CssSemanticAnalyser needs to flatten OffsetRanges for highlights

CssSemanticAnalyser reported overlapping ranges for highlights, for
example when an attribute is used in a :not() pseudo class construct.

The formatting behind the embedded range is lost and results in a
broken view.

The embedded OffsetRanges need to be flattened into a sequenze of
non-overlapping ranges.

Closes: #5012

ide/css.editor/src/org/netbeans/modules/css/editor/module/CssModuleSupport.java

@@ -31,6 +31,7 @@
 import java.util.SortedSet;
 import java.util.TreeSet;
 import java.util.concurrent.atomic.AtomicReference;
+import java.util.logging.Level;
 import java.util.logging.Logger;
 import javax.swing.text.Document;
 import org.netbeans.modules.csl.api.ColoringAttributes;
@@ -94,11 +95,13 @@ public static SemanticAnalyzerResult analyzeDeclaration(Node declarationNode) {
     }
 
     public static Map<OffsetRange, Set<ColoringAttributes>> getSemanticHighlights(FeatureContext context, FeatureCancel cancel) {
-        Map<OffsetRange, Set<ColoringAttributes>> all = new HashMap<>();
+        long start = System.nanoTime();
+
+        Map<OffsetRange, Set<ColoringAttributes>> allPrecursor = new HashMap<>();
         final Collection<NodeVisitor<Map<OffsetRange, Set<ColoringAttributes>>>> visitors = new ArrayList<>();
 
         for (CssEditorModule module : getModules()) {
-            NodeVisitor<Map<OffsetRange, Set<ColoringAttributes>>> visitor = module.getSemanticHighlightingNodeVisitor(context, all);
+            NodeVisitor<Map<OffsetRange, Set<ColoringAttributes>>> visitor = module.getSemanticHighlightingNodeVisitor(context, allPrecursor);
             //modules may return null visitor instead of a dummy empty visitor 
             //to speed up the parse tree visiting when there're no result
             if (visitor != null) {
@@ -122,6 +125,59 @@ public void run() {
 
         NodeVisitor.visitChildren(context.getParseTreeRoot(), visitors);
 
+        long preparation = System.nanoTime();
+
+        Map<OffsetRange, Set<ColoringAttributes>> all = new HashMap<>();
+
+        List<OffsetRange> sortedRanges = new ArrayList<>(allPrecursor.keySet());
+        sortedRanges.sort(null);
+
+
+        List<OffsetRange> stack = new ArrayList<>();
+        OffsetRange lastAdded;
+
+        for(int i = 0; i < sortedRanges.size(); i++) {
+            OffsetRange currentItem = sortedRanges.get(i);
+            Set<ColoringAttributes> attributes = allPrecursor.get(currentItem);
+            OffsetRange nextItem = (i < (sortedRanges.size() - 1)) ? sortedRanges.get(i + 1) : null;
+            if(nextItem != null && currentItem.getEnd() > nextItem.getStart()) {
+                stack.add(currentItem);
+                currentItem = currentItem.boundTo(0, nextItem.getStart());
+            }
+            if(! currentItem.isEmpty()) {
+                all.put(currentItem, attributes);
+            }
+            lastAdded = currentItem;
+            while(true) {
+                if(stack.isEmpty()) {
+                    break;
+                }
+                OffsetRange stackElement = stack.remove(stack.size() - 1);
+                boolean endStackProcessing = false;
+                if(nextItem != null && stackElement.getEnd() > nextItem.getStart()) {
+                    stack.add(stackElement);
+                    endStackProcessing = true;
+                }
+                Set<ColoringAttributes> stackAttributes = allPrecursor.get(stackElement);
+                stackElement = stackElement.boundTo(lastAdded.getEnd(), nextItem != null ? nextItem.getStart() : Integer.MAX_VALUE);
+                if(! stackElement.isEmpty()) {
+                    all.put(stackElement, stackAttributes);
+                    lastAdded = stackElement;
+                }
+                if(endStackProcessing) {
+                    break;
+                }
+            }
+        }
+
+        long consolidation = System.nanoTime();
+
+        if(LOGGER.isLoggable(Level.FINE)) {
+            LOGGER.log(Level.FINE, "Preparation: {0} ms, Consolidation: {1} ms", new Object[]{preparation - start, consolidation - preparation});
+            LOGGER.log(Level.FINER, "Precursor: {0}", allPrecursor);
+            LOGGER.log(Level.FINER, "Final: {0}", all);
+        }
+
         return all;
     }
 

ide/css.editor/test/unit/data/testfiles/coloring1.css

@@ -0,0 +1,6 @@
+[type="checkbox"]:nth-child(2n),
+[type="checkbox"]:not([hidden]),
+[type="checkbox"]:not(.active),
+[type="checkbox"]:not(:checked),
+[type="checkbox"]:checked {
+}

ide/css.editor/test/unit/data/testfiles/coloring1.css.semantic

@@ -0,0 +1,6 @@
+[|>CUSTOM1:type<|="checkbox"]|>CLASS::nth-child(2n)<|,
+[|>CUSTOM1:type<|="checkbox"]|>CLASS::not([|>CUSTOM1:<|hidden|>CLASS:<|])<|,
+[|>CUSTOM1:type<|="checkbox"]|>CLASS::not(|>METHOD:<|.active|>CLASS:<|)<|,
+[|>CUSTOM1:type<|="checkbox"]|>CLASS::not(|>CLASS:<|:checked|>CLASS:<|)<|,
+[|>CUSTOM1:type<|="checkbox"]|>CLASS::checked<| {
+}

ide/css.editor/test/unit/src/org/netbeans/modules/css/editor/csl/CssSemanticAnalyzerTest.java

@@ -0,0 +1,39 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.netbeans.modules.css.editor.csl;
+
+import org.netbeans.modules.css.editor.module.main.CssModuleTestBase;
+import org.netbeans.modules.css.lib.api.CssParserResult;
+
+public class CssSemanticAnalyzerTest extends CssModuleTestBase {
+
+    public CssSemanticAnalyzerTest(String name) {
+        super(name);
+    }
+
+    @Override
+    protected void setUp() throws Exception {
+        super.setUp();
+        CssParserResult.IN_UNIT_TESTS = true;
+    }
+
+    public void testColoring1() throws Exception {
+        checkSemantic("testfiles/coloring1.css");
+    }
+}