[patch] Show warning on invalid MapCSS validator rule parsing

[skyper]

What steps will reproduce the problem?

1. Have a typo in a validator mapcss rule file, like the missing y below:

   way[highway =~ /^(motorway|motorway_link|trunk|trunk_link)$/] {
     set MotorwayTrunk;
   }
   way.MotorwaTrunk[lanes][turn:lanes              ][tag(lanes)!=eval(count(split("|", tag("turn:lanes"))))],
   way.MotorwaTrunk[lanes][change:lanes            ][tag(lanes)!=eval(count(split("|", tag("change:lanes"))))],
   way.MotorwaTrunk[lanes][maxspeed:lanes          ][tag(lanes)!=eval(count(split("|", tag("maxspeed:lanes"))))],
   way.MotorwaTrunk[lanes][minspeed:lanes          ][tag(lanes)!=eval(count(split("|", tag("minspeed:lanes"))))],
   way.MotorwaTrunk[lanes][destination:lanes       ][tag(lanes)!=eval(count(split("|", tag("destination:lanes"))))],
   way.MotorwaTrunk[lanes][destination:ref:lanes   ][tag(lanes)!=eval(count(split("|", tag("destination:ref:lanes"))))],
   way.MotorwaTrunk[lanes][destination:symbol:lanes][tag(lanes)!=eval(count(split("|", tag("destination:symbol:lanes"))))] {
       throwWarning: tr("Different number of lanes in the keys {0} and {1}", "{1.key}", "{2.key}");
       group: tr("suspicious tag combination");
   }
   

2. (Re-)Load file

What is the expected result?

A warning about an unknown class in use.

What happens instead?

No warning

Please provide any additional information below. Attach a screenshot if possible.

Some Information about existing but not use classes would be nice, too.

Relative:URL: ^/trunk
Repository:UUID: 0c6e7542-c601-0410-84e7-c038aed88b3b
Last:Changed Date: 2020-08-06 21:47:58 +0200 (Thu, 06 Aug 2020)
Revision:16851
Build-Date:2020-08-07 01:30:47
URL:https://josm.openstreetmap.de/svn/trunk

[gaben]

While experimenting with a custom MapCSS rule, I noticed parsing of invalid rules silently fail on the GUI side. In case of error, the console prints detailed information. Add this or parts to a warning dialog to help diagnose the problem.

URL:https://josm.openstreetmap.de/svn/trunk
Repository:UUID: 0c6e7542-c601-0410-84e7-c038aed88b3b
Last:Changed Date: 2022-01-09 17:28:53 +0100 (Sun, 09 Jan 2022)
Build-Date:2022-01-10 02:31:03
Revision:18364
Relative:URL: ^/trunk

[gaben]

The issue is coming from the MapCSSParser.jj file. I have a patch that makes JOSM print the messages but at the same time introduces some GUI exceptions (EDT violations).

[gaben]

src/org/openstreetmap/josm/gui/mappaint/mapcss/MapCSSParser.jj

@@ -14 +14 @@
 import java.util.Collections;
 import java.util.List;
 
+import javax.swing.JOptionPane;
+
 import org.openstreetmap.josm.data.preferences.NamedColorProperty;
+import org.openstreetmap.josm.gui.MainApplication;
 import org.openstreetmap.josm.gui.mappaint.Keyword;
 import org.openstreetmap.josm.gui.mappaint.Range;
 import org.openstreetmap.josm.gui.mappaint.mapcss.Condition;
@@ -78 +81 @@
             this.idx = idx;
         }
     }
-    
+
     /**
      * Constructor which initializes the parser with a certain lexical state.
      * @param in input
@@ -1164 +1167 @@
     
     Logging.error("Skipping to the next rule, because of an error:");
     Logging.error(e);
+
+    JOptionPane.showMessageDialog(MainApplication.getMainFrame(), e.getMessage(), "MapCSS rule parsing error", JOptionPane.ERROR_MESSAGE);
     if (sheet != null) {
         sheet.logError(e);
     }

The patch introduces some EDT violations, which needs to be solved first. If someone knows how to fix it, please do it.

[GerdP]

See GuiHelper.runInEDT() or one of the variants.

[gaben]

Thank you @GerdP! Now the EDT violations are gone. I think the patch is good enough, but please review it.

[GerdP]

You can simplify that to GuiHelper.runInEDT(() -> JOptionPane.showMessageDialog(..));
like in MainLayerManager:

            GuiHelper.runInEDT(() -> JOptionPane.showMessageDialog(MainApplication.getMainFrame(),
                    tr("Trying to delete the layer with background upload. Please wait until the upload is finished."))); 
}

[gaben]

I tried that, but JavaCC didn't like it :/

[taylor.smock]

Looking at the ​release-notes.md, v7.0.5 "[added] support for Java7 language features". So I don't think Java 8 language features are supported.