Add support for mouse drag using long press

app/src/main/java/com/limelight/binding/input/TouchContext.java

@@ -3,6 +3,9 @@ package com.limelight.binding.input;
 import com.limelight.nvstream.NvConnection;
 import com.limelight.nvstream.input.MouseButtonPacket;
 
+import java.util.Timer;
+import java.util.TimerTask;
+
 public class TouchContext {
     private int lastTouchX = 0;
     private int lastTouchY = 0;
@@ -10,14 +13,20 @@ public class TouchContext {
     private int originalTouchY = 0;
     private long originalTouchTime = 0;
     private boolean cancelled;
+    private boolean confirmedMove;
+    private boolean confirmedDrag;
+    private Timer dragTimer;
+    private double distanceMoved;
 
     private final NvConnection conn;
     private final int actionIndex;
     private final double xFactor;
     private final double yFactor;
 
-    private static final int TAP_MOVEMENT_THRESHOLD = 10;
+    private static final int TAP_MOVEMENT_THRESHOLD = 20;
+    private static final int TAP_DISTANCE_THRESHOLD = 25;
     private static final int TAP_TIME_THRESHOLD = 250;
+    private static final int DRAG_TIME_THRESHOLD = 650;
 
     public TouchContext(NvConnection conn, int actionIndex, double xFactor, double yFactor)
     {
@@ -32,15 +41,19 @@ public class TouchContext {
         return actionIndex;
     }
 
+    private boolean isWithinTapBounds(int touchX, int touchY)
+    {
+        int xDelta = Math.abs(touchX - originalTouchX);
+        int yDelta = Math.abs(touchY - originalTouchY);
+        return xDelta <= TAP_MOVEMENT_THRESHOLD &&
+                yDelta <= TAP_MOVEMENT_THRESHOLD;
+    }
+
     private boolean isTap()
     {
-        int xDelta = Math.abs(lastTouchX - originalTouchX);
-        int yDelta = Math.abs(lastTouchY - originalTouchY);
         long timeDelta = System.currentTimeMillis() - originalTouchTime;
 
-        return xDelta <= TAP_MOVEMENT_THRESHOLD &&
-                yDelta <= TAP_MOVEMENT_THRESHOLD &&
-                timeDelta <= TAP_TIME_THRESHOLD;
+        return isWithinTapBounds(lastTouchX, lastTouchY) && timeDelta <= TAP_TIME_THRESHOLD;
     }
 
     private byte getMouseButtonIndex()
@@ -58,7 +71,13 @@ public class TouchContext {
         originalTouchX = lastTouchX = eventX;
         originalTouchY = lastTouchY = eventY;
         originalTouchTime = System.currentTimeMillis();
-        cancelled = false;
+        cancelled = confirmedDrag = confirmedMove = false;
+        distanceMoved = 0;
+
+        if (actionIndex == 0) {
+            // Start the timer for engaging a drag
+            startDragTimer();
+        }
 
         return true;
     }
@@ -69,10 +88,17 @@ public class TouchContext {
             return;
         }
 
-        if (isTap())
-        {
+        // Cancel the drag timer
+        cancelDragTimer();
+
         byte buttonIndex = getMouseButtonIndex();
 
+        if (confirmedDrag) {
+            // Raise the button after a drag
+            conn.sendMouseButtonUp(buttonIndex);
+        }
+        else if (isTap())
+        {
             // Lower the mouse button
             conn.sendMouseButtonDown(buttonIndex);
 
@@ -87,12 +113,70 @@ public class TouchContext {
         }
     }
 
+    private synchronized void startDragTimer() {
+        dragTimer = new Timer(true);
+        dragTimer.schedule(new TimerTask() {
+            @Override
+            public void run() {
+                synchronized (TouchContext.this) {
+                    // Check if someone already set move
+                    if (confirmedMove) {
+                        return;
+                    }
+
+                    // Check if someone cancelled us
+                    if (dragTimer == null) {
+                        return;
+                    }
+
+                    // Uncancellable now
+                    dragTimer = null;
+
+                    // We haven't been cancelled before the timer expired so begin dragging
+                    confirmedDrag = true;
+                    conn.sendMouseButtonDown(getMouseButtonIndex());
+                }
+            }
+        }, DRAG_TIME_THRESHOLD);
+    }
+
+    private synchronized void cancelDragTimer() {
+        if (dragTimer != null) {
+            dragTimer.cancel();
+            dragTimer = null;
+        }
+    }
+
+    private synchronized void checkForConfirmedMove(int eventX, int eventY) {
+        // If we've already confirmed something, get out now
+        if (confirmedMove || confirmedDrag) {
+            return;
+        }
+
+        // If it leaves the tap bounds before the drag time expires, it's a move.
+        if (!isWithinTapBounds(eventX, eventY)) {
+            confirmedMove = true;
+            cancelDragTimer();
+            return;
+        }
+
+        // Check if we've exceeded the maximum distance moved
+        distanceMoved += Math.sqrt(Math.pow(eventX - lastTouchX, 2) + Math.pow(eventY - lastTouchY, 2));
+        if (distanceMoved >= TAP_DISTANCE_THRESHOLD) {
+            confirmedMove = true;
+            cancelDragTimer();
+            return;
+        }
+    }
+
     public boolean touchMoveEvent(int eventX, int eventY)
     {
         if (eventX != lastTouchX || eventY != lastTouchY)
         {
-            // We only send moves for the primary touch point
+            // We only send moves and drags for the primary touch point
             if (actionIndex == 0) {
+                checkForConfirmedMove(eventX, eventY);
+
                 int deltaX = eventX - lastTouchX;
                 int deltaY = eventY - lastTouchY;
 
@@ -131,6 +215,14 @@ public class TouchContext {
 
     public void cancelTouch() {
         cancelled = true;
+
+        // Cancel the drag timer
+        cancelDragTimer();
+
+        // If it was a confirmed drag, we'll need to raise the button now
+        if (confirmedDrag) {
+            conn.sendMouseButtonUp(getMouseButtonIndex());
+        }
     }
 
     public boolean isCancelled() {