minSdk 19

.github/workflows/main.yml

@@ -8,11 +8,11 @@ jobs:
 
     steps:
     - uses: actions/checkout@v2
-    - name: set up JDK 11
+    - name: set up JDK 17
       uses: actions/setup-java@v2
       with:
         distribution: 'adopt'
-        java-version: '11'
+        java-version: '17'
     - name: Grant execute permission for gradlew
       run: chmod +x gradlew
     - name: Test with Gradle
@@ -24,11 +24,11 @@ jobs:
  
     steps:
     - uses: actions/checkout@v2
-    - name: set up JDK 11
+    - name: set up JDK 17
       uses: actions/setup-java@v2
       with:
         distribution: 'adopt'
-        java-version: '11'
+        java-version: '17'
     - name: Grant execute permission for gradlew
       run: chmod +x gradlew
     - name: Release with Gradle

conductor-lint/src/main/java/com/bluelinelabs/conductor/lint/ControllerChangeHandlerIssueDetector.java

@@ -18,6 +18,7 @@ import org.jetbrains.uast.UMethod;
 import java.util.Collections;
 import java.util.List;
 
+@SuppressWarnings("UnstableApiUsage")
 public final class ControllerChangeHandlerIssueDetector extends Detector implements Detector.UastScanner {
 
     static final Issue ISSUE =
@@ -31,7 +32,7 @@ public final class ControllerChangeHandlerIssueDetector extends Detector impleme
 
     @Override
     public List<Class<? extends UElement>> getApplicableUastTypes() {
-        return Collections.singletonList(UClass.class);
+        return Collections.<Class<? extends UElement>>singletonList(UClass.class);
     }
 
     @Override
@@ -46,41 +47,42 @@ public final class ControllerChangeHandlerIssueDetector extends Detector impleme
                     return;
                 }
 
-                final boolean hasSuperType = evaluator.extendsClass(node.getJavaPsi(), CLASS_NAME, true);
+                final boolean hasSuperType = evaluator.extendsClass(node.getPsi(), CLASS_NAME, true);
                 if (!hasSuperType) {
                     return;
                 }
 
                 if (!evaluator.isPublic(node)) {
                     String message = String.format("This ControllerChangeHandler class should be public (%1$s)", node.getQualifiedName());
-                    context.report(ISSUE, node, context.getLocation(Identify.byName(node)), message);
+                    context.report(ISSUE, node, context.getLocation((UElement) node), message);
                     return;
                 }
 
                 if (node.getContainingClass() != null && !evaluator.isStatic(node)) {
                     String message = String.format("This ControllerChangeHandler inner class should be static (%1$s)", node.getQualifiedName());
-                    context.report(ISSUE, node, context.getLocation(Identify.byName(node)), message);
+                    context.report(ISSUE, node, context.getLocation((UElement) node), message);
                     return;
                 }
 
-                UMethod constructor = null;
+                boolean hasConstructor = false;
                 boolean hasDefaultConstructor = false;
                 for (UMethod method : node.getMethods()) {
                     if (method.isConstructor()) {
-                        constructor = method;
-                        if (evaluator.isPublic(method) && method.getUastParameters().isEmpty()) {
+                        hasConstructor = true;
+                        if (evaluator.isPublic(method) && method.getUastParameters().size() == 0) {
                             hasDefaultConstructor = true;
                             break;
                         }
                     }
                 }
 
-                if (constructor != null && !hasDefaultConstructor) {
+                if (hasConstructor && !hasDefaultConstructor) {
                     String message = String.format(
                             "This ControllerChangeHandler needs to have a public default constructor (`%1$s`)", node.getQualifiedName());
-                    context.report(ISSUE, node, context.getLocation(Identify.byName(constructor)), message);
+                    context.report(ISSUE, node, context.getLocation((UElement) node), message);
                 }
             }
         };
     }
+
 }

conductor-lint/src/main/java/com/bluelinelabs/conductor/lint/ControllerIssueDetector.java

@@ -10,7 +10,6 @@ import com.android.tools.lint.detector.api.Issue;
 import com.android.tools.lint.detector.api.JavaContext;
 import com.android.tools.lint.detector.api.Scope;
 import com.android.tools.lint.detector.api.Severity;
-import com.intellij.psi.PsiType;
 
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.uast.UClass;
@@ -21,6 +20,7 @@ import org.jetbrains.uast.UParameter;
 import java.util.Collections;
 import java.util.List;
 
+@SuppressWarnings("UnstableApiUsage")
 public final class ControllerIssueDetector extends Detector implements Detector.UastScanner {
 
     static final Issue ISSUE =
@@ -48,53 +48,52 @@ public final class ControllerIssueDetector extends Detector implements Detector.
                     return;
                 }
 
-                final boolean hasSuperType = evaluator.extendsClass(node.getJavaPsi(), CLASS_NAME, true);
+                final boolean hasSuperType = evaluator.extendsClass(node.getPsi(), CLASS_NAME, true);
                 if (!hasSuperType) {
                     return;
                 }
 
                 if (!evaluator.isPublic(node)) {
                     String message = String.format("This Controller class should be public (%1$s)", node.getQualifiedName());
-                    context.report(ISSUE, node, context.getLocation(Identify.byName(node)), message);
+                    context.report(ISSUE, node, context.getLocation((UElement) node), message);
                     return;
                 }
 
                 if (node.getContainingClass() != null && !evaluator.isStatic(node)) {
                     String message = String.format("This Controller inner class should be static (%1$s)", node.getQualifiedName());
-                    context.report(ISSUE, node, context.getLocation(Identify.byName(node)), message);
+                    context.report(ISSUE, node, context.getLocation((UElement) node), message);
                     return;
                 }
 
-                UMethod constructor = null;
+                boolean hasConstructor = false;
                 boolean hasDefaultConstructor = false;
                 boolean hasBundleConstructor = false;
                 for (UMethod method : node.getMethods()) {
                     if (method.isConstructor()) {
-                        constructor = method;
+                        hasConstructor = true;
                         if (evaluator.isPublic(method)) {
                             List<UParameter> parameters = method.getUastParameters();
-                            if (parameters.isEmpty()) {
+                            if (parameters.size() == 0) {
                                 hasDefaultConstructor = true;
                                 break;
-                            } else if (parameters.size() == 1) {
-                                PsiType type = parameters.get(0).getType();
-                                if (type.equalsToText(SdkConstants.CLASS_BUNDLE) || type.equalsToText("Bundle")) {
-                                    hasBundleConstructor = true;
-                                    break;
-                                }
+                            } else if (parameters.size() == 1 &&
+                                    (parameters.get(0).getType().equalsToText(SdkConstants.CLASS_BUNDLE)) ||
+                                    parameters.get(0).getType().equalsToText("Bundle")) {
+                                hasBundleConstructor = true;
                             }
                         }
                     }
                 }
 
-                if (constructor != null && !hasDefaultConstructor && !hasBundleConstructor) {
+                if (hasConstructor && !hasDefaultConstructor && !hasBundleConstructor) {
                     String message = String.format(
                             "This Controller needs to have either a public default constructor or a" +
                                     " public single-argument constructor that takes a Bundle. (`%1$s`)",
                             node.getQualifiedName());
-                    context.report(ISSUE, node, context.getLocation(Identify.byName(constructor)), message);
+                    context.report(ISSUE, node, context.getLocation((UElement) node), message);
                 }
             }
         };
     }
+
 }

conductor-lint/src/main/java/com/bluelinelabs/conductor/lint/Identify.java

@@ -1,15 +0,0 @@
-package com.bluelinelabs.conductor.lint;
-
-import com.intellij.psi.PsiElement;
-import com.intellij.psi.PsiNameIdentifierOwner;
-
-final class Identify {
-    private Identify() {}
-
-    static PsiElement byName(PsiNameIdentifierOwner psiNameIdentifierOwner) {
-        if (psiNameIdentifierOwner.getNameIdentifier() != null) {
-            return psiNameIdentifierOwner.getNameIdentifier();
-        }
-        return psiNameIdentifierOwner;
-    }
-}

conductor-lint/src/test/java/com/bluelinelabs/conductor/lint/ControllerChangeHandlerDetectorTest.java

@@ -8,8 +8,15 @@ import com.android.tools.lint.checks.infrastructure.TestFile;
 import org.intellij.lang.annotations.Language;
 import org.junit.Test;
 
+@SuppressWarnings("UnstableApiUsage")
 public class ControllerChangeHandlerDetectorTest {
 
+    private static final String CONSTRUCTOR =
+            "src/test/SampleHandler.java:2: Error: This ControllerChangeHandler needs to have a public default constructor (test.SampleHandler) [ValidControllerChangeHandler]\n"
+                    + "public class SampleHandler extends com.bluelinelabs.conductor.ControllerChangeHandler {\n"
+                    + "^\n"
+                    + "1 errors, 0 warnings\n";
+
     private final TestFile controllerChangeHandlerStub = java(
             "package com.bluelinelabs.conductor;\n"
                     + "abstract class ControllerChangeHandler {}"
@@ -56,12 +63,7 @@ public class ControllerChangeHandlerDetectorTest {
                 .files(controllerChangeHandlerStub, java(source))
                 .issues(ControllerIssueDetector.ISSUE, ControllerChangeHandlerIssueDetector.ISSUE)
                 .run()
-                .expect(""
-                        + "src/test/SampleHandler.java:3: Error: This ControllerChangeHandler needs to have a public default constructor (test.SampleHandler) [ValidControllerChangeHandler]\n"
-                        + "    public SampleHandler(int number) { }\n"
-                        + "           ~~~~~~~~~~~~~\n"
-                        + "1 errors, 0 warnings\n"
-                );
+                .expect(CONSTRUCTOR);
     }
 
     @Test
@@ -92,12 +94,7 @@ public class ControllerChangeHandlerDetectorTest {
                 .files(controllerChangeHandlerStub, java(source))
                 .issues(ControllerIssueDetector.ISSUE, ControllerChangeHandlerIssueDetector.ISSUE)
                 .run()
-                .expect(""
-                        + "src/test/SampleHandler.java:3: Error: This ControllerChangeHandler needs to have a public default constructor (test.SampleHandler) [ValidControllerChangeHandler]\n"
-                        + "    private SampleHandler() { }\n"
-                        + "            ~~~~~~~~~~~~~\n"
-                        + "1 errors, 0 warnings\n"
-                );
+                .expect(CONSTRUCTOR);
     }
 
     @Test
@@ -114,7 +111,7 @@ public class ControllerChangeHandlerDetectorTest {
                 .run()
                 .expect("src/test/SampleHandler.java:2: Error: This ControllerChangeHandler class should be public (test.SampleHandler) [ValidControllerChangeHandler]\n"
                         + "private class SampleHandler extends com.bluelinelabs.conductor.ControllerChangeHandler {\n"
-                        + "              ~~~~~~~~~~~~~\n"
+                        + "^\n"
                         + "1 errors, 0 warnings\n");
     }
 
@@ -134,7 +131,7 @@ public class ControllerChangeHandlerDetectorTest {
                 .run()
                 .expect("src/test/SampleHandler.java:2: Error: This ControllerChangeHandler class should be public (test.SampleHandler) [ValidControllerChangeHandler]\n" +
                         "private class SampleHandler extends test.BaseChangeHandler {}\n" +
-                        "              ~~~~~~~~~~~~~\n" +
+                        "~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~\n" +
                         "1 errors, 0 warnings");
     }
 }

conductor-lint/src/test/java/com/bluelinelabs/conductor/lint/ControllerDetectorTest.java

@@ -8,12 +8,18 @@ import com.android.tools.lint.checks.infrastructure.TestFile;
 import org.intellij.lang.annotations.Language;
 import org.junit.Test;
 
+@SuppressWarnings("UnstableApiUsage")
 public class ControllerDetectorTest {
 
+    private static final String CONSTRUCTOR_ERROR =
+            "src/test/SampleController.java:2: Error: This Controller needs to have either a public default constructor or a public single-argument constructor that takes a Bundle. (test.SampleController) [ValidController]\n"
+                    + "public class SampleController extends com.bluelinelabs.conductor.Controller {\n"
+                    + "^\n"
+                    + "1 errors, 0 warnings\n";
     private static final String CLASS_ERROR =
             "src/test/SampleController.java:2: Error: This Controller class should be public (test.SampleController) [ValidController]\n"
                     + "private class SampleController extends com.bluelinelabs.conductor.Controller {\n"
-                    + "              ~~~~~~~~~~~~~~~~\n"
+                    + "^\n"
                     + "1 errors, 0 warnings\n";
 
     private final TestFile controllerStub = java(
@@ -63,12 +69,7 @@ public class ControllerDetectorTest {
                 .files(controllerStub, java(source))
                 .issues(ControllerIssueDetector.ISSUE, ControllerChangeHandlerIssueDetector.ISSUE)
                 .run()
-                .expect(""
-                        + "src/test/SampleController.java:3: Error: This Controller needs to have either a public default constructor or a public single-argument constructor that takes a Bundle. (test.SampleController) [ValidController]\n"
-                        + "    public SampleController(int number) { }\n"
-                        + "           ~~~~~~~~~~~~~~~~\n"
-                        + "1 errors, 0 warnings\n"
-                );
+                .expect(CONSTRUCTOR_ERROR);
     }
 
     @Test
@@ -105,11 +106,11 @@ public class ControllerDetectorTest {
                 .files(controllerStub, java(baseClass), java(source))
                 .issues(ControllerIssueDetector.ISSUE, ControllerChangeHandlerIssueDetector.ISSUE)
                 .run()
-                .expect(""
-                        + "src/test/SampleController.java:3: Error: This Controller needs to have either a public default constructor or a public single-argument constructor that takes a Bundle. (test.SampleController) [ValidController]\n"
-                        + "    private SampleController() { }\n"
-                        + "            ~~~~~~~~~~~~~~~~\n"
-                        + "1 errors, 0 warnings"
+                .expect(
+                        "src/test/SampleController.java:2: Error: This Controller needs to have either a public default constructor or a public single-argument constructor that takes a Bundle. (test.SampleController) [ValidController]\n" +
+                                "public class SampleController extends BaseController {\n" +
+                                "^\n" +
+                                "1 errors, 0 warnings"
                 );
     }
 
@@ -125,12 +126,7 @@ public class ControllerDetectorTest {
                 .files(controllerStub, java(source))
                 .issues(ControllerIssueDetector.ISSUE, ControllerChangeHandlerIssueDetector.ISSUE)
                 .run()
-                .expect(""
-                        + "src/test/SampleController.java:3: Error: This Controller needs to have either a public default constructor or a public single-argument constructor that takes a Bundle. (test.SampleController) [ValidController]\n"
-                        + "    private SampleController() { }\n"
-                        + "            ~~~~~~~~~~~~~~~~\n"
-                        + "1 errors, 0 warnings\n"
-                );
+                .expect(CONSTRUCTOR_ERROR);
     }
 
     @Test

conductor-modules/androidx-transition/build.gradle

@@ -4,7 +4,12 @@ plugins {
 }
 
 android {
-    compileSdkVersion libs.versions.compilesdk.get() as Integer
+    compileSdk libs.versions.compilesdk.get() as Integer
+
+    compileOptions {
+        sourceCompatibility JavaVersion.VERSION_11
+        targetCompatibility JavaVersion.VERSION_11
+    }
 
     defaultConfig {
         minSdkVersion libs.versions.minsdk.get()
@@ -12,6 +17,8 @@ android {
         versionCode Integer.parseInt(project.VERSION_CODE)
         versionName project.VERSION_NAME
     }
+
+    namespace "com.bluelinelabs.conductor.androidxtransition"
 }
 
 dependencies {

conductor-modules/androidx-transition/src/main/AndroidManifest.xml

@@ -1,3 +0,0 @@
-<manifest package="com.bluelinelabs.conductor.androidxtransition">
-    <application />
-</manifest>

conductor-modules/viewpager/build.gradle

@@ -5,7 +5,16 @@ plugins {
 }
 
 android {
-    compileSdkVersion libs.versions.compilesdk.get() as Integer
+    compileSdk libs.versions.compilesdk.get() as Integer
+
+    compileOptions {
+        sourceCompatibility JavaVersion.VERSION_11
+        targetCompatibility JavaVersion.VERSION_11
+    }
+
+    kotlinOptions {
+        jvmTarget = "11"
+    }
 
     defaultConfig {
         minSdkVersion libs.versions.minsdk.get()
@@ -13,6 +22,8 @@ android {
         versionCode Integer.parseInt(project.VERSION_CODE)
         versionName project.VERSION_NAME
     }
+
+    namespace "com.bluelinelabs.conductor.viewpager"
 }
 
 dependencies {

conductor-modules/viewpager/src/main/AndroidManifest.xml

@@ -1,3 +0,0 @@
-<manifest package="com.bluelinelabs.conductor.viewpager">
-    <application />
-</manifest>

conductor-modules/viewpager2/build.gradle

@@ -6,7 +6,16 @@ plugins {
 }
 
 android {
-    compileSdkVersion libs.versions.compilesdk.get() as Integer
+    compileSdk libs.versions.compilesdk.get() as Integer
+
+    compileOptions {
+        sourceCompatibility JavaVersion.VERSION_11
+        targetCompatibility JavaVersion.VERSION_11
+    }
+
+    kotlinOptions {
+        jvmTarget = "11"
+    }
 
     defaultConfig {
         minSdkVersion libs.versions.minsdk.get()
@@ -20,6 +29,8 @@ android {
             includeAndroidResources = true
         }
     }
+
+    namespace "com.bluelinelabs.conductor.viewpager2"
 }
 
 dependencies {

conductor-modules/viewpager2/src/main/AndroidManifest.xml

@@ -1,3 +0,0 @@
-<manifest package="com.bluelinelabs.conductor.viewpager2">
-    <application />
-</manifest>

conductor/build.gradle

@@ -6,7 +6,16 @@ plugins {
 }
 
 android {
-    compileSdkVersion libs.versions.compilesdk.get() as Integer
+    compileSdk libs.versions.compilesdk.get() as Integer
+
+    compileOptions {
+        sourceCompatibility JavaVersion.VERSION_11
+        targetCompatibility JavaVersion.VERSION_11
+    }
+
+    kotlinOptions {
+        jvmTarget = "11"
+    }
 
     defaultConfig {
         minSdkVersion libs.versions.minsdk.get()
@@ -15,6 +24,8 @@ android {
         versionName project.VERSION_NAME
         consumerProguardFiles 'proguard-rules.txt'
     }
+
+    namespace "com.bluelinelabs.conductor"
 }
 
 dependencies {

conductor/src/main/AndroidManifest.xml

@@ -1,3 +0,0 @@
-<manifest package="com.bluelinelabs.conductor">
-    <application />
-</manifest>

conductor/src/main/java/com/bluelinelabs/conductor/Controller.java

@@ -8,6 +8,7 @@ import android.content.res.Resources;
 import android.os.Build;
 import android.os.Bundle;
 import android.os.Parcelable;
+import android.util.Log;
 import android.util.SparseArray;
 import android.view.LayoutInflater;
 import android.view.Menu;
@@ -16,6 +17,7 @@ import android.view.MenuItem;
 import android.view.View;
 import android.view.ViewGroup;
 
+import androidx.activity.BackEventCompat;
 import androidx.activity.ComponentActivity;
 import androidx.activity.OnBackPressedCallback;
 import androidx.activity.OnBackPressedDispatcher;
@@ -24,6 +26,8 @@ import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 import androidx.lifecycle.LifecycleOwner;
 
+import com.bluelinelabs.conductor.internal.BackGestureControllerView;
+import com.bluelinelabs.conductor.internal.BackGestureViewState;
 import com.bluelinelabs.conductor.internal.ClassUtils;
 import com.bluelinelabs.conductor.internal.ControllerLifecycleOwner;
 import com.bluelinelabs.conductor.internal.OwnViewTreeLifecycleAndRegistry;
@@ -97,6 +101,9 @@ public abstract class Controller {
     private boolean isContextAvailable;
 
     final OnBackPressedCallback onBackPressedCallback = new OnBackPressedCallback(true) {
+        ControllerChangeHandler.ChangeTransaction popTransaction = null;
+        BackGestureViewState backGestureViewState = null;
+
         @Override
         public void handleOnBackPressed() {
             // Root-level routers should have PopRootControllerMode.NEVER, and so should never return false here.
@@ -111,6 +118,116 @@ public abstract class Controller {
                 }
             }
         }
+
+        @Override
+        public void handleOnBackStarted(@NonNull BackEventCompat backEvent) {
+            Log.d("KUCK", "it has begun");
+            ControllerChangeHandler.ChangeTransaction transaction = getPopTransaction();
+            if (transaction != null && transaction.changeHandler != null && transaction.changeHandler.getEnableOnBackGestureCallbacks()) {
+                List<BackGestureControllerView> toViews;
+                if (transaction.to != null && transaction.to.view == null) {
+                    toViews = toViewsForGesture(transaction, new ArrayList<>());
+                } else {
+                    toViews = Collections.emptyList();
+                }
+
+                for (int i = toViews.size() - 1; i > 0; i--) {
+                    transaction.container.addView(toViews.get(i).getView());
+                }
+
+                backGestureViewState = new BackGestureViewState(transaction.from.view, toViews);
+
+                transaction.changeHandler.handleOnBackStarted(
+                    transaction.container,
+                    getToView(),
+                    backGestureViewState.getFromView(),
+                    backEvent
+                );
+            }
+        }
+
+        @Override
+        public void handleOnBackProgressed(@NonNull BackEventCompat backEvent) {
+            Log.d("KUCK", "it has progressed");
+
+            ControllerChangeHandler.ChangeTransaction transaction = getPopTransaction();
+            if (transaction != null && transaction.changeHandler != null && transaction.changeHandler.getEnableOnBackGestureCallbacks()) {
+                transaction.changeHandler.handleOnBackProgressed(
+                    transaction.container,
+                    getToView(),
+                    backGestureViewState.getFromView(),
+                    backEvent
+                );
+            }
+        }
+
+        @Override
+        public void handleOnBackCancelled() {
+            Log.d("KUCK", "it has canceled");
+
+            ControllerChangeHandler.ChangeTransaction transaction = getPopTransaction();
+            if (transaction != null && transaction.changeHandler != null && transaction.changeHandler.getEnableOnBackGestureCallbacks()) {
+                transaction.changeHandler.handleOnBackCancelled(
+                    transaction.container,
+                    getToView(),
+                    backGestureViewState.getFromView()
+                );
+
+                for (int i = 0; i < backGestureViewState.getToViews().size(); i++) {
+                    BackGestureControllerView state = backGestureViewState.getToViews().get(i);
+                    ViewGroup parent = (ViewGroup) state.getView().getParent();
+                    if (parent != null) {
+                        parent.removeView(state.getView());
+                    }
+
+                    if (state.getInflatedForGesture()) {
+                        state.getController().removeViewReference(state.getView().getContext());
+                    }
+                }
+            }
+
+            backGestureViewState = null;
+        }
+
+        private ControllerChangeHandler.ChangeTransaction getPopTransaction() {
+            if (popTransaction == null) {
+                popTransaction = router.popTransaction(Controller.this);
+            }
+            return popTransaction;
+        }
+
+        private List<BackGestureControllerView> toViewsForGesture(
+            ControllerChangeHandler.ChangeTransaction transaction,
+            List<BackGestureControllerView> aggregator
+        ) {
+            if (transaction.to != null) {
+                View view = transaction.to.view;
+                boolean inflated = false;
+                if (view == null) {
+                    view = transaction.to.inflate(transaction.container);
+                    inflated = true;
+                } else if (view.getParent() != null) {
+                    return aggregator;
+                }
+
+                aggregator.add(new BackGestureControllerView(transaction.to, view, inflated));
+
+                if (!transaction.changeHandler.getRemovesFromViewOnPush()) {
+                    toViewsForGesture(router.popTransaction(transaction.to), aggregator);
+                }
+            }
+
+            return aggregator;
+        }
+
+        @Nullable
+        private View getToView() {
+            if (backGestureViewState.getToViews().size() == 0) {
+                return null;
+            } else {
+                return backGestureViewState.getToViews().get(0).getView();
+            }
+        }
     };
 
     public final LifecycleOwner lifecycleOwner = new ControllerLifecycleOwner(this);

conductor/src/main/java/com/bluelinelabs/conductor/ControllerChangeHandler.kt

@@ -3,6 +3,7 @@ package com.bluelinelabs.conductor
 import android.os.Bundle
 import android.view.View
 import android.view.ViewGroup
+import androidx.activity.BackEventCompat
 import androidx.annotation.RestrictTo
 import com.bluelinelabs.conductor.changehandler.SimpleSwapChangeHandler
 import com.bluelinelabs.conductor.internal.ClassUtils
@@ -50,6 +51,8 @@ abstract class ControllerChangeHandler {
 
   private var hasBeenUsed = false
 
+  open val enableOnBackGestureCallbacks = false
+
   init {
     try {
       javaClass.getConstructor()
@@ -112,9 +115,9 @@ abstract class ControllerChangeHandler {
    */
   open fun copy(): ControllerChangeHandler = fromBundle(toBundle())!!
 
-  open fun handleOnBackStarted(container: ViewGroup, to: View?, from: View, swipeEdge: Int) {}
+  open fun handleOnBackStarted(container: ViewGroup, to: View?, from: View, event: BackEventCompat) {}
 
-  open fun handleOnBackProgressed(container: ViewGroup, to: View?, from: View, progress: Float, swipeEdge: Int) {}
+  open fun handleOnBackProgressed(container: ViewGroup, to: View?, from: View, event: BackEventCompat) {}
 
   open fun handleOnBackCancelled(container: ViewGroup, to: View?, from: View) {}
 

conductor/src/main/java/com/bluelinelabs/conductor/Router.java

@@ -804,6 +804,37 @@ public abstract class Router {
         }
     }
 
+    @Nullable
+    ChangeTransaction popTransaction(@NonNull Controller controller) {
+        RouterTransaction from = null;
+        RouterTransaction to = null;
+
+        Iterator<RouterTransaction> iterator = backstack.iterator();
+        while (iterator.hasNext()) {
+            RouterTransaction transaction = iterator.next();
+            if (transaction.controller() == controller) {
+                from = transaction;
+                if (iterator.hasNext()) {
+                    to = iterator.next();
+                }
+                break;
+            }
+        }
+
+        if (from == null) {
+            return null;
+        }
+
+        return new ChangeTransaction(
+            to != null ? to.controller() : null,
+            from.controller(),
+            false,
+            container,
+            from.popChangeHandler(),
+            Collections.emptyList()
+        );
+    }
+
     void watchContainerAttach() {
         container.post(new Runnable() {
             @Override

conductor/src/main/java/com/bluelinelabs/conductor/internal/BackGestureViewState.kt

@@ -0,0 +1,15 @@
+package com.bluelinelabs.conductor.internal
+
+import android.view.View
+import com.bluelinelabs.conductor.Controller
+
+class BackGestureViewState(
+  val fromView: View,
+  val toViews: List<BackGestureControllerView>,
+)
+
+class BackGestureControllerView(
+  val controller: Controller,
+  val view: View,
+  val inflatedForGesture: Boolean,
+)

conductor/src/main/java/com/bluelinelabs/conductor/internal/OwnViewTreeLifecycleAndRegistry.kt

@@ -14,7 +14,6 @@ import androidx.savedstate.setViewTreeSavedStateRegistryOwner
 import com.bluelinelabs.conductor.Controller
 import com.bluelinelabs.conductor.ControllerChangeHandler
 import com.bluelinelabs.conductor.ControllerChangeType
-import com.bluelinelabs.conductor.R
 
 /**
  * This class sets the [ViewTreeLifecycleOwner] and [ViewTreeSavedStateRegistryOwner] which is
@@ -56,8 +55,8 @@ internal class OwnViewTreeLifecycleAndRegistry private constructor(
          * it on purpose.
          */
         if (
-          view.getTag(R.id.view_tree_lifecycle_owner) == null &&
-          view.getTag(R.id.view_tree_saved_state_registry_owner) == null
+          view.getTag(androidx.lifecycle.runtime.R.id.view_tree_lifecycle_owner) == null &&
+          view.getTag(androidx.savedstate.R.id.view_tree_saved_state_registry_owner) == null
         ) {
           view.setViewTreeLifecycleOwner(this@OwnViewTreeLifecycleAndRegistry)
           view.setViewTreeSavedStateRegistryOwner(this@OwnViewTreeLifecycleAndRegistry)

demo/build.gradle

@@ -27,20 +27,22 @@ android {
         compose = true
     }
 
-    compileSdkVersion 33
+    compileSdk 34
 
     compileOptions {
-        sourceCompatibility JavaVersion.VERSION_1_8
-        targetCompatibility JavaVersion.VERSION_1_8
+        sourceCompatibility JavaVersion.VERSION_11
+        targetCompatibility JavaVersion.VERSION_11
     }
 
     kotlinOptions {
-        jvmTarget = "1.8"
+        jvmTarget = "11"
     }
 
     composeOptions {
         kotlinCompilerExtensionVersion libs.versions.compose.compiler.get()
     }
+
+    namespace "com.bluelinelabs.conductor.demo"
 }
 
 dependencies {

demo/src/main/AndroidManifest.xml

@@ -1,31 +1,31 @@
 <?xml version="1.0" encoding="utf-8"?>
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
-    xmlns:tools="http://schemas.android.com/tools"
-    package="com.bluelinelabs.conductor.demo">
+  xmlns:tools="http://schemas.android.com/tools">
 
-    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
-    <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
+  <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
+  <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
 
-    <application
-        android:allowBackup="true"
-        android:fullBackupContent="true"
-        android:icon="@mipmap/ic_launcher"
-        android:label="@string/app_name"
-        android:theme="@style/AppTheme"
-        tools:ignore="GoogleAppIndexingWarning">
+  <application
+    android:allowBackup="true"
+    android:enableOnBackInvokedCallback="true"
+    android:fullBackupContent="true"
+    android:icon="@mipmap/ic_launcher"
+    android:label="@string/app_name"
+    android:theme="@style/AppTheme"
+    tools:ignore="GoogleAppIndexingWarning">
 
-        <activity
-            android:name="com.bluelinelabs.conductor.demo.MainActivity"
-            android:exported="true"
-            android:label="@string/app_name"
-            android:launchMode="singleTask"
-            android:windowSoftInputMode="adjustResize">
-            <intent-filter>
-                <action android:name="android.intent.action.MAIN" />
-                <category android:name="android.intent.category.LAUNCHER" />
-            </intent-filter>
-        </activity>
+    <activity
+      android:name="com.bluelinelabs.conductor.demo.MainActivity"
+      android:exported="true"
+      android:label="@string/app_name"
+      android:launchMode="singleTask"
+      android:windowSoftInputMode="adjustResize">
+      <intent-filter>
+        <action android:name="android.intent.action.MAIN" />
+        <category android:name="android.intent.category.LAUNCHER" />
+      </intent-filter>
+    </activity>
 
-    </application>
+  </application>
 
 </manifest>

demo/src/main/java/com/bluelinelabs/conductor/demo/controllers/HomeController.kt

@@ -10,6 +10,7 @@ import android.text.style.URLSpan
 import android.view.LayoutInflater
 import android.view.View
 import android.view.ViewGroup
+import androidx.activity.BackEventCompat
 import androidx.annotation.ColorRes
 import androidx.appcompat.widget.Toolbar
 import androidx.core.content.ContextCompat
@@ -18,6 +19,7 @@ import androidx.core.graphics.BlendModeCompat
 import androidx.core.text.buildSpannedString
 import androidx.recyclerview.widget.LinearLayoutManager
 import androidx.recyclerview.widget.RecyclerView
+import com.bluelinelabs.conductor.ControllerChangeHandler
 import com.bluelinelabs.conductor.RouterTransaction
 import com.bluelinelabs.conductor.asTransaction
 import com.bluelinelabs.conductor.changehandler.FadeChangeHandler
@@ -76,12 +78,13 @@ class HomeController : BaseController(R.layout.controller_home) {
   }
 
   private fun onModelRowClick(model: DemoModel, position: Int) {
+    println("onModelRowClick")
     when (model) {
       DemoModel.NAVIGATION -> {
         router.pushController(
           RouterTransaction.with(NavigationDemoController(0, DisplayUpMode.SHOW_FOR_CHILDREN_ONLY))
-            .pushChangeHandler(FadeChangeHandler())
-            .popChangeHandler(FadeChangeHandler())
+            .pushChangeHandler(WhateverChangeHandler())
+            .popChangeHandler(WhateverChangeHandler())
             .tag(NavigationDemoController.TAG_UP_TRANSACTION)
         )
       }
@@ -233,3 +236,47 @@ private class HomeAdapter(
     }
   }
 }
+
+class WhateverChangeHandler : ControllerChangeHandler() {
+  override val enableOnBackGestureCallbacks = true
+
+  override fun handleOnBackStarted(container: ViewGroup, to: View?, from: View, event: BackEventCompat) {
+    println("handleOnBackStarted")
+    to?.let { container.addView(it) }
+  }
+
+  override fun handleOnBackProgressed(container: ViewGroup, to: View?, from: View, event: BackEventCompat) {
+    if (event.swipeEdge == BackEventCompat.EDGE_LEFT) {
+      from.translationX = event.progress * container.width
+      to?.translationX = -container.width + event.progress * container.width
+    } else {
+      from.translationX = -event.progress * container.width
+      to?.translationX = container.width + -event.progress * container.width
+    }
+  }
+
+  override fun handleOnBackCancelled(container: ViewGroup, to: View?, from: View) {
+    to?.let { container.removeView(it) }
+  }
+
+  override fun performChange(
+    container: ViewGroup,
+    from: View?,
+    to: View?,
+    isPush: Boolean,
+    changeListener: ControllerChangeCompletedListener,
+  ) {
+    from?.translationX = 0f
+    to?.translationX = 0f
+    println("perform change called")
+    if (isPush) {
+      to?.let { container.addView(it) }
+      from?.let { container.removeView(it) }
+    } else {
+      to?.let { if (it.parent == null) container.addView(it) }
+      from?.let { container.removeView(it) }
+    }
+
+    changeListener.onChangeCompleted()
+  }
+}

gradle.properties

@@ -1,5 +1,5 @@
 VERSION_CODE=4
-VERSION_NAME=4.0.0-SNAPSHOT
+VERSION_NAME=4.0.0-SNAPSHOT-PREDICTIVE
 android.useAndroidX=true
 org.gradle.jvmargs=-Xmx1536m
 

gradle/libs.versions.toml

@@ -1,32 +1,30 @@
 [versions]
-minsdk = "16"
-compilesdk = "33"
+minsdk = "19"
+compilesdk = "34"
 targetsdk = "28"
 
-agp = "7.4.2" # Note: update lint version whenever this is updated
-androidx-activity = "1.6.1"
-androidx-annotation = "1.1.0"
-androidx-appcompat = "1.4.2"
-androidx-collection = "1.1.0"
-androidx-core = "1.3.2"
-androidx-lifecycle = "2.6.0"
-androidx-savedstate = "1.2.0"
-androidx-transition = "1.3.1"
+agp = "8.1.4" # Note: update lint version whenever this is updated
+androidx-activity = "1.8.2"
+androidx-annotation = "1.7.1"
+androidx-appcompat = "1.6.1"
+androidx-collection = "1.3.0"
+androidx-core = "1.12.0"
+androidx-lifecycle = "2.7.0"
+androidx-savedstate = "1.2.1"
+androidx-transition = "1.4.1"
 androidx-viewpager2 = "1.0.0"
-autodispose = "1.0.0"
-compose = "1.3.1"
-compose-compiler = "1.4.3"
-dokka = "1.8.10"
-junit = "4.13"
+compose = "1.5.4"
+compose-compiler = "1.5.3"
+dokka = "1.9.0"
+junit = "4.13.2"
 kotest = "4.6.0"
-kotlin = "1.8.10"
-leakCanary = "2.7"
-lint = "30.4.2" # Should always be agp + 23
-material = "1.2.1"
-mvnpublish = "0.23.2"
+kotlin = "1.9.10"
+leakCanary = "2.12"
+lint = "31.1.4" # Should always be agp + 23
+material = "1.11.0"
+mvnpublish = "0.27.0"
 picasso = "2.5.2"
-robolectric = "4.5.1"
-rxjava2 = "2.1.14"
+robolectric = "4.11.1"
 
 [libraries]
 activity-compose = { module = "androidx.activity:activity-compose", version.ref = "androidx-activity" }
@@ -37,14 +35,12 @@ androidx-appcompat = { module = "androidx.appcompat:appcompat", version.ref = "a
 androidx-collection = { module = "androidx.collection:collection", version.ref = "androidx-collection" }
 androidx-core-ktx = { module = "androidx.core:core-ktx", version.ref = "androidx-core" }
 androidx-lifecycle-runtime = { module = "androidx.lifecycle:lifecycle-runtime", version.ref = "androidx-lifecycle" }
-androidx-lifecycle-livedata-core = { module = "androidx.lifecycle:lifecycle-livedata-core", version.ref = "androidx-lifecycle" }
 androidx-savedstate-ktx = { module = "androidx.savedstate:savedstate-ktx", version.ref = "androidx-savedstate" }
 androidx-transition = { module = "androidx.transition:transition", version.ref = "androidx-transition" }
 androidx-viewpager2 = { module = "androidx.viewpager2:viewpager2", version.ref = "androidx-viewpager2" }
 compose-foundation = { module = "androidx.compose.foundation:foundation", version.ref = "compose" }
 compose-ui = { module = "androidx.compose.ui:ui", version.ref = "compose" }
 compose-ui-tooling = { module = "androidx.compose.ui:ui-tooling", version.ref = "compose" }
-compose-ui-tooling-preview = { module = "androidx.compose.ui:ui-tooling-preview", version.ref = "compose" }
 compose-material = { module = "androidx.compose.material:material", version.ref = "compose" }
 dokka = { module = "org.jetbrains.dokka:dokka-gradle-plugin", version.ref = "dokka" }
 junit = { module = "junit:junit", version.ref = "junit" }
@@ -59,7 +55,6 @@ lint-tests = { module = "com.android.tools.lint:lint-tests", version.ref = "lint
 material = { module = "com.google.android.material:material", version.ref = "material" }
 picasso = { module = "com.squareup.picasso:picasso", version.ref = "picasso" }
 robolectric = { module = "org.robolectric:robolectric", version.ref = "robolectric" }
-rxjava2 = { module = "io.reactivex.rxjava2:rxjava", version.ref = "rxjava2" }
 
 [plugins]
 mvnpublish = { id = "com.vanniktech.maven.publish", version.ref = "mvnpublish" }

gradle/wrapper/gradle-wrapper.properties

@@ -1,5 +1,5 @@
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-7.5-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-8.4-bin.zip
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists