predicate-suppressor.ts.patch

diff --git a/ts/predicate-suppressor.ts b/ts/predicate-suppressor.ts
index 3dc854c..ef178a8 100644
--- a/ts/predicate-suppressor.ts
+++ b/ts/predicate-suppressor.ts
@@ -5,7 +5,6 @@ import {
     Decoration,
     DisplayLayer,
     Disposable,
-    Marker,
     Point,
     Range
 } from 'atom';
@@ -25,7 +24,6 @@ declare module 'atom' {
     }
 }
 
-type Direction = 'up' | 'down';
 type emitFoldSig = (nextHunk: any, decorationIterator: any, endBufferRow: any) => void;
 type emitOpenTagSig = (number, boolean) => void;
 type FoldId = number
@@ -59,6 +57,29 @@ class Predicate {
         }
     }
 
+    addClass(classname: string) {
+        let properties = this.decoration.getProperties();
+        if (properties.class && properties.class.indexOf(classname) === -1) {
+            properties.class += ` {classname}`;
+        }
+        else {
+            properties.class = classname;
+        }
+        this.decoration.setProperties(properties);
+    }
+
+    removeClass(classname: string) {
+        let properties = this.decoration.getProperties();
+        if (properties.class === classname) {
+            delete properties['class'];
+        }
+        else if (properties.class) {
+            properties.class = properties.class.replace(classname, '');
+        }
+
+        this.decoration.setProperties(properties);
+    }
+
     createFoldRange(): Range {
         return new Range([this.range.start.row - 1, Infinity], this.range.end);
     }
@@ -135,7 +156,7 @@ export class PredicateSuppressor {
         this.skipCursorCB = false;
 
         // This stylesheet will make the folds created by LineSuppressor invisible.
-        this.stylesheet = atom.styles.addStyleSheet('.line .fold-marker.suppress-line { visibility: hidden };')
+        this.stylesheet = atom.styles.addStyleSheet('.line .fold-marker.suppress-line { visibility: hidden; }\natom-text-editor div.hide-background.line { background-color: inherit !important; }\n');
     }
 
     destroy() {
@@ -160,6 +181,9 @@ export class PredicateSuppressor {
             const predicate = new Predicate(bufferRow);
             predicate.hide();
             this.predicates.push(predicate);
+            // Update the class names for each decoration since a new one was
+            // added.
+            this.updateClassNames();
         }
     }
 
@@ -229,6 +253,7 @@ export class PredicateSuppressor {
         }
     }
 
+    // Return all hidden predicates in range.
     findHiddenPredicateForRange(range: Range): Predicate {
         for (let predicate of this.predicates) {
             if (predicate.hidden && predicate.hiddenRange.isEqual(range)) {
@@ -238,10 +263,12 @@ export class PredicateSuppressor {
         return null;
     }
 
+    // Return the predicate at bufferRow.
     findPredicateForRow(bufferRow: number): Predicate {
         return this.findPredicateForPoint(new Point(bufferRow, 0));
     }
 
+    // Return the predicate at point.
     findPredicateForPoint(point: Point): Predicate {
         for (let predicate of this.predicates) {
             if (predicate.range.containsPoint(point)) {
@@ -251,6 +278,7 @@ export class PredicateSuppressor {
         return null;
     }
 
+    // Return all predicates in range.
     findPredicateForRange(range: Range): Predicate {
         for (let predicate of this.predicates) {
             if (predicate.range.isEqual(range)) {
@@ -259,4 +287,19 @@ export class PredicateSuppressor {
         }
         return null;
     }
+
+    // Update the class names of each decoration. If a predicate is on a line
+    // directly below another predicate, add the class name that sets the
+    // background-color to inherit.
+    updateClassNames() {
+        const className = 'inherit-background'
+        for (let predicate of this.predicates) {
+            if (this.findPredicateForRow(predicate.range.start.row) !== null) {
+                predicate.addClass(className);
+            }
+            else {
+                predicate.removeClass(className);
+            }
+        }
+    }
 }