Overview
Usability:Icons | |
2 | warning MonochromeLauncherIcon: Monochrome icon is not defined |
Included Additional Checks (46) | |
Disabled Checks (40) |
Monochrome icon is not defined
../../src/main/res/mipmap-anydpi-v26/ic_launcher.xml:6: The application adaptive icon is missing a monochrome tag
3 - License, v. 2.0. If a copy of the MPL was not distributed with this 4 - file, You can obtain one at http://mozilla.org/MPL/2.0/. --> 5 6 <adaptive-icon xmlns:android="http://schemas.android.com/apk/res/android"> 7 <background android:drawable="@color/ic_launcher_background"/> 8 <foreground android:drawable="@mipmap/ic_launcher_foreground"/> 9 </adaptive-icon>../../src/main/res/mipmap-anydpi-v26/ic_launcher_round.xml:6: The application adaptive roundIcon is missing a monochrome tag
3 - License, v. 2.0. If a copy of the MPL was not distributed with this 4 - file, You can obtain one at http://mozilla.org/MPL/2.0/. --> 5 6 <adaptive-icon xmlns:android="http://schemas.android.com/apk/res/android"> 7 <background android:drawable="@color/ic_launcher_background"/> 8 <foreground android:drawable="@mipmap/ic_launcher_foreground"/> 9 </adaptive-icon>
If
For example, if
To suppress this error, use the issue id "MonochromeLauncherIcon" as explained in the Suppressing Warnings and Errors section.
android:roundIcon
and android:icon
are both in your manifest, you must either remove the reference to android:roundIcon
if it is not needed; or, supply the monochrome icon in the drawable defined by the android:roundIcon
and android:icon
attribute.For example, if
android:roundIcon
and android:icon
are both in the manifest, a launcher might choose to use android:roundIcon
over android:icon
to display the adaptive app icon. Therefore, your themed application iconwill not show if your monochrome attribute is not also specified in android:roundIcon
.To suppress this error, use the issue id "MonochromeLauncherIcon" as explained in the Suppressing Warnings and Errors section.
MonochromeLauncherIcon
Icons
Usability
Warning
Priority 6/10
Included Additional Checks
This card lists all the extra checks run by lint, provided from libraries,
build configuration and extra flags. This is included to help you verify
whether a particular check is included in analysis when configuring builds.
(Note that the list does not include the hundreds of built-in checks into lint,
only additional ones.)
AndroidSrcXmlDetector
ImageView (and descendants) images should be declared using app:srcCompat
Identifier: mozilla.components.tooling.lint.lint
AndroidSrcXmlDetector
ImageView (and descendants) should be tinted using app:tint
Identifier: mozilla.components.tooling.lint.lint
BadConfigurationProvider
An
for on-demand initialization.
android.app.Application
must implement androidx.work.Configuration.Provider
for on-demand initialization.
Vendor: Android Open Source Project
Identifier: androidx.work
Feedback: https://issuetracker.google.com/issues/new?component=409906
Identifier: androidx.work
Feedback: https://issuetracker.google.com/issues/new?component=409906
BadPeriodicWorkRequestEnqueue
When using
duplicate requests unintentionally. You should be using
enqueue()
for `PeriodicWorkRequest`s, you might end up enqueuingduplicate requests unintentionally. You should be using
enqueueUniquePeriodicWork
with an ExistingPeriodicWorkPolicy.KEEP
instead.
Vendor: Android Open Source Project
Identifier: androidx.work
Feedback: https://issuetracker.google.com/issues/new?component=409906
Identifier: androidx.work
Feedback: https://issuetracker.google.com/issues/new?component=409906
DetachAndAttachSameFragment
When doing a FragmentTransaction that includes both attach() and detach() operations being committed on the same fragment instance, it is a no-op. The reason for this is that the FragmentManager optimizes all operations within a single transaction so the attach() and detach() cancel each other out and neither is actually executed. To get the desired behavior, you should separate the attach() and detach() calls into separate FragmentTransactions.
Vendor: Android Open Source Project
Identifier: androidx.fragment
Feedback: https://issuetracker.google.com/issues/new?component=460964
Identifier: androidx.fragment
Feedback: https://issuetracker.google.com/issues/new?component=460964
DialogFragmentCallbacksDetector
When using a
DialogFragment
, the setOnCancelListener
and setOnDismissListener
callback functions within the onCreateDialog
function __must not be used__ because the DialogFragment
owns these callbacks. Instead the respective onCancel
and onDismiss
functions can be used to achieve the desired effect.
Vendor: Android Open Source Project
Identifier: androidx.fragment
Feedback: https://issuetracker.google.com/issues/new?component=460964
Identifier: androidx.fragment
Feedback: https://issuetracker.google.com/issues/new?component=460964
EnsureInitializerMetadata
When a library defines a Initializer, it needs to be accompanied by a corresponding <meta-data> entry in the AndroidManifest.xml file.
Vendor: Android Open Source Project
Identifier: androidx.startup
Feedback: https://issuetracker.google.com/issues/new?component=823348
Identifier: androidx.startup
Feedback: https://issuetracker.google.com/issues/new?component=823348
EnsureInitializerNoArgConstr
Every
Initializer
must have a no argument constructor.
Vendor: Android Open Source Project
Identifier: androidx.startup
Feedback: https://issuetracker.google.com/issues/new?component=823348
Identifier: androidx.startup
Feedback: https://issuetracker.google.com/issues/new?component=823348
ExperimentalAnnotationRetention
Experimental annotations defined in Java source should use default (
CLASS
) retention, while Kotlin-sourced annotations should use BINARY
retention.
Vendor: Android Open Source Project
Identifier: androidx.annotation.experimental
Feedback: https://issuetracker.google.com/issues/new?component=459778
Identifier: androidx.annotation.experimental
Feedback: https://issuetracker.google.com/issues/new?component=459778
FactCollect
An instance of
Fact
was created but not collected. You must callcollect()
on the instance to actually process it.
Identifier: mozilla.components.tooling.lint.lint
FetchResponseClose
A
a
resource managed cases, we need to ensure that
Additionally, all methods on
those will release those resources after execution.
Client.fetch
returns a Response
that, on success, is consumed typically witha
use
stream in Kotlin or a try-with-resources in Java. In the failure or manualresource managed cases, we need to ensure that
Response.close
is always called.Additionally, all methods on
Response.body
are AutoCloseable so using any ofthose will release those resources after execution.
Identifier: mozilla.components.tooling.lint.lint
FragmentAddMenuProvider
The Fragment lifecycle can result in a Fragment being active longer than its view. This can lead to unexpected behavior from lifecycle aware objects remaining active longer than the Fragment's view. To solve this issue, getViewLifecycleOwner() should be used as a LifecycleOwner rather than the Fragment instance once it is safe to access the view lifecycle in a Fragment's onCreateView, onViewCreated, onActivityCreated, or onViewStateRestored methods.
Vendor: Android Open Source Project
Identifier: androidx.fragment
Feedback: https://issuetracker.google.com/issues/new?component=460964
Identifier: androidx.fragment
Feedback: https://issuetracker.google.com/issues/new?component=460964
FragmentBackPressedCallback
The Fragment lifecycle can result in a Fragment being active longer than its view. This can lead to unexpected behavior from lifecycle aware objects remaining active longer than the Fragment's view. To solve this issue, getViewLifecycleOwner() should be used as a LifecycleOwner rather than the Fragment instance once it is safe to access the view lifecycle in a Fragment's onCreateView, onViewCreated, onActivityCreated, or onViewStateRestored methods.
Vendor: Android Open Source Project
Identifier: androidx.fragment
Feedback: https://issuetracker.google.com/issues/new?component=460964
Identifier: androidx.fragment
Feedback: https://issuetracker.google.com/issues/new?component=460964
FragmentLiveDataObserve
When observing a LiveData object from a fragment's onCreateView, onViewCreated, onActivityCreated, or onViewStateRestored method getViewLifecycleOwner() should be used as the LifecycleOwner rather than the Fragment instance. The Fragment lifecycle can result in the Fragment being active longer than its view. This can lead to unexpected behavior from LiveData objects being observed longer than the Fragment's view is active.
Vendor: Android Open Source Project
Identifier: androidx.fragment
Feedback: https://issuetracker.google.com/issues/new?component=460964
Identifier: androidx.fragment
Feedback: https://issuetracker.google.com/issues/new?component=460964
FragmentTagUsage
FragmentContainerView replaces the <fragment> tag as the preferred way of adding fragments via XML. Unlike the <fragment> tag, FragmentContainerView uses a normal
FragmentTransaction
under the hood to add the initial fragment, allowing further FragmentTransaction operations on the FragmentContainerView and providing a consistent timing for lifecycle events.
Vendor: Android Open Source Project
Identifier: androidx.fragment
Feedback: https://issuetracker.google.com/issues/new?component=460964
Identifier: androidx.fragment
Feedback: https://issuetracker.google.com/issues/new?component=460964
IdleBatteryChargingConstraints
Some devices are never considered charging and idle at the same time.
Consider removing one of these constraints.
Consider removing one of these constraints.
Vendor: Android Open Source Project
Identifier: androidx.work
Feedback: https://issuetracker.google.com/issues/new?component=409906
Identifier: androidx.work
Feedback: https://issuetracker.google.com/issues/new?component=409906
InvalidFragmentVersionForActivityResult
In order to use the ActivityResult APIs you must upgrade your Fragment version to 1.3.0. Previous versions of FragmentActivity failed to call super.onRequestPermissionsResult() and used invalid request codes
Vendor: Android Open Source Project
Identifier: androidx.activity
Feedback: https://issuetracker.google.com/issues/new?component=527362
Identifier: androidx.activity
Feedback: https://issuetracker.google.com/issues/new?component=527362
InvalidPeriodicWorkRequestInterval
The interval duration for a
PeriodicWorkRequest
must be at least 15 minutes.
Vendor: Android Open Source Project
Identifier: androidx.work
Feedback: https://issuetracker.google.com/issues/new?component=409906
Identifier: androidx.work
Feedback: https://issuetracker.google.com/issues/new?component=409906
InvalidSetHasFixedSize
When a RecyclerView uses
setHasFixedSize(...)
you cannot use wrap_content
for size in the scrolling direction.
Vendor: Android Open Source Project
Identifier: androidx.recyclerview
Feedback: https://issuetracker.google.com/issues/new?component=460887
Identifier: androidx.recyclerview
Feedback: https://issuetracker.google.com/issues/new?component=460887
LogUsage
The Log or Logger class from the base component should be used for logging instead of
Android's Log class. This will allow the app to control what logs should be accepted
and how they should be processed.
Android's Log class. This will allow the app to control what logs should be accepted
and how they should be processed.
Identifier: mozilla.components.tooling.lint.lint
NotifyUsage
NotificationsDelegate should be used for showing notifications instead of a NotificationManager
or a NotificationManagerCompat. This will allow the app to control requesting the notification permission
when needed and handling the request result.
or a NotificationManagerCompat. This will allow the app to control requesting the notification permission
when needed and handling the request result.
Identifier: mozilla.components.tooling.lint.lint
NullSafeMutableLiveData
This check ensures that LiveData values are not null when explicitly declared as non-nullable.
Kotlin interoperability does not support enforcing explicit null-safety when using generic Java type parameters. Since LiveData is a Java class its value can always be null even when its type is explicitly declared as non-nullable. This can lead to runtime exceptions from reading a null LiveData value that is assumed to be non-nullable.
Kotlin interoperability does not support enforcing explicit null-safety when using generic Java type parameters. Since LiveData is a Java class its value can always be null even when its type is explicitly declared as non-nullable. This can lead to runtime exceptions from reading a null LiveData value that is assumed to be non-nullable.
Vendor: Android Open Source Project
Identifier: androidx.lifecycle
Feedback: https://issuetracker.google.com/issues/new?component=413132
Identifier: androidx.lifecycle
Feedback: https://issuetracker.google.com/issues/new?component=413132
RemoveWorkManagerInitializer
If an
the default
AndroidManifest.xml file.
android.app.Application
implements androidx.work.Configuration.Provider
,the default
androidx.startup.InitializationProvider
needs to be removed from theAndroidManifest.xml file.
Vendor: Android Open Source Project
Identifier: androidx.work
Feedback: https://issuetracker.google.com/issues/new?component=409906
Identifier: androidx.work
Feedback: https://issuetracker.google.com/issues/new?component=409906
RepeatOnLifecycleWrongUsage
The repeatOnLifecycle APIs should be used when the View is created, that is in the
onCreate
lifecycle method for Activities, or onViewCreated
in case you're using Fragments.
Vendor: Android Open Source Project
Identifier: androidx.lifecycle
Feedback: https://issuetracker.google.com/issues/new?component=413132
Identifier: androidx.lifecycle
Feedback: https://issuetracker.google.com/issues/new?component=413132
SpecifyForegroundServiceType
When using the setForegroundAsync() API, the application must override <service /> entry for
SystemForegroundService
to include the foreground service type in the AndroidManifest.xml
file.
Vendor: Android Open Source Project
Identifier: androidx.work
Feedback: https://issuetracker.google.com/issues/new?component=409906
Identifier: androidx.work
Feedback: https://issuetracker.google.com/issues/new?component=409906
SpecifyJobSchedulerIdRange
When using
For more information look at
JobScheduler
APIs directly, WorkManager
requires that developers specify a range of JobScheduler
ids that are safe for WorkManager
to use so the `id`s do not collide. For more information look at
androidx.work.Configuration.Builder.setJobSchedulerJobIdRange(int, int)
.
Vendor: Android Open Source Project
Identifier: androidx.work
Feedback: https://issuetracker.google.com/issues/new?component=409906
Identifier: androidx.work
Feedback: https://issuetracker.google.com/issues/new?component=409906
TextViewAndroidSrcXmlDetector
TextView drawables should be declared using app:drawableXCompat
Identifier: mozilla.components.tooling.lint.lint
UnsafeLifecycleWhenUsage
If the
Lifecycle
is destroyed within the block of Lifecycle.whenStarted
or any similar Lifecycle.when
method is suspended, the block will be cancelled, which will also cancel any child coroutine launched inside the block. As as a result, If you have a try finally block in your code, the finally might run after the Lifecycle moves outside the desired state. It is recommended to check the Lifecycle.isAtLeast
before accessing UI in finally block. Similarly, if you have a catch statement that might catch CancellationException
, you should check the Lifecycle.isAtLeast
before accessing the UI. See documentation of Lifecycle.whenStateAtLeast
for more details
Vendor: Android Open Source Project
Identifier: androidx.lifecycle
Feedback: https://issuetracker.google.com/issues/new?component=413132
Identifier: androidx.lifecycle
Feedback: https://issuetracker.google.com/issues/new?component=413132
UnsafeOptInUsageError
This API has been flagged as opt-in with error-level severity.
Any declaration annotated with this marker is considered part of an unstable or
otherwise non-standard API surface and its call sites should accept the opt-in
aspect of it by using the
effectively causing further propagation of the opt-in aspect -- or configuring
the
To configure project-wide opt-in, specify the
as a comma-delimited list of opted-in annotations:
Any declaration annotated with this marker is considered part of an unstable or
otherwise non-standard API surface and its call sites should accept the opt-in
aspect of it by using the
@OptIn
annotation, using the marker annotation --effectively causing further propagation of the opt-in aspect -- or configuring
the
UnsafeOptInUsageError
check's options for project-wide opt-in.To configure project-wide opt-in, specify the
opt-in
option value in lint.xml
as a comma-delimited list of opted-in annotations:
<lint> <issue id="UnsafeOptInUsageError"> <option name="opt-in" value="com.foo.ExperimentalBarAnnotation" /> </issue> </lint>
Vendor: Android Open Source Project
Identifier: androidx.annotation.experimental
Feedback: https://issuetracker.google.com/issues/new?component=459778
Identifier: androidx.annotation.experimental
Feedback: https://issuetracker.google.com/issues/new?component=459778
UnsafeOptInUsageWarning
This API has been flagged as opt-in with warning-level severity.
Any declaration annotated with this marker is considered part of an unstable or
otherwise non-standard API surface and its call sites should accept the opt-in
aspect of it by using the
effectively causing further propagation of the opt-in aspect -- or configuring
the
To configure project-wide opt-in, specify the
as a comma-delimited list of opted-in annotations:
Any declaration annotated with this marker is considered part of an unstable or
otherwise non-standard API surface and its call sites should accept the opt-in
aspect of it by using the
@OptIn
annotation, using the marker annotation --effectively causing further propagation of the opt-in aspect -- or configuring
the
UnsafeOptInUsageWarning
check's options for project-wide opt-in.To configure project-wide opt-in, specify the
opt-in
option value in lint.xml
as a comma-delimited list of opted-in annotations:
<lint> <issue id="UnsafeOptInUsageWarning"> <option name="opt-in" value="com.foo.ExperimentalBarAnnotation" /> </issue> </lint>
Vendor: Android Open Source Project
Identifier: androidx.annotation.experimental
Feedback: https://issuetracker.google.com/issues/new?component=459778
Identifier: androidx.annotation.experimental
Feedback: https://issuetracker.google.com/issues/new?component=459778
UnsafeRepeatOnLifecycleDetector
The repeatOnLifecycle APIs should be used with the viewLifecycleOwner in Fragments as opposed to lifecycleOwner.
Vendor: Android Open Source Project
Identifier: androidx.fragment
Feedback: https://issuetracker.google.com/issues/new?component=460964
Identifier: androidx.fragment
Feedback: https://issuetracker.google.com/issues/new?component=460964
UseAndroidAlpha
ColorStateList
uses app:alpha without android:alpha
Vendor: Android Open Source Project
Identifier: androidx.appcompat
Feedback: https://issuetracker.google.com/issues/new?component=460343
Identifier: androidx.appcompat
Feedback: https://issuetracker.google.com/issues/new?component=460343
UseAppTint
ImageView
or ImageButton
uses android:tint
instead of app:tint
Vendor: Android Open Source Project
Identifier: androidx.appcompat
Feedback: https://issuetracker.google.com/issues/new?component=460343
Identifier: androidx.appcompat
Feedback: https://issuetracker.google.com/issues/new?component=460343
UseCompatLoadingForColorStateLists
Use Compat loading of color state lists
Vendor: Android Open Source Project
Identifier: androidx.appcompat
Feedback: https://issuetracker.google.com/issues/new?component=460343
Identifier: androidx.appcompat
Feedback: https://issuetracker.google.com/issues/new?component=460343
UseCompatLoadingForDrawables
Use Compat loading of drawables
Vendor: Android Open Source Project
Identifier: androidx.appcompat
Feedback: https://issuetracker.google.com/issues/new?component=460343
Identifier: androidx.appcompat
Feedback: https://issuetracker.google.com/issues/new?component=460343
UseCompatTextViewDrawableApis
Use Compat loading of compound text view drawables
Vendor: Android Open Source Project
Identifier: androidx.appcompat
Feedback: https://issuetracker.google.com/issues/new?component=460343
Identifier: androidx.appcompat
Feedback: https://issuetracker.google.com/issues/new?component=460343
UseCompatTextViewDrawableXml
TextView
uses android:
compound drawable attributes instead of app:
ones
Vendor: Android Open Source Project
Identifier: androidx.appcompat
Feedback: https://issuetracker.google.com/issues/new?component=460343
Identifier: androidx.appcompat
Feedback: https://issuetracker.google.com/issues/new?component=460343
UseGetLayoutInflater
Using LayoutInflater.from(Context) can return a LayoutInflater that does not have the correct theme.
Vendor: Android Open Source Project
Identifier: androidx.fragment
Feedback: https://issuetracker.google.com/issues/new?component=460964
Identifier: androidx.fragment
Feedback: https://issuetracker.google.com/issues/new?component=460964
UseRequireInsteadOfGet
AndroidX added new "require____()" versions of common "get___()" APIs, such as getContext/getActivity/getArguments/etc. Rather than wrap these in something like requireNotNull(), using these APIs will allow the underlying component to try to tell you _why_ it was null, and thus yield a better error message.
Vendor: Android Open Source Project
Identifier: androidx.fragment
Feedback: https://issuetracker.google.com/issues/new?component=460964
Identifier: androidx.fragment
Feedback: https://issuetracker.google.com/issues/new?component=460964
UseRxSetProgress2
Use
setCompletableProgress(...)
instead of `setProgress(...) in RxWorker
.
Vendor: Android Open Source Project
Identifier: androidx.work
Feedback: https://issuetracker.google.com/issues/new?component=409906
Identifier: androidx.work
Feedback: https://issuetracker.google.com/issues/new?component=409906
UseSupportActionBar
Use
AppCompatActivity.setSupportActionBar
Vendor: Android Open Source Project
Identifier: androidx.appcompat
Feedback: https://issuetracker.google.com/issues/new?component=460343
Identifier: androidx.appcompat
Feedback: https://issuetracker.google.com/issues/new?component=460343
UseSwitchCompatOrMaterialCode
Use
SwitchCompat
from AppCompat or MaterialSwitch
from Material library
Vendor: Android Open Source Project
Identifier: androidx.appcompat
Feedback: https://issuetracker.google.com/issues/new?component=460343
Identifier: androidx.appcompat
Feedback: https://issuetracker.google.com/issues/new?component=460343
UseSwitchCompatOrMaterialXml
Use
SwitchCompat
from AppCompat or MaterialSwitch
from Material library
Vendor: Android Open Source Project
Identifier: androidx.appcompat
Feedback: https://issuetracker.google.com/issues/new?component=460343
Identifier: androidx.appcompat
Feedback: https://issuetracker.google.com/issues/new?component=460343
UsingOnClickInXml
Old versions of the platform do not properly support resolving
android:onClick
Vendor: Android Open Source Project
Identifier: androidx.appcompat
Feedback: https://issuetracker.google.com/issues/new?component=460343
Identifier: androidx.appcompat
Feedback: https://issuetracker.google.com/issues/new?component=460343
WorkerHasAPublicModifier
When you define a ListenableWorker which is constructed using the
default WorkerFactory, the ListenableWorker sub-type needs to be public.
default WorkerFactory, the ListenableWorker sub-type needs to be public.
Vendor: Android Open Source Project
Identifier: androidx.work
Feedback: https://issuetracker.google.com/issues/new?component=409906
Identifier: androidx.work
Feedback: https://issuetracker.google.com/issues/new?component=409906
WrongRequiresOptIn
Experimental features defined in Kotlin source code must be annotated with the Kotlin
Kotlin compiler from enforcing its opt-in policies.
@RequiresOptIn
annotation. Using androidx.annotation.RequiresOptIn
will prevent theKotlin compiler from enforcing its opt-in policies.
Vendor: Android Open Source Project
Identifier: androidx.annotation.experimental
Feedback: https://issuetracker.google.com/issues/new?component=459778
Identifier: androidx.annotation.experimental
Feedback: https://issuetracker.google.com/issues/new?component=459778
Disabled Checks
One or more issues were not run by lint, either
because the check is not enabled by default, or because
it was disabled with a command line flag or via one or
more
lint.xml
configuration files in the project directories.
AppCompatMethod
Disabled By: Default
When using the appcompat library, there are some methods you should be calling instead of the normal ones; for example,
Note: This issue has an associated quickfix operation in Android Studio and IntelliJ IDEA.
getSupportActionBar()
instead of getActionBar()
. This lint check looks for calls to the wrong method.Note: This issue has an associated quickfix operation in Android Studio and IntelliJ IDEA.
AppLinksAutoVerify
Disabled By: Default
Ensures that app links are correctly set and associated with website.
More info: https://g.co/appindexing/applinks
BackButton
Disabled By: Default
According to the Android Design Guide,
"Other platforms use an explicit back button with label to allow the user to navigate up the application's hierarchy. Instead, Android uses the main action bar's app icon for hierarchical navigation and the navigation bar's back button for temporal navigation."
This check is not very sophisticated (it just looks for buttons with the label "Back"), so it is disabled by default to not trigger on common scenarios like pairs of Back/Next buttons to paginate through screens.
"Other platforms use an explicit back button with label to allow the user to navigate up the application's hierarchy. Instead, Android uses the main action bar's app icon for hierarchical navigation and the navigation bar's back button for temporal navigation."
This check is not very sophisticated (it just looks for buttons with the label "Back"), so it is disabled by default to not trigger on common scenarios like pairs of Back/Next buttons to paginate through screens.
ConvertToWebp
Disabled By: Default
The WebP format is typically more compact than PNG and JPEG. As of Android 4.2.1 it supports transparency and lossless conversion as well. Note that there is a quickfix in the IDE which lets you perform conversion.
Previously, launcher icons were required to be in the PNG format but that restriction is no longer there, so lint now flags these.
Note: This issue has an associated quickfix operation in Android Studio and IntelliJ IDEA.
Previously, launcher icons were required to be in the PNG format but that restriction is no longer there, so lint now flags these.
Note: This issue has an associated quickfix operation in Android Studio and IntelliJ IDEA.
DalvikOverride
Disabled By: Default
The Dalvik virtual machine will treat a package private method in one class as overriding a package private method in its super class, even if they are in separate packages.
If you really did intend for this method to override the other, make the method
If you did not intend the override, consider making the method private, or changing its name or signature.
Note that this check is disabled be default, because ART (the successor to Dalvik) no longer has this behavior.
If you really did intend for this method to override the other, make the method
protected
instead.If you did not intend the override, consider making the method private, or changing its name or signature.
Note that this check is disabled be default, because ART (the successor to Dalvik) no longer has this behavior.
DefaultEncoding
Disabled By: Default
Some APIs will implicitly use the default system character encoding instead of UTF-8 when converting to or from bytes, such as when creating a default
This is usually not correct; you only want to do this if you need to read files created by other programs where they have deliberately written in the same encoding. The default encoding varies from platform to platform and can vary from locale to locale, so this makes it difficult to interpret files containing non-ASCII characters.
We recommend using UTF-8 everywhere.
Note that on Android, the default file encoding is always UTF-8 (see https://developer.android.com/reference/java/nio/charset/Charset#defaultCharset() for more), so this lint check deliberately does not flag any problems in Android code, since it is always safe to rely on the default character encoding there.
FileReader
.This is usually not correct; you only want to do this if you need to read files created by other programs where they have deliberately written in the same encoding. The default encoding varies from platform to platform and can vary from locale to locale, so this makes it difficult to interpret files containing non-ASCII characters.
We recommend using UTF-8 everywhere.
Note that on Android, the default file encoding is always UTF-8 (see https://developer.android.com/reference/java/nio/charset/Charset#defaultCharset() for more), so this lint check deliberately does not flag any problems in Android code, since it is always safe to rely on the default character encoding there.
DuplicateStrings
Disabled By: Default
Duplicate strings can make applications larger unnecessarily.
This lint check looks for duplicate strings, including differences for strings where the only difference is in capitalization. Title casing and all uppercase can all be adjusted in the layout or in code.
This lint check looks for duplicate strings, including differences for strings where the only difference is in capitalization. Title casing and all uppercase can all be adjusted in the layout or in code.
More info: https://developer.android.com/reference/android/widget/TextView.html#attr_android:inputType
EasterEgg
Disabled By: Default
An "easter egg" is code deliberately hidden in the code, both from potential users and even from other developers. This lint check looks for code which looks like it may be hidden from sight.
ExpensiveAssertion
Disabled By: Default
In Kotlin, assertions are not handled the same way as from the Java programming language. In particular, they're just implemented as a library call, and inside the library call the error is only thrown if assertions are enabled.
This means that the arguments to the
This check looks for cases where the assertion condition is nontrivial, e.g. it is performing method calls or doing more work than simple comparisons on local variables or fields.
You can work around this by writing your own inline assert method instead:
In Android, because assertions are not enforced at runtime, instead use this:
Note: This issue has an associated quickfix operation in Android Studio and IntelliJ IDEA.
This means that the arguments to the
assert
call will always be evaluated. If you're doing any computation in the expression being asserted, that computation will unconditionally be performed whether or not assertions are turned on. This typically turns into wasted work in release builds.This check looks for cases where the assertion condition is nontrivial, e.g. it is performing method calls or doing more work than simple comparisons on local variables or fields.
You can work around this by writing your own inline assert method instead:
@Suppress("INVISIBLE_REFERENCE", "INVISIBLE_MEMBER") inline fun assert(condition: () -> Boolean) { if (_Assertions.ENABLED && !condition()) { throw AssertionError() } }
In Android, because assertions are not enforced at runtime, instead use this:
inline fun assert(condition: () -> Boolean) { if (BuildConfig.DEBUG && !condition()) { throw AssertionError() } }
Note: This issue has an associated quickfix operation in Android Studio and IntelliJ IDEA.
IconExpectedSize
Disabled By: Default
There are predefined sizes (for each density) for launcher icons. You should follow these conventions to make sure your icons fit in with the overall look of the platform.
IconMissingDensityFolder
Disabled By: Project lint.xml file
Icons will look best if a custom version is provided for each of the major screen density classes (low, medium, high, extra-high, extra-extra-high). This lint check identifies folders which are missing, such as
Low density is not really used much anymore, so this check ignores the ldpi density. To force lint to include it, set the environment variable
drawable-hdpi
.Low density is not really used much anymore, so this check ignores the ldpi density. To force lint to include it, set the environment variable
ANDROID_LINT_INCLUDE_LDPI=true
. For more information on current density usage, see https://developer.android.com/about/dashboardsImplicitSamInstance
Disabled By: Default
Kotlin's support for SAM (single accessor method) interfaces lets you pass a lambda to the interface. This will create a new instance on the fly even though there is no explicit constructor call. If you pass one of these lambdas or method references into a method which (for example) stores or compares the object identity, unexpected results may happen.
Note: This issue has an associated quickfix operation in Android Studio and IntelliJ IDEA.
Note: This issue has an associated quickfix operation in Android Studio and IntelliJ IDEA.
InvalidPackage
Disabled By: Default
This check scans through libraries looking for calls to APIs that are not included in Android.
When you create Android projects, the classpath is set up such that you can only access classes in the API packages that are included in Android. However, if you add other projects to your libs/ folder, there is no guarantee that those .jar files were built with an Android specific classpath, and in particular, they could be accessing unsupported APIs such as java.applet.
This check scans through library jars and looks for references to API packages that are not included in Android and flags these. This is only an error if your code calls one of the library classes which wind up referencing the unsupported package.
When you create Android projects, the classpath is set up such that you can only access classes in the API packages that are included in Android. However, if you add other projects to your libs/ folder, there is no guarantee that those .jar files were built with an Android specific classpath, and in particular, they could be accessing unsupported APIs such as java.applet.
This check scans through library jars and looks for references to API packages that are not included in Android and flags these. This is only an error if your code calls one of the library classes which wind up referencing the unsupported package.
KotlinPropertyAccess
Disabled By: Default
For a method to be represented as a property in Kotlin, strict “bean”-style prefixing must be used.
Accessor methods require a
Accessor methods require a
get
prefix or for boolean-returning methods an is
prefix can be used.KotlincFE10
Disabled By: Default
K2, the new version of Kotlin compiler, which encompasses the new frontend, is coming. Try to avoid using internal APIs from the old frontend if possible.
LambdaLast
Disabled By: Default
To improve calling this code from Kotlin, parameter types eligible for SAM conversion should be last.
LintDocExample
Disabled By: Default
Lint's tool for generating documentation for each issue has special support for including a code example which shows how to trigger the report. It will pick the first unit test it can find and pick out the source file referenced from the error message, but you can instead designate a unit test to be the documentation example, and in that case, all the files are included.
To designate a unit test as the documentation example for an issue, name the test
To designate a unit test as the documentation example for an issue, name the test
testDocumentationExample
, or if your detector reports multiple issues, testDocumentationExample
<Id>, such as testDocumentationExampleMyId
.LintImplPsiEquals
Disabled By: Default
You should never compare two PSI elements for equality with
equals
; use isEquivalentTo(PsiElement)
instead.LintImplUnexpectedDomain
Disabled By: Default
This checks flags URLs to domains that have not been explicitly allowed for use as a documentation source.
LogConditional
Disabled By: Default
The
If you really intend for the logging to be present in release mode, you can suppress this warning with a
BuildConfig
class provides a constant, DEBUG
, which indicates whether the code is being built in release mode or in debug mode. In release mode, you typically want to strip out all the logging calls. Since the compiler will automatically remove all code which is inside a if (false)
check, surrounding your logging calls with a check for BuildConfig.DEBUG
is a good idea.If you really intend for the logging to be present in release mode, you can suppress this warning with a
@SuppressLint
annotation for the intentional logging calls.MangledCRLF
Disabled By: Default
On Windows, line endings are typically recorded as carriage return plus newline: \r\n.
This detector looks for invalid line endings with repeated carriage return characters (without newlines). Previous versions of the ADT plugin could accidentally introduce these into the file, and when editing the file, the editor could produce confusing visual artifacts.
This detector looks for invalid line endings with repeated carriage return characters (without newlines). Previous versions of the ADT plugin could accidentally introduce these into the file, and when editing the file, the editor could produce confusing visual artifacts.
MinSdkTooLow
Disabled By: Default
The value of the
Note: This issue has an associated quickfix operation in Android Studio and IntelliJ IDEA.
minSdkVersion
property is too low and can be incremented without noticeably reducing the number of supported devices.Note: This issue has an associated quickfix operation in Android Studio and IntelliJ IDEA.
NegativeMargin
Disabled By: Default
Margin values should be positive. Negative values are generally a sign that you are making assumptions about views surrounding the current one, or may be tempted to turn off child clipping to allow a view to escape its parent. Turning off child clipping to do this not only leads to poor graphical performance, it also results in wrong touch event handling since touch events are based strictly on a chain of parent-rect hit tests. Finally, making assumptions about the size of strings can lead to localization problems.
NewerVersionAvailable
Disabled By: Default
This detector checks with a central repository to see if there are newer versions available for the dependencies used by this project. This is similar to the
Note: This issue has an associated quickfix operation in Android Studio and IntelliJ IDEA.
GradleDependency
check, which checks for newer versions available in the Android SDK tools and libraries, but this works with any MavenCentral dependency, and connects to the library every time, which makes it more flexible but also much slower.Note: This issue has an associated quickfix operation in Android Studio and IntelliJ IDEA.
NoHardKeywords
Disabled By: Default
Do not use Kotlin’s hard keywords as the name of methods or fields. These require the use of backticks to escape when calling from Kotlin. Soft keywords, modifier keywords, and special identifiers are allowed.
For example, ActionEvent's
For example, ActionEvent's
getWhen()
method requires backticks when used from Kotlin:
val timestamp = event.`when`
NoOp
Disabled By: Default
This check looks for code which looks like it's a no-op -- usually leftover expressions from interactive debugging, but in some cases bugs where you had intended to do something with the expression such as assign it to a field.
This check can be configured via the following options:
This check can be configured via the following options:
pure-getters (default is false):
Whether to assume methods with getter-names have no side effects.
Getter methods (where names start with
To configure this option, use a `lint.xml` file in the project or source folder using an
Whether to assume methods with getter-names have no side effects.
Getter methods (where names start with
get
or is
, and have non-void return types, and no arguments) should not have side effects. With this option turned on, lint will assume that is the case and will list any getter calls whose results are ignored as suspicious code.To configure this option, use a `lint.xml` file in the project or source folder using an
<option>
block like the following:
1 <lint> 2 <issue id="NoOp"> 3 <option name="pure-getters" value="false" /> 4 </issue> 5 </lint>
PermissionNamingConvention
Disabled By: Default
Permissions should be prefixed with an app's package name, using reverse-domain-style naming. This prefix should be followed by
Following this recommendation avoids naming collisions, and helps clearly identify the owner and intention of a custom permission.
.permission.
, and then a description of the capability that the permission represents, in upper SNAKE_CASE. For example, com.example.myapp.permission.ENGAGE_HYPERSPACE
.Following this recommendation avoids naming collisions, and helps clearly identify the owner and intention of a custom permission.
Registered
Disabled By: Default
Activities, services and content providers should be registered in the
If your activity is simply a parent class intended to be subclassed by other "real" activities, make it an abstract class.
AndroidManifest.xml
file using <activity>
, <service>
and <provider>
tags.If your activity is simply a parent class intended to be subclassed by other "real" activities, make it an abstract class.
RequiredSize
Disabled By: Default
All views must specify an explicit
It's possible to specify these widths via styles as well. GridLayout, as a special case, does not require you to specify a size.
layout_width
and layout_height
attribute. There is a runtime check for this, so if you fail to specify a size, an exception is thrown at runtime.It's possible to specify these widths via styles as well. GridLayout, as a special case, does not require you to specify a size.
SelectableText
Disabled By: Default
If a
This lint check looks for TextViews which are likely to be displaying data: views whose text is set dynamically.
Note: This issue has an associated quickfix operation in Android Studio and IntelliJ IDEA.
<TextView>
is used to display data, the user might want to copy that data and paste it elsewhere. To allow this, the <TextView>
should specify android:textIsSelectable="true"
.This lint check looks for TextViews which are likely to be displaying data: views whose text is set dynamically.
Note: This issue has an associated quickfix operation in Android Studio and IntelliJ IDEA.
StopShip
Disabled By: Default
Using the comment
In Kotlin, the
Note: This issue has an associated quickfix operation in Android Studio and IntelliJ IDEA.
// STOPSHIP
can be used to flag code that is incomplete but checked in. This comment marker can be used to indicate that the code should not be shipped until the issue is addressed, and lint will look for these. In Gradle projects, this is only checked for non-debug (release) builds.In Kotlin, the
TODO()
method is also treated as a stop ship marker; you can use it to make incomplete code compile, but it will throw an exception at runtime and therefore should be fixed before shipping releases.Note: This issue has an associated quickfix operation in Android Studio and IntelliJ IDEA.
StringFormatTrivial
Disabled By: Default
Every call to
String.format
creates a new Formatter
instance, which will decrease the performance of your app. String.format
should only be used when necessary--if the formatted string contains only trivial conversions (e.g. b
, s
, c
) and there are no translation concerns, it will be more efficient to replace them and concatenate with +
.SyntheticAccessor
Disabled By: Default
A private inner class which is accessed from the outer class will force the compiler to insert a synthetic accessor; this means that you are causing extra overhead. This is not important in small projects, but is important for large apps running up against the 64K method handle limit, and especially for libraries where you want to make sure your library is as small as possible for the cases where your library is used in an app running up against the 64K limit.
Note: This issue has an associated quickfix operation in Android Studio and IntelliJ IDEA.
Note: This issue has an associated quickfix operation in Android Studio and IntelliJ IDEA.
TypographyQuotes
Disabled By: Default
Straight single quotes and double quotes, when used as a pair, can be replaced by "curvy quotes" (or directional quotes). Use the right single quotation mark for apostrophes. Never use generic quotes ", ' or free-standing accents `, ยด for quotation marks, apostrophes, or primes. This can make the text more readable.
More info: https://en.wikipedia.org/wiki/Quotation_mark
Note: This issue has an associated quickfix operation in Android Studio and IntelliJ IDEA.UnknownNullness
Disabled By: Default
To improve referencing this code from Kotlin, consider adding explicit nullness information here with either
This check can be configured via the following options:
@NonNull
or @Nullable
.This check can be configured via the following options:
ignore-deprecated (default is false):
Whether to ignore classes and members that have been annotated with
Normally this lint check will flag all unannotated elements, but by setting this option to
To configure this option, use a `lint.xml` file in the project or source folder using an
Note: This issue has an associated quickfix operation in Android Studio and IntelliJ IDEA.Whether to ignore classes and members that have been annotated with
@Deprecated
.Normally this lint check will flag all unannotated elements, but by setting this option to
true
it will skip any deprecated elements.To configure this option, use a `lint.xml` file in the project or source folder using an
<option>
block like the following:
1 <lint> 2 <issue id="UnknownNullness"> 3 <option name="ignore-deprecated" value="false" /> 4 </issue> 5 </lint>
UnsupportedChromeOsHardware
Disabled By: Default
The
Note: This issue has an associated quickfix operation in Android Studio and IntelliJ IDEA.
<uses-feature>
element should not require this unsupported large screen hardware feature. Any <uses-feature> not explicitly marked with required="false"
is necessary on the device to be installed on. Ensure that any features that might prevent it from being installed on a ChromeOS, large screen, or foldable device are reviewed and marked as not required in the manifest.Note: This issue has an associated quickfix operation in Android Studio and IntelliJ IDEA.
UnusedIds
Disabled By: Default
This resource id definition appears not to be needed since it is not referenced from anywhere. Having id definitions, even if unused, is not necessarily a bad idea since they make working on layouts and menus easier, so there is not a strong reason to delete these.
The unused resource check can ignore tests. If you want to include resources that are only referenced from tests, consider packaging them in a test source set instead.
You can include test sources in the unused resource check by setting the system property lint.unused-resources.include-tests =true, and to exclude them (usually for performance reasons), use lint.unused-resources.exclude-tests =true.
Note: This issue has an associated quickfix operation in Android Studio and IntelliJ IDEA.
The unused resource check can ignore tests. If you want to include resources that are only referenced from tests, consider packaging them in a test source set instead.
You can include test sources in the unused resource check by setting the system property lint.unused-resources.include-tests =true, and to exclude them (usually for performance reasons), use lint.unused-resources.exclude-tests =true.
Note: This issue has an associated quickfix operation in Android Studio and IntelliJ IDEA.
ValidActionsXml
Disabled By: Default
Ensures that an actions XML file is properly formed
Note: This issue has an associated quickfix operation in Android Studio and IntelliJ IDEA.
Note: This issue has an associated quickfix operation in Android Studio and IntelliJ IDEA.
VulnerableCordovaVersion
Disabled By: Default
The version of Cordova used in the app is vulnerable to security issues. Please update to the latest Apache Cordova version.
WrongThreadInterprocedural
Disabled By: Default
Searches for interprocedural call paths that violate thread annotations in the program. Tracks the flow of instantiated types and lambda expressions to increase accuracy across method boundaries.
Suppressing Warnings and Errors
Lint errors can be suppressed in a variety of ways:
1. With a
2. With a
3. With a //noinspection comment in the source code
4. With ignore flags specified in the
5. With a
6. With a
7. With the --ignore flag passed to lint.
To suppress a lint warning with an annotation, add a
To suppress a lint warning with a comment, add a
To suppress a lint warning in an XML file, add a
To suppress a lint warning in a
Here we specify a comma separated list of issue id's after the disable command. You can also use
To suppress lint warnings with a configuration XML file, create a file named
The format of the
To suppress lint checks from the command line, pass the --ignore flag with a comma separated list of ids to be suppressed, such as:
For more information, see https://developer.android.com/studio/write/lint.html#config
1. With a
@SuppressLint
annotation in the Java code2. With a
tools:ignore
attribute in the XML file3. With a //noinspection comment in the source code
4. With ignore flags specified in the
build.gradle
file, as explained below5. With a
lint.xml
configuration file in the project6. With a
lint.xml
configuration file passed to lint via the --config flag7. With the --ignore flag passed to lint.
To suppress a lint warning with an annotation, add a
@SuppressLint("id")
annotation on the class, method or variable declaration closest to the warning instance you want to disable. The id can be one or more issue id's, such as "UnusedResources"
or {"UnusedResources","UnusedIds"}
, or it can be "all"
to suppress all lint warnings in the given scope.To suppress a lint warning with a comment, add a
//noinspection id
comment on the line before the statement with the error.To suppress a lint warning in an XML file, add a
tools:ignore="id"
attribute on the element containing the error, or one of its surrounding elements. You also need to define the namespace for the tools prefix on the root element in your document, next to the xmlns:android
declaration:xmlns:tools="http://schemas.android.com/tools"
To suppress a lint warning in a
build.gradle
file, add a section like this:android { lintOptions { disable 'TypographyFractions','TypographyQuotes' } }
Here we specify a comma separated list of issue id's after the disable command. You can also use
warning
or error
instead of disable
to change the severity of issues.To suppress lint warnings with a configuration XML file, create a file named
lint.xml
and place it at the root directory of the module in which it applies.The format of the
lint.xml
file is something like the following:<?xml version="1.0" encoding="UTF-8"?> <lint> <!-- Ignore everything in the test source set --> <issue id="all"> <ignore path="\*/test/\*" /> </issue> <!-- Disable this given check in this project --> <issue id="IconMissingDensityFolder" severity="ignore" /> <!-- Ignore the ObsoleteLayoutParam issue in the given files --> <issue id="ObsoleteLayoutParam"> <ignore path="res/layout/activation.xml" /> <ignore path="res/layout-xlarge/activation.xml" /> <ignore regexp="(foo|bar)\.java" /> </issue> <!-- Ignore the UselessLeaf issue in the given file --> <issue id="UselessLeaf"> <ignore path="res/layout/main.xml" /> </issue> <!-- Change the severity of hardcoded strings to "error" --> <issue id="HardcodedText" severity="error" /> </lint>
To suppress lint checks from the command line, pass the --ignore flag with a comma separated list of ids to be suppressed, such as:
$ lint --ignore UnusedResources,UselessLeaf /my/project/path
For more information, see https://developer.android.com/studio/write/lint.html#config