diff --git a/Jenkinsfile b/Jenkinsfile
index d0ecd8e85a..7910c3890d 100644
--- a/Jenkinsfile
+++ b/Jenkinsfile
@@ -1,5 +1,45 @@
 #!groovy
 
+class DockerParameters {
+
+    // 'docker build' would normally copy the whole build-dir to the container, changing the
+    // docker build directory avoids that overhead
+    def dir = 'docker'
+    def args = '--device /dev/kvm:/dev/kvm -v /var/local/container_shared/gradle_cache/$EXECUTOR_NUMBER:/home/user/.gradle -m=6.5G'
+    def label = 'LimitedEmulator'
+    def image = 'floriankanduth/paintroid_java17:latest'
+
+}
+
+def dockerParameters = new DockerParameters()
+
+def startEmulator(String android_version, String stageName) {
+    sh 'adb start-server'
+    // creates a new avd, and if it already exists it does nothing.
+    sh "echo no | avdmanager create avd --force --name android${android_version}" + " --package 'system-images;android-${android_version};default;x86_64'"
+    sh "/home/user/android/sdk/emulator/emulator -no-window -no-boot-anim -noaudio -avd android${android_version} > ${stageName}_emulator.log 2>&1 &"
+}
+
+def waitForEmulatorAndPressWakeUpKey() {
+    sh 'adb devices'
+    sh 'timeout 5m adb wait-for-device'
+    sh '''#!/bin/bash
+adb devices
+timeout 5m adb wait-for-device shell 'while [[ -z $(getprop sys.boot_completed) ]]; do sleep 1;
+done'
+echo "Emulator started"
+'''
+    sh '''
+        adb shell settings put global window_animation_scale 0 &
+        adb shell settings put global transition_animation_scale 0 &
+        adb shell settings put global animator_duration_scale 0 &
+    '''
+
+
+    // In case the device went to sleep
+    sh 'adb shell input keyevent KEYCODE_WAKEUP'
+}
+
 def reports = 'Paintroid/build/reports'
 
 // place the cobertura xml relative to the source, so that the source can be found
@@ -22,7 +62,21 @@ def useDebugLabelParameter(defaultLabel) {
     return env.DEBUG_LABEL?.trim() ? env.DEBUG_LABEL : defaultLabel
 }
 
+def checkAnimationScale(scaleName) {
+        def output = sh(script: "adb shell settings get global ${scaleName}", returnStdout: true).trim()
+        if (output != "0" && output != "0.0") {
+            error("Animation scale '${scaleName}' is NOT disabled. Current value: ${output}")
+        } else {
+            echo("Animation scale '${scaleName}' is disabled (Value: ${output})")
+        }
+    }
+
 pipeline {
+    environment {
+        ANDROID_VERSION = 33
+        ADB_INSTALL_TIMEOUT = 60
+    }
+
     parameters {
         string name: 'DEBUG_LABEL', defaultValue: '', description: 'For debugging when entered will be used as label to decide on which slaves the jobs will run.'
         booleanParam name: 'BUILD_WITH_CATROID', defaultValue: false, description: 'When checked then the current Paintroid build will be built with the current develop branch of Catroid'
@@ -30,10 +84,10 @@ pipeline {
     }
 
     agent {
-         docker {
-            image 'catrobat/catrobat-paintroid:stable'
-            args '--device /dev/kvm:/dev/kvm -v /var/local/container_shared/gradle_cache/$EXECUTOR_NUMBER:/home/user/.gradle -m=6.5G'
-            label 'LimitedEmulator'
+        docker {
+            image dockerParameters.image
+            args dockerParameters.args
+            label dockerParameters.label
             alwaysPull true
         }
     }
@@ -70,14 +124,14 @@ pipeline {
                 sh 'rm -rf Catroid; mkdir Catroid'
                 dir('Catroid') {
                     git branch: params.CATROID_BRANCH, url: 'https://github.com/Catrobat/Catroid.git'
-                    sh "rm -f catroid/src/main/libs/*.aar"
-                    sh "mv -f ../colorpicker/build/outputs/aar/colorpicker-debug.aar catroid/src/main/libs/colorpicker-LOCAL.aar"
-                    sh "mv -f ../Paintroid/build/outputs/aar/Paintroid-debug.aar catroid/src/main/libs/Paintroid-LOCAL.aar"
+                    sh 'rm -f catroid/src/main/libs/*.aar'
+                    sh 'mv -f ../colorpicker/build/outputs/aar/colorpicker-debug.aar catroid/src/main/libs/colorpicker-LOCAL.aar'
+                    sh 'mv -f ../Paintroid/build/outputs/aar/Paintroid-debug.aar catroid/src/main/libs/Paintroid-LOCAL.aar'
                 }
                 renameApks("${env.BRANCH_NAME}-${env.BUILD_NUMBER}")
                 dir('Catroid') {
-                    archiveArtifacts "catroid/src/main/libs/*.aar"
-                    sh "./gradlew assembleCatroidDebug"
+                    archiveArtifacts 'catroid/src/main/libs/*.aar'
+                    sh './gradlew assembleCatroidDebug'
                     archiveArtifacts 'catroid/build/outputs/apk/catroid/debug/catroid-catroid-debug.apk'
                 }
             }
@@ -114,9 +168,16 @@ pipeline {
 
                 stage('Device Tests') {
                     steps {
-                        sh "echo no | avdmanager create avd --force --name android28 --package 'system-images;android-28;default;x86_64'"
-                        sh "/home/user/android/sdk/emulator/emulator -no-window -no-boot-anim -noaudio -avd android28 > /dev/null 2>&1 &"
-                        sh './gradlew -PenableCoverage -Pjenkins -Pemulator=android28 -Pci createDebugCoverageReport -i'
+                        catchError(buildResult: 'SUCCESS', stageResult: 'FAILURE') {
+                            startEmulator(ANDROID_VERSION, 'device_tests')
+                            waitForEmulatorAndPressWakeUpKey()
+                            script {
+                                checkAnimationScale("window_animation_scale")
+                                checkAnimationScale("transition_animation_scale")
+                                checkAnimationScale("animator_duration_scale")
+                            }
+                            sh "./gradlew disableAnimations -PenableCoverage -Pjenkins -Pemulator=android${android_version} -Pci createDebugCoverageReport -i"
+                        }
                     }
                     post {
                         always {
@@ -145,4 +206,4 @@ pipeline {
             notifyChat()
         }
     }
-}
+}
\ No newline at end of file
diff --git a/Paintroid/build.gradle b/Paintroid/build.gradle
index 9ffbde1915..c0c90f81c2 100644
--- a/Paintroid/build.gradle
+++ b/Paintroid/build.gradle
@@ -17,35 +17,33 @@
  *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-apply plugin: 'com.android.library'
-apply plugin: 'com.hiya.jacoco-android'
-apply plugin: 'com.getkeepsafe.dexcount'
-apply plugin: 'kotlin-android'
-apply plugin: 'org.catrobat.gradle.androidemulators'
-apply plugin: 'maven-publish'
+plugins {
+    id "com.android.library"
+    id "jacoco"
+    id "com.getkeepsafe.dexcount"
+    id "org.jetbrains.kotlin.android"
+    id "org.catrobat.gradle.androidemulators"
+    id "maven-publish"
+}
 
-apply from: 'gradle/adb_tasks.gradle'
-apply from: 'gradle/code_quality_tasks.gradle'
+apply from: "gradle/adb_tasks.gradle"
+apply from: "gradle/code_quality_tasks.gradle"
 
 emulators {
-    install project.hasProperty('installSdk')
-
-    dependencies {
-        sdk()
-    }
+    install project.hasProperty("installSdk")
+    dependencies { sdk() }
 
-    emulator 'android28', {
+    emulator "android28", {
         avd {
-            systemImage = 'system-images;android-28;default;x86_64'
+            systemImage = "system-images;android-28;default;x86_64"
             sdcardSizeMb = 1024
-            hardwareProperties += ['hw.ramSize': 4096, 'vm.heapSize': 1024]
-            screenDensity = 'xhdpi'
+            hardwareProperties += ["hw.ramSize": 4096, "vm.heapSize": 1024]
+            screenDensity = "xhdpi"
         }
-
         parameters {
-            resolution = '768x1280'
-            language = 'en'
-            country = 'US'
+            resolution = "768x1280"
+            language = "en"
+            country = "US"
         }
     }
 }
@@ -54,54 +52,50 @@ jacoco {
     toolVersion = "0.8.7"
 }
 
-jacocoAndroidUnitTestReport {
-    csv.enabled false
-    html.enabled true
-    xml.enabled true
-    destination project.getBuildDir().getPath() + "/reports/jacoco/jacocoTestDebugUnitTestReport"
-}
-
 android {
-    compileSdkVersion rootProject.ext.androidCompileSdkVersion
+    namespace "org.catrobat.paintroid"
+
+    // New AGP DSL
+    compileSdk = rootProject.ext.androidCompileSdkVersion
 
     defaultConfig {
-        minSdkVersion rootProject.ext.androidMinSdkVersion
-        targetSdkVersion rootProject.ext.androidTargetSdkVersion
-        testInstrumentationRunner 'androidx.test.runner.AndroidJUnitRunner'
-        versionCode rootProject.ext.androidVersionCode
-        versionName rootProject.ext.androidVersionName
+        minSdk    = rootProject.ext.androidMinSdkVersion
+        targetSdk = rootProject.ext.androidTargetSdkVersion
+        testInstrumentationRunner = "androidx.test.runner.AndroidJUnitRunner"
+    }
+
+    buildFeatures {
+        buildConfig = true
     }
 
     compileOptions {
-        sourceCompatibility JavaVersion.VERSION_11
-        targetCompatibility JavaVersion.VERSION_11
+        sourceCompatibility = JavaVersion.VERSION_17
+        targetCompatibility = JavaVersion.VERSION_17
     }
+    kotlinOptions { jvmTarget = "17" }
 
     buildTypes {
         release {
-            minifyEnabled false
-            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
-        }
-        signedRelease {
+            minifyEnabled = false
+            proguardFiles(
+                    getDefaultProguardFile("proguard-android.txt"),
+                    "proguard-rules.pro"
+            )
         }
+        create("signedRelease")
         debug {
-            testCoverageEnabled = project.hasProperty('enableCoverage')
-            // Multidex is required as espresso and mockito/bytebuddy are adding more functions
-            // than should be allowed by law.
-            // See https://github.com/mockito/mockito/issues/1112
-            multiDexEnabled true
         }
     }
 
-    lintOptions {
-        // specific ignores should be defined via lint.xml file
-        lintConfig file('config/lint.xml')
-        ignore 'ClickableViewAccessibility', 'StaticFieldLeak', 'GradleDependency', 'OldTargetApi', 'LintBaseline'
-        textReport true
-        xmlReport true
-        htmlReport true
-        xmlOutput file("build/reports/lint-report.xml")
-        htmlOutput file("build/reports/lint-report.html")
+    lint {
+        lintConfig file("config/lint.xml")
+        disable "ClickableViewAccessibility", "StaticFieldLeak",
+                "GradleDependency", "OldTargetApi", "LintBaseline"
+        textReport = true
+        xmlReport  = true
+        htmlReport = true
+        xmlOutput  = file("build/reports/lint-report.xml")
+        htmlOutput = file("build/reports/lint-report.html")
     }
 
     testOptions {
@@ -111,54 +105,51 @@ android {
 
     packagingOptions {
         resources {
-            excludes += ['META-INF/AL2.0', 'META-INF/LGPL2.1', "**/attach_hotspot_windows.dll"]
-            merges += ['META-INF/licenses/ASM']
+            excludes += ["META-INF/AL2.0", "META-INF/LGPL2.1", "**/attach_hotspot_windows.dll"]
+            merges   += ["META-INF/licenses/ASM"]
         }
     }
 }
 
 dependencies {
-    implementation 'androidx.appcompat:appcompat:1.0.0'
-    implementation 'com.google.android.material:material:1.2.1'
-    implementation project(':colorpicker')
+    implementation "androidx.appcompat:appcompat:1.0.0"
+    implementation "com.google.android.material:material:1.2.1"
+    implementation project(":colorpicker")
 
-    implementation 'androidx.core:core-ktx:1.3.2'
+    implementation "androidx.core:core-ktx:1.3.2"
     implementation "org.jetbrains.kotlin:kotlin-stdlib:$kotlin_version"
-    implementation 'org.jetbrains.kotlinx:kotlinx-coroutines-android:1.3.8'
-    implementation 'org.jetbrains.kotlinx:kotlinx-coroutines-core:1.3.8'
-    implementation 'androidx.exifinterface:exifinterface:1.3.2'
-    implementation 'com.esotericsoftware:kryo:5.5.0'
-    implementation 'id.zelory:compressor:2.1.1'
-    implementation 'androidx.constraintlayout:constraintlayout:2.1.4'
-
-    debugImplementation 'androidx.multidex:multidex:2.0.0'
-
-    implementation 'com.nostra13.universalimageloader:universal-image-loader:1.9.5'
-    implementation 'com.jraska:falcon:2.2.0'
-
-    testImplementation 'junit:junit:4.12'
-    testImplementation 'org.mockito:mockito-core:2.18.3'
-    testImplementation 'com.nhaarman.mockitokotlin2:mockito-kotlin:2.2.0'
-
-    androidTestImplementation 'org.jetbrains.kotlinx:kotlinx-coroutines-test:1.4.3'
-    androidTestImplementation 'androidx.test.ext:junit:1.1.3'
-    androidTestImplementation 'androidx.test:rules:1.1.1'
-    androidTestImplementation 'org.mockito:mockito-android:3.6.28'
-    androidTestImplementation 'tools.fastlane:screengrab:2.1.0'
-    androidTestImplementation 'com.nhaarman.mockitokotlin2:mockito-kotlin:2.2.0'
-
-    androidTestImplementation 'androidx.test.espresso:espresso-core:3.5.1'
-    androidTestImplementation 'androidx.test.espresso:espresso-contrib:3.1.0'
-    androidTestImplementation 'androidx.test.espresso:espresso-intents:3.1.0'
+    implementation "org.jetbrains.kotlinx:kotlinx-coroutines-android:1.3.8"
+    implementation "org.jetbrains.kotlinx:kotlinx-coroutines-core:1.3.8"
+    implementation "androidx.exifinterface:exifinterface:1.3.2"
+    implementation "com.esotericsoftware:kryo:5.5.0"
+    implementation "id.zelory:compressor:2.1.1"
+    implementation "androidx.constraintlayout:constraintlayout:2.1.4"
+    implementation 'androidx.test:monitor:1.8.0'
+
+    debugImplementation "androidx.multidex:multidex:2.0.0"
+
+    implementation "com.nostra13.universalimageloader:universal-image-loader:1.9.5"
+    implementation "com.jraska:falcon:2.2.0"
+
+    testImplementation "junit:junit:4.12"
+    testImplementation "org.mockito:mockito-core:2.18.3"
+    testImplementation "com.nhaarman.mockitokotlin2:mockito-kotlin:2.2.0"
+
+    androidTestImplementation "org.jetbrains.kotlinx:kotlinx-coroutines-test:1.4.3"
+    androidTestImplementation "androidx.test.ext:junit:1.1.3"
+    androidTestImplementation "androidx.test:rules:1.1.1"
+    androidTestImplementation "org.mockito:mockito-android:3.6.28"
+    androidTestImplementation "tools.fastlane:screengrab:2.1.0"
+    androidTestImplementation "com.nhaarman.mockitokotlin2:mockito-kotlin:2.2.0"
+
+    androidTestImplementation "androidx.test.espresso:espresso-core:3.5.1"
+    androidTestImplementation "androidx.test.espresso:espresso-contrib:3.1.0"
+    androidTestImplementation "androidx.test.espresso:espresso-intents:3.1.0"
     androidTestImplementation "androidx.test.uiautomator:uiautomator:2.2.0"
     testImplementation "androidx.test:core-ktx:1.4.0"
-    implementation 'com.android.support.test.espresso:espresso-idling-resource:3.1.0'
-}
 
-tasks.withType(Javadoc).all {
-    enabled = false
+    implementation "androidx.test.espresso:espresso-idling-resource:3.5.1"
 }
 
-if (project.hasProperty('jenkins')) {
-    android.dexOptions.preDexLibraries = false
-}
+tasks.withType(Javadoc).configureEach { enabled = false }
+
diff --git a/Paintroid/gradle/code_quality_tasks.gradle b/Paintroid/gradle/code_quality_tasks.gradle
index c86a9788de..00d17898e0 100644
--- a/Paintroid/gradle/code_quality_tasks.gradle
+++ b/Paintroid/gradle/code_quality_tasks.gradle
@@ -42,30 +42,30 @@ task checkstyle(type: Checkstyle) {
 
     classpath = files()
 
-    // needed for console output of warnings/errors
-    showViolations true
-    ignoreFailures false
+    // console printing is automatic; use ignoreFailures to fail or not
+    ignoreFailures = false
 
     reports {
-        xml.enabled = true
-        xml.destination file("build/reports/checkstyle.xml")
+        xml.required.set(true)
+        html.required.set(false)
+        xml.outputLocation.set(file("$buildDir/reports/checkstyle.xml"))
     }
 }
 
 task pmd(type: Pmd) {
     ruleSetFiles = files('config/pmd.xml')
-    ruleSets = []
+    ruleSets = [] // don't use built-in default sets
 
     source '.'
     include '**/*.java'
     exclude '**/gen/**', '**/build/**', '**/res/**'
 
-    ignoreFailures false
+    ignoreFailures = false
 
     reports {
-        xml.enabled = true
-        html.enabled = true
-        xml.destination file("build/reports/pmd.xml")
+        xml.required.set(true)
+        html.required.set(true)
+        xml.outputLocation.set(file("$buildDir/reports/pmd.xml"))
     }
 }
 
diff --git a/Paintroid/src/androidTest/java/org/catrobat/paintroid/test/espresso/CatrobatImageIOIntegrationTest.kt b/Paintroid/src/androidTest/java/org/catrobat/paintroid/test/espresso/CatrobatImageIOIntegrationTest.kt
index 86ee6283b3..2fe9b47de3 100644
--- a/Paintroid/src/androidTest/java/org/catrobat/paintroid/test/espresso/CatrobatImageIOIntegrationTest.kt
+++ b/Paintroid/src/androidTest/java/org/catrobat/paintroid/test/espresso/CatrobatImageIOIntegrationTest.kt
@@ -20,7 +20,9 @@
 
 package org.catrobat.paintroid.test.espresso
 
+import android.Manifest
 import android.net.Uri
+import android.os.Build
 import android.os.Environment
 import androidx.test.espresso.Espresso
 import androidx.test.espresso.Espresso.onView
@@ -32,15 +34,14 @@ import androidx.test.espresso.matcher.ViewMatchers.isDisplayed
 import androidx.test.espresso.matcher.ViewMatchers.withId
 import androidx.test.espresso.matcher.ViewMatchers.withText
 import androidx.test.ext.junit.runners.AndroidJUnit4
+import androidx.test.platform.app.InstrumentationRegistry
 import androidx.test.rule.ActivityTestRule
-import androidx.test.rule.GrantPermissionRule
 import org.catrobat.paintroid.FileIO
 import org.catrobat.paintroid.MainActivity
 import org.catrobat.paintroid.command.serialization.CommandSerializer
 import org.catrobat.paintroid.R
 import org.catrobat.paintroid.common.CATROBAT_IMAGE_ENDING
 import org.catrobat.paintroid.test.espresso.util.DrawingSurfaceLocationProvider
-import org.catrobat.paintroid.test.espresso.util.EspressoUtils
 import org.catrobat.paintroid.test.espresso.util.UiInteractions
 import org.catrobat.paintroid.test.espresso.util.wrappers.DrawingSurfaceInteraction.Companion.onDrawingSurfaceView
 import org.catrobat.paintroid.test.espresso.util.wrappers.TopBarViewInteraction
@@ -52,6 +53,7 @@ import org.junit.Assert
 import org.junit.Before
 import org.junit.Rule
 import org.junit.Test
+import org.junit.rules.RuleChain
 import org.junit.runner.RunWith
 import java.io.File
 
@@ -59,14 +61,12 @@ import java.io.File
 class CatrobatImageIOIntegrationTest {
 
     @get:Rule
-    val launchActivityRule = ActivityTestRule(MainActivity::class.java)
+    val launchActivityRule =
+        ActivityTestRule(MainActivity::class.java, true, false)
 
     @get:Rule
     val screenshotOnFailRule = ScreenshotOnFailRule()
 
-    @get:Rule
-    val grantPermissionRule: GrantPermissionRule = EspressoUtils.grantPermissionRulesVersionCheck()
-
     private var uriFile: Uri? = null
     private lateinit var activity: MainActivity
 
@@ -75,12 +75,38 @@ class CatrobatImageIOIntegrationTest {
     }
 
     @Before
-    fun setUp() { activity = launchActivityRule.activity }
+    fun setUp() {
+        val inst = InstrumentationRegistry.getInstrumentation()
+        val targetPkg = inst.targetContext.packageName
+        val perms = when {
+            Build.VERSION.SDK_INT >= 34 -> arrayOf(
+                Manifest.permission.READ_MEDIA_IMAGES,
+                Manifest.permission.READ_MEDIA_VIDEO,
+                "android.permission.READ_MEDIA_VISUAL_USER_SELECTED"
+            )
+            Build.VERSION.SDK_INT >= 33 -> arrayOf(
+                Manifest.permission.READ_MEDIA_IMAGES,
+                Manifest.permission.READ_MEDIA_VIDEO
+            )
+            else -> arrayOf(
+                Manifest.permission.READ_EXTERNAL_STORAGE
+            )
+        }
+        perms.forEach {
+            try {
+                inst.uiAutomation.grantRuntimePermission(targetPkg, it)
+            } catch (_: Exception) {
+            }
+        }
+
+        launchActivityRule.launchActivity(null)
+        activity = launchActivityRule.activity
+    }
 
     @After
     fun tearDown() {
         val imagesDirectory =
-                Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS).toString()
+            Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS).toString()
         val pathToFile = imagesDirectory + File.separator + IMAGE_NAME + "." + CATROBAT_IMAGE_ENDING
         val imageFile = File(pathToFile)
         if (imageFile.exists()) {
diff --git a/Paintroid/src/androidTest/java/org/catrobat/paintroid/test/espresso/LayerBackgroundTest.kt b/Paintroid/src/androidTest/java/org/catrobat/paintroid/test/espresso/LayerBackgroundTest.kt
index bfbf53ff64..d9bf34e538 100644
--- a/Paintroid/src/androidTest/java/org/catrobat/paintroid/test/espresso/LayerBackgroundTest.kt
+++ b/Paintroid/src/androidTest/java/org/catrobat/paintroid/test/espresso/LayerBackgroundTest.kt
@@ -49,7 +49,7 @@ class LayerBackgroundTest(private val language: String) {
     @Test
     fun testOneLayer() {
         var actualBackground = getActualBackground(0)
-        Assert.assertEquals(actualBackground, getSingleBackground()?.constantState)
+        Assert.assertEquals(actualBackground, getSingleBackground().constantState)
     }
 
     @Test
@@ -61,8 +61,8 @@ class LayerBackgroundTest(private val language: String) {
         var backgroundTop = getActualBackground(0)
         var backgroundBottom = getActualBackground(1)
 
-        Assert.assertEquals(backgroundTop, getTopBackground(true)?.constantState)
-        Assert.assertEquals(backgroundBottom, getBottomBackground(false)?.constantState)
+        Assert.assertEquals(backgroundTop, getTopBackground(true).constantState)
+        Assert.assertEquals(backgroundBottom, getBottomBackground(false).constantState)
     }
 
     @Test
@@ -75,8 +75,8 @@ class LayerBackgroundTest(private val language: String) {
         var backgroundTop = getActualBackground(0)
         var backgroundBottom = getActualBackground(1)
 
-        Assert.assertEquals(backgroundTop, getTopBackground(false)?.constantState)
-        Assert.assertEquals(backgroundBottom, getBottomBackground(true)?.constantState)
+        Assert.assertEquals(backgroundTop, getTopBackground(false).constantState)
+        Assert.assertEquals(backgroundBottom, getBottomBackground(true).constantState)
     }
 
     @Test
@@ -90,9 +90,9 @@ class LayerBackgroundTest(private val language: String) {
         var backgroundCenter = getActualBackground(1)
         var backgroundBottom = getActualBackground(2)
 
-        Assert.assertEquals(backgroundTop, getTopBackground(true)?.constantState)
+        Assert.assertEquals(backgroundTop, getTopBackground(true).constantState)
         Assert.assertEquals(backgroundCenter, getCenterBackground(false)?.constantState)
-        Assert.assertEquals(backgroundBottom, getBottomBackground(false)?.constantState)
+        Assert.assertEquals(backgroundBottom, getBottomBackground(false).constantState)
     }
 
     @Test
@@ -107,9 +107,9 @@ class LayerBackgroundTest(private val language: String) {
         var backgroundCenter = getActualBackground(1)
         var backgroundBottom = getActualBackground(2)
 
-        Assert.assertEquals(backgroundTop, getTopBackground(false)?.constantState)
+        Assert.assertEquals(backgroundTop, getTopBackground(false).constantState)
         Assert.assertEquals(backgroundCenter, getCenterBackground(true)?.constantState)
-        Assert.assertEquals(backgroundBottom, getBottomBackground(false)?.constantState)
+        Assert.assertEquals(backgroundBottom, getBottomBackground(false).constantState)
     }
 
     @Test
@@ -125,9 +125,9 @@ class LayerBackgroundTest(private val language: String) {
         var backgroundCenter = getActualBackground(1)
         var backgroundBottom = getActualBackground(2)
 
-        Assert.assertEquals(backgroundTop, getTopBackground(false)?.constantState)
+        Assert.assertEquals(backgroundTop, getTopBackground(false).constantState)
         Assert.assertEquals(backgroundCenter, getCenterBackground(false)?.constantState)
-        Assert.assertEquals(backgroundBottom, getBottomBackground(true)?.constantState)
+        Assert.assertEquals(backgroundBottom, getBottomBackground(true).constantState)
     }
 
     @Test
@@ -143,10 +143,10 @@ class LayerBackgroundTest(private val language: String) {
         val backgroundLowerCenter = getActualBackground(2)
         val backgroundBottom = getActualBackground(3)
 
-        Assert.assertEquals(backgroundTop, getTopBackground(true)?.constantState)
+        Assert.assertEquals(backgroundTop, getTopBackground(true).constantState)
         Assert.assertEquals(backgroundUpperCenter, getCenterBackground(false)?.constantState)
         Assert.assertEquals(backgroundLowerCenter, getCenterBackground(false)?.constantState)
-        Assert.assertEquals(backgroundBottom, getBottomBackground(false)?.constantState)
+        Assert.assertEquals(backgroundBottom, getBottomBackground(false).constantState)
     }
 
     @Test
@@ -163,10 +163,10 @@ class LayerBackgroundTest(private val language: String) {
         val backgroundLowerCenter = getActualBackground(2)
         val backgroundBottom = getActualBackground(3)
 
-        Assert.assertEquals(backgroundTop, getTopBackground(false)?.constantState)
+        Assert.assertEquals(backgroundTop, getTopBackground(false).constantState)
         Assert.assertEquals(backgroundUpperCenter, getCenterBackground(true)?.constantState)
         Assert.assertEquals(backgroundLowerCenter, getCenterBackground(false)?.constantState)
-        Assert.assertEquals(backgroundBottom, getBottomBackground(false)?.constantState)
+        Assert.assertEquals(backgroundBottom, getBottomBackground(false).constantState)
     }
 
     @Test
@@ -184,10 +184,10 @@ class LayerBackgroundTest(private val language: String) {
         val backgroundLowerCenter = getActualBackground(2)
         val backgroundBottom = getActualBackground(3)
 
-        Assert.assertEquals(backgroundTop, getTopBackground(false)?.constantState)
+        Assert.assertEquals(backgroundTop, getTopBackground(false).constantState)
         Assert.assertEquals(backgroundUpperCenter, getCenterBackground(false)?.constantState)
         Assert.assertEquals(backgroundLowerCenter, getCenterBackground(true)?.constantState)
-        Assert.assertEquals(backgroundBottom, getBottomBackground(false)?.constantState)
+        Assert.assertEquals(backgroundBottom, getBottomBackground(false).constantState)
     }
 
     @Test
@@ -205,14 +205,14 @@ class LayerBackgroundTest(private val language: String) {
         val backgroundLowerCenter = getActualBackground(2)
         val backgroundBottom = getActualBackground(3)
 
-        Assert.assertEquals(backgroundTop, getTopBackground(false)?.constantState)
+        Assert.assertEquals(backgroundTop, getTopBackground(false).constantState)
         Assert.assertEquals(backgroundUpperCenter, getCenterBackground(false)?.constantState)
         Assert.assertEquals(backgroundLowerCenter, getCenterBackground(false)?.constantState)
-        Assert.assertEquals(backgroundBottom, getBottomBackground(true)?.constantState)
+        Assert.assertEquals(backgroundBottom, getBottomBackground(true).constantState)
     }
 
     private fun getActualBackground(position: Int): Drawable.ConstantState? {
-        val layout = layerAdapter?.getViewHolderAt(position)?.getViewLayout()
+        val layout = layerAdapter.getViewHolderAt(position)?.getViewLayout()
         return layout?.background?.constantState
     }
 
diff --git a/Paintroid/src/androidTest/java/org/catrobat/paintroid/test/espresso/OraFileIntentTest.kt b/Paintroid/src/androidTest/java/org/catrobat/paintroid/test/espresso/OraFileIntentTest.kt
index bad8c3b90c..1a6cb40583 100644
--- a/Paintroid/src/androidTest/java/org/catrobat/paintroid/test/espresso/OraFileIntentTest.kt
+++ b/Paintroid/src/androidTest/java/org/catrobat/paintroid/test/espresso/OraFileIntentTest.kt
@@ -124,7 +124,7 @@ class OraFileIntentTest {
         } catch (e: IOException) {
             throw AssertionError("Picture file could not be created.", e)
         }
-        val imageFile = File(imageUri!!.path, "testfile.ora")
+        val imageFile = File(imageUri.path, "testfile.ora")
         deletionFileList!!.add(imageFile)
         return imageUri
     }
diff --git a/Paintroid/src/androidTest/java/org/catrobat/paintroid/test/espresso/SaveCompressImageIntegrationTest.kt b/Paintroid/src/androidTest/java/org/catrobat/paintroid/test/espresso/SaveCompressImageIntegrationTest.kt
index 8695392047..ed66b8fe93 100644
--- a/Paintroid/src/androidTest/java/org/catrobat/paintroid/test/espresso/SaveCompressImageIntegrationTest.kt
+++ b/Paintroid/src/androidTest/java/org/catrobat/paintroid/test/espresso/SaveCompressImageIntegrationTest.kt
@@ -119,11 +119,12 @@ class SaveCompressImageIntegrationTest {
 
         val options = BitmapFactory.Options()
         options.inMutable = true
-        val compressedBitmap = Objects.requireNonNull(
-            activity?.model?.savedPictureUri
-        )?.let {
-            activity?.let { it1 ->
-                getScaledBitmapFromUri(it1.contentResolver, it, activity?.applicationContext)
+        val savedUri = activity?.model?.savedPictureUri
+        Assert.assertNotNull("Saved picture URI should not be null", savedUri) // Fail test if null
+
+        val compressedBitmap = savedUri?.let { uri -> // 'uri' is now non-nullable Uri
+            activity?.let { activityNonNull ->
+                getScaledBitmapFromUri(activityNonNull.contentResolver, uri, activityNonNull.applicationContext)
             }
         }
         val testBitmap = getBitmapFromFile(testImageFile)
diff --git a/Paintroid/src/androidTest/java/org/catrobat/paintroid/test/junit/command/ClipboardCommandTest.kt b/Paintroid/src/androidTest/java/org/catrobat/paintroid/test/junit/command/ClipboardCommandTest.kt
index c4908c687a..e95f7e99b6 100644
--- a/Paintroid/src/androidTest/java/org/catrobat/paintroid/test/junit/command/ClipboardCommandTest.kt
+++ b/Paintroid/src/androidTest/java/org/catrobat/paintroid/test/junit/command/ClipboardCommandTest.kt
@@ -52,7 +52,7 @@ class ClipboardCommandTest {
         val bitmapUnderTest = canvasBitmapUnderTest.copy(Bitmap.Config.ARGB_8888, true)
         val layerUnderTest = Layer(bitmapUnderTest)
         canvasUnderTest = Canvas()
-        canvasUnderTest!!.setBitmap(canvasBitmapUnderTest)
+        canvasUnderTest.setBitmap(canvasBitmapUnderTest)
         pointUnderTest = PointF((INITIAL_WIDTH / 2).toFloat(), (INITIAL_HEIGHT / 2).toFloat())
         layerModel!!.addLayerAt(0, layerUnderTest)
         layerModel!!.currentLayer = layerUnderTest
@@ -70,7 +70,7 @@ class ClipboardCommandTest {
         val model = LayerModel()
         model.addLayerAt(0, layer)
         model.currentLayer = layer
-        commandUnderTest!!.run(canvasUnderTest!!, model)
+        commandUnderTest!!.run(canvasUnderTest, model)
         PaintroidAsserts.assertBitmapEquals(stampBitmapUnderTest, canvasBitmapUnderTest)
         Assert.assertNull("Stamp bitmap not recycled.", commandUnderTest!!.bitmap)
         Assert.assertNotNull("Bitmap not stored", commandUnderTest!!.fileToStoredBitmap)
@@ -78,17 +78,18 @@ class ClipboardCommandTest {
         val secondModel = LayerModel()
         secondModel.addLayerAt(0, secondLayer)
         secondModel.currentLayer = secondLayer
-        commandUnderTest!!.run(canvasUnderTest!!, secondModel)
+        commandUnderTest!!.run(canvasUnderTest, secondModel)
         PaintroidAsserts.assertBitmapEquals(stampBitmapUnderTest, canvasBitmapUnderTest)
     }
 
     @Test
     fun testRunRotateStamp() {
-        stampBitmapUnderTest!!.setPixel(0, 0, Color.GREEN)
-        commandUnderTest = ClipboardCommand(stampBitmapUnderTest!!, Point(pointUnderTest!!.x.toInt(), pointUnderTest!!.y.toInt()), canvasBitmapUnderTest!!.width.toFloat(), canvasBitmapUnderTest!!.height.toFloat(), 180f)
-        commandUnderTest!!.run(canvasUnderTest!!, LayerModel())
-        stampBitmapUnderTest!!.setPixel(0, 0, Color.CYAN)
-        stampBitmapUnderTest!!.setPixel(stampBitmapUnderTest!!.width - 1, stampBitmapUnderTest!!.height - 1,
+        stampBitmapUnderTest.setPixel(0, 0, Color.GREEN)
+        commandUnderTest = ClipboardCommand(stampBitmapUnderTest, Point(pointUnderTest!!.x.toInt(), pointUnderTest!!.y.toInt()), canvasBitmapUnderTest!!.width.toFloat(), canvasBitmapUnderTest!!.height.toFloat(), 180f)
+        commandUnderTest!!.run(canvasUnderTest, LayerModel())
+        stampBitmapUnderTest.setPixel(0, 0, Color.CYAN)
+        stampBitmapUnderTest.setPixel(
+            stampBitmapUnderTest.width - 1, stampBitmapUnderTest.height - 1,
                 Color.GREEN)
         PaintroidAsserts.assertBitmapEquals(stampBitmapUnderTest, canvasBitmapUnderTest)
         Assert.assertNull("Stamp bitmap not recycled.", commandUnderTest!!.bitmap)
@@ -120,7 +121,7 @@ class ClipboardCommandTest {
     fun testStoreBitmap() {
         var storedBitmap: File? = null
         try {
-            val bitmapCopy = canvasBitmapUnderTest!!.copy(canvasBitmapUnderTest!!.config, canvasBitmapUnderTest!!.isMutable)
+            val bitmapCopy = canvasBitmapUnderTest.copy(canvasBitmapUnderTest.config ?: Bitmap.Config.ARGB_8888, canvasBitmapUnderTest.isMutable)
             commandUnderTest!!.storeBitmap(bitmapCopy, bitmapCopy.width.toFloat(), bitmapCopy.height.toFloat())
             storedBitmap = commandUnderTest!!.fileToStoredBitmap
             Assert.assertNotNull(storedBitmap)
diff --git a/Paintroid/src/androidTest/java/org/catrobat/paintroid/test/junit/command/CropCommandTest.kt b/Paintroid/src/androidTest/java/org/catrobat/paintroid/test/junit/command/CropCommandTest.kt
index 7bbd3b5009..632936c77f 100644
--- a/Paintroid/src/androidTest/java/org/catrobat/paintroid/test/junit/command/CropCommandTest.kt
+++ b/Paintroid/src/androidTest/java/org/catrobat/paintroid/test/junit/command/CropCommandTest.kt
@@ -43,16 +43,16 @@ class CropCommandTest {
     @Before
     fun setUp() {
         layerModel = LayerModel()
-        layerModel!!.width = INITIAL_WIDTH
-        layerModel!!.height = INITIAL_HEIGHT
+        layerModel.width = INITIAL_WIDTH
+        layerModel.height = INITIAL_HEIGHT
         val canvasBitmapUnderTest = Bitmap.createBitmap(INITIAL_WIDTH, INITIAL_HEIGHT, Bitmap.Config.ARGB_8888)
         canvasBitmapUnderTest.eraseColor(BITMAP_BASE_COLOR)
         bitmapUnderTest = canvasBitmapUnderTest.copy(Bitmap.Config.ARGB_8888, true)
         layerUnderTest = Layer(bitmapUnderTest)
         canvasUnderTest = Canvas()
-        canvasUnderTest!!.setBitmap(canvasBitmapUnderTest)
-        layerModel!!.addLayerAt(0, layerUnderTest!!)
-        layerModel!!.currentLayer = layerUnderTest
+        canvasUnderTest.setBitmap(canvasBitmapUnderTest)
+        layerModel.addLayerAt(0, layerUnderTest)
+        layerModel.currentLayer = layerUnderTest
         resizeCoordinateXLeft = 0
         resizeCoordinateYTop = 0
         resizeCoordinateXRight = bitmapUnderTest.width - 1
@@ -64,16 +64,16 @@ class CropCommandTest {
 
     @Test
     fun testIfBitmapIsCropped() {
-        val widthOriginal = bitmapUnderTest!!.width
-        val heightOriginal = bitmapUnderTest!!.height
+        val widthOriginal = bitmapUnderTest.width
+        val heightOriginal = bitmapUnderTest.height
         resizeCoordinateXLeft = 1
         resizeCoordinateYTop = 1
-        resizeCoordinateXRight = bitmapUnderTest!!.width - 2
-        resizeCoordinateYBottom = bitmapUnderTest!!.height - 2
+        resizeCoordinateXRight = bitmapUnderTest.width - 2
+        resizeCoordinateYBottom = bitmapUnderTest.height - 2
         commandUnderTest = CropCommand(resizeCoordinateXLeft, resizeCoordinateYTop,
                 resizeCoordinateXRight, resizeCoordinateYBottom, maximumBitmapResolution)
-        commandUnderTest.run(canvasUnderTest!!, layerModel!!)
-        val croppedBitmap = layerUnderTest!!.bitmap
+        commandUnderTest.run(canvasUnderTest, layerModel)
+        val croppedBitmap = layerUnderTest.bitmap
         Assert.assertEquals("Cropping failed, width not correct ", (widthOriginal - resizeCoordinateXLeft - (widthOriginal - (resizeCoordinateXRight + 1))).toLong(), croppedBitmap.width.toLong())
         Assert.assertEquals("Cropping failed, height not correct ", (heightOriginal - resizeCoordinateYTop - (widthOriginal - (resizeCoordinateYBottom + 1))).toLong(), croppedBitmap.height.toLong())
         croppedBitmap.recycle()
@@ -81,16 +81,16 @@ class CropCommandTest {
 
     @Test
     fun testIfBitmapIsEnlarged() {
-        val widthOriginal = bitmapUnderTest!!.width
-        val heightOriginal = bitmapUnderTest!!.height
+        val widthOriginal = bitmapUnderTest.width
+        val heightOriginal = bitmapUnderTest.height
         resizeCoordinateXLeft = -1
         resizeCoordinateYTop = -1
-        resizeCoordinateXRight = bitmapUnderTest!!.width
-        resizeCoordinateYBottom = bitmapUnderTest!!.height
+        resizeCoordinateXRight = bitmapUnderTest.width
+        resizeCoordinateYBottom = bitmapUnderTest.height
         commandUnderTest = CropCommand(resizeCoordinateXLeft, resizeCoordinateYTop,
                 resizeCoordinateXRight, resizeCoordinateYBottom, maximumBitmapResolution)
-        commandUnderTest.run(canvasUnderTest!!, layerModel!!)
-        val enlargedBitmap = layerUnderTest!!.bitmap
+        commandUnderTest.run(canvasUnderTest, layerModel)
+        val enlargedBitmap = layerUnderTest.bitmap
         Assert.assertEquals("Enlarging failed, width not correct ", (widthOriginal - resizeCoordinateXLeft - (widthOriginal - (resizeCoordinateXRight + 1))).toLong(), enlargedBitmap.width.toLong())
         Assert.assertEquals("Enlarging failed, height not correct ", (heightOriginal - resizeCoordinateYTop - (widthOriginal - (resizeCoordinateYBottom + 1))).toLong(), enlargedBitmap.height.toLong())
         enlargedBitmap.recycle()
@@ -98,16 +98,16 @@ class CropCommandTest {
 
     @Test
     fun testIfBitmapIsShifted() {
-        val widthOriginal = bitmapUnderTest!!.width
-        val heightOriginal = bitmapUnderTest!!.height
-        resizeCoordinateXLeft = bitmapUnderTest!!.width / 2 - 1
-        resizeCoordinateYTop = bitmapUnderTest!!.height / 2 - 1
-        resizeCoordinateXRight = resizeCoordinateXLeft + bitmapUnderTest!!.width - 1
-        resizeCoordinateYBottom = resizeCoordinateYTop + bitmapUnderTest!!.height - 1
+        val widthOriginal = bitmapUnderTest.width
+        val heightOriginal = bitmapUnderTest.height
+        resizeCoordinateXLeft = bitmapUnderTest.width / 2 - 1
+        resizeCoordinateYTop = bitmapUnderTest.height / 2 - 1
+        resizeCoordinateXRight = resizeCoordinateXLeft + bitmapUnderTest.width - 1
+        resizeCoordinateYBottom = resizeCoordinateYTop + bitmapUnderTest.height - 1
         commandUnderTest = CropCommand(resizeCoordinateXLeft, resizeCoordinateYTop,
                 resizeCoordinateXRight, resizeCoordinateYBottom, maximumBitmapResolution)
-        commandUnderTest.run(canvasUnderTest!!, layerModel!!)
-        val enlargedBitmap = layerUnderTest!!.bitmap
+        commandUnderTest.run(canvasUnderTest, layerModel)
+        val enlargedBitmap = layerUnderTest.bitmap
         Assert.assertEquals("Enlarging failed, width not correct ", widthOriginal.toLong(), enlargedBitmap.width.toLong())
         Assert.assertEquals("Enlarging failed, height not correct ", heightOriginal.toLong(), enlargedBitmap.height.toLong())
         enlargedBitmap.recycle()
@@ -115,41 +115,49 @@ class CropCommandTest {
 
     @Test
     fun testIfMaximumResolutionIsRespected() {
-        val widthOriginal = bitmapUnderTest!!.width
-        val heightOriginal = bitmapUnderTest!!.height
+        val widthOriginal = bitmapUnderTest.width
+        val heightOriginal = bitmapUnderTest.height
         commandUnderTest = CropCommand(0, 0, widthOriginal * 2, heightOriginal * 2, maximumBitmapResolution)
-        commandUnderTest.run(canvasUnderTest!!, layerModel!!)
-        Assert.assertEquals("Width should not have changed", widthOriginal.toLong(), layerUnderTest!!.bitmap.width.toLong())
-        Assert.assertEquals("Height should not have changed", heightOriginal.toLong(), layerUnderTest!!.bitmap.height.toLong())
+        commandUnderTest.run(canvasUnderTest, layerModel)
+        Assert.assertEquals("Width should not have changed", widthOriginal.toLong(), layerUnderTest.bitmap.width.toLong())
+        Assert.assertEquals("Height should not have changed", heightOriginal.toLong(), layerUnderTest.bitmap.height.toLong())
     }
 
     @Test
     fun testIfBitmapIsNotResizedWithInvalidBounds() {
-        val originalBitmap = layerUnderTest!!.bitmap
-        commandUnderTest = CropCommand(bitmapUnderTest!!.width, 0, bitmapUnderTest!!.width,
+        val originalBitmap = layerUnderTest.bitmap
+        commandUnderTest = CropCommand(
+            bitmapUnderTest.width, 0, bitmapUnderTest.width,
                 0, maximumBitmapResolution)
-        commandUnderTest.run(canvasUnderTest!!, layerModel!!)
-        Assert.assertTrue("bitmap must not change if X left is larger than bitmap scope", originalBitmap.sameAs(layerUnderTest!!.bitmap))
+        commandUnderTest.run(canvasUnderTest, layerModel)
+        Assert.assertTrue("bitmap must not change if X left is larger than bitmap scope", originalBitmap.sameAs(
+            layerUnderTest.bitmap))
         commandUnderTest = CropCommand(-1, 0, -1, 0, maximumBitmapResolution)
-        commandUnderTest.run(canvasUnderTest!!, layerModel!!)
-        Assert.assertTrue("bitmap must not change if X right is smaller than bitmap scope", originalBitmap.sameAs(layerUnderTest!!.bitmap))
-        commandUnderTest = CropCommand(0, bitmapUnderTest!!.height, 0,
-                bitmapUnderTest!!.height, maximumBitmapResolution)
-        commandUnderTest.run(canvasUnderTest!!, layerModel!!)
-        Assert.assertTrue("bitmap must not change if Y top is larger than bitmap scope", originalBitmap.sameAs(layerUnderTest!!.bitmap))
+        commandUnderTest.run(canvasUnderTest, layerModel)
+        Assert.assertTrue("bitmap must not change if X right is smaller than bitmap scope", originalBitmap.sameAs(
+            layerUnderTest.bitmap))
+        commandUnderTest = CropCommand(0, bitmapUnderTest.height, 0,
+                bitmapUnderTest.height, maximumBitmapResolution)
+        commandUnderTest.run(canvasUnderTest, layerModel)
+        Assert.assertTrue("bitmap must not change if Y top is larger than bitmap scope", originalBitmap.sameAs(
+            layerUnderTest.bitmap))
         commandUnderTest = CropCommand(0, -1, 0, -1, maximumBitmapResolution)
-        commandUnderTest.run(canvasUnderTest!!, layerModel!!)
-        Assert.assertTrue("bitmap must not change if Y bottom is smaller than bitmap scope", originalBitmap.sameAs(layerUnderTest!!.bitmap))
+        commandUnderTest.run(canvasUnderTest, layerModel)
+        Assert.assertTrue("bitmap must not change if Y bottom is smaller than bitmap scope", originalBitmap.sameAs(
+            layerUnderTest.bitmap))
         commandUnderTest = CropCommand(1, 0, 0, 0, maximumBitmapResolution)
-        commandUnderTest.run(canvasUnderTest!!, layerModel!!)
-        Assert.assertTrue("bitmap must not change with widthXRight < widthXLeft bound", originalBitmap.sameAs(layerUnderTest!!.bitmap))
+        commandUnderTest.run(canvasUnderTest, layerModel)
+        Assert.assertTrue("bitmap must not change with widthXRight < widthXLeft bound", originalBitmap.sameAs(
+            layerUnderTest.bitmap))
         commandUnderTest = CropCommand(0, 1, 0, 0, maximumBitmapResolution)
-        commandUnderTest.run(canvasUnderTest!!, layerModel!!)
-        Assert.assertTrue("bitmap must not change with widthYBottom < widthYTop bound", originalBitmap.sameAs(layerUnderTest!!.bitmap))
-        commandUnderTest = CropCommand(0, 0, bitmapUnderTest!!.width - 1,
-                bitmapUnderTest!!.height - 1, maximumBitmapResolution)
-        commandUnderTest.run(canvasUnderTest!!, layerModel!!)
-        Assert.assertTrue("bitmap must not change because bounds are the same as original bitmap", originalBitmap.sameAs(layerUnderTest!!.bitmap))
+        commandUnderTest.run(canvasUnderTest, layerModel)
+        Assert.assertTrue("bitmap must not change with widthYBottom < widthYTop bound", originalBitmap.sameAs(
+            layerUnderTest.bitmap))
+        commandUnderTest = CropCommand(0, 0, bitmapUnderTest.width - 1,
+                bitmapUnderTest.height - 1, maximumBitmapResolution)
+        commandUnderTest.run(canvasUnderTest, layerModel)
+        Assert.assertTrue("bitmap must not change because bounds are the same as original bitmap", originalBitmap.sameAs(
+            layerUnderTest.bitmap))
     }
 
     companion object {
diff --git a/Paintroid/src/androidTest/java/org/catrobat/paintroid/test/junit/command/FlipCommandTest.kt b/Paintroid/src/androidTest/java/org/catrobat/paintroid/test/junit/command/FlipCommandTest.kt
index fc837defb0..5758ee19a0 100644
--- a/Paintroid/src/androidTest/java/org/catrobat/paintroid/test/junit/command/FlipCommandTest.kt
+++ b/Paintroid/src/androidTest/java/org/catrobat/paintroid/test/junit/command/FlipCommandTest.kt
@@ -53,18 +53,18 @@ class FlipCommandTest {
     @Test
     fun testVerticalFlip() {
         commandUnderTest = FlipCommand(FlipDirection.FLIP_VERTICAL)
-        bitmapUnderTest!!.setPixel(0, INITIAL_HEIGHT / 2, PAINT_BASE_COLOR)
+        bitmapUnderTest.setPixel(0, INITIAL_HEIGHT / 2, PAINT_BASE_COLOR)
         commandUnderTest.run(canvasUnderTest!!, layerModel!!)
-        val pixel = bitmapUnderTest!!.getPixel(INITIAL_WIDTH - 1, INITIAL_WIDTH / 2)
+        val pixel = bitmapUnderTest.getPixel(INITIAL_WIDTH - 1, INITIAL_WIDTH / 2)
         Assert.assertEquals(PAINT_BASE_COLOR.toLong(), pixel.toLong())
     }
 
     @Test
     fun testHorizontalFlip() {
         commandUnderTest = FlipCommand(FlipDirection.FLIP_HORIZONTAL)
-        bitmapUnderTest!!.setPixel(INITIAL_WIDTH / 2, 0, PAINT_BASE_COLOR)
+        bitmapUnderTest.setPixel(INITIAL_WIDTH / 2, 0, PAINT_BASE_COLOR)
         commandUnderTest.run(canvasUnderTest!!, layerModel!!)
-        val pixel = bitmapUnderTest!!.getPixel(INITIAL_WIDTH / 2, INITIAL_WIDTH - 1)
+        val pixel = bitmapUnderTest.getPixel(INITIAL_WIDTH / 2, INITIAL_WIDTH - 1)
         Assert.assertEquals(PAINT_BASE_COLOR.toLong(), pixel.toLong())
     }
 
diff --git a/Paintroid/src/androidTest/java/org/catrobat/paintroid/test/junit/command/MergeLayersCommandTest.kt b/Paintroid/src/androidTest/java/org/catrobat/paintroid/test/junit/command/MergeLayersCommandTest.kt
index 7dcdb3c100..c4a754cccc 100644
--- a/Paintroid/src/androidTest/java/org/catrobat/paintroid/test/junit/command/MergeLayersCommandTest.kt
+++ b/Paintroid/src/androidTest/java/org/catrobat/paintroid/test/junit/command/MergeLayersCommandTest.kt
@@ -74,10 +74,10 @@ class MergeLayersCommandTest {
     @Test
     fun testRun() {
         commandUnderTest.run(canvasUnderTest, layerModel)
-        Assert.assertEquals(layerModel.getLayerAt(0)!!.bitmap!!.getPixel(5, 5), PAINT_BASE_COLOR)
-        Assert.assertEquals(layerModel.getLayerAt(0)!!.bitmap!!.getPixel(8, 8), PAINT_BASE_COLOR)
-        Assert.assertEquals(layerModel.getLayerAt(0)!!.bitmap!!.getPixel(3, 3), 0)
-        Assert.assertEquals(layerModel.getLayerAt(0)!!.bitmap!!.getPixel(0, 0), 0)
+        Assert.assertEquals(layerModel.getLayerAt(0)!!.bitmap.getPixel(5, 5), PAINT_BASE_COLOR)
+        Assert.assertEquals(layerModel.getLayerAt(0)!!.bitmap.getPixel(8, 8), PAINT_BASE_COLOR)
+        Assert.assertEquals(layerModel.getLayerAt(0)!!.bitmap.getPixel(3, 3), 0)
+        Assert.assertEquals(layerModel.getLayerAt(0)!!.bitmap.getPixel(0, 0), 0)
     }
 
     @Test
@@ -92,10 +92,10 @@ class MergeLayersCommandTest {
     fun testRunMergeSeparatedLayers() {
         commandUnderTest = MergeLayersCommand(2, 0)
         commandUnderTest.run(canvasUnderTest, layerModel)
-        Assert.assertEquals(layerModel.currentLayer!!.bitmap!!.getPixel(0, 0), PAINT_BASE_COLOR)
-        Assert.assertEquals(layerModel.currentLayer!!.bitmap!!.getPixel(8, 8), PAINT_BASE_COLOR)
-        Assert.assertEquals(layerModel.currentLayer!!.bitmap!!.getPixel(3, 3), 0)
-        Assert.assertEquals(layerModel.currentLayer!!.bitmap!!.getPixel(5, 5), 0)
-        Assert.assertEquals(layerModel.getLayerAt(1)!!.bitmap!!.getPixel(5, 5), PAINT_BASE_COLOR)
+        Assert.assertEquals(layerModel.currentLayer!!.bitmap.getPixel(0, 0), PAINT_BASE_COLOR)
+        Assert.assertEquals(layerModel.currentLayer!!.bitmap.getPixel(8, 8), PAINT_BASE_COLOR)
+        Assert.assertEquals(layerModel.currentLayer!!.bitmap.getPixel(3, 3), 0)
+        Assert.assertEquals(layerModel.currentLayer!!.bitmap.getPixel(5, 5), 0)
+        Assert.assertEquals(layerModel.getLayerAt(1)!!.bitmap.getPixel(5, 5), PAINT_BASE_COLOR)
     }
 }
diff --git a/Paintroid/src/androidTest/java/org/catrobat/paintroid/test/junit/command/PathCommandTest.kt b/Paintroid/src/androidTest/java/org/catrobat/paintroid/test/junit/command/PathCommandTest.kt
index 507eb0749a..1ee5e3ed36 100644
--- a/Paintroid/src/androidTest/java/org/catrobat/paintroid/test/junit/command/PathCommandTest.kt
+++ b/Paintroid/src/androidTest/java/org/catrobat/paintroid/test/junit/command/PathCommandTest.kt
@@ -66,10 +66,10 @@ class PathCommandTest {
     @Test
     fun testPathOutOfBounds() {
         val path = Path()
-        val left = (canvasBitmapUnderTest!!.width + 50).toFloat()
-        val top = (canvasBitmapUnderTest!!.height + 50).toFloat()
-        val right = (canvasBitmapUnderTest!!.width + 100).toFloat()
-        val bottom = (canvasBitmapUnderTest!!.height + 100).toFloat()
+        val left = (canvasBitmapUnderTest.width + 50).toFloat()
+        val top = (canvasBitmapUnderTest.height + 50).toFloat()
+        val right = (canvasBitmapUnderTest.width + 100).toFloat()
+        val bottom = (canvasBitmapUnderTest.height + 100).toFloat()
         path.addRect(RectF(left, top, right, bottom), Path.Direction.CW)
         commandUnderTest = PathCommand(paintUnderTest!!, path)
         commandUnderTest.run(canvasUnderTest!!, LayerModel())
diff --git a/Paintroid/src/androidTest/java/org/catrobat/paintroid/test/junit/command/PointCommandTest.kt b/Paintroid/src/androidTest/java/org/catrobat/paintroid/test/junit/command/PointCommandTest.kt
index 78533fb97d..55a27af4d1 100644
--- a/Paintroid/src/androidTest/java/org/catrobat/paintroid/test/junit/command/PointCommandTest.kt
+++ b/Paintroid/src/androidTest/java/org/catrobat/paintroid/test/junit/command/PointCommandTest.kt
@@ -63,17 +63,17 @@ class PointCommandTest {
 
     @Test
     fun testRun() {
-        bitmapUnderTest!!.setPixel(pointUnderTest!!.x.toInt(), pointUnderTest!!.y.toInt(), paintUnderTest!!.color)
-        commandUnderTest!!.run(canvasUnderTest!!, LayerModel())
-        assertBitmapEquals(bitmapUnderTest!!, canvasBitmapUnderTest)
+        bitmapUnderTest.setPixel(pointUnderTest!!.x.toInt(), pointUnderTest!!.y.toInt(), paintUnderTest!!.color)
+        commandUnderTest.run(canvasUnderTest!!, LayerModel())
+        assertBitmapEquals(bitmapUnderTest, canvasBitmapUnderTest)
     }
 
     @Test
     fun testRunOutOfBounds() {
-        pointUnderTest = PointF((canvasBitmapUnderTest!!.height + 1).toFloat(), (canvasBitmapUnderTest!!.width + 1).toFloat())
+        pointUnderTest = PointF((canvasBitmapUnderTest.height + 1).toFloat(), (canvasBitmapUnderTest.width + 1).toFloat())
         commandUnderTest = PointCommand(paintUnderTest!!, pointUnderTest!!)
         commandUnderTest.run(canvasUnderTest!!, LayerModel())
-        assertBitmapEquals(bitmapUnderTest!!, canvasBitmapUnderTest)
+        assertBitmapEquals(bitmapUnderTest, canvasBitmapUnderTest)
     }
 
     companion object {
diff --git a/Paintroid/src/main/java/org/catrobat/paintroid/FileIO.kt b/Paintroid/src/main/java/org/catrobat/paintroid/FileIO.kt
index 432399538f..a61e19e3ac 100644
--- a/Paintroid/src/main/java/org/catrobat/paintroid/FileIO.kt
+++ b/Paintroid/src/main/java/org/catrobat/paintroid/FileIO.kt
@@ -115,7 +115,7 @@ object FileIO {
         require(currentBitmap != null && !currentBitmap.isRecycled) { "Bitmap is invalid" }
         if (compressFormat == CompressFormat.JPEG) {
             val newBitmap =
-                Bitmap.createBitmap(currentBitmap.width, currentBitmap.height, currentBitmap.config)
+                Bitmap.createBitmap(currentBitmap.width, currentBitmap.height, currentBitmap.config ?: Bitmap.Config.ARGB_8888)
             val canvas = Canvas(newBitmap)
             canvas.drawColor(Color.WHITE)
             canvas.drawBitmap(currentBitmap, 0f, 0f, null)
diff --git a/Paintroid/src/main/java/org/catrobat/paintroid/MainActivity.kt b/Paintroid/src/main/java/org/catrobat/paintroid/MainActivity.kt
index dffb83df93..23988489f8 100644
--- a/Paintroid/src/main/java/org/catrobat/paintroid/MainActivity.kt
+++ b/Paintroid/src/main/java/org/catrobat/paintroid/MainActivity.kt
@@ -21,6 +21,7 @@ package org.catrobat.paintroid
 import android.content.ContentResolver
 import android.content.Context
 import android.content.Intent
+import android.content.pm.PackageManager
 import android.graphics.Color
 import android.graphics.Paint
 import android.graphics.PointF
@@ -810,7 +811,14 @@ class MainActivity : AppCompatActivity(), MainView, CommandListener {
         }
     }
 
-    fun getVersionCode(): String = runCatching {
-        packageManager.getPackageInfo(packageName, 0).versionName
+    fun getVersionName(): String = runCatching {
+        val pm = packageManager
+        val pkgInfo = if (Build.VERSION.SDK_INT >= 33) {
+            pm.getPackageInfo(packageName, PackageManager.PackageInfoFlags.of(0))
+        } else {
+            @Suppress("DEPRECATION")
+            pm.getPackageInfo(packageName, 0)
+        }
+        pkgInfo.versionName ?: ""
     }.getOrDefault("")
 }
diff --git a/Paintroid/src/main/java/org/catrobat/paintroid/command/implementation/ClippingCommand.kt b/Paintroid/src/main/java/org/catrobat/paintroid/command/implementation/ClippingCommand.kt
index 2ebf7f70e8..c38a393cf5 100644
--- a/Paintroid/src/main/java/org/catrobat/paintroid/command/implementation/ClippingCommand.kt
+++ b/Paintroid/src/main/java/org/catrobat/paintroid/command/implementation/ClippingCommand.kt
@@ -12,8 +12,8 @@ import org.catrobat.paintroid.contract.LayerContracts
 
 class ClippingCommand(bitmap: Bitmap, pathBitmap: Bitmap) : Command {
 
-    var bitmap: Bitmap? = bitmap.copy(bitmap.config, true); private set
-    var pathBitmap: Bitmap? = pathBitmap.copy(pathBitmap.config, true); private set
+    var bitmap: Bitmap? = bitmap.copy(bitmap.config ?: Bitmap.Config.ARGB_8888, true); private set
+    var pathBitmap: Bitmap? = pathBitmap.copy(pathBitmap.config ?: Bitmap.Config.ARGB_8888, true); private set
 
     override fun run(canvas: Canvas, layerModel: LayerContracts.Model) {
         val bitmapToDraw = bitmap
diff --git a/Paintroid/src/main/java/org/catrobat/paintroid/command/implementation/CropCommand.kt b/Paintroid/src/main/java/org/catrobat/paintroid/command/implementation/CropCommand.kt
index 874d249ad7..58eb0bbd4f 100644
--- a/Paintroid/src/main/java/org/catrobat/paintroid/command/implementation/CropCommand.kt
+++ b/Paintroid/src/main/java/org/catrobat/paintroid/command/implementation/CropCommand.kt
@@ -57,7 +57,7 @@ class CropCommand(
         while (iterator.hasNext()) {
             val currentLayer = iterator.next()
             val currentBitmap = currentLayer.bitmap ?: Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888)
-            val resizedBitmap = Bitmap.createBitmap(width, height, currentBitmap.config)
+            val resizedBitmap = Bitmap.createBitmap(width, height, currentBitmap.config ?: Bitmap.Config.ARGB_8888)
             val resizedCanvas = Canvas(resizedBitmap)
             resizedCanvas.drawBitmap(currentBitmap, -resizeCoordinateXLeft.toFloat(), -resizeCoordinateYTop.toFloat(), null)
             currentLayer.bitmap = resizedBitmap
diff --git a/Paintroid/src/main/java/org/catrobat/paintroid/command/implementation/FlipCommand.kt b/Paintroid/src/main/java/org/catrobat/paintroid/command/implementation/FlipCommand.kt
index aefd9a5dcf..ea930150c6 100644
--- a/Paintroid/src/main/java/org/catrobat/paintroid/command/implementation/FlipCommand.kt
+++ b/Paintroid/src/main/java/org/catrobat/paintroid/command/implementation/FlipCommand.kt
@@ -19,6 +19,7 @@
 
 package org.catrobat.paintroid.command.implementation
 
+import android.graphics.Bitmap
 import android.graphics.Canvas
 import android.graphics.Color
 import android.graphics.Matrix
@@ -44,7 +45,7 @@ class FlipCommand(flipDirection: FlipDirection) : Command {
             }
         }
         layerModel.currentLayer?.bitmap?.let { bitmap ->
-            val bitmapCopy = bitmap.copy(bitmap.config, bitmap.isMutable)
+            val bitmapCopy = bitmap.copy(bitmap.config ?: Bitmap.Config.ARGB_8888, bitmap.isMutable)
             val flipCanvas = Canvas(bitmap)
             bitmap.eraseColor(Color.TRANSPARENT)
             flipCanvas.drawBitmap(bitmapCopy, flipMatrix, Paint())
diff --git a/Paintroid/src/main/java/org/catrobat/paintroid/command/implementation/MergeLayersCommand.kt b/Paintroid/src/main/java/org/catrobat/paintroid/command/implementation/MergeLayersCommand.kt
index c4b43491f6..e4b579681b 100644
--- a/Paintroid/src/main/java/org/catrobat/paintroid/command/implementation/MergeLayersCommand.kt
+++ b/Paintroid/src/main/java/org/catrobat/paintroid/command/implementation/MergeLayersCommand.kt
@@ -19,6 +19,7 @@
 
 package org.catrobat.paintroid.command.implementation
 
+import android.graphics.Bitmap
 import android.graphics.Canvas
 import android.util.Log
 import org.catrobat.paintroid.command.Command
@@ -40,7 +41,7 @@ class MergeLayersCommand(position: Int, mergeWith: Int) : Command {
         if (sourceLayer != null && destinationLayer != null) {
             val destinationBitmap = destinationLayer.bitmap
             destinationBitmap ?: return
-            val copyBitmap = destinationBitmap.copy(destinationBitmap.config, true)
+            val copyBitmap = destinationBitmap.copy(destinationBitmap.config ?: Bitmap.Config.ARGB_8888, true)
             val copyCanvas = Canvas(copyBitmap)
             copyCanvas.drawBitmap(sourceLayer.bitmap ?: return, 0f, 0f, null)
             if (layerModel.removeLayerAt(position)) {
diff --git a/Paintroid/src/main/java/org/catrobat/paintroid/dialog/AboutDialog.kt b/Paintroid/src/main/java/org/catrobat/paintroid/dialog/AboutDialog.kt
index d6a44a777c..aeae3ec679 100644
--- a/Paintroid/src/main/java/org/catrobat/paintroid/dialog/AboutDialog.kt
+++ b/Paintroid/src/main/java/org/catrobat/paintroid/dialog/AboutDialog.kt
@@ -52,7 +52,7 @@ class AboutDialog : AppCompatDialogFragment() {
         val aboutLicenseView = view.findViewById<TextView>(R.id.pocketpaint_about_license_url)
         val aboutCatrobatView = view.findViewById<TextView>(R.id.pocketpaint_about_catrobat_url)
         val activity = requireActivity() as MainActivity
-        val aboutVersion = getString(R.string.pocketpaint_about_version, activity.getVersionCode())
+        val aboutVersion = getString(R.string.pocketpaint_about_version, activity.getVersionName())
         aboutVersionView.text = aboutVersion
         val aboutContent = getString(
             R.string.pocketpaint_about_content,
diff --git a/Paintroid/src/main/java/org/catrobat/paintroid/tools/implementation/DefaultContextCallback.kt b/Paintroid/src/main/java/org/catrobat/paintroid/tools/implementation/DefaultContextCallback.kt
index b963cff2ba..a173bf305a 100644
--- a/Paintroid/src/main/java/org/catrobat/paintroid/tools/implementation/DefaultContextCallback.kt
+++ b/Paintroid/src/main/java/org/catrobat/paintroid/tools/implementation/DefaultContextCallback.kt
@@ -37,7 +37,7 @@ import androidx.annotation.StringRes
 import androidx.appcompat.content.res.AppCompatResources
 import androidx.core.content.ContextCompat
 import androidx.core.content.res.ResourcesCompat
-import org.catrobat.paintroid.R
+import org.catrobat.paintroid.colorpicker.R
 import org.catrobat.paintroid.tools.ContextCallback
 import org.catrobat.paintroid.tools.ContextCallback.NotificationDuration
 import org.catrobat.paintroid.tools.ContextCallback.NotificationDuration.SHORT
diff --git a/Paintroid/src/main/java/org/catrobat/paintroid/tools/implementation/DefaultToolPaint.kt b/Paintroid/src/main/java/org/catrobat/paintroid/tools/implementation/DefaultToolPaint.kt
index 230792c5d9..99909d9c22 100644
--- a/Paintroid/src/main/java/org/catrobat/paintroid/tools/implementation/DefaultToolPaint.kt
+++ b/Paintroid/src/main/java/org/catrobat/paintroid/tools/implementation/DefaultToolPaint.kt
@@ -27,7 +27,7 @@ import android.graphics.Paint.Cap
 import android.graphics.PorterDuff
 import android.graphics.PorterDuffXfermode
 import android.graphics.Shader
-import org.catrobat.paintroid.R
+import org.catrobat.paintroid.colorpicker.R
 import org.catrobat.paintroid.tools.ToolPaint
 
 const val STROKE_25 = 25f
diff --git a/Paintroid/src/main/java/org/catrobat/paintroid/ui/tools/BrushToolView.kt b/Paintroid/src/main/java/org/catrobat/paintroid/ui/tools/BrushToolView.kt
index f5bb3c6542..74efedfbaa 100644
--- a/Paintroid/src/main/java/org/catrobat/paintroid/ui/tools/BrushToolView.kt
+++ b/Paintroid/src/main/java/org/catrobat/paintroid/ui/tools/BrushToolView.kt
@@ -27,7 +27,7 @@ import android.graphics.Paint
 import android.graphics.Shader
 import android.util.AttributeSet
 import android.view.View
-import org.catrobat.paintroid.R
+import org.catrobat.paintroid.colorpicker.R
 import org.catrobat.paintroid.tools.ToolType
 import org.catrobat.paintroid.tools.options.BrushToolOptionsView.OnBrushPreviewListener
 import org.catrobat.paintroid.tools.options.BrushToolPreview
diff --git a/Paintroid/src/main/java/org/catrobat/paintroid/web/MediaGalleryWebViewClient.java b/Paintroid/src/main/java/org/catrobat/paintroid/web/MediaGalleryWebViewClient.java
index 4690e2aa6e..dbc72a31aa 100644
--- a/Paintroid/src/main/java/org/catrobat/paintroid/web/MediaGalleryWebViewClient.java
+++ b/Paintroid/src/main/java/org/catrobat/paintroid/web/MediaGalleryWebViewClient.java
@@ -22,34 +22,36 @@
  */
 package org.catrobat.paintroid.web;
 
-import android.app.ProgressDialog;
 import android.graphics.Bitmap;
 import android.webkit.WebView;
 import android.webkit.WebViewClient;
-
-import org.catrobat.paintroid.R;
+import android.net.Uri;
+import android.view.View;
+import android.webkit.WebResourceError;
+import android.webkit.WebResourceRequest;
+import androidx.appcompat.app.AlertDialog;
+import androidx.core.view.ViewCompat;
+import android.widget.ProgressBar;
 
 public class MediaGalleryWebViewClient extends WebViewClient {
-	private ProgressDialog webViewLoadingDialog;
-	private WebClientCallback callback;
+	private AlertDialog loadingDialog;
+	private final WebClientCallback callback;
 
 	public interface WebClientCallback {
 		void finish();
 	}
 
 	public MediaGalleryWebViewClient(WebClientCallback callback) {
-		super();
 		this.callback = callback;
 	}
 
+	private static final String GALLERY_ROOT = "https://share.catrob.at/pocketcode/";
+
 	@Override
-	public void onPageStarted(WebView view, String urlClient, Bitmap favicon) {
-		if (webViewLoadingDialog == null && !urlClient.matches("https://share.catrob.at/pocketcode/")) {
-			webViewLoadingDialog = new ProgressDialog(view.getContext(), R.style.WebViewLoadingCircle);
-			webViewLoadingDialog.setCancelable(true);
-			webViewLoadingDialog.setCanceledOnTouchOutside(false);
-			webViewLoadingDialog.setProgressStyle(android.R.style.Widget_ProgressBar_Small);
-			webViewLoadingDialog.show();
+	public void onPageStarted(WebView view, String url, Bitmap favicon) {
+		// avoid regex 'matches' – we only want a prefix check
+		if (!startsWithGalleryRoot(url)) {
+			showLoading(view);
 		} else {
 			callback.finish();
 		}
@@ -57,19 +59,71 @@ public void onPageStarted(WebView view, String urlClient, Bitmap favicon) {
 
 	@Override
 	public void onPageFinished(WebView view, String url) {
-		if (webViewLoadingDialog != null) {
-			webViewLoadingDialog.dismiss();
-			webViewLoadingDialog = null;
-		}
+		dismissLoading();
 	}
 
+	// New API (M+) — preferred
+	@Override
+	public boolean shouldOverrideUrlLoading(WebView view, WebResourceRequest request) {
+		// Return false to let the WebView load the URL
+		return false;
+	}
+
+	// Legacy shim for < M
+	@SuppressWarnings("deprecation")
 	@Override
 	public boolean shouldOverrideUrlLoading(WebView view, String url) {
 		return false;
 	}
 
+	// New API (M+) — preferred
+	@Override
+	public void onReceivedError(WebView view, WebResourceRequest request, WebResourceError error) {
+		dismissLoading();
+		callback.finish();
+	}
+
+	// Legacy shim for < M
+	@SuppressWarnings("deprecation")
 	@Override
 	public void onReceivedError(WebView view, int errorCode, String description, String failingUrl) {
+		dismissLoading();
 		callback.finish();
 	}
+
+	private boolean startsWithGalleryRoot(String url) {
+		try {
+			Uri u = Uri.parse(url);
+			// normalize to compare robustly
+			String normalized = u.getScheme() + "://" + u.getHost() + (u.getPort() != -1 ? (":" + u.getPort()) : "") + u.getPath();
+			return normalized.startsWith(GALLERY_ROOT);
+		} catch (Exception ignored) {
+			return false;
+		}
+	}
+
+	private void showLoading(View anchor) {
+		if (loadingDialog != null) return;
+
+		ProgressBar progress = new ProgressBar(anchor.getContext());
+		// make it large enough and accessible
+		int padding = (int) (anchor.getResources().getDisplayMetrics().density * 24);
+		progress.setPadding(padding, padding, padding, padding);
+		ViewCompat.setImportantForAccessibility(progress, ViewCompat.IMPORTANT_FOR_ACCESSIBILITY_YES);
+
+		loadingDialog = new AlertDialog.Builder(anchor.getContext())
+				.setView(progress)
+				.setCancelable(true)
+				.create();
+		loadingDialog.setCanceledOnTouchOutside(false);
+		loadingDialog.show();
+	}
+
+	private void dismissLoading() {
+		if (loadingDialog != null) {
+			loadingDialog.dismiss();
+			loadingDialog = null;
+		}
+	}
 }
+
diff --git a/app/build.gradle b/app/build.gradle
index 2c7e76738b..0aa6689eab 100644
--- a/app/build.gradle
+++ b/app/build.gradle
@@ -19,42 +19,48 @@ import io.gitlab.arturbosch.detekt.Detekt
  *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-apply plugin: 'com.android.application'
+plugins {
+    id "com.android.application"
+    id "org.jetbrains.kotlin.android"
+}
 
 ext {
-    appId = 'org.catrobat.paintroid'
-    appName = '@string/pocketpaint_app_name'
+    appId = "org.catrobat.paintroid"
+    appName = "@string/pocketpaint_app_name"
 }
 
-// When -Pindependent was provided on the gradle command the APP name is changed.
-// This allows to have multiple Paintroid versions installed in parallel for testing purposes.
-// Furthermore these installations do not interfere with the actual Paintroid app.
-if (project.hasProperty('independent')) {
+// Allow multiple side-by-side installs when run with -Pindependent
+if (project.hasProperty("independent")) {
     def today = new Date()
-    appId += '.independent_' + today.format('YYYYMMdd_HHmm')
-    appName = property('independent') ?: 'Paint ' + today.format('MMdd HH:mm')
+    appId += ".independent_${today.format('yyyyMMdd_HHmm')}"
+    appName = property("independent") ?: "Paint ${today.format('MMdd HH:mm')}"
 }
 
+// Provide a dummy keystore if none is passed
 if (!project.hasProperty("signingKeystore")) {
     ext.signingKeystore = "dummyKeystore"
 }
 
 android {
-    compileSdkVersion rootProject.ext.androidCompileSdkVersion
+    namespace "org.catrobat.paintroid.app"
+    compileSdk = rootProject.ext.androidCompileSdkVersion
+
     defaultConfig {
         applicationId appId
-        minSdkVersion rootProject.ext.androidMinSdkVersion
-        //noinspection OldTargetApi
-        targetSdkVersion rootProject.ext.androidTargetSdkVersion
-        versionCode rootProject.ext.androidVersionCode
-        versionName rootProject.ext.androidVersionName
+        minSdk  = rootProject.ext.androidMinSdkVersion
+        targetSdk = rootProject.ext.androidTargetSdkVersion
+        versionCode = rootProject.ext.androidVersionCode
+        versionName = rootProject.ext.androidVersionName
         manifestPlaceholders += [appName: appName]
         setProperty("archivesBaseName", "paintroid")
     }
 
     compileOptions {
-        sourceCompatibility JavaVersion.VERSION_11
-        targetCompatibility JavaVersion.VERSION_11
+        sourceCompatibility = JavaVersion.VERSION_17
+        targetCompatibility = JavaVersion.VERSION_17
+    }
+    kotlinOptions {
+        jvmTarget = "17"
     }
 
     signingConfigs {
@@ -66,40 +72,48 @@ android {
         }
     }
 
-    if (project.hasProperty("signingKeystore") && project.hasProperty("signingKeystorePassword") &&
-            project.hasProperty("signingKeyAlias") && project.hasProperty("signingKeyPassword")) {
-        android.signingConfigs.signedRelease.storePassword = project.property("signingKeystorePassword")
-        android.signingConfigs.signedRelease.keyAlias = project.property("signingKeyAlias")
-        android.signingConfigs.signedRelease.keyPassword = project.property("signingKeyPassword")
+    if (project.hasProperty("signingKeystore") &&
+            project.hasProperty("signingKeystorePassword") &&
+            project.hasProperty("signingKeyAlias") &&
+            project.hasProperty("signingKeyPassword")) {
+
+        signingConfigs.signedRelease.storePassword = project.property("signingKeystorePassword")
+        signingConfigs.signedRelease.keyAlias      = project.property("signingKeyAlias")
+        signingConfigs.signedRelease.keyPassword   = project.property("signingKeyPassword")
     }
 
     buildTypes {
         release {
             minifyEnabled true
             shrinkResources true
-            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
+            proguardFiles getDefaultProguardFile("proguard-android.txt"), "proguard-rules.pro"
         }
-        signedRelease.initWith(buildTypes.release)
-        signedRelease {
-            signingConfig signingConfigs.signedRelease
+        create("signedRelease") {
+            initWith(buildTypes.release)
+            signingConfig = signingConfigs.signedRelease
         }
     }
 
     publishing {
-        singleVariant('release') {
+        singleVariant("release") {
             withSourcesJar()
         }
     }
+    packaging {
+        jniLibs {
+            useLegacyPackaging false
+        }
+    }
 }
 
-tasks.withType(Detekt).configureEach {
-    jvmTarget = "1.8"
+tasks.withType(io.gitlab.arturbosch.detekt.Detekt).configureEach {
+    jvmTarget = "17"
     exclude("**/resources/**")
     exclude("**/build/**")
 }
 
 dependencies {
-    implementation project(':Paintroid')
-
-    implementation 'com.android.support:support-core-utils:28.0.0'
+    implementation project(":Paintroid")
+    implementation "com.android.support:support-core-utils:28.0.0"
 }
+
diff --git a/app/src/main/AndroidManifest.xml b/app/src/main/AndroidManifest.xml
index 4ffe27c5a3..7811fe1b30 100644
--- a/app/src/main/AndroidManifest.xml
+++ b/app/src/main/AndroidManifest.xml
@@ -21,11 +21,16 @@
     xmlns:tools="http://schemas.android.com/tools"
     package="org.catrobat.paintroid.app">
 
+    <uses-permission android:name="android.permission.READ_MEDIA_IMAGES" />
+    <uses-permission android:name="android.permission.READ_MEDIA_VIDEO" />
+    <uses-permission
+        android:name="android.permission.READ_EXTERNAL_STORAGE"
+        android:maxSdkVersion="32" />
+
     <application
         android:allowBackup="false"
         android:icon="@mipmap/ic_launcher"
         android:label="${appName}"
-        android:extractNativeLibs="false"
         tools:ignore="GoogleAppIndexingWarning,UnusedAttribute">
 
         <provider
@@ -35,7 +40,7 @@
             android:grantUriPermissions="true">
             <meta-data
                 android:name="android.support.FILE_PROVIDER_PATHS"
-                android:resource="@xml/filepaths"/>
+                android:resource="@xml/filepaths" />
         </provider>
 
         <activity
diff --git a/build.gradle b/build.gradle
index 5b1e4b098c..6769803184 100644
--- a/build.gradle
+++ b/build.gradle
@@ -17,33 +17,31 @@
  *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-// Top-level build file where you can add configuration options common to all sub-projects/modules.
 buildscript {
-    ext.kotlin_version = '1.7.10'
+    ext.kotlin_version = '1.9.24'
     repositories {
-        mavenCentral()
         google()
+        mavenCentral()
         maven { url "https://plugins.gradle.org/m2/" }
         maven { url 'https://jitpack.io' }
     }
     dependencies {
-        classpath 'com.android.tools.build:gradle:7.2.1'
-        classpath 'com.hiya:jacoco-android:0.2'
         classpath 'com.github.Catrobat:Gradle:1.6.2'
-        classpath 'com.getkeepsafe.dexcount:dexcount-gradle-plugin:3.1.0'
-        classpath "io.gitlab.arturbosch.detekt:detekt-gradle-plugin:1.20.0"
-        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
     }
 }
 
 plugins {
-    id "io.gitlab.arturbosch.detekt" version "1.20.0"
+    id "com.android.application" version '8.13.0' apply false
+    id "com.android.library"     version '8.13.0' apply false
+    id "org.jetbrains.kotlin.android" version "1.9.24" apply false
+    id "io.gitlab.arturbosch.detekt" version "1.23.6" apply false
+    id "com.getkeepsafe.dexcount"     version "4.0.0" apply false
 }
 
 ext {
-    androidCompileSdkVersion = 34
+    androidCompileSdkVersion = 35
+    androidTargetSdkVersion = 35
     androidMinSdkVersion = 21
-    androidTargetSdkVersion = 34
 
     androidSupportLibraryVersion = '28.0.0'
 
diff --git a/colorpicker/build.gradle b/colorpicker/build.gradle
index e1f8ea1e11..3af101c7a4 100644
--- a/colorpicker/build.gradle
+++ b/colorpicker/build.gradle
@@ -21,23 +21,22 @@ apply plugin: 'com.android.library'
 apply plugin: 'kotlin-android'
 
 android {
+    namespace "org.catrobat.paintroid.colorpicker"
     compileSdkVersion rootProject.ext.androidCompileSdkVersion
 
     defaultConfig {
         minSdkVersion rootProject.ext.androidMinSdkVersion
         targetSdkVersion rootProject.ext.androidTargetSdkVersion
         testInstrumentationRunner 'androidx.test.runner.AndroidJUnitRunner'
-        versionCode rootProject.ext.androidVersionCode
-        versionName rootProject.ext.androidVersionName
     }
 
     compileOptions {
-        sourceCompatibility JavaVersion.VERSION_11
-        targetCompatibility JavaVersion.VERSION_11
+        sourceCompatibility JavaVersion.VERSION_17
+        targetCompatibility JavaVersion.VERSION_17
     }
 
     kotlinOptions {
-        jvmTarget = JavaVersion.VERSION_11.toString()
+        jvmTarget = "17"
     }
 
     buildTypes {
@@ -57,4 +56,4 @@ dependencies {
     implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
     implementation 'org.jetbrains.kotlinx:kotlinx-coroutines-android:1.3.8'
     implementation 'org.jetbrains.kotlinx:kotlinx-coroutines-core:1.3.8'
-}
+}
\ No newline at end of file
diff --git a/colorpicker/src/main/java/org/catrobat/paintroid/colorpicker/ColorPickerPresetColorButton.kt b/colorpicker/src/main/java/org/catrobat/paintroid/colorpicker/ColorPickerPresetColorButton.kt
index 7176cabef7..f072acf183 100644
--- a/colorpicker/src/main/java/org/catrobat/paintroid/colorpicker/ColorPickerPresetColorButton.kt
+++ b/colorpicker/src/main/java/org/catrobat/paintroid/colorpicker/ColorPickerPresetColorButton.kt
@@ -32,7 +32,7 @@ class ColorPickerPresetColorButton @JvmOverloads constructor(
     context: Context,
     @field:ColorInt @get:ColorInt
     @param:ColorInt var color: Int = Color.BLACK
-) : AppCompatImageButton(context, null, R.attr.borderlessButtonStyle) {
+) : AppCompatImageButton(context, null, android.R.attr.borderlessButtonStyle) {
 
     init {
         val checkeredBitmap =
diff --git a/gradle.properties b/gradle.properties
index 5e9758afa7..d91fa61429 100644
--- a/gradle.properties
+++ b/gradle.properties
@@ -1,4 +1,4 @@
 android.enableJetifier=true
 android.useAndroidX=true
-org.gradle.jvmargs=-XX:MaxPermSize=1024m -Xmx4096m
-android.disableAutomaticComponentCreation=true
\ No newline at end of file
+org.gradle.jvmargs=-Xmx4g -Dfile.encoding=UTF-8
+android.nonTransitiveRClass=false
\ No newline at end of file
diff --git a/gradle/wrapper/gradle-wrapper.properties b/gradle/wrapper/gradle-wrapper.properties
index eb250c9aae..af685a4a17 100644
--- a/gradle/wrapper/gradle-wrapper.properties
+++ b/gradle/wrapper/gradle-wrapper.properties
@@ -1,6 +1,6 @@
-#Tue Feb 02 16:23:53 CET 2021
+#Thu Sep 04 16:50:59 CEST 2025
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-8.13-bin.zip
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-7.4.2-all.zip
diff --git a/settings.gradle b/settings.gradle
index ee2027bde3..da41808e20 100644
--- a/settings.gradle
+++ b/settings.gradle
@@ -17,4 +17,26 @@
  *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-include ':Paintroid', ':app', ':colorpicker'
+// settings.gradle (Groovy)
+
+pluginManagement {
+    repositories {
+        google()              // needed for com.android.application / com.android.library
+        mavenCentral()
+        gradlePluginPortal()  // Gradle Central Plugin Repository
+    }
+}
+
+dependencyResolutionManagement {
+    repositoriesMode.set(RepositoriesMode.PREFER_PROJECT)
+    repositories {
+        google()
+        mavenCentral()
+        mavenLocal()
+    }
+}
+
+rootProject.name = "Paintroid"
+
+include(":Paintroid", ":app", ":colorpicker")
+