Lint Report

Overview

	Correctness
1	UnusedAttribute: Attribute unused on older versions
1	DiscouragedApi: Using discouraged APIs
	Security
1	DataExtractionRules: Missing data extraction rules
	Performance
1	ObsoleteSdkInt: Obsolete SDK_INT Version Check
	Usability:Icons
1	MonochromeLauncherIcon: Monochrome icon is not defined
	Disabled Checks (40)

Attribute unused on older versions

../../src/main/AndroidManifest.xml:17: Attribute enableOnBackInvokedCallback is only used in API level 33 and higher (current min is 30)

 14             android:exported="true"
 15             android:screenOrientation="sensorLandscape"
 16             android:configChanges="orientation|screenSize|keyboardHidden"
 17             android:enableOnBackInvokedCallback="false"                                             
 18             android:windowSoftInputMode="adjustResize">
 19             <intent-filter>
 20                 <action android:name="android.intent.action.MAIN" />

This check finds attributes set in XML files that were introduced in a version newer than the oldest version targeted by your application (with the minSdkVersion attribute).

This is not an error; the application will simply ignore the attribute. However, if the attribute is important to the appearance or functionality of your application, you should consider finding an alternative way to achieve the same result with only available attributes, and then you can optionally create a copy of the layout in a layout-vNN folder which will be used on API NN or higher where you can take advantage of the newer attribute.

Note: This check does not only apply to attributes. For example, some tags can be unused too, such as the new <tag> element in layouts introduced in API 21.
Note: This issue has an associated quickfix operation in Android Studio and IntelliJ IDEA.
To suppress this error, use the issue id "UnusedAttribute" as explained in the Suppressing Warnings and Errors section.

UnusedAttribute Correctness Warning Priority 6/10

Using discouraged APIs

../../src/main/AndroidManifest.xml:15: Fixed screen orientations will be ignored in most cases, starting from Android 16. Android is moving toward a model where apps are expected to adapt to various orientations, display sizes, and aspect ratios.

 12         <activity
 13             android:name="sg.selfservice.bigbait.kitchen.MainActivity"
 14             android:exported="true"
 15             android:screenOrientation="sensorLandscape"                                             
 16             android:configChanges="orientation|screenSize|keyboardHidden"
 17             android:enableOnBackInvokedCallback="false"
 18             android:windowSoftInputMode="adjustResize">

DiscouragedApi Correctness Warning Priority 2/10

Missing data extraction rules

../../src/main/AndroidManifest.xml:9: The attribute android:allowBackup is deprecated from Android 12 and higher and may be removed in future versions. Consider adding the attribute android:dataExtractionRules specifying an @xml resource which configures cloud backups and device transfers on Android 12 and higher.

  6         android:icon="@mipmap/ic_launcher"
  7         android:roundIcon="@mipmap/ic_launcher"
  8         android:theme="@style/KitchenTheme"
  9         android:allowBackup="false"                                                                 
 10         android:usesCleartextTraffic="false"
 11         android:supportsRtl="true">
 12         <activity

Before Android 12, the attributes android:allowBackup and android:fullBackupContent were used to configure all forms of backup, including cloud backups, device-to-device transfers and adb backup.

In Android 12 and higher, these attributes have been deprecated and will only apply to cloud backups. You should instead use the attribute android:dataExtractionRules, specifying an @xml resource that configures which files to back up, for cloud backups and for device-to-device transfers, separately. If your minSdkVersion supports older versions, you'll still want to specify an android:fullBackupContent resource if the default behavior is not right for your app.

More info:

Note: This issue has an associated quickfix operation in Android Studio and IntelliJ IDEA.
To suppress this error, use the issue id "DataExtractionRules" as explained in the Suppressing Warnings and Errors section.

DataExtractionRules Security Warning Priority 3/10

Obsolete SDK_INT Version Check

../../src/main/res/mipmap-anydpi-v26: This folder configuration (v26) is unnecessary; minSdkVersion is 30. Merge all the resources in this folder into mipmap-anydpi.

This check flags version checks that are not necessary, because the minSdkVersion (or surrounding known API level) is already at least as high as the version checked for.

Similarly, it also looks for resources in -vNN folders, such as values-v14 where the version qualifier is less than or equal to the minSdkVersion, where the contents should be merged into the best folder.
Note: This issue has an associated quickfix operation in Android Studio and IntelliJ IDEA.
To suppress this error, use the issue id "ObsoleteSdkInt" as explained in the Suppressing Warnings and Errors section.

ObsoleteSdkInt Performance Warning Priority 6/10

Monochrome icon is not defined

../../src/main/res/mipmap-anydpi-v26/ic_launcher.xml:2: The application adaptive icon is missing a monochrome tag

 1 <?xml version="1.0" encoding="utf-8"?>
 2 <adaptive-icon xmlns:android="http://schemas.android.com/apk/res/android">                          
 3     <background android:drawable="@color/icon_background" />
 4     <foreground android:drawable="@drawable/ic_kitchen" />
 5 </adaptive-icon>

The system may use the coloring of the user's chosen wallpaper and theme to tint app icons. Providing a <monochrome> layer (which will be used for tinting) for every adaptive icon is strongly recommended, otherwise Android 16 QPR 2 and above will simply tint the color version of the icon, which may look unusual. Devices running earlier Android versions will (with no monochrome layer) show the untinted color icon for your app, which will look inconsistent.
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

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, getSupportActionBar() instead of getActionBar(). This lint check looks for calls to the wrong method.

More info: https://developer.android.com/topic/libraries/support-library/

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.

More info: https://d.android.com/r/studio-ui/designer/material/design

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.

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 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 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.

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 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.

More info: https://d.android.com/r/studio-ui/designer/material/iconography

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.

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 get prefix or for boolean-returning methods an is prefix can be used.

More info: https://android.github.io/kotlin-guides/interop.html#property-prefixes

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.

More info: https://android.github.io/kotlin-guides/interop.html#lambda-parameters-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 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 PsiEquivalenceUtil.areElementsEquivalent(PsiElement, 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 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.

More info: https://bugs.eclipse.org/bugs/show_bug.cgi?id=375421

MemberExtensionConflict

Disabled By: Default

When both member and extension declarations are applicable, the resolution takes the member. This also implies that, if an extension existed first, but then a member is added later, the same call-site may end up with different call resolutions depending on target environment. This results in a potential runtime exception if the generated binary (library or app) targets earlier environment (i.e., without the new member, but only extension). More concrete example is found at: https://issuetracker.google.com/issues/350432371

MinSdkTooLow

Disabled By: Default

The value of the 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.

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 getWhen() method requires backticks when used from Kotlin:

val timestamp = event.`when`

More info: https://android.github.io/kotlin-guides/interop.html#no-hard-keywords

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:

pure-getters (default is false):
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 .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.

ReflectionAnnotation

Disabled By: Default

When methods are using reflection to access APIs, they should declare what APIs they are accessing using the new @UsesReflectionToAccessMethod and @UsesReflectionToAccessField annotations. This makes it possible for the shrinker (R8) to correctly remove unused code and resources without accidentally also removing reflectively accessed code, which can lead to program crashes.

Registered

Disabled By: Default

Activities, services and content providers should be registered in the 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.

More info: https://developer.android.com/guide/topics/manifest/manifest-intro.html

RequiredSize

Disabled By: Default

All views must specify an explicit 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 <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 // 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.

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 `, ´ 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 @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 @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>

More info: https://developer.android.com/kotlin/interop#nullability_annotations

Note: This issue has an associated quickfix operation in Android Studio and IntelliJ IDEA.

UnsupportedChromeOsHardware

Disabled By: Default

The <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.

More info: https://developer.android.com/topic/arc/manifest.html#incompat-entries

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.

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.

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.

More info: https://cordova.apache.org/announcements/2015/11/20/security.html

WrongThread

Disabled By: Default

Ensures that a method which expects to be called on a specific thread, is actually called from that thread. For example, calls on methods in widgets should always be made on the UI thread.

More info: https://developer.android.com/guide/components/processes-and-threads.html#Threads

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.

More info: https://developer.android.com/guide/components/processes-and-threads.html#Threads

Suppressing Warnings and Errors

Lint errors can be suppressed in a variety of ways:

1. With a @SuppressLint annotation in the Java code
2. With a tools:ignore attribute in the XML file
3. With a //noinspection comment in the source code
4. With ignore flags specified in the build.gradle file, as explained below
5. With a lint.xml configuration file in the project
6. With a lint.xml configuration file passed to lint via the --config flag
7. 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