[Compose-CL] Autocomplete IDs on special anchors

Special anchors only need the ID they're being constrained to.

Bug: 207030860
Test: completeConstraintIdsInSpecialAnchors
Change-Id: I73ea5a1ad7178b5f47274d4d299eb3f8cc817852

3 files changed, 42 insertions, 3 deletions

diff --git a/compose-ide-plugin/src/com/android/tools/compose/code/completion/constraintlayout/ConstraintLayoutJsonCompletionContributor.kt b/compose-ide-plugin/src/com/android/tools/compose/code/completion/constraintlayout/ConstraintLayoutJsonCompletionContributor.kt
index 26d8955f872..33b99776a7c 100644
--- a/compose-ide-plugin/src/com/android/tools/compose/code/completion/constraintlayout/ConstraintLayoutJsonCompletionContributor.kt
+++ b/compose-ide-plugin/src/com/android/tools/compose/code/completion/constraintlayout/ConstraintLayoutJsonCompletionContributor.kt
@@ -64,11 +64,18 @@ class ConstraintLayoutJsonCompletionContributor : CompletionContributor() {
       CompletionType.BASIC,
       // Complete ConstraintSet names in Extends keyword
       jsonStringValue()
-        .withPropertyParentAtLevel(2, KeyWords.Extends),
+        .withPropertyParentAtLevel(BASE_DEPTH_FOR_LITERAL_IN_PROPERTY, KeyWords.Extends),
       ConstraintSetNamesProvider
     )
     extend(
       CompletionType.BASIC,
+      // Complete IDs on special anchors, they take a single string value
+      jsonStringValue()
+        .withPropertyParentAtLevel(BASE_DEPTH_FOR_LITERAL_IN_PROPERTY, SpecialAnchor.values().map { it.keyWord }),
+      ConstraintIdsProvider
+    )
+    extend(
+      CompletionType.BASIC,
       // Complete IDs in the constraint array (first position)
       jsonStringValue()
         // First element in the array, ie: there is no PsiElement preceding the desired one at this level
diff --git a/compose-ide-plugin/src/com/android/tools/compose/code/completion/constraintlayout/PatternUtils.kt b/compose-ide-plugin/src/com/android/tools/compose/code/completion/constraintlayout/PatternUtils.kt
index 84f14bb15d9..19ce943f492 100644
--- a/compose-ide-plugin/src/com/android/tools/compose/code/completion/constraintlayout/PatternUtils.kt
+++ b/compose-ide-plugin/src/com/android/tools/compose/code/completion/constraintlayout/PatternUtils.kt
@@ -55,12 +55,19 @@ internal inline fun <reified T : PsiElement> psiElement(): PsiElementPattern<T,
 internal inline fun <reified T : PsiElement> PsiElementPattern<*, *>.withParent() = this.withParent(T::class.java)
 
 /**
+ * Pattern such that when traversing up the tree from the current element, the element at [level] is a [JsonProperty]. And its name matches
+ * the given [name].
+ */
+internal fun PsiElementPattern<*, *>.withPropertyParentAtLevel(level: Int, name: String) =
+  withPropertyParentAtLevel(level, listOf(name))
+
+/**
  * Pattern such that when traversing up the tree from the current element, the element at [level] is a [JsonProperty]. Which name matches
  * one of the given [names].
  */
-internal fun PsiElementPattern<*, *>.withPropertyParentAtLevel(level: Int, vararg names: String) =
+internal fun PsiElementPattern<*, *>.withPropertyParentAtLevel(level: Int, names: Collection<String>) =
   this.withSuperParent(level, psiElement<JsonProperty>().withChild(
-    psiElement<JsonReferenceExpression>().withText(StandardPatterns.string().oneOf(*names)))
+    psiElement<JsonReferenceExpression>().withText(StandardPatterns.string().oneOf(names)))
   )
 
 /**
diff --git a/compose-ide-plugin/testSrc/com/android/tools/compose/code/completion/constraintlayout/ConstraintLayoutJsonCompletionContributorTest.kt b/compose-ide-plugin/testSrc/com/android/tools/compose/code/completion/constraintlayout/ConstraintLayoutJsonCompletionContributorTest.kt
index 91b4da64308..cffbee036db 100644
--- a/compose-ide-plugin/testSrc/com/android/tools/compose/code/completion/constraintlayout/ConstraintLayoutJsonCompletionContributorTest.kt
+++ b/compose-ide-plugin/testSrc/com/android/tools/compose/code/completion/constraintlayout/ConstraintLayoutJsonCompletionContributorTest.kt
@@ -149,6 +149,31 @@ internal class ConstraintLayoutJsonCompletionContributorTest {
   }
 
   @Test
+  fun completeConstraintIdsInSpecialAnchors() {
+    @Language("JSON5")
+    val content =
+      """
+      {
+        ConstraintSets: {
+          start: {
+            id1: {
+              center: '$caret'
+            },
+            id2: {},
+            id3: {}
+          }
+        }
+      }
+    """.trimIndent()
+    myFixture.configureByText("myscene.json", content)
+    myFixture.completeBasic()
+    val lookupElements = myFixture.lookupElementStrings!!
+
+    assertThat(lookupElements).hasSize(3)
+    assertThat(lookupElements).containsExactly("id2", "id3", "parent")
+  }
+
+  @Test
   fun completeAnchorsInConstraintArray() {
     @Language("JSON5")
     var content: String =