyActivity being fully transparent. – Mr-IDE Jan 13 '18 at 21:48
1

404 - "The author deleted this Medium story" – Leo supports Monica Cellio Sep 15 '18 at 12:13
as far as I remember the solution was to create a dummy transparent activity and use it as an exit activity..... – humble_wolf Sep 15 '18 at 14:07
Link says its deleted... – Renetik Apr 04 '22 at 20:24
@humble_wolf what an "elegant" solution now I understand why article is deleted ;) – Renetik Apr 04 '22 at 20:25

score 0 · Answer 4 · answered Jan 07 '16 at 14:42

LeakCanary is already take this leak as a Android OS fault. But still happening, what it annoyed me. If someone gets into this and wants to fix it, there is a workaround for it.

https://gist.github.com/pyricau/4df64341cc978a7de414

Just call on the onCreate of your Activity this

IMMLeaks.fixFocusedViewLeak(getApplication());

LeakCanary report leak in InputMethodManager

4 Answers4

EDIT April 2022:-