Tweaks to breadcrumb bar content provider

Change from interface to abstract class so that it can track its current loading job and cancel it if necessary. For #8
kirill-grouchnikov · Jan 14, 2022 · deaec36 · deaec36
1 parent f471f81
commit deaec36
Show file tree

Hide file tree

Showing 2 changed files with 23 additions and 16 deletions.
diff --git a/...nt/src/desktopMain/kotlin/org/pushingpixels/aurora/component/model/BreadcrumbBarModels.kt b/...nt/src/desktopMain/kotlin/org/pushingpixels/aurora/component/model/BreadcrumbBarModels.kt
@@ -19,7 +19,8 @@ import androidx.compose.runtime.*
 import androidx.compose.runtime.snapshots.SnapshotStateList
 import androidx.compose.ui.graphics.painter.Painter
 import kotlinx.coroutines.CoroutineScope
-import kotlinx.coroutines.coroutineScope
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.Job
 import kotlinx.coroutines.launch
 import org.pushingpixels.aurora.theming.BackgroundAppearanceStrategy
 import org.pushingpixels.aurora.theming.IconFilterStrategy
@@ -28,12 +29,14 @@ import java.io.InputStream
 /**
  * Content provider for a breadcrumb bar.
  */
-interface BreadcrumbBarContentProvider<T> {
+abstract class BreadcrumbBarContentProvider<T> {
+    internal var currentJob: Job? = null
+
     /** Returns the display text for the item, or for the root is `null` is passed. */
-    fun getDisplayText(item: T?): String
+    abstract fun getDisplayText(item: T?): String
 
     /** Returns the icon for the item, or for the root is `null` is passed. */
-    fun getIcon(item: T?): Painter? = null
+    open fun getIcon(item: T?): Painter? = null
 
     /**
      * Returns the choice elements that correspond to the specified path. If the
@@ -42,7 +45,7 @@ interface BreadcrumbBarContentProvider<T> {
      * @param item Breadcrumb bar item.
      * @return The choice elements that correspond to the specified item.
      */
-    suspend fun getPathChoices(item: T?): List<T>
+    abstract suspend fun getPathChoices(item: T?): List<T>
 
     /**
      * Returns the leaf elements that correspond to the specified item. If the specified
@@ -51,7 +54,7 @@ interface BreadcrumbBarContentProvider<T> {
      * @param item Breadcrumb bar item.
      * @return The leaf elements that correspond to the specified item.
      */
-    suspend fun getLeaves(item: T): List<T>
+    abstract suspend fun getLeaves(item: T): List<T>
 
     /**
      * Returns the input stream with the leaf content. Some implementations may
@@ -61,7 +64,7 @@ interface BreadcrumbBarContentProvider<T> {
      * @return Input stream with the leaf content. May be `null` if
      * this is not applicable.
      */
-    suspend fun getLeafContent(leaf: T): InputStream? = null
+    open suspend fun getLeafContent(leaf: T): InputStream? = null
 }
 
 suspend fun <T> BreadcrumbBarContentProvider<T>.getPathCommand(
@@ -78,11 +81,12 @@ suspend fun <T> BreadcrumbBarContentProvider<T>.getPathCommand(
         text = this.getDisplayText(item),
         icon = this.getIcon(item),
         action = {
+            currentJob?.cancel()
             // This is called when the path item is clicked
             while (commands.size > level) {
                 commands.removeLast()
             }
-            scope.launch {
+            scope.launch(Dispatchers.Default) {
                 onItemSelected.invoke(item!!)
             }
         },
@@ -96,7 +100,8 @@ suspend fun <T> BreadcrumbBarContentProvider<T>.getPathCommand(
                             while (commands.size > level) {
                                 commands.removeLast()
                             }
-                            scope.launch {
+                            currentJob?.cancel()
+                            currentJob = scope.launch(Dispatchers.Default) {
                                 commands.add(
                                     getPathCommand(
                                         scope = scope,
@@ -124,7 +129,7 @@ fun <T> BreadcrumbBarContentModel(
     val scope = rememberCoroutineScope()
 
     LaunchedEffect(null) {
-        coroutineScope {
+        scope.launch(Dispatchers.Default) {
             // Root content for the breadcrumb bar
             commands.add(
                 contentProvider.getPathCommand(

diff --git a/demo/src/desktopMain/kotlin/org/pushingpixels/aurora/demo/AuroraBreadcrumbBarDemo.kt b/demo/src/desktopMain/kotlin/org/pushingpixels/aurora/demo/AuroraBreadcrumbBarDemo.kt
@@ -25,6 +25,7 @@ import androidx.compose.ui.unit.dp
 import androidx.compose.ui.window.WindowPlacement
 import androidx.compose.ui.window.WindowPosition
 import androidx.compose.ui.window.rememberWindowState
+import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.launch
 import org.pushingpixels.aurora.component.AuroraBreadcrumbBar
 import org.pushingpixels.aurora.component.model.*
@@ -98,8 +99,8 @@ fun AuroraWindowScope.BreadcrumbContent(auroraSkinDefinition: MutableState<Auror
     val scope = rememberCoroutineScope()
 
     val fileSystemView = FileSystemView.getFileSystemView()
-    val breadcrumbBarContentProvider: BreadcrumbBarContentProvider<File> =
-        object : BreadcrumbBarContentProvider<File> {
+    val breadcrumbBarContentProvider =
+        object: BreadcrumbBarContentProvider<File>() {
             override fun getDisplayText(item: File?): String {
                 if (item == null) {
                     return ""
@@ -136,7 +137,7 @@ fun AuroraWindowScope.BreadcrumbContent(auroraSkinDefinition: MutableState<Auror
 
     val commandPanelContentModel = remember { mutableStateOf<CommandPanelContentModel?>(null) }
     val onBreadcrumbItemSelected: (File) -> Unit = {
-        scope.launch {
+        scope.launch(Dispatchers.Default) {
             commandPanelContentModel.value = getCommandPanelContent(breadcrumbBarContentProvider, it)
         }
     }
@@ -203,7 +204,7 @@ fun AuroraWindowScope.BreadcrumbContent(auroraSkinDefinition: MutableState<Auror
                                         filePath.add(0, currentFile)
                                         currentFile = fileSystemView.getParentDirectory(currentFile)
                                     }
-                                    // Convert to list of commands
+                                    // Convert to list of commands and set as content model
                                     breadcrumbBarContentModel.clear()
                                     for ((index, file) in filePath.withIndex()) {
                                         breadcrumbBarContentModel.add(
@@ -216,8 +217,9 @@ fun AuroraWindowScope.BreadcrumbContent(auroraSkinDefinition: MutableState<Auror
                                             )
                                         )
                                     }
-                                    commandPanelContentModel.value =
-                                        getCommandPanelContent(breadcrumbBarContentProvider, selected)
+                                    // And trigger the item selected callback to populate the
+                                    // our command panel
+                                    onBreadcrumbItemSelected.invoke(selected)
                                 }
                             }
                         }),