feat: Amend bringIntoView Modifier extension to be compatibel with nay ScrollableState type

Author: BiancaMihaila

patterns/src/main/java/uk/gov/android/ui/patterns/centrealignedscreen/CentreAlignedScreen.kt

@@ -46,8 +46,8 @@ import uk.gov.android.ui.patterns.centrealignedscreen.CentreAlignedScreenDefault
 import uk.gov.android.ui.patterns.centrealignedscreen.CentreAlignedScreenDefaults.NoPadding
 import uk.gov.android.ui.patterns.centrealignedscreen.CentreAlignedScreenDefaults.VerticalPadding
 import uk.gov.android.ui.patterns.centrealignedscreen.CentreAlignedScreenTestTag.BODY_LAZY_COLUMN_TEST_TAG
+import uk.gov.android.ui.patterns.utils.ModifierExtensions.bringIntoView
 import uk.gov.android.ui.patterns.utils.clearListSemanticsForTalkBack
-import uk.gov.android.ui.patterns.utils.scroll.bringIntoView
 import uk.gov.android.ui.theme.m3.GdsTheme
 import uk.gov.android.ui.theme.m3.Typography
 import uk.gov.android.ui.theme.meta.ExcludeFromJacocoGeneratedReport

patterns/src/main/java/uk/gov/android/ui/patterns/errorscreen/v2/ErrorScreen.kt

@@ -39,8 +39,8 @@ import uk.gov.android.ui.patterns.errorscreen.v2.ErrorScreenDefaults.HorizontalP
 import uk.gov.android.ui.patterns.errorscreen.v2.ErrorScreenDefaults.VerticalPadding
 import uk.gov.android.ui.patterns.errorscreen.v2.ErrorScreenTitleTestTag.ERROR_BODY_LAZY_COLUMN_TEST_TAG
 import uk.gov.android.ui.patterns.errorscreen.v2.ErrorScreenTitleTestTag.ERROR_SCREEN_TITLE_TEST_TAG
+import uk.gov.android.ui.patterns.utils.ModifierExtensions.bringIntoView
 import uk.gov.android.ui.patterns.utils.clearListSemanticsForTalkBack
-import uk.gov.android.ui.patterns.utils.scroll.bringIntoView
 import uk.gov.android.ui.theme.m3.GdsTheme
 import uk.gov.android.ui.theme.meta.ExcludeFromJacocoGeneratedReport
 import uk.gov.android.ui.theme.spacingDouble

patterns/src/main/java/uk/gov/android/ui/patterns/leftalignedscreen/LeftAlignedScreen.kt

@@ -36,7 +36,7 @@ import uk.gov.android.ui.patterns.leftalignedscreen.LeftAlignedScreenTestTag.BOD
 import uk.gov.android.ui.patterns.utils.clearListSemanticsForTalkBack
 import uk.gov.android.ui.theme.m3.GdsTheme
 import uk.gov.android.ui.theme.spacingDouble
-import uk.gov.android.ui.patterns.utils.scroll.bringIntoView as bringIntoViewV2
+import uk.gov.android.ui.patterns.utils.ModifierExtensions.bringIntoView as bringIntoViewV2
 
 private const val ONE_THIRD = 1f / 3f
 private const val FONT_SCALE_DOUBLE = 2f

patterns/src/main/java/uk/gov/android/ui/patterns/leftalignedscreen/LeftAlignedScreenContentV2.kt

@@ -41,7 +41,7 @@ import uk.gov.android.ui.componentsv2.row.RowList
 import uk.gov.android.ui.componentsv2.supportingtext.GdsSupportingText
 import uk.gov.android.ui.componentsv2.warning.GdsWarningText
 import uk.gov.android.ui.theme.dividerThickness
-import uk.gov.android.ui.patterns.utils.scroll.bringIntoView as bringIntoViewV2
+import uk.gov.android.ui.patterns.utils.ModifierExtensions.bringIntoView as bringIntoViewV2
 
 internal data class LeftAlignedScreenContentV2(
     val title: String,
@@ -345,6 +345,9 @@ private fun LazyListScope.toAnnotatedText(
  * @param scrollState [LazyListState] represents the list state
  * @return augmented [Modifier]
  */
-@Deprecated("Use uk.gov.android.ui.patterns.utils.scroll.bringIntoView")
+@Deprecated(
+    "Use uk.gov.android.ui.patterns.utils.scroll.bringIntoView",
+    level = DeprecationLevel.WARNING,
+)
 @Composable
 fun Modifier.bringIntoView(scrollState: LazyListState): Modifier = this.bringIntoViewV2(scrollState)

patterns/src/main/java/uk/gov/android/ui/patterns/utils/ModifierExtensions.kt

@@ -0,0 +1,71 @@
+package uk.gov.android.ui.patterns.utils
+
+import androidx.compose.foundation.ScrollState
+import androidx.compose.foundation.focusable
+import androidx.compose.foundation.gestures.ScrollableState
+import androidx.compose.foundation.gestures.animateScrollBy
+import androidx.compose.foundation.interaction.MutableInteractionSource
+import androidx.compose.foundation.lazy.LazyListState
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.rememberCoroutineScope
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.focus.FocusRequester
+import androidx.compose.ui.focus.focusRequester
+import androidx.compose.ui.input.key.Key
+import androidx.compose.ui.input.key.KeyEventType
+import androidx.compose.ui.input.key.key
+import androidx.compose.ui.input.key.onKeyEvent
+import androidx.compose.ui.input.key.type
+import kotlinx.coroutines.launch
+
+object ModifierExtensions {
+    /**
+     * Adds a downwards and upwards scroll when a keyboard down or up arrow is pressed
+     *
+     * @param scrollState [ScrollState] represents the list state
+     * @return augmented [Modifier]
+     */
+    @Composable
+    fun Modifier.bringIntoView(scrollState: ScrollableState): Modifier {
+        val coroutineScope = rememberCoroutineScope()
+        val interactionSource = remember { MutableInteractionSource() }
+        val focusRequester = remember { FocusRequester() }
+        return this
+            .onKeyEvent {
+                when {
+                    it.type == KeyEventType.KeyDown && it.key == Key.DirectionDown &&
+                        scrollState.canScrollForward -> {
+                        coroutineScope.launch {
+                            scrollState.animateScrollBy(
+                                SCROLL_MULTIPLIER * scrollState.viewportHeight(),
+                            )
+                        }
+                        true
+                    }
+
+                    it.type == KeyEventType.KeyDown && it.key == Key.DirectionUp &&
+                        scrollState.canScrollBackward -> {
+                        coroutineScope.launch {
+                            scrollState.animateScrollBy(
+                                -SCROLL_MULTIPLIER * scrollState.viewportHeight(),
+                            )
+                        }
+                        true
+                    }
+
+                    else -> false
+                }
+            }
+            .focusRequester(focusRequester)
+            .focusable(interactionSource = interactionSource)
+    }
+
+    private fun ScrollableState.viewportHeight(): Float = when (this) {
+        is LazyListState -> layoutInfo.viewportSize.height.toFloat()
+        is ScrollState -> viewportSize.toFloat()
+        else -> error("scrollable type not yet supported")
+    }
+
+    private const val SCROLL_MULTIPLIER = 0.4f
+}