Narrow autocomplete options as user types

Author: lawson89

sierra-previewer/src/main/java/org/httprpc/sierra/previewer/SierraXMLCompletionProvider.java

@@ -119,7 +119,20 @@ public List<Completion> getCompletions(JTextComponent comp) {
         var context = getCompletionContext(comp, offset);
 
         if (context.type == CompletionType.TAG_NAME) {
-            return new ArrayList<>(tagCompletions);
+            // Narrow tag suggestions by the already-entered prefix (case-insensitive)
+            var prefix = getAlreadyEnteredText(comp);
+            var lowerPrefix = prefix == null ? "" : prefix.toLowerCase();
+
+            List<Completion> filtered = new ArrayList<>();
+            for (var c : tagCompletions) {
+                var text = c.getInputText();
+                if (!lowerPrefix.isEmpty() && !text.toLowerCase().startsWith(lowerPrefix)) {
+                    continue;
+                }
+                filtered.add(c);
+            }
+
+            return filtered;
         }
 
         if (context.type == CompletionType.ATTRIBUTE_NAME && context.tagName != null) {
@@ -145,8 +158,17 @@ public List<Completion> getCompletions(JTextComponent comp) {
 
             Collections.sort(availableAttributeNames);
 
+            // Determine the already-entered text (prefix) so we can narrow suggestions
+            var prefix = getAlreadyEnteredText(comp);
+            var lowerPrefix = prefix == null ? "" : prefix.toLowerCase();
+
             List<Completion> suggestions = new ArrayList<>();
             for (var attr : availableAttributeNames) {
+                // If there's a prefix, filter attributes that don't start with it (case-insensitive)
+                if (!lowerPrefix.isEmpty() && !attr.toLowerCase().startsWith(lowerPrefix)) {
+                    continue;
+                }
+
                 var description = allAttributes.get(attr);
 
                 // Create a richer HTML tooltip using the full description
@@ -198,12 +220,17 @@ private CompletionContext getCompletionContext(JTextComponent comp, int offset)
             }
 
             var textSinceOpen = text.substring(lastOpenAngle);
+            // If there is no space after the tag name, we're still typing the tag name
             if (!textSinceOpen.contains(" ") && !textSinceOpen.contains("\n")) {
                 return new CompletionContext(CompletionType.TAG_NAME, tagName, lastOpenAngle);
             }
 
-            var lastChar = text.charAt(offset - 1);
-            if (Character.isWhitespace(lastChar)) {
+            // If we have reached the attribute area (there is a space/newline after '<...'),
+            // consider this attribute name completion context even if the last character
+            // isn't whitespace (so typing 'na' after '<button ' still triggers attribute
+            // suggestions). We already checked for being inside a quoted attribute value
+            // above.
+            if (textSinceOpen.contains(" ") || textSinceOpen.contains("\n")) {
                 return new CompletionContext(CompletionType.ATTRIBUTE_NAME, tagName, lastOpenAngle);
             }
 
@@ -213,6 +240,35 @@ private CompletionContext getCompletionContext(JTextComponent comp, int offset)
         return new CompletionContext(CompletionType.NONE);
     }
 
+    @Override
+    public String getAlreadyEnteredText(JTextComponent comp) {
+        // Return the partial attribute name currently being typed so AutoCompletion
+        // can filter the list of completions.
+        int pos = comp.getCaretPosition();
+        try {
+            var text = comp.getText(0, pos);
+            var lastOpen = text.lastIndexOf('<');
+            if (lastOpen == -1) {
+                return "";
+            }
+
+            // Scan backwards from the caret until we hit whitespace or a character that
+            // can't be part of an attribute name (e.g., '=', '<', quotes).
+            int i = pos - 1;
+            while (i > lastOpen) {
+                char c = text.charAt(i);
+                if (Character.isWhitespace(c) || c == '<' || c == '=' || c == '"' || c == '\'') {
+                    break;
+                }
+                i--;
+            }
+
+            return text.substring(i + 1, pos);
+        } catch (BadLocationException e) {
+            return "";
+        }
+    }
+
     private Set<String> getAlreadyDefinedAttributes(JTextComponent comp, int tagStartOffset, int caretOffset) {
         Set<String> definedAttributes = new HashSet<>();
         try {

sierra-previewer/src/test/java/org/httprpc/sierra/previewer/SierraXMLCompletionProviderTest.java

@@ -64,10 +64,8 @@ private void setComponentText(String text, int caretOffset) throws BadLocationEx
         when(mockComponent.getCaretPosition()).thenReturn(caretOffset);
     }
 
-    // --- Core Test Case: 1. Tag Completion ---
-
     @Test
-    void testCompletion_StartTag_SuggestsAllUIElements() throws BadLocationException {
+    void testAllUiElements() throws BadLocationException {
         // Simulate typing '<' to trigger tag completion (caret at offset 1)
         setComponentText("<", 1);
 
@@ -96,10 +94,8 @@ void testCompletion_StartTag_SuggestsAllUIElements() throws BadLocationException
         }
     }
 
-    // --- Core Test Case: 2. Attribute Completion for <button> ---
-
     @Test
-    void testCompletion_InsideButtonTag_SuggestsCoreAttributes() throws BadLocationException {
+    void testButtonAttributes() throws BadLocationException {
         var text = "<button ";
         var caretOffset = text.length(); // Caret is right after the space in "<button "
 
@@ -114,7 +110,7 @@ void testCompletion_InsideButtonTag_SuggestsCoreAttributes() throws BadLocationE
             .collect(Collectors.toSet());
 
         assertTrue(attributeNames.contains("name"), "Should suggest the mandatory 'name' attribute.");
-        //assertTrue(attributeNames.contains("text"), "Should suggest the mandatory 'text' attribute.");
+        assertTrue(attributeNames.contains("text"), "Should suggest the mandatory 'text' attribute.");
 
         // Verify other essential attributes are present (from the DTD)
         assertTrue(attributeNames.contains("background"), "Should also suggest the 'background' attribute.");
@@ -127,8 +123,8 @@ void testCompletion_InsideButtonTag_SuggestsCoreAttributes() throws BadLocationE
         }
     }
 
-        @Test
-    void testCompletion_InsideTextAreaTag_SuggestsCoreAttributes() throws BadLocationException {
+    @Test
+    void testTextAreaAtttributes() throws BadLocationException {
         var text = "<text-area ";
         var caretOffset = text.length();
 
@@ -143,7 +139,7 @@ void testCompletion_InsideTextAreaTag_SuggestsCoreAttributes() throws BadLocatio
             .collect(Collectors.toSet());
 
         assertTrue(attributeNames.contains("name"), "Should suggest the mandatory 'name' attribute.");
-        //assertTrue(attributeNames.contains("text"), "Should suggest the mandatory 'text' attribute.");
+        assertTrue(attributeNames.contains("text"), "Should suggest the mandatory 'text' attribute.");
 
         // specific to text area
         assertTrue(attributeNames.contains("lineWrap"), "Should suggest the mandatory 'lineWrap' attribute.");
@@ -158,4 +154,76 @@ void testCompletion_InsideTextAreaTag_SuggestsCoreAttributes() throws BadLocatio
             assertTrue(current.compareTo(next) <= 0, "Suggestions should be sorted alphabetically.");
         }
     }
+
+    @Test
+    void testAttributeNarrowing() throws BadLocationException {
+        // Start with just '<button ' (caret after space)
+        var base = "<button ";
+        setComponentText(base, base.length());
+
+        var suggestionsAll = provider.getCompletions(mockComponent);
+        assertFalse(suggestionsAll.isEmpty(), "Should suggest attributes when inside a tag.");
+        assertTrue(suggestionsAll.stream().anyMatch(c -> c.getInputText().equals("name")),
+            "Suggestions should include 'name' initially.");
+
+        // Type one character: 'n'
+        var oneChar = "<button n";
+        setComponentText(oneChar, oneChar.length());
+
+        var suggestionsN = provider.getCompletions(mockComponent);
+        assertFalse(suggestionsN.isEmpty(), "Should still suggest attributes after typing 'n'.");
+        for (var c : suggestionsN) {
+            assertTrue(c.getInputText().toLowerCase().startsWith("n"),
+                "All suggestions after typing 'n' should start with 'n'.");
+        }
+
+        // Type a second character: 'a' -> prefix 'na'
+        var twoChar = "<button na";
+        setComponentText(twoChar, twoChar.length());
+
+        var suggestionsNA = provider.getCompletions(mockComponent);
+        assertFalse(suggestionsNA.isEmpty(), "Should still suggest attributes after typing 'na'.");
+        for (var c : suggestionsNA) {
+            assertTrue(c.getInputText().toLowerCase().startsWith("na"),
+                "All suggestions after typing 'na' should start with 'na'.");
+        }
+        assertTrue(suggestionsNA.stream().anyMatch(c -> c.getInputText().equals("name")),
+            "Suggestions after 'na' should include the 'name' attribute.");
+    }
+
+    @Test
+    void testTagNarrowing() throws BadLocationException {
+        // Start with just '<' (caret after '<')
+        var base = "<";
+        setComponentText(base, base.length());
+
+        var suggestionsAll = provider.getCompletions(mockComponent);
+        assertFalse(suggestionsAll.isEmpty(), "Should suggest tags when starting a tag.");
+        assertTrue(suggestionsAll.stream().anyMatch(c -> c.getInputText().equals("button")),
+            "Suggestions should include 'button' initially.");
+
+        // Type one character: 'b'
+        var oneChar = "<b";
+        setComponentText(oneChar, oneChar.length());
+
+        var suggestionsB = provider.getCompletions(mockComponent);
+        assertFalse(suggestionsB.isEmpty(), "Should still suggest tags after typing 'b'.");
+        for (var c : suggestionsB) {
+            assertTrue(c.getInputText().toLowerCase().startsWith("b"),
+                "All tag suggestions after typing 'b' should start with 'b'.");
+        }
+
+        // Type a second character: 'u' -> prefix 'bu'
+        var twoChar = "<bu";
+        setComponentText(twoChar, twoChar.length());
+
+        var suggestionsBU = provider.getCompletions(mockComponent);
+        assertFalse(suggestionsBU.isEmpty(), "Should still suggest tags after typing 'bu'.");
+        for (var c : suggestionsBU) {
+            assertTrue(c.getInputText().toLowerCase().startsWith("bu"),
+                "All tag suggestions after typing 'bu' should start with 'bu'.");
+        }
+        assertTrue(suggestionsBU.stream().anyMatch(c -> c.getInputText().equals("button")),
+            "Suggestions after 'bu' should include the 'button' tag.");
+    }
 }

sierra-test/src/main/resources/org/httprpc/sierra/test/AlignmentXTest.xml

@@ -2,7 +2,7 @@
 
 <!DOCTYPE column-panel SYSTEM "sierra.dtd">
 
-<column-panel spacing="4" padding="8" alignToGrid="true" opaque="true">
+<column-panel spacing="4" padding="8" alignToGrid="true" opaque="false" background="white">
     <row-panel>
         <text-pane text="0.0" alignmentX="0.0" border="silver"/>
         <text-pane text="0.25" horizontalAlignment="center" alignmentX="0.25" border="silver"/>