From 520930c5eb79a2045ba5b5be40351ecd85abfd6e Mon Sep 17 00:00:00 2001
From: Kirill Grouchnikov <kirillg@google.com>
Date: Fri, 14 Jan 2022 16:00:36 -0500
Subject: [PATCH] Horizontal auto-reveal scrolling for breadcrumb bar

For #8
---
 .../aurora/component/AuroraBreadcrumbBar.kt   | 19 ++++++++++---------
 .../aurora/demo/AuroraBreadcrumbBarDemo.kt    |  7 +++++++
 2 files changed, 17 insertions(+), 9 deletions(-)

diff --git a/component/src/desktopMain/kotlin/org/pushingpixels/aurora/component/AuroraBreadcrumbBar.kt b/component/src/desktopMain/kotlin/org/pushingpixels/aurora/component/AuroraBreadcrumbBar.kt
index 782c493e..53cd8c36 100644
--- a/component/src/desktopMain/kotlin/org/pushingpixels/aurora/component/AuroraBreadcrumbBar.kt
+++ b/component/src/desktopMain/kotlin/org/pushingpixels/aurora/component/AuroraBreadcrumbBar.kt
@@ -15,6 +15,7 @@
  */
 package org.pushingpixels.aurora.component
 
+import androidx.compose.foundation.ScrollState
 import androidx.compose.foundation.horizontalScroll
 import androidx.compose.foundation.interaction.MutableInteractionSource
 import androidx.compose.foundation.layout.*
@@ -47,6 +48,7 @@ import org.pushingpixels.aurora.theming.*
 fun AuroraBreadcrumbBar(
     contentModel: List<Command>,
     presentationModel: BreadcrumbBarPresentationModel = BreadcrumbBarPresentationModel(),
+    horizontalScrollState: ScrollState = rememberScrollState(0),
     modifier: Modifier
 ) {
     val colors = AuroraSkin.colors
@@ -102,7 +104,6 @@ fun AuroraBreadcrumbBar(
         resourceLoader = resourceLoader
     )
 
-    val stateHorizontal = rememberScrollState(0)
     val scope = rememberCoroutineScope()
     val scrollAmount = 12.dp.value * density.density
 
@@ -146,11 +147,11 @@ fun AuroraBreadcrumbBar(
                 )
             }
         },
-        isActionEnabled = (stateHorizontal.value > 0),
+        isActionEnabled = (horizontalScrollState.value > 0),
         action = {
             scope.launch {
-                stateHorizontal.scrollTo(
-                    (stateHorizontal.value - scrollAmount.toInt()).coerceAtLeast(0)
+                horizontalScrollState.scrollTo(
+                    (horizontalScrollState.value - scrollAmount.toInt()).coerceAtLeast(0)
                 )
             }
         })
@@ -194,12 +195,12 @@ fun AuroraBreadcrumbBar(
                 )
             }
         },
-        isActionEnabled = (stateHorizontal.value < stateHorizontal.maxValue),
+        isActionEnabled = (horizontalScrollState.value < horizontalScrollState.maxValue),
         action = {
             scope.launch {
-                stateHorizontal.scrollTo(
-                    (stateHorizontal.value + scrollAmount.toInt()).coerceAtMost(
-                        stateHorizontal.maxValue
+                horizontalScrollState.scrollTo(
+                    (horizontalScrollState.value + scrollAmount.toInt()).coerceAtMost(
+                        horizontalScrollState.maxValue
                     )
                 )
             }
@@ -221,7 +222,7 @@ fun AuroraBreadcrumbBar(
                 )
             ).project()
 
-            Box(modifier = Modifier.horizontalScroll(stateHorizontal)) {
+            Box(modifier = Modifier.horizontalScroll(horizontalScrollState)) {
                 Row(modifier = Modifier.fillMaxWidth().wrapContentHeight()) {
                     for (command in contentModel) {
                         AuroraCommandButton(
diff --git a/demo/src/desktopMain/kotlin/org/pushingpixels/aurora/demo/AuroraBreadcrumbBarDemo.kt b/demo/src/desktopMain/kotlin/org/pushingpixels/aurora/demo/AuroraBreadcrumbBarDemo.kt
index 36eca417..502e5d4e 100644
--- a/demo/src/desktopMain/kotlin/org/pushingpixels/aurora/demo/AuroraBreadcrumbBarDemo.kt
+++ b/demo/src/desktopMain/kotlin/org/pushingpixels/aurora/demo/AuroraBreadcrumbBarDemo.kt
@@ -16,6 +16,7 @@
 package org.pushingpixels.aurora.demo
 
 import androidx.compose.foundation.layout.*
+import androidx.compose.foundation.rememberScrollState
 import androidx.compose.runtime.*
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
@@ -26,6 +27,7 @@ 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.delay
 import kotlinx.coroutines.launch
 import org.pushingpixels.aurora.component.AuroraBreadcrumbBar
 import org.pushingpixels.aurora.component.model.*
@@ -136,9 +138,13 @@ fun AuroraWindowScope.BreadcrumbContent(auroraSkinDefinition: MutableState<Auror
         }
 
     val commandPanelContentModel = remember { mutableStateOf<CommandPanelContentModel?>(null) }
+    val breadcrumbBarHorizontalScrollState = rememberScrollState(0)
     val onBreadcrumbItemSelected: (File) -> Unit = {
         scope.launch(Dispatchers.Default) {
             commandPanelContentModel.value = getCommandPanelContent(breadcrumbBarContentProvider, it)
+            delay(150)
+            breadcrumbBarHorizontalScrollState.animateScrollTo(
+                breadcrumbBarHorizontalScrollState.maxValue)
         }
     }
 
@@ -156,6 +162,7 @@ fun AuroraWindowScope.BreadcrumbContent(auroraSkinDefinition: MutableState<Auror
                     iconEnabledFilterStrategy = IconFilterStrategy.ThemedFollowText,
                     iconDisabledFilterStrategy = IconFilterStrategy.ThemedFollowText
                 ),
+                horizontalScrollState = breadcrumbBarHorizontalScrollState,
                 modifier = Modifier.fillMaxWidth().auroraBackground()
                     .padding(horizontal = 2.dp, vertical = 4.dp)
             )