diff --git a/app/src/main/java/com/termux/drawer/DrawerLayout.java b/app/src/main/java/com/termux/drawer/DrawerLayout.java
index cff39d93..81feb556 100644
--- a/app/src/main/java/com/termux/drawer/DrawerLayout.java
+++ b/app/src/main/java/com/termux/drawer/DrawerLayout.java
@@ -138,11 +138,11 @@ public class DrawerLayout extends ViewGroup {
 
 	private final ChildAccessibilityDelegate mChildAccessibilityDelegate = new ChildAccessibilityDelegate();
 
-	private int mMinDrawerMargin;
+	private final int mMinDrawerMargin;
 
 	private int mScrimColor = DEFAULT_SCRIM_COLOR;
 	private float mScrimOpacity;
-	private Paint mScrimPaint = new Paint();
+	private final Paint mScrimPaint = new Paint();
 
 	private final ViewDragHelper mLeftDragger;
 	private final ViewDragHelper mRightDragger;
diff --git a/app/src/main/java/com/termux/drawer/ViewDragHelper.java b/app/src/main/java/com/termux/drawer/ViewDragHelper.java
index 41a10189..d423ec7c 100644
--- a/app/src/main/java/com/termux/drawer/ViewDragHelper.java
+++ b/app/src/main/java/com/termux/drawer/ViewDragHelper.java
@@ -57,7 +57,7 @@ public class ViewDragHelper {
 	/**
 	 * Edge flag indicating that the left edge should be affected.
 	 */
-	public static final int EDGE_LEFT = 1 << 0;
+	public static final int EDGE_LEFT = 1 /*1 << 0*/;
 
 	/**
 	 * Edge flag indicating that the right edge should be affected.
@@ -82,7 +82,7 @@ public class ViewDragHelper {
 	/**
 	 * Indicates that a check should occur along the horizontal axis
 	 */
-	public static final int DIRECTION_HORIZONTAL = 1 << 0;
+	public static final int DIRECTION_HORIZONTAL = 1 /*1 << 0*/;
 
 	/**
 	 * Indicates that a check should occur along the vertical axis
diff --git a/app/src/main/java/com/termux/terminal/TerminalEmulator.java b/app/src/main/java/com/termux/terminal/TerminalEmulator.java
index 6889ae95..39f3fb81 100644
--- a/app/src/main/java/com/termux/terminal/TerminalEmulator.java
+++ b/app/src/main/java/com/termux/terminal/TerminalEmulator.java
@@ -33,8 +33,7 @@ public final class TerminalEmulator {
 	private static final boolean LOG_ESCAPE_SEQUENCES = false;
 
 	public static final int MOUSE_LEFT_BUTTON = 0;
-	public static final int MOUSE_MIDDLE_BUTTON = 1;
-	public static final int MOUSE_RIGHT_BUTTON = 2;
+
 	/** Mouse moving while having left mouse button pressed. */
 	public static final int MOUSE_LEFT_BUTTON_MOVED = 32;
 	public static final int MOUSE_WHEELUP_BUTTON = 64;