Revert color preview patch (#6780)

This time it is signed. Turns out you cannot create a PR from the GitHub
window, since they are not signed.

Author: stevemessick

flutter-idea/src/io/flutter/editor/FlutterColorProvider.java

@@ -14,7 +14,10 @@
 import com.intellij.psi.impl.source.tree.AstBufferUtil;
 import com.jetbrains.lang.dart.DartLanguage;
 import com.jetbrains.lang.dart.DartTokenTypes;
-import com.jetbrains.lang.dart.psi.*;
+import com.jetbrains.lang.dart.psi.DartArgumentList;
+import com.jetbrains.lang.dart.psi.DartArguments;
+import com.jetbrains.lang.dart.psi.DartExpression;
+import com.jetbrains.lang.dart.psi.DartLiteralExpression;
 import io.flutter.FlutterBundle;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
@@ -35,6 +38,7 @@ public Color getColorFrom(@NotNull PsiElement element) {
     if (element.getNode().getElementType() != DartTokenTypes.IDENTIFIER) return null;
 
     final String name = element.getText();
+    if (!(name.equals("Colors") || name.equals("CupertinoColors") || name.equals("Color"))) return null;
 
     final PsiElement refExpr = topmostReferenceExpression(element);
     if (refExpr == null) return null;
@@ -58,28 +62,6 @@ else if (parent.getNode().getElementType() == DartTokenTypes.SIMPLE_TYPE) {
       return parseColorElements(parent, refExpr);
     }
     else {
-      if (parent.getNode().getElementType() == DartTokenTypes.VAR_INIT ||
-          parent.getNode().getElementType() == DartTokenTypes.FUNCTION_BODY) {
-        final PsiElement reference = resolveReferencedElement(refExpr);
-        if (reference != null && reference.getLastChild() != null) {
-          Color tryParseColor = null;
-          if (reference instanceof DartCallExpression) {
-            final DartExpression expression = ((DartCallExpression)reference).getExpression();
-            if (expression != null && expression.getLastChild() instanceof DartReferenceExpression) {
-              tryParseColor = parseColorElements(reference, expression);
-              if (tryParseColor != null) return tryParseColor;
-            }
-          }
-          final PsiElement lastChild = reference.getLastChild();
-          if (lastChild instanceof DartArguments && reference.getParent() != null) {
-            tryParseColor = parseColorElements(reference, reference.getParent());
-          }
-          else {
-            tryParseColor = parseColorElements(reference, reference.getLastChild());
-          }
-          if (tryParseColor != null) return tryParseColor;
-        }
-      }
       // name.equals(refExpr.getFirstChild().getText()) -> Colors.blue
       final PsiElement idNode = refExpr.getFirstChild();
       if (idNode == null) return null;
@@ -100,36 +82,6 @@ else if (parent.getNode().getElementType() == DartTokenTypes.SIMPLE_TYPE) {
     return null;
   }
 
-  @Nullable
-  private PsiElement resolveReferencedElement(@NotNull PsiElement element) {
-    if (element instanceof DartCallExpression && element.getFirstChild().getText().equals("Color")) {
-      return element;
-    }
-    final PsiElement symbol = element.getLastChild();
-    final PsiElement result;
-    if (symbol instanceof DartReference) {
-      result = ((DartReference)symbol).resolve();
-    }
-    else if (element instanceof DartReference) {
-      result = ((DartReference)element).resolve();
-    }
-    else {
-      return null;
-    }
-    if (!(result instanceof DartComponentName) || result.getParent() == null) return null;
-    final PsiElement declaration = result.getParent().getParent();
-    if (!(declaration instanceof DartVarDeclarationList)) return null;
-    final PsiElement lastChild = declaration.getLastChild();
-    if (!(lastChild instanceof DartVarInit)) return null;
-
-    final PsiElement effectiveElement = lastChild.getLastChild();
-    // Recursively determine reference if the initialization is still a `DartReference`.
-    if (effectiveElement instanceof DartReference && !(effectiveElement instanceof DartCallExpression)) {
-      return resolveReferencedElement(effectiveElement);
-    }
-    return effectiveElement;
-  }
-
   @Nullable
   private Color parseColorElements(@NotNull PsiElement parent, @NotNull PsiElement refExpr) {
     final PsiElement selectorNode = refExpr.getLastChild();
@@ -270,4 +222,4 @@ private void replaceDouble(DartExpression expr, Double value) {
       }
     }
   }
-}
+}