Fix null pointer in ADS1299SettingsController and fix front end bug

Author: retiutut

OpenBCI_GUI/ADS1299SettingsController.pde

@@ -2,7 +2,7 @@ import org.apache.commons.lang3.tuple.Pair;
 
 
 class ADS1299SettingsController {
-    private PApplet _parentApplet;
+    private PApplet parentApplet;
     private boolean isVisible = false;
     protected int x, y, w, h;
     protected final int PADDING_3 = 3;
@@ -71,9 +71,9 @@ class ADS1299SettingsController {
         h = _h;
         channelBarHeight = _channelBarHeight;
 
-        _parentApplet = _parentApplet;
-        hwsCp5 = new ControlP5(_parentApplet);
-        hwsCp5.setGraphics(_parentApplet, 0,0);
+        this.parentApplet = _parentApplet;
+        hwsCp5 = new ControlP5(parentApplet);
+        hwsCp5.setGraphics(parentApplet, 0,0);
         hwsCp5.setAutoDraw(false);
 
         int colOffset = (w / CONTROL_BUTTON_COUNT) / 2;
@@ -180,7 +180,7 @@ class ADS1299SettingsController {
             toggleWidthAndHeight = DEFAULT_TOGGLE_WIDTH;
         }
 
-        hwsCp5.setGraphics(_parentApplet, 0, 0);
+        hwsCp5.setGraphics(parentApplet, 0, 0);
 
         int colOffset = (w / CONTROL_BUTTON_COUNT) / 2;
         int button_y = y + h + PADDING_3;
@@ -233,7 +233,7 @@ class ADS1299SettingsController {
             dropdownY = int(y + (channelBarHeight * rowCount) + ((channelBarHeight - dropdownH) / 2));
             final int buttonXIncrement = spaceBetweenButtons + dropdownW;
 
-            int toggleX = dropdownX + (dropdownW / 2) - (toggleWidthAndHeight);
+            int toggleX = dropdownX + (dropdownW / 2) - (toggleWidthAndHeight / 2);
             channelSelectToggles[i].setPosition(toggleX, dropdownY);
             channelSelectToggles[i].setSize(toggleWidthAndHeight, toggleWidthAndHeight);