timeline behaves more responsively, performance increase

Interaction.pde

   }
 }
 void mouseReleased() {
-  timeline.clicked = false;
-}
-int currentYear;
-void mouseDragged() {
   if (timeline.clicked) {
+    timeline.clicked = false;
     timelinectrl();
   }
 }
+int currentYear;
 void timelinectrl() {
   if (interactiveTimeline && displayTimeline) {
     int toYear = (int)constrain(map(mouseX, timeline.x, timeline.x + timeline.l, 1966, 2012), 1966, 2012);
     if (toYear != currentYear) {
       timeline.cursorPos = constrain(mouseX, timeline.x, timeline.x +timeline.l);
+      boolean succ = false;
       for (int i = 0; i < notebooks.size(); i ++) {
         if (notebooks.get(i).year == toYear) {
           nextSlide(i, 0);
+          succ = true;
           break;
         }
       }
+      if (!succ) {
+        for (int i = 0; i < notebooks.size(); i ++) {
+          if (notebooks.get(i).year == toYear-1 || notebooks.get(i).year == toYear+1) {
+            nextSlide(i, 0);
+            succ = true;
+            break;
+          }
+        }
+      }
     }
   }
 }
     stroke(255, 127);
     strokeWeight(4);
     line(x, y, l+x, y);
+    if (clicked) {
+      cursorPos = (int)constrain(mouseX, x, x+l);
+    }
     ellipse(cursorPos, height-30, 20, 20);
-    if (displayText) text(notebooks.get(currentNotebookNo).year, cursorPos, y-20);
+    if (displayText){
+      String labelText;
+      if(!clicked) labelText = str(notebooks.get(currentNotebookNo).year);
+      else labelText = str((int)constrain(map(mouseX, timeline.x, timeline.x + timeline.l, 1966, 2012), 1966, 2012));
+      text(labelText, cursorPos, y-20);
+    }
   }
 }

data/save.sav

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