display visual errors on css reload

h2d/domkit/Style.hx

@@ -4,6 +4,8 @@ class Style extends domkit.CssStyle {
 
 	var currentObjects : Array<h2d.domkit.Object> = [];
 	var resources : Array<hxd.res.Resource> = [];
+	var errors : Array<String>;
+	var errorsText : h2d.Text;
 
 	public function new() {
 		super();
@@ -27,17 +29,55 @@ class Style extends domkit.CssStyle {
 		currentObjects.remove(obj);
 	}
 
+	override function onInvalidProperty(e:domkit.Element<Dynamic>, s:domkit.CssStyle.RuleStyle, msg:String) {
+		if( errors != null ) {
+			if( msg == null ) msg = "Invalid property value '"+(domkit.CssParser.valueStr(s.value))+"'";
+			errors.push(msg+" for "+e.component.name+"."+s.p.name);
+		}
+	}
+
 	function onChange( ntry : Int = 0 ) {
 		if( ntry >= 10 ) return;
 		ntry++;
 		var oldRules = rules;
+		errors = [];
 		rules = [];
 		for( r in resources ) {
 			var txt = try r.entry.getText() catch( e : Dynamic ) { haxe.Timer.delay(onChange.bind(ntry),100); rules = oldRules; return; }
-			add(new domkit.CssParser().parseSheet(txt));
+			var parser = new domkit.CssParser();
+			try {
+				add(parser.parseSheet(txt));
+			} catch( e : domkit.Error ) {
+				parser.warnings.push({ msg : e.message, pmin : e.pmin, pmax : e.pmax });
+			}
+			for( w in parser.warnings ) {
+				var line = txt.substr(0,w.pmin).split("\n").length;
+				errors.push(r.entry.path+":"+line+": " + w.msg);
+		 	}
 		}
 		for( o in currentObjects )
 			getDocument(o).setStyle(this);
+		if( errors.length == 0 ) {
+			if( errorsText != null ) {
+				errorsText.parent.remove();
+				errorsText = null;
+			}
+		} else {
+			if( errorsText == null ) {
+				if( currentObjects.length == 0 ) return;
+				var scene = getDocument(currentObjects[0]).root.obj.getScene();
+				var fl = new h2d.Flow(scene);
+				fl.backgroundTile = h2d.Tile.fromColor(0x400000,0.9);
+				fl.padding = 10;
+				errorsText = new h2d.Text(hxd.res.DefaultFont.get(), fl);
+			}
+			var fl = Std.instance(errorsText.parent, h2d.Flow);
+			var sc = fl.getScene();
+			fl.maxWidth = sc.width;
+			errorsText.text = errors.join("\n");
+			var b = fl.getBounds();
+			fl.y = sc.height - Std.int(b.height);
+		}
 	}
 
 	function getDocument( o : h2d.domkit.Object ) : domkit.Document<h2d.Object> {