Friendly error messages

app/src/processing/app/Problem.java

@@ -20,16 +20,117 @@
 
 package processing.app;
 
+import java.util.Optional;
 
+
+/**
+ * Structure describing a problem encountered in sketch compilation.
+ */
 public interface Problem {
+
+  /**
+   * Strategy converting line number in tab to character offset from tab start.
+   */
+  public interface LineToTabOffsetGetter {
+
+    /**
+     * Convert a line number to the number of characters past tab start.
+     * 
+     * @param line The line number to convert.
+     * @return The number of characters past tab start where that line starts.
+     */
+    public int get(int line);
+
+  }
+
+  /**
+   * Get if the problem is an error that prevented compilation.
+   * 
+   * @return True if an error such that the sketch did not compile and false
+   *    otherwise.
+   */
   public boolean isError();
+
+  /**
+   * Get if the problem is an warning that did not prevent compilation.
+   * 
+   * @return True if a warning and the sketch compiled and false otherwise.
+   */
   public boolean isWarning();
 
+  /**
+   * Get which tab (sketch file) the problem was encountered.
+   * 
+   * @return The index of the tab in which the problem was encountered.
+   */
   public int getTabIndex();
-  public int getLineNumber();  // 0-indexed
+
+  /**
+   * Get at which line the problem was encountered.
+   * 
+   * @return Zero-indexed line number within the tab at getTabIndex in which
+   *    this problem was encountered. Note that this is not the line in the
+   *    generated Java file.
+   */
+  public int getLineNumber();
+
+  /**
+   * Get a human-reabable description of the problem encountered.
+   * 
+   * @return String describing the error or warning encountered.
+   */
   public String getMessage();
 
-  public int getStartOffset();
-  public int getStopOffset();
+  /**
+   * Get the exact character on which this problem starts in code tab relative.
+   * 
+   * @return Number of characters past the start of the tab if known where the
+   *    code associated with the Problem starts. Returns empty if not provided.
+   */
+  public Optional<Integer> getTabStartOffset();
+
+  /**
+   * Get the exact character on which this problem ends in code tab relative.
+   * 
+   * @return Number of characters past the start of the tab if known where the
+   *    code associated with the Problem ends. Returns empty if not provided.
+   */
+  public Optional<Integer> getTabStopOffset();
+
+  /**
+   * Get the exact character on which this problem starts in code line relative.
+   * 
+   * @return Number of characters past the start of the line if known where the
+   *    code associated with the Problem starts. Returns empty if not provided.
+   */
+  public Optional<Integer> getLineStartOffset();
+
+  /**
+   * Get the exact character on which this problem ends in code line relative.
+   * 
+   * @return Number of characters past the start of the line if known where the
+   *    code associated with the Problem ends. Returns empty if not provided.
+   */
+  public Optional<Integer> getLineStopOffset();
+
+  /**
+   * Get the exact character on which this problem ends in code tab relative.
+   * 
+   * @param strategy Strategy to convert line to tab start if needed.
+   * @return Number of characters past the start of the tab if known where the
+   *    code associated with the Problem ends, using the provided conversion
+   *    if needed. Returns line start if character position not given.
+   */
+  public int computeTabStartOffset(LineToTabOffsetGetter strategy);
+
+  /**
+   * Get the exact character on which this problem ends in code tab relative.
+   * 
+   * @param strategy Strategy to convert line to tab start if needed.
+   * @return Number of characters past the start of the tab if known where the
+   *    code associated with the Problem ends, using the provided conversion
+   *    if needed. Returns line start if character position not given.
+   */
+  public int computeTabStopOffset(LineToTabOffsetGetter strategy);
 }
 

app/src/processing/app/syntax/PdeTextAreaPainter.java

@@ -46,6 +46,8 @@ public class PdeTextAreaPainter extends TextAreaPainter {
   protected Color gutterTextInactiveColor;
   protected Color gutterHighlightColor;
 
+  private final Problem.LineToTabOffsetGetter lineToTabOffsetGetter;
+
 
   public PdeTextAreaPainter(JEditTextArea textArea, TextAreaDefaults defaults) {
     super(textArea, defaults);
@@ -76,6 +78,10 @@ public void mousePressed(MouseEvent event) {
         }
       }
     });
+
+    lineToTabOffsetGetter = (x) -> {
+      return textArea.getLineStartOffset(x);
+    };
   }
 
 
@@ -147,13 +153,14 @@ protected void paintLine(Graphics gfx, int line, int x, TokenMarkerState marker)
   protected void paintErrorLine(Graphics gfx, int line, int x) {
     List<Problem> problems = getEditor().findProblems(line);
     for (Problem problem : problems) {
-      int startOffset = problem.getStartOffset();
-      int stopOffset = problem.getStopOffset();
+      int startOffset = problem.computeTabStartOffset(lineToTabOffsetGetter);
+      int stopOffset = problem.computeTabStopOffset(lineToTabOffsetGetter);
 
-      int lineOffset = textArea.getLineStartOffset(line);
+      int lineOffsetStart = textArea.getLineStartOffset(line);
+      int lineOffsetStop = textArea.getLineStopOffset(line);
 
-      int wiggleStart = Math.max(startOffset, lineOffset);
-      int wiggleStop = Math.min(stopOffset, textArea.getLineStopOffset(line));
+      int wiggleStart = Math.max(startOffset, lineOffsetStart);
+      int wiggleStop = Math.min(stopOffset, lineOffsetStop);
 
       int y = textArea.lineToY(line) + getLineDisplacement();
 
@@ -163,7 +170,10 @@ protected void paintErrorLine(Graphics gfx, int line, int x) {
         try {
           SyntaxDocument doc = textArea.getDocument();
           badCode = doc.getText(wiggleStart, wiggleStop - wiggleStart);
-          goodCode = doc.getText(lineOffset, wiggleStart - lineOffset);
+          goodCode = doc.getText(
+            lineOffsetStart,
+            wiggleStart - lineOffsetStart
+          );
           //log("paintErrorLine() LineText GC: " + goodCode);
           //log("paintErrorLine() LineText BC: " + badCode);
         } catch (BadLocationException bl) {
@@ -328,8 +338,8 @@ public String getToolTipText(MouseEvent event) {
         int lineStart = textArea.getLineStartOffset(line);
         int lineEnd = textArea.getLineStopOffset(line);
 
-        int errorStart = problem.getStartOffset();
-        int errorEnd = problem.getStopOffset() + 1;
+        int errorStart = problem.computeTabStartOffset(lineToTabOffsetGetter);
+        int errorEnd = problem.computeTabStopOffset(lineToTabOffsetGetter) + 1;
 
         int startOffset = Math.max(errorStart, lineStart) - lineStart;
         int stopOffset = Math.min(errorEnd, lineEnd) - lineStart;

app/src/processing/app/ui/Editor.java

@@ -2556,8 +2556,15 @@ public void updateErrorTable(List<Problem> problems) {
 
 
   public void highlight(Problem p) {
+    Problem.LineToTabOffsetGetter getter = (x) -> {
+      return textarea.getLineStartOffset(x);
+    };
+
     if (p != null) {
-      highlight(p.getTabIndex(), p.getStartOffset(), p.getStopOffset());
+      int tabIndex = p.getTabIndex();
+      int tabToStartOffset = p.computeTabStartOffset(getter);
+      int tabToStopOffset = p.computeTabStopOffset(getter);
+      highlight(tabIndex, tabToStartOffset, tabToStopOffset);
     }
   }
 
@@ -2623,8 +2630,11 @@ public List<Problem> findProblems(int line) {
         .filter(p -> p.getTabIndex() == currentTab)
         .filter(p -> {
           int pStartLine = p.getLineNumber();
-          int pEndOffset = p.getStopOffset();
+          int pEndOffset = p.computeTabStopOffset(
+            (startLine) -> textarea.getLineStartOffset(pStartLine)
+          );
           int pEndLine = textarea.getLineOfOffset(pEndOffset);
+
           return line >= pStartLine && line <= pEndLine;
         })
         .collect(Collectors.toList());

build/shared/lib/languages/PDE.properties

@@ -420,7 +420,7 @@ editor.status.hiding_enclosing_type = The class “%s” cannot have the same na
 
 editor.status.bad.assignment = Possible error on variable assignment near ‘%s’?
 editor.status.bad.generic = Possibly missing type in generic near ‘%s’?
-editor.status.bad.identifier = Bad identifier? Did you forget a variable or start an identifier with digits near ‘%s’?
+editor.status.bad.identifier = There's an issue with a "bad identifier" in your code near '%s'.
 editor.status.bad.parameter = Error on parameter or method declaration near ‘%s’?
 editor.status.bad.import = Import not allowed here.
 editor.status.bad.mixed_mode = You may be mixing active and static modes.

java/src/processing/mode/java/ErrorChecker.java

@@ -277,9 +277,16 @@ static private List<JavaProblem> checkForCurlyQuotes(PreprocSketch ps) {
             String q = matcher.group();
             int tabStart = in.startTabOffset + offset;
             int tabStop = tabStart + 1;
+            int line = ps.tabOffsetToTabLine(in.tabIndex, tabStart);
+
             // Prevent duplicate problems
-            if (problems.stream().noneMatch(p -> p.getStartOffset() == tabStart)) {
-              int line = ps.tabOffsetToTabLine(in.tabIndex, tabStart);
+            boolean isDupe = problems.stream()
+              .filter(p -> p.getTabIndex() == in.tabIndex)
+              .filter(p -> p.getLineNumber() == line)
+              .findAny()
+              .isPresent();
+
+            if (isDupe) {
               String message;
               if (iproblem.getID() == IProblem.UnterminatedString) {
                 message = Language.interpolate("editor.status.unterm_string_curly", q);

java/src/processing/mode/java/JavaProblem.java

@@ -20,6 +20,8 @@
 
 package processing.mode.java;
 
+import java.util.Optional;
+
 import org.eclipse.jdt.core.compiler.IProblem;
 
 import processing.app.Problem;
@@ -42,9 +44,9 @@ public class JavaProblem implements Problem {
   /** Line number (pde code) of the error */
   private final int lineNumber;
 
-  private int startOffset;
+  private Optional<Integer> startOffset;
 
-  private int stopOffset;
+  private Optional<Integer> stopOffset;
 
   /**
    * If the error is a 'cannot find type' contains the list of suggested imports
@@ -60,6 +62,8 @@ public JavaProblem(String message, int type, int tabIndex, int lineNumber) {
     this.type = type;
     this.tabIndex = tabIndex;
     this.lineNumber = lineNumber;
+    this.startOffset = Optional.empty();
+    this.stopOffset = Optional.empty();
   }
 
 
@@ -83,22 +87,31 @@ static public JavaProblem fromIProblem(IProblem iProblem, int tabIndex,
 
 
   public void setPDEOffsets(int startOffset, int stopOffset){
-    this.startOffset = startOffset;
-    this.stopOffset = stopOffset;
+    this.startOffset = Optional.of(startOffset);
+    this.stopOffset = Optional.of(stopOffset);
   }
 
 
   @Override
-  public int getStartOffset() {
+  public Optional<Integer> getTabStartOffset() {
     return startOffset;
   }
 
 
   @Override
-  public int getStopOffset() {
+  public Optional<Integer> getTabStopOffset() {
     return stopOffset;
   }
 
+  @Override
+  public Optional<Integer> getLineStartOffset() {
+    return Optional.empty();
+  }
+
+  @Override
+  public Optional<Integer> getLineStopOffset() {
+    return Optional.empty();
+  }
 
   @Override
   public boolean isError() {
@@ -139,11 +152,47 @@ public void setImportSuggestions(String[] a) {
     importSuggestions = a;
   }
 
+  public boolean usesLineOffset() {
+    return false;
+  }
 
   @Override
   public String toString() {
     return "TAB " + tabIndex + ",LN " + lineNumber + "LN START OFF: "
         + startOffset + ",LN STOP OFF: " + stopOffset + ",PROB: "
         + message;
   }
+
+  @Override
+  public int computeTabStartOffset(LineToTabOffsetGetter strategy) {
+    Optional<Integer> nativeTabStartOffset = getTabStartOffset();
+    if (nativeTabStartOffset.isPresent()) {
+      return nativeTabStartOffset.get();
+    }
+
+    Optional<Integer> lineStartOffset = getLineStartOffset();
+    int lineOffset = strategy.get(getLineNumber());
+    if (lineStartOffset.isPresent()) {
+      return lineOffset + lineStartOffset.get();
+    } else {
+      return lineOffset;
+    }
+  }
+
+  @Override
+  public int computeTabStopOffset(LineToTabOffsetGetter strategy) {
+    Optional<Integer> nativeTabStopOffset = getTabStopOffset();
+    if (nativeTabStopOffset.isPresent()) {
+      return nativeTabStopOffset.get();
+    }
+
+    Optional<Integer> lineStopOffset = getLineStopOffset();
+    int lineOffset = strategy.get(getLineNumber());
+    if (lineStopOffset.isPresent()) {
+      return lineOffset + lineStopOffset.get();
+    } else {
+      return lineOffset;
+    }
+  }
+
 }

java/src/processing/mode/java/ProblemFactory.java

@@ -53,7 +53,8 @@ public static Problem build(PdePreprocessIssue pdePreprocessIssue, List<Integer>
         localLine,
         message,
         lineStart,
-        lineStop
+        lineStop,
+        false
     );
   }
 
@@ -83,8 +84,9 @@ public static Problem build(PdePreprocessIssue pdePreprocessIssue, List<Integer>
         tab,
         localLine,
         message,
-        localLine,
-        localLine + col
+        0,
+        col,
+        true
     );
   }