Replaced navigateBackImmediately with onNavigateBack to support more options on navigating back. Added support for caching screens.

Author: Johann Blake

README.md

@@ -43,9 +43,9 @@ android {
 dependencies {
 
     def lifecycle_version = "2.4.0-alpha01"
-    def activity_version = "1.3.0-alpha06"
+    def activity_version = "1.3.0-alpha07"
     def retrofit_version = "2.9.0"
-    def paging_version = "3.0.0-beta03"
+    def paging_version = "3.0.0-rc01"
 
     implementation 'androidx.core:core-ktx:1.6.0-alpha01'
     implementation 'androidx.appcompat:appcompat:1.3.0-rc01'

app/build.gradle

@@ -1,7 +1,7 @@
 // Top-level build file where you can add configuration options common to all sub-projects/modules.
 buildscript {
     ext {
-        compose_version = '1.0.0-beta04'
+        compose_version = '1.0.0-beta05'
     }
     repositories {
         google()

build.gradle

@@ -35,10 +35,10 @@ android {
 }
 
 dependencies {
-    def lifecycle_version = "2.3.0"
+    def lifecycle_version = "2.4.0-alpha01"
 
-    implementation 'androidx.core:core-ktx:1.5.0-beta01'
+    implementation 'androidx.core:core-ktx:1.6.0-alpha02'
     implementation "androidx.lifecycle:lifecycle-runtime-ktx:$lifecycle_version"
     implementation "androidx.lifecycle:lifecycle-livedata-ktx:$lifecycle_version"
-    implementation 'androidx.lifecycle:lifecycle-viewmodel-compose:1.0.0-alpha03'
+    implementation 'androidx.lifecycle:lifecycle-viewmodel-compose:1.0.0-alpha04'
 }

navigation/build.gradle

@@ -21,16 +21,16 @@ data class NavigationInfo(
     var screen: Any? = null,
 
     /**
-     * Any data that is communicated to the screen from the previous screen. This is typically used
-     * to pass data that the screen needs to display its data.
+     * Any data that is communicated to the screen from the previous screen. This is typically used to pass data that
+     * the screen needs to display its data.
      */
     var screenData: Any? = null,
 
     /**
-     * An optional viewmodel that is associated with the screen. Pass in a reference to a class that
-     * inherits from ViewModel and not a reference to an actual instance. Navigation Manager will
-     * create the viewmodel when the user navigates to the screen and will remove it from the navigation
-     * stack when the user navigates to the previous screen.
+     * An optional viewmodel that is associated with the screen. Pass in a reference to a class that inherits from
+     * ViewModel and not a reference to an actual instance. Navigation Manager will create the viewmodel when the user
+     * navigates to the screen and will remove it from the navigation stack when the user navigates to the previous
+     * screen.
      */
     var viewmodel: ViewModel? = null,
 
@@ -43,9 +43,9 @@ data class NavigationInfo(
     internal var _onCloseScreen: MutableLiveData<Boolean>? = null,
 
     /**
-     * Used to notify clients to close their screens. In Jetpack Compose, this typically means
-     * preventing the screen from being displayed such as setting the visible property of AnimatedVisibility
-     * to false or if no animations are used, just to prevent the composable from generating the UI.
+     * Used to notify clients to close their screens. In Jetpack Compose, this typically means preventing the screen
+     * from being displayed such as setting the visible property of AnimatedVisibility to false or if no animations
+     * are used, just to prevent the composable from generating the UI.
      */
     var onCloseScreen: LiveData<Boolean>? = null
 )

navigation/src/main/java/dev/wirespec/navigation/NavigationInfo.kt

@@ -1,5 +1,34 @@
 package dev.wirespec.navigation
 
 interface NavigationManagerHelper {
-    fun navigateBackImmediately(): Boolean
+    fun onNavigateBack(): NavigateBackOptions
+}
+
+enum class NavigateBackOptions {
+    /**
+     * Causes the Navigation Manager to navigate to the previous screen without checking to see if the onNavigateBack
+     * interface function is defined.
+     */
+    GoBackImmediately,
+
+    /**
+     * Same as GoBackImmediately but the navigation info for the current screen is cached so that it can be re-used
+     * later on. The nav info only gets cached if it isn't in the cache already. In order to be cached, the id
+     * parameter of the navigateTo function must be provided. If it is not provided, an exception is thrown. Note: The
+     * cache is not the same thing as the navigation stack. The cache is a separate cache used to keep an instance of
+     * the nav info when moving back. The nav info is removed from the navigation stack when navigating back.
+     */
+    GoBackImmediatelyAndCacheScreen,
+
+    /**
+     * Same as GoBackImmediately but the navigation info for the current screen is removed from the cache (if it exist
+     * in the cache). In order to be removed from  the cache, the id parameter of the navigateTo function must be
+     * provided. If it is not provided, an exception is thrown.
+     */
+    GoBackImmediatelyAndRemoveCachedScreen,
+
+    /**
+     * Cancels navigating to the previous screen.
+     */
+    Cancel
 }

navigation/src/main/java/dev/wirespec/navigation/NavigationManager.kt

@@ -5,15 +5,15 @@ package dev.wirespec.navigation
  */
 open class ScreenInfo<T>(
     /**
-     * Identifies the type of screen. It is recommended to use objects based on a sealed class to create a quasi
-     * enum, although using regular enums or even constants are also valid.
+     * Identifies the type of screen. It is recommended to use objects based on a sealed class to create a quasi enum,
+     * although using regular enums or even constants are also valid.
      */
     val screen: Any,
 
     /**
      * The viewmodel that should be associated with the screen. This is optional. A screen is not required to use a
-     * viewmodel and can even manage its own viewmodel. If a viewmodel class is provided and the client navigates to
-     * a screen, the Navigation Manager will create the viewmodel and remove it when the user navigates either backwards
+     * viewmodel and can even manage its own viewmodel. If a viewmodel class is provided and the client navigates to a
+     * screen, the Navigation Manager will create the viewmodel and remove it when the user navigates either backwards
      * or navigates to the home screen.
      */
     val viewmodel: Class<T>? = null,